Infección de piel y tejidos blandos por Burkholderia stabilis en un niño con quemaduras graves / Skin and soft tissue infection due to Burkholderia stabilis in a severely burned child

Resumen Las heridas por quemadura representan un grave problema, sobre todo en la población pediátrica, dada la severidad de su presentación y la morbimortalidad asociada. La infección es la complicación más frecuente y grave en el paciente quemado. Las bacterias que conforman el complejo Burkholderia cepacia (CBc) son capaces de causar enfermedades en plantas, humanos y animales. En el hombre pueden establecer infecciones crónicas y frecuentemente graves, por lo general en pacientes con fibrosis quística y en inmunocomprometidos. El CBc está compuesto por al menos 22 especies filogenéticamente muy relacionadas. El objetivo de esta publicación fue describir el primer caso de una infección de piel y partes blandas por Burkholderia stabilis, una especie poco frecuente, en un niño con grandes quemaduras en la Argentina. Las especies del CBc son intrínsecamente resistentes a la mayoría de los antimicrobianos disponibles clínicamente, como aminoglucósidos, quinolonas, polimixinas y β-lactámicos. Esto representa un serio problema en el momento de tratar las infecciones por las escasas opciones terapéuticas.

Abstract Burn wounds represent a serious problem, especially in the pediatric population, given the severity of their presentation and the associated morbidity and mortality. Infection is the most frequent and serious complication in the burned patient. Burkholderia cepacia (CBc) complex bacteria are capable of causing disease in plants, humans, and animals. In human beings they can establish chronic and frequently serious infections, generally in patients with cystic fibrosis and in immunocompromised patients. The CBc is composed of 22 phylogenetically closely related species. The objective of this publication was to describe the first report of a skin and soft tissue infection by Burkholderia stabilis, a rare species, in a child with extensive burns in Argentina. CBc species are inherently resistant to most clinically available antimicrobials, such as aminoglycosides, quinolones, polymyxins, and β-lactams. This represents a serious problem when treating infections, due to the limited therapeutic options.

Resumo As feridas por queimadura representam um grave problema, principalmente na população pediátrica, devido à gravidade de sua apresentação e morbimortalidade associada. A infecção é a complicação mais frequente e grave do paciente queimado. As bactérias que compõem o complexo Burkholderia cepacia (CBc) são capazes de causar doenças em plantas, humanos e animais. No homem, podem estabelecer infecções crônicas e freqüentemente graves, geralmente em pacientes com fibrose cística e imunocomprometidos. O CBc é composto, no mínimo, por 22 espécies filogeneticamente muito relacionadas. O objetivo desta publicação é descrever o primeiro caso de uma infecção de pele e tecidos moles por Burkholderia stabilis, uma espécie rara, em uma criança com queimaduras extensas na Argentina. As espécies do CBc são inerentemente resistentes à maioria dos antimicrobianos disponíveis clinicamente, como aminoglicosídeos, quinolonas, polimixinas e β-lactâmicos. Isso representa um problema sério na hora de tratar as infecções devido às opções terapêuticas limitadas.

Resistencia a antibióticos ß-lactámicos y eritromicina en bacterias de la cavidad oral / Resistance to ß-lactam Antibiotics and Erythromycin in Bacteria of the Oral Cavity

Resumen Introducción. La microbiota humana como fuente de bacterias y genes de resistencia constituyen un problema de salud pública. En este estudio se investigó la prevalencia de bacilos entéricos Gram negativos resistentes a β-lactámicos y de los Streptococcus del grupo viridans (EGV) con resistencia a eritromicina en la cavidad oral. Métodos. Se realizó un estudio descriptivo de corte transversal con 193 aislamientos de la cavidad oral sana de 178 adultos que asistieron a una Clínica Odontológica de la ciudad de Cali durante el 2018. La evaluación de la sensibilidad antimicrobiana se realizó en 59 bacilos entéricos y 134 EGV y se identificó por PCR los genes que confieren resistencia a β-lactámicos y eritromicina. El análisis estadístico se realizó mediante el empleo del paquete SPSS vs 23. Resultados. El 84,7% de los bacilos entéricos fueron multirresistentes y presentaron genes bla, siendo blaTEM-1 (49,2%) y blaVIM-2 (30,5%,) los más prevalentes. Los EGV fueron resistentes a eritromicina (38,8%) y clindamicina (28,4%). El 18,7% presentaron el fenotipo cMLSβ, 4,5% el iMLSβ y el 14,9% fueron M. El gen ermB se detectó en los cMLSβ, (13,4%) y el gen mef en los M (9,7%). Conclusión. En este estudio se demostró la presencia de EGV y bacilos entéricos resistentes a los antibióticos y portadores de genes de resistencia a eritromicina y genes bla en la cavidad oral sana. La presencia de estas bacterias representa un riesgo para la salud de los individuos portadores y contribuyen a la creciente epidemia de resistencia bacteriana.

Abstract Introduction. The human microbiota as a source of bacteria and resistance genes is a public health problem. This study researched the prevalence of Gram-negative enteric bacilli resistant to β-lactams and erythromycin resistance in the oral cavity. Methods. A descriptive cross-sectional study was carried out with 193 isolates obtained from the oral cavity of 178 healthy adults who were treated at a Dental Clinic in the city of Cali during 2018. The evaluation of antimicrobial sensitivity was performed in 59 enteric bacilli and 134 EGV and the genes that confer resistance to β-lactam and erythromycin were identified by PCR. Statistical analysis was performed using the SPSS statistical package vs. 25.0. Results. 84.7% of the enteric bacilli presented the MDR phenotype and all presented the bla genes, blaTEM-1 (49.2%) and blaVIM-2 (30.5%) being the most prevalent. EGVs were resistant to erythromycin (38.8%) and clindamycin (28.4%). 18.7% presented the cMLSβ phenotype, 4.5% the iMLSβ and 14.9% were M. The ermB gene was detected more frequently in the cMLSβ, (13.4%) and the mef gene in the M (9.7%). Conclusion. This study demonstrated the presence of antibiotics and Gram-negative enteric bacilli resistant to antibiotics and carriers of erythromycin resistance genes and bla genes, respectively in the healthy oral cavity. The presence of these bacteria represents a risk to the health of carrier individuals and contributes to the growing epidemic of bacterial resistance.

Aporphine alkaloids from Piper erecticaule and acetylcholinesterase inhibitory activity / Alcaloides de aporfina obtenida de Piper erecticaule y actividad inhibitoria de la acetilcolinesterasa

Chemical constituents and biological activities of the aerial parts of Piper erecticaule C.DC. have been studied for the first time. Fractionation and purification of the extracts afforded aristolactam AII (1), aristolactam BII (2), piperolactam A (3), piperolactam C (4), piperolactam D (5), together with terpenoids of ß-sitosterol, ß-sitostenone, taraxerol, and lupeol. The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that compounds 1 and 3 showed strong AChE inhibitory effects with the percentage inhibition of 75.8% and 74.8%, respectively.

Se estudiaron por primera vez los constituyentes químicos y actividad biológica de las partes aéreas de Piper erecticaule C.DC. El fraccionamiento y la purificación de los extractos proporcionaron aristolactama AII (1), aristolactama BII (2), piperolactama A (3), piperolactama C (4), piperolactama D (5), junto con terpenoides de ß-sitosterol, ß-sitostenona, taraxerol, y el lupeol. Las estructuras de estos compuestos se obtuvieron mediante el análisis de sus datos espectroscópicos, así como mediante la comparación con datos ya informados. La actividad inhibidora de la acetilcolinesterasa reveló que los compuestos 1 y 3 mostraron un potente efecto inhibidor de la AChE con un porcentaje de inhibición del 75.8% y 74.8%, respectivamente.

Comparación de métodos fenotípico y genotípico en la detección de Staphylococcus aureus meticilino resistente en centros hospitalarios de Pereira / Comparison between phenotype and genotype methods in the detection of Methicillin-Resistant Staphylococcus aureus in Center Hospital of Pereira

Resumen Introducción: Staphylococcus aureus es un importante patógeno, puede causar infecciones leves de piel, hasta enfermedades con compromiso vital. La aparición de Staphylococcus aureus meticilino-resistentes, MRSA; ha aumentado su resistencia antimicrobiana, especialmente a β-lactámicos; dificultando el manejo de las infecciones, aumentando las tasas de morbi-mortalidad, convirtiéndose en un problema de salud pública. La expresión fenotípica de la resistencia suele ser heterogénea, dificultando su detección en el laboratorio por métodos convencionales; lo cual, incrementa los costos en la atención hospitalaria de infecciones por MRSA. Objetivo: Comparar métodos fenotípico y genotípico para la identificación de aislamientos hospitalarios de MRSA en centros hospitalarios de Pereira. Métodos: A partir de aislamientos de S. aureus obtenidos de tres instituciones de salud de alta complejidad clasificadas como A, B y C; se determinó la resistencia a meticilina por concentración mínima inhibitoria en sistemas automatizados y el gen mecA por PCR múltiple. Resultados: La prevalencia fenotípica de MRSA fue 44,4%, la institución A presentó la mayor tasa con 48,65%. La prevalencia genotípica fue 57,4%; en las instituciones A, B y C fue 55,2%, 41,7% y 75%, respectivamente, con diferencia estadísticamente significativa (p<0.05). La sensibilidad y especificidad del método fenotípico fue 99,0% y 94,7%, respectivamente, frente al método gold estándar de la PCR. El índice Kappa fue 0,942 indicando un nivel de concordancia muy bueno entre métodos. Conclusión: La prevalencia de aislamientos MRSA en las instituciones de Pereira fue alta. Los índices de concordancia de los métodos fenotípicos demostraron que son confiables para el diagnóstico de infecciones por MRSA.

Abstract Introduction: Staphylococcus aureus is an important pathogen, can cause mild skin infections, to diseases with compromise vital. The appearance of Methicillin-Resistant Staphylococcus aureus MRSA; It has increased its antimicrobial resistance, especially to β-lactam; hampering the handling of them infections, increasing the rates of morbidity-mortality, becoming a health public problem. The phenotype expression of the resistance tend to be heterogeneous, hindering its detection in the laboratory by conventional methods; which increases costs in the hospital care of MRSA infections. Objective: To compare the phenotypes and genotypes methods for identification of hospital isolates MRSA in Pereira. Methods: From isolates of S. aureus obtained of three high complexity institutions of health classified as A, B and C; determined resistance to Methicillin by minimum inhibitory concentration in automated systems and mecA gene by multiplex PCR. Results: The phenotype prevalence of MRSA was 44.4%, the institution A presented the highest rate with 48.65%. The genotype prevalence was 57.4%; in the institutions A, B and C was 55.2%, 41.7% and 75%, respectively, with difference statistically significant (p < 0.05). The sensitivity and specificity of the phenotype method were 99.0% and 94.7%, respectively, against the gold standard of the PCR method. The Kappa index was 0,942 indicating a very good level of concordance between methods. Conclusion: The prevalence of isolates MRSA in the institutions of Pereira was high. The concordance index of phenotype methods showed that they are reliable for the diagnosis of MRSA infections.

Studies on chemical constituents from fruits of Morus alba L / 药学学报

Chemical investigation of fruits of Mours alba L. lead to the isolation of fifteen compounds by various chromatographies such as silica gel, Sephadex LH-20, RP-C18 column chromatography. Their structures were determined to be: 1-[5-(2-formlfuryl) methyl] dihydrogen 2-hydroxypropane-1, 2, 3-tricarboxylate 2, 3-diethyl ester (1), 1-[2-(furan-2-yl)-2-oxoethyl] pyrrolidin-2-one (2), divaricataester A (3), methyl 1-[2-(furan-2-yl)-2-oxoethyl]-5-oxopyrrolidine-2-carboxylate (4), 1-[2-(furan-2-yl)-2-oxoethyl]-5-oxopyrrolidine-2-carboxylic acid (5), L-pyroglutamic acid (6), L-pyroglutamic acid ethyl ester (7), 3-O-caffeoylquinic acid methyl ester (8), 3-O-caffeoylquinic acid ethyl ester (9), 5-O-caffeoylquinic acid methyl ester (10), 5-O-caffeoylquinic acid ethyl ester (11), 4-O-caffeoylquinic acid methyl ester (12), 4-O-caffeoylquinic acid methyl ester (13), 4-O-caffeoylquinic acid (14), 3-O-caffeoylquinic acid (15), respectively, based on the spectral analysis such as NMR, MS etc. Compounds 1-14 were isolated from this genus for the first time, among which 1 was a new compound.

Phenolic aristolactams from leaves and stems of Aristolochia chilensis / Aristolactamas fenólicas de hojas y tallos de Aristolochia chilensis

Three phenolic aristolactams, aristolactam AII (3), velutinam (4) and piperolactam A (5), were identified from the leaves and stems of Aristolochia chilensis Bridges ex Lindl. The structures of these compounds were elucidated using a combination of HPLC-DAD, GC-MS and NMR experiments.

Tres aristolactamas fenólicas aristolactama AII(3), velutinam(4) y piperolactama A(5), se identificaron en hojas y tallos de Aristolochia chilensis Bridges ex Lindl. Las estructuras de estos compuestos se determinaron por combinación de CLAE-DAD, CG-EM y experimentos de RMN.

Transformation of strictosamide to vincoside lactam by acid catalysis / 中国天然药物

AIM@#To identify the structure of the acid-catalyzed product of strictosamide and explore the reaction mechanism.@*METHODS@#The acid-catalyzed reaction process of strictosamide was monitored by HPLC, and a macroporous resin was used to purify the reaction solution. The structure of the product was confirmed by MS, NMR, and ROESY spectra.@*RESULTS@#The acid-catalyzed transformation yield from strictosamide to vincoside lactam was 52%.@*CONCLUSION@#The reaction mechanism of the transformation from strictosamide to vincoside lactam may be related to the stability of the three-dimensional configuration of the compound. These results offer a new way to obtain vincoside lactam from the widely distributed indole alkaloid strictosamide by acid-catalysis.

Targeting the substrate binding domain of polo-like kinase 1: advances in the study of PBD1 inhibitors / 药学学报

Polo-box domain 1 (PBD1) is a characteristic domain of polo-like kinase 1 (PLK1), which locates in C-terminal and can influence the catalytic activity and specific subcellular locations of PLK1. At present, most PLK1 inhibitors are developed to occupy the ATP pocket or its close sites. However, this kind of PLK1 inhibitors is difficult to pursue target selectivity and may encounter cross drug resistance with other kinase inhibitors due to the conserved sequence of ATP pocket. Recently, PBD1, with aberrant specificity in sequence and structure, has attracted enormous interests as the alternative target to the discovery of corresponding inhibitors for anti-tumor drugs. The structure and function of PBD1 as well as the advances of its inhibitors are reviewed in this paper.

Protective effect of (-) clausenamide against neurotoxicity induced by okadaic acid and beta-amyloid peptide25-35 / 药学学报

This study is to investigate the protective effect of (-) clausenamide against the neurotoxicity of okadaic acid in SH-SY5Y cell line, and injection beta-amyloid peptide25-35 (Abeta25-35) to the cerebral ventricle in ovariectomy (OVX) rats. MTT assay, LDH assay, and Hoechst 33258 staining were used to detect the effect of (-) clausenamide on the toxicity of okadaic acid in SH-SY5Y cell line. The animal model was induced by ovariectomized and injection of Abeta25-35 in the cerebroventricle of rats. The effect of (-) clausenamide on learning and memory deficiency was observed by step-through test. Electron microscope, Nissl body staining, and HE staining were used to examine the morphological changes in hippocampus and cerebral cortex neurons. Pretreatment of (-) clausenamide and LiCl decreased the rate of cell death from MTT, LDH release, and apoptosis from Hoechst 33258 staining in SH-SY5Y cell line. The step-through tests showed (-) clausenamide could improve the ability of learning and memory. The Nissl body staining and HE staining experiments also showed the neuroprotective effects of (-) clausenamide on the neurons of hippocampus and cerebral cortex. (-) Clausenamide has the protective effects against the neurotoxicity induced by okadaic acid and Abeta25-35.

Advances in studies on pharmacokinetics of aristolochic acid I / 中国中药杂志

Aristolochic acid I (AA-I) was absorbed and distributed quickly in vivo, the plasma concentration-time curve were fit with the open two-compartment model and one-compartment model, respectively. The elimination of AA-I has relationship with the dosage, the low dose group eliminates more quickly than the high dose group. The characters of pharmacokinetics of AA-I induce the cumulation of AA-I in vivo and the nephrotoxin to the kidney and other viscera.

1[st] line antimicrobial therapy for febrile neutropenic cancer patients

Empiric antibiotic regimens used in febrile neutropenic patients often include an extended spectrum cephalosporin, but the response of therapy in Gram positive coccal bacteremia has been unsatisfactory, thus new antibiotic with better activity against Gram positive bacteria should be tested. Antipseudomonal penicillins including piperacillin are effective against many Gram positive and Gram negative organisms. The aim of this work is to compare combination therapy with piperacillin-tazobactam plus amikacin versus ceftazidime plus amikacin as first line in treatment of febrile neutropenic cancer patients. This study is a single center, prospective and randomized trial performed in pediatric branch wards, of the National Cancer Institute, Cairo University. All patients were subjected to full clinical and laboratory evaluation including microbiological study. Doses were given according to the International Antimicrobial Therapy Cooperative Group [IATCG] of the European Organization for the Research and Treatment of Cancer [EORTC]. 164 febrile neutropenic episodes were enrolled on this study. 82 patients with 105 [64%] high risk febrile granulocytopenic episodes were considered eligible. 53 were treated with piperacillin-tazobactam plus amikacin [group A], and 52 were treated with ceftazidime plus amikacin [group B]. The overall success in group A was higher than group B, yet, the difference was statistically insignificant with a p value=0.2. Time of defervecence was significantly shorter in piperacillin-tazobactam group [p=0.001]. There was no infection related mortality in this study. Side effects were encountered in 3 [5.6%] cases receiving piperacillin-tazobactam in the form of mild skin reaction. 55.7% of positive cultures yielded Gram positive organisms. Staphylococcus species were the most common organism in both groups. Both Gram positive and negative organisms showed higher sensitivity to pipercillin-tazobactam compared to ceftazidime with a significant p value=0.05. Piperacillin-tazobactam is safe and more effective than ceftazidime in febrile neutropenia in pediatric cancer patients

Excretion of (-)-clausenamide in rats / 药学学报

<p><b>AIM</b>To study the excretion of (-)-clausenamide in rats.</p><p><b>METHODS</b>The urine, feces and bile were collected at predetermined time points after (-)-clausenamide was orally administrated to 6 rats (30 mg x kg(-1)). The concentrations of (-)-clausenamide and its metabolite 6-OH-(-)-clausnamide were determined by HPLC-MS/MS method using glipzide as the internal reference, and the accumulative excretion amount of (-)-clausenamide and 6-OH-(-)-clausenamide was calculated in the urine, feces and bile, separately.</p><p><b>RESULTS</b>(-)-Clausenamide was recovered mostly (44%) from feces in 112 hours, 7.1% was found from urine in 120 hours and 0.013% was detected from bile in 24 hours. The accumulative excretions of 6-OH-(-)-clausenamide were 0.92% , 0.46% and 0.0003% of the administered dose from feces, urine and bile, respectively.</p><p><b>CONCLUSION</b>The major amount of (-)-clausenamide was recovered from feces after (-)-clausenamide was orally administrated to rats (30 mg kg(-1)).</p>

Pharmacokinetics of (-)-clausenamide and its major metabolite 6-hydroxyl-clausenamide in beagle dogs by HPLC/MS / 药学学报

<p><b>UNLABELLED</b>To establish a sensitive and accurate method to study the pharmacokinetics of (-)-clausenamide [(-)-clau] and its major metabolite 6-hydroxyl-clausenamide (6-OH-clau) in the plasma of the Beagle dog.</p><p><b>METHODS</b>(-)-Clau was orally administered to six Beagle dogs at the dose of 30 mg x kg(-1), venous blood from front leg was sampled and plasma was separated for analysis. After extraction with ethyl acetate, the plasma samples were analyzed by HPLC/MS and the mobile phase was a mixture of methanol-water-acetic acid (60: 40: 0. 8) at the flow rate of 1.0 mL x min(-1). The API-ES positive ion SIM detection was carried out for the detection of both (-)-clau ([M + H] (+), m/z 298 ) and 6-OH-clau ([M + H - H2 O](+), m/z 296) with glipzide (glip) ([M + H](+), m/z 446) as internal standard. The pharmacokinetic parameters were calculated by 3P97 software.</p><p><b>RESULTS</b>There was good linear relationship ( r > 0. 999) between the SIM responses and the concentrations for (-)-clau and 6-OH-clau at the range from 1.0 to 200 ng x mL(-1) and 0.2 to 40.0 ng x mL(-1), respectively. The absolute recovery was greater than 85%. The plasma concentration-time curves of (-)-clau and 6-OH-clau were both best fitted to a two-compartment model. The C(max) of (-)-clau and 6-OH-clau were (21 +/- 10) ng x mL(-1) and (3.9 +/- 2.2) ng x mL(-1), T(max) were (0.8 +/- 0.5) h and (1.3 +/- 0.5) h, T 1/2 alpha were (0.9 +/- 0.6) hand (1.4 +/- 0.6) h, T 1/2 beta were (19 +/- 23) hand (13 +/- 12) h, AUC(0-24 h) were (69 +/- 14) h x ng x mL(-1) and (12 +/- 7) h x ng x mL(-1) respectively.</p><p><b>CONCLUSION</b>The established HPLC/MS method was sensitive and specific for the determination of (-)-clau. It was shown that the absorption and first phase elimination of (-)-clau were very quick in Beagle dogs, but the terminal elimination was very slow. The plasma concentration profile of its major metabolite 6-OH-clau was similar to (-)-clau and the AUC was relatively small in comparison with (-)-clau.</p>

Métodos fenotípicos para detección de betalactamasas de espectro extendido en cepas de escherichia coli y klebsiella pneumoneae / Fenotypic method for detection of extended spectrum batalactamase in escherichia coli and klebsiella pneumoniae strains

La producción de BLEE por cepas de Escherichia coli y Klebsiella pneumoneae es un grave problema de salud pública, ya que causa la pérdidad de eficacia terapéutica a los antibióticos ß-lactámicos. En este trabajo se utilizaron cinco métodos para la detección fenotípica de BLEE. Se estudiaron 130 cepas de E. coli y 67 de K. pneumoneae. aisladas de los cultivos bacteriológicos realizados en el CRB-SAHUM. Los métodos de descarte confirmatorios del NCCLS mostraron ser muy efectivos en la detección de cepas BLEE positivas, especialmente los métodos basados en la CIM. Adicionalmente se utilizó el método estandarizados del NCCLS, ya que los resultados no demostraron diferencias significativas. Todos los métodos empleados tuvieron desempeño parecido; se recomienda ampliamente el empleo del método del doble disco, por ser de bajo costo y de fácil aplicación en la rutina diaria de un laboratorio de Bacteriología

Alergia a beta-lactámicos / Allergy to betalactams

La alergia a b-lactámicos es la primera causa de alergia medicamentosa en el mundo. En nuestro país, el estudio in vivo (pruebas cutááneas) realizado regularmente no se efectúa de acuerdo a patrones internacionales establecidos. Este artículo revisa el diagnóstico y manejo de estas reacciones. Las reacciones alérgicas a b-lactámicos pueden clasificarse, según su perfil temporal, en inmediatas, aceleradas y tardías, lo que se relaciona con las manifestaciones clínicas y mecanismos patogénicos. La mayor parte de las reacciones inmediatas y aceleradas son mediadas por IgE, con expresión clínica de hipersensibilidad inmediata. Entre las reacciones tardías destacan las toxidermias y exantemas máculo-papulares, mediadas probablemente por hipersensibilidad retardada. Los alergenos implicados en las reacciones de hipersensibilidad inmediata a b-lactámicos pueden ser los determinantes mayores (75 por ciento de los casos), determinantes menores o las cadenas laterales de los fármacos sospechosos. El estudio de estos pacientes incluye IgE específicas, pruebas cutáneas y pruebas de provocación. Los objetivos de estos estudios son diagnosticar reactividades cruzadas o monosensibilizaciones, y autorizar o prohibir la utilización de todos los b-lactámicos o sólo algunos de los fármacos del grupo, además de asegurar la tolerancia a fármacos alternativos.

Effects of (-), (+)-7-hydroxy-clausenamide on synaptic transmission in rat dentate gyrus in vivo / 药学学报

<p><b>AIM</b>To investigate effects of (-), (+)-7-hydroxy-clausenamide (7-OH-Clau) on basal synaptic transmission in the dentate gyrus of anesthetized rats.</p><p><b>METHODS</b>Extracellular recording of the population spike (PS) of hippocampal dentate gyrus following application of low-frequency stimulation (1/30 Hz, 1.0 mA).</p><p><b>RESULTS</b>Fifteen, thirty and sixty minutes after intracerebroventricular (icv) administration of an estimated final brain concentration of 2 x 10(-6) mol.L-1, (-)-7-OH-Clau caused over 30% increase relative to basal PS amplitude before administration, and 27%-41% increase relative to vehicle control (P < 0.05), while (+)-7-OH-Clau exhibited 18%-25% and 11%-20% decrease in the PS amplitude when compared with basal PS amplitude and vehicle control (P < 0.05), respectively.</p><p><b>CONCLUSION</b>The basal synaptic transmission in the dentate gyrus of the rat hippocampus can be potentiated by (-)-7-OH-Clau and attenuated by (+)-7-OH-Clau, indicating that there was a stereoselective difference between the two enantiomers in the modulation of synaptic responses and plasticity.</p>

Nuevo agente betalactámico en el manejo de la sepsis intra-abdominal: Estudio de fase III, doble ciego y randomizado del Ertapenem vs. Piperacilina/Tazobactam / New beta-lactam agent in the treatment of intra-abdominal sepsis: double blind and randomized stage III study of Ertapenem versus Piperacillin/Tazobactam

Se evalúa la eficacia clínica y de seguridad de un nuevo agente betalactámico de amplio espectro de nombre químico ertapenem (MK-0826) para la mayoría de gérmenes patógenos de infección intra-abdominal. Sus características farmacocinéticas y el espectro antimicrobiano conocido permite el uso potencial de dosis única diaria en el tratamiento de infecciones bacterianas aeróbicas y anaeróbicas. Este es un sub grupo de pacientes tratados en un estudio multinacional, prospectivo, randomizado, controlado y doble ciego para comparar la seguridad y eficacia del ertapenem con la piperacilina/tazobactam en pacientes operados por infección intraabdominal complicada de abril de 1998 a octubre de 1999, de acuerdo con las normas de la IDSA/FDA. 20 pacientes nacionales fueron evaluados de un total de 623 pacientes en 17 países. La apendicitis aguda perforada fue la patología más frecuente en ambos grupos. El índice de curación fue discretamente mayor en el grupo del ertapenem (100 por ciento vs 88 por ciento), sin haberse documentado ninguna falla clínica. El presente estudio nos muestra la eficacia del ertapenem, en dosis única de 1 gr/día, siendo equivalente a la piperacilina/tazobactam de 3.375 gr cada seis horas en el manejo de las infecciones intra-abdominales. La tolerancia y seguridad fueron similares en ambos grupos. No se presentaron efectos secundarios, ni hubo mortalidad. Los resultados de esta investigación indican que el ertapenem puede ser la opción terapeútica que permita descartar la necesidad de combinar antibióticos o el uso de multidosis en la sinfecciones intra-abdominales.

Guías para el uso racional de antibióticos Beta-lactámicos: mecanismos de resistencia y su interpretación clínica / Guides for rational use of Beta-Lactam antibiotics: resistance mechanisms and clinical interpretation

Los antibióticos á-lact micos son los compuestos más ampliamente usados para tratar infecciones adquiridas en el hospital o en la comunidad. Sin embargo, la resistencia a estos antibióticos en bacterias Gram negativas y Gram positivas se ha incrementado, lo cual limita su eficacia terapéutica. Se debe estar alerta a este fenómeno y seleccionar la terapia de acuerdo con el mecanismo de resistencia probable del germen aislado. La lectura interpretativa de los patrones de susceptibilidad permite un enfoque más racional del problema de resistencia y se convierte en una guía fundamental para el manejo de situaciones específicas. Dada la complejidad de los mecanismos de resistencia, es indispensable que el laboratorio identifique los microorganismos según especie y determine la susceptibilidad de un número razonable de antimicrobianos. La resistencia a á-lact micos en Enterobacteriaceae se debe principalmente a la producción de á-lactamasas codificadas cromosómicamente o en plásmidos. Los mecanismos de impermeabilidad y la producción de bombas de exclusión molecular son los más comunes en microorganismos 'no fermentadores', por lo cual la terapia debe responder a estos fenómenos. En bacterias Gram positivas existen varios mecanismos involucrados: producción de proteínas de unión a penicilina (PBP) alteradas, síntesis de nuevas PBP o producción de á-lactamasas. Se discuten aquí las opciones terapéuticas basadas en el conocimiento de los mecanismos de resistencia.

Liver abscess due to Salmonella enteritidis in a returned traveler with HIV infection: case report and review of the literature

Bacteremia due to non-typhi Salmonella is more frequent in patients infected with the human immunodeficiency virus (HIV). However, focal complications have been rarely described. We report a case of liver abscess due to Salmonella enteritidis in an HIV-infected patient who recently returned to Sao Paulo, Brazil, from a trip in the Caribbean. A good clinical and radiological response was seen with both percutaneous catheter drainage and antibiotic treatment. To our knowledge, this is the first culture proven case of non-typhi Salmonellaliver abscess in an HIV-infected patient in Brazil