Antimalarial evaluation of alkyl-linked bis-thiadiazine derivatives in murine model infected with two Plasmodium strains.

Background and Purpose: Plasmodium falciparum and P. vivax are responsible for most malaria cases in humans in the African Region and the Americas; these parasites have developed resistance to classic antimalarial drugs. On the other hand, previous investigations of the alkyl-linked bis tetrahydro-(2H)-1,3,5-thiadiazine-2-thione (bis-THTT) derivatives compounds show satisfactory results against protozoan parasites such as Trypanosoma cruzi, Trypanosoma vaginalis, Trypanosoma brucei rhodesiense and Leishmania donovani. Therefore, it is possible to see some effect of bis-THTT derivatives on other protozoan parasites, such as Plasmodium. Experimental Approach: This study aimed to perform an in vivo biological evaluation of bis-THTT (JH1 to JH6) derivatives compounds as possible anti-malaria drugs in BALB/c mice infected with Plasmodium berghei ANKA and Plasmodium yoelii 17XL strains. In this work, we evaluated the compounds as potential antimalarial drugs in BALB/c mice infected with Plasmodium strains. Key Results: For each compound, we assess the percentages of parasitemia by smears from tail blood and the humoral response by indirect ELISA test using each compound as an antigen. We also evaluated the B lymphocyte response and the cytotoxicity of the bis-THTT derivatives compounds with MTT cell proliferation assays. Conclusions: Our results show that the bis-THTT derivatives JH2 and JH4 presented effective parasitemia control in mice infected with P. berghei; JH5 and JH6 compounds have similar infection control results as chloroquine in mice infected P. yoelii strain. The evaluation of bis-THTT derivatives compounds in a model of BALB/c mice infected with P. berghei and P. yoelii allowed us to conclude that some of them have an antimalarial effect; however, none of the tested compounds exceeded the efficiency of chloroquine.

Cysteine-Based Perfluorinated Derivatives: A Theoretical and Experimental Study.

Cysteine-based perfluoroaromatic (hexafluorobenzene (HFB) and decafluorobiphenyl (DFBP)) were synthesized and established as a chemoselective and available core to construct molecular systems ranging from small molecules to biomolecules with interesting properties. The DFBP was found more effective than HFB for the monoalkylation of decorated thiol molecules. As proof of concept of the potential application of perfluorinated derivatives as non-cleavable linkers, some antibody-perfluorinated conjugates were prepared via thiol through two different strategies, i) using thiol from reduced cystamine coupling to carboxylic acids from mAb by amide bond, and ii) using thiols from reduction of mAb disulfide bond. Conjugates cell binding analysis demonstrated that the bioconjugation does not affect the macromolecular entity. Besides, some molecular properties of synthesized compounds are evaluated through spectroscopic characterization (FTIR and 19 F NMR chemical shifts) and theoretical calculations. The comparison of calculated and experimental 19 F NMR shifts and IR wavenumbers give excellent correlations, asserting as powerful tools in structurally identifying HFB and DFBP derivatives. Moreover, molecular docking was also developed to predict cysteine-based perfluorated derivatives' affinity against topoisomerase Il and cyclooxygenase 2 (COX-2). The results suggested that mainly cysteine-based DFBP derivatives could be potential topoisomerase II α and COX-2 binders, becoming potential anticancer agents and candidates for anti-inflammatory treatment.

3,4-Dihydro-2(1H)-Pyridones as Building Blocks of Synthetic Relevance.

3,4-Dihydro-2(1H)-pyridones (3,4-DHPo) and their derivatives are privileged structures, which has increased their relevance due to their biological activity in front of a broad range of targets, but especially for their importance as synthetic precursors of a variety of compounds with marked biological activity. Taking into account the large number of contributions published over the years regarding this kind of heterocycle, here, we presented a current view of 3,4-dihydro-2(1H)-pyridones (3,4-DHPo). The review includes general aspects such as those related to nomenclature, synthesis, and biological activity, but also highlights the importance of DHPos as building blocks of other relevant structures. Additional to the conventional multicomponent synthesis of the mentioned heterocycle, nonconventional procedures are revised, demonstrating the increasing efficiency and allowing reactions to be carried out in the absence of the solvent, becoming an important contribution to green chemistry. Biological activities of 3,4-DHPo, such as vasorelaxant, anti-HIV, antitumor, antibacterial, and antifungal, have demonstrated this heterocycle's potential in medicinal chemistry.

Chemical Conjugation in Drug Delivery Systems.

Cancer is one of the diseases with the highest mortality rate. Treatments to mitigate cancer are usually so intense and invasive that they weaken the patient to cure as dangerous as the own disease. From some time ago until today, to reduce resistance generated by the constant administration of the drug and improve its pharmacokinetics, scientists have been developing drug delivery system (DDS) technology. DDS platforms aim to maximize the drugs' effectiveness by directing them to reach the affected area by the disease and, therefore, reduce the potential side effects. Erythrocytes, antibodies, and nanoparticles have been used as carriers. Eleven antibody-drug conjugates (ADCs) involving covalent linkage has been commercialized as a promising cancer treatment in the last years. This review describes the general features and applications of DDS focused on the covalent conjugation system that binds the antibody carrier to the cytotoxic drug.

An Androsterone-H2 @C60 hybrid: Synthesis, Properties and Molecular Docking Simulations with SARS-Cov-2.

Invited for this month's cover are the collaborating groups of Dr. Margarita Suárez at Universidad de La Habana, Cuba, and Dr. Nazario Martín at Universidad Complutense de Madrid, Spain, together with groups at other institutions worldwide. The Front Cover shows a representation of the H2 @C60 hybrid molecule with a dehydroepiandrosterone moiety interacting with the active site of the SARS Cov-2. Read the full text of the article at 10.1002/cplu.202000770.

An Androsterone-H2 @C60 hybrid: Synthesis, Properties and Molecular Docking Simulations with SARS-Cov-2.

We report the synthesis and characterization of a fullerene-steroid hybrid that contains H2 @C60 and a dehydroepiandrosterone moiety synthesized by a cyclopropanation reaction with 76 % yield. Theoretical calculations at the DFT-D3(BJ)/PBE 6-311G(d,p) level predict the most stable conformation and that the saturation of a double bond is the main factor causing the upfield shielding of the signal appearing at -3.13 ppm, which corresponds to the H2 located inside the fullerene cage. Relevant stereoelectronic parameters were also investigated and reinforce the idea that electronic interactions must be considered to develop studies on chemical-biological interactions. A molecular docking simulation predicted that the binding energy values for the protease-hybrid complexes were -9.9 kcal/mol and -13.5 kcal/mol for PLpro and 3CLpro respectively, indicating the potential use of the synthesized steroid-H2 @C60 as anti-SARS-Cov-2 agent.

Diastereoselective Synthesis of Steroid-[60]Fullerene Hybrids and Theoretical Underpinning.

The reaction of C60 with pregnen-20-carboxaldehyde, a biologically active synthetic steroid, by using a 1,3-dipolar cycloaddition reaction (Prato's protocol) results in the formation of pyrrolidine rings bearing a new stereogenic center on the C2 of the five-membered ring. The formation of the fullerene-steroid hybrids proceeds with preference for the Re face of the 1,3-dipole, with formation of a diastereomeric mixture in 73:15 ratio. The investigation of the chiroptical properties of these conjugates allowed determining the absolute configuration of the new fulleropyrrolidines. In addition, a thorough spectroscopical study permitted to determine the structure of the two mono-cycloadducts. The electrochemical properties of the new hybrids were also evaluated by cyclic voltammetry, both systems exhibit three quasi-reversible reduction waves which are cathodically shifted in regard to the parent C60. Theoretical calculations help supporting the experimental data. A conformational study combining semiempirical methods and density functional theory has predicted the most stable diastereomer. On the basis of this agreement, a possible reaction mechanism is presented. Additionally, a molecular docking simulation has been carried out using the HIV-1 protease as receptor, thus paving the way to study the possible application of these stereoisomers in biomedicine.

Catalytic Stereodivergent Synthesis of Steroid-Fulleropyrrolidine Hybrids.

The diastereoselective synthesis of cis and trans steroid-fulleropyrrolidines hybrids by reaction of N-metalated azomethine ylides [Cu(II) or Ag(I)] with the appropriate chiral ligand and C60 is described. The experimental findings reveal that the azomethine ylide stabilized by an allylic group cycloadds to [60]fullerene in an efficient manner and with a good diastereomeric excess. Furthermore, the new generated stereocenters are fully controlled by the catalytic systems used without being influenced by the chirality of the steroid. Interestingly, by this synthetic methodology the each one of the four possible stereoisomers have efficiently been obtained and characterized by CD spectra.

Theoretical Study on the Mechanism of the Thermal Retro-Cycloaddition of Isoxazolinofullerenes.

The retro-cycloaddition thermal reaction of isoxazolino[4,5:1,2][60]fullerenes to pristine fullerene seems to be guided by the electronic nature of the substituted nitrile oxide 1,3-dipole in the isoxazoline ring. Trapping experiments proved that the reaction mechanism occurs by thermal removal of the nitrile oxide 1,3-dipole in a process that is favored in the presence of a big excess of a highly efficient dipolarophile such as maleic anhydride. Theoretical gas phase calculations carried out at the B3LYP/6-31G(d) and M06-2X/6-31G(d) levels of theory underpin the experimental findings and predict that compound 1c, bearing the p-(CH3)2N-Ph substituent on the isoxazoline ring and with a remarkable experimental conversion efficiency in just 12 h, showed the lowest activation energy. Solvent calculations have predicted the same behavior in gas phase. Different approaches such as electrostatic natural population analysis and Houk's distortion/interaction model have been applied to understand how the electronic nature of these substituents affects the retro-cycloaddition reaction process. Analysis of the values of the condensed Fukui functions and dual descriptor shed light on the mechanism of the retro-cycloaddition reaction.

Competitive retro-cycloaddition reactions in heterocyclic fullerene bis-adducts ions: selective removal of the heterocyclic moieties.

RATIONALE: We have investigated the fragmentation reactions of ions from bis-adducts containing isoxazolino-, pyrrolidino- and methanofullerene moieties. METHODS: The fragmentation reactions induced by collision-induced dissociation (CID) of ions generated under electrospray ionization (ESI) in positive and negative modes of detection using an ion-trap spectrometer have been investigated. RESULTS: The competitive retro-cycloaddition process between isoxazoline and pyrrolidine rings fused to [60]fullerene reveals that it is strongly dependent on the experimental negative or positive ESI experimental conditions. Thus, whereas retro-cycloaddition reaction is favored in the pyrrolidine ring under negative conditions, the protonation occurring on the nitrogen atom of the pyrrolidine ring under positive conditions precludes its retro-cycloaddition and, therefore, only the isoxazoline ring undergoes the retro-cycloaddition process. The obtained experimental results are different from those reported when the reaction is carried out under thermal conditions. Competitive retro-cycloaddition reactions of isoxazolino- and methanofullerenes show that the heterocyclic ring undergoes cycloelimination, leaving the methanofullerene moiety unchanged. In this case, the same selectivity is observed under thermal and gas-phase conditions. CONCLUSIONS: The observed selectivity in the heterocyclic removal in these [60]fullerene derivatives is reversed from negative conditions (radical anions) to positive conditions (protonated molecules). Moreover, the retro-cycloaddition reaction behaves differently under spectrometric and thermal conditions.

Resistance profile for pathogens causing urinary tract infection in a pediatric population, and antibiotic treatment response at a university hospital, 2010-2011.

INTRODUCTION: Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and causes acute and chronic morbidity and long-term hypertension and chronic kidney disease. OBJECTIVES: To describe the demographic characteristics, infectious agents, patterns of antibiotic resistance, etiologic agent and profile of susceptibility and response to empirical treatment of UTI in a pediatric population. METHODS: This is a descriptive, retrospective study. RESULTS: Included in the study were 144 patients, 1:2.06 male to female ratio. The most common symptom was fever (79.9%) and 31.3% had a history of previous UTI. 72.0% of the patients had positive urine leukocyte count (>5 per field), urine gram was positive in 85.0% of samples and gram negative bacilli accounted for 77.8% for the total pathogens isolated. The most frequent uropathogens isolated were Escherichia coli and Klebsiella pneumoniae. Our E.coli isolates had a susceptibility rate higher than 90% to most of the antibiotics used, but a resistance rate of 42.6% to TMP SMX and 45.5% to ampicillin sulbactam. 6.3% of E. coli was extended-spectrum beta-lactamases producer strains. The most frequent empirical antibiotic used was amikacin, which was used in 66.0% of the patients. 17 of 90 patients who underwent voiding cistouretrography (VCUG) had vesicoureteral reflux. CONCLUSION: This study revealed that E. coli was the most frequent pathogen of community acquired UTI. We found that E. coli and other uropathogens had a high resistance rate against TMP SMX and ampicillin sulbactam. In order to ensure a successful empirical treatment, protocols should be based on local epidemiology and susceptibility rates.

ANTECEDENTES: La infección del tracto urinario (ITU) es una de las infecciones bacterianas más frecuentes en la infancia, se asocia con alta morbilidad aguda y de enfermedades a largo plazo como hipertensión arterial e insuficiencia renal crónica. OBJETIVO: Describir las características demográficas, agente etiológico, perfil de sensibilidad y respuesta al tratamiento empírico de una población pediátrica. MÉTODOS: Estudio descriptivo, retrospectivo realizado en el Hospital Pablo Tobón Uribe (HPTU), Medellín (Colombia), entre enero de 2010 y diciembre de 2011. RESULTADOS: Se incluyeron 144 pacientes, con una relación hombre: mujer de 1:2.06. El 79.9% consultó por fiebre objetiva y el 31.3% había tenido un episodio de ITU previa. El 72.0% presentó leucocituria y el gram de gota de orina sin centrifugar fue positivo en el 86.0% (77.8% de bacilos con tinción de gram negativos). Los uropatógenos más frecuentes fueron Escherichia coli y Klebsiella pneumoniae. Escherichia coli tuvo una sensibilidad mayor al 90% para la mayoría de antibióticos, excepto en el de trimetropín sulfametoxazol, con una resistencia del 42.6% y del 45.5% a la ampicilina sulbactam. Se usó la amikacina como tratamiento empírico en el 66.0%. En 17 de 90 pacientes se encontró algún grado de reflujo vesicoureteral (RVU). CONCLUSIÓN: La elección del tratamiento empírico precoz debe basarse en el conocimiento de la epidemiología y el perfil de sensibilidad y resistencia de cada institución. En este estudio se encontró elevado porcentaje de resistencia de la E. coli y otros uropatógenos a trimetropín sulfametoxazol y ampicilina sulbactam.

Morphological characterization of fullerene-androsterone conjugates.

Here we report on the self-organization characteristics in water of two diastereomer pairs of fullerene-androsterone hybrids that have the hydrophobic C60 appendage in the A and D ring of the androsterone moiety, respectively. The morphology and particle size in aqueous solution were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS), with satisfactory agreement between both techniques. In general, these fullerene derivatives are shown to organize into spherical nano-scale structures with diameters in the ranges of 10-20 and 30-50 nm, respectively.

Dumbbell-type fullerene-steroid hybrids: a join experimental and theoretical investigation for conformational, configurational, and circular dichroism assignments.

New [60]fullerene-steroid conjugates (4-6) have been synthesized by 1,3-dipolar cycloaddition and Bingel-Hirsch cyclopropanation reactions from suitably functionalized epiandrosterone and [60]fullerene. Since a new stereocenter is created in the formation of the Prato monoaduct, two different diastereomers were isolated by HPLC (4, 5) whose absolute configurations were assigned according to the highly reliable "sector rule" on fullerenes. A further reaction of the malonate-containing diastereomer 5 with a second C60 molecule has afforded dumbbell fullerene 6 in which the two fullerene units are covalently connected through an epiandrosterone moiety. The new compounds have been spectroscopically characterized and their redox potentials, determined by cyclic voltametry, reveal three reversible reduction waves for hybrids 4 and 5, whereas these signals are split in dumbbell 6. Theoretical calculations at semiempirical (AM1) and single point B3LYP/6-31G(d) levels have predicted the most stable conformations for the hybrid compounds (4-6), showing the importance of the chlorine atom on the D ring of the steroid. Furthermore, TDDFT calculations have allowed assignments of the experimentally determined circular dichroism (CD) of the [60]fullerene-steroid hybrids based on the sign and position of the Cotton effects, despite the exceptionally large systems under study.

Profile resistance of pathogens causing urinary tract infection in the pediatric population, and antibiotic treatment response, at a University Hospital 2010-2011 / Perfil de resistencia de los patógenos causantes de infección urinaria en la población pediátrica y respuesta al tratamiento antibiótico, en un hospital universitario 2010-2011

Abstract Background: Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and causes acute and chronic morbidity as hypertension and chronic kidney disease. Objectives: To describe the demographic characteristics, infectious agent, antibiotic resistance patterns and empiric therapy response of UTI in pediatric population. Methods: This is a descriptive, retrospective study. Results: Were included 144 patients, 1:2.06 male to female ratio. The most common symptom was fever (79.9%) and 31.3% had history of previous UTI. 72.0% of the patients had positive urine leukocyte count (>5 per field), urine gram was positive in 85.0% of samples and gram negative bacilli accounted for 77.8% for the total pathogens isolated. The most frequent uropathogens isolated were Escherichia coli and Klebsiella pneumoniae. Our E.coli isolates had a susceptibility rate higher than 90% to most of the antibiotics used, but a resistance rate of 42.6% to TMP SMX and 45.5% to ampicillin sulbactam. 6.3% of E. coli was extended-spectrum beta-lactamases producer strains. The most frequent empirical antibiotic used was amikacin, used in 66.0% of the patients. 17 of 90 patients who undergone voiding cistouretrography (VCUG) had vesicoureteral reflux. Conclusion: This study revealed that E. coli was the most frequent pathogen of community acquired UTI. We found that E. coli and other uropathogens had a high resistance rate against TMP SMX and ampicillin sulbactam. In order to ensure a successful empirical treatment, protocols should be based on local epidemiology and susceptibility rates.

Resumen Antecedentes: La infección del tracto urinario (ITU) es una de las infecciones bacterianas más frecuentes en la infancia, se asocia con alta morbilidad aguda y de enfermedades a largo plazo como hipertensión arterial e insuficiencia renal crónica. Objetivo: Describir las características demográficas, agente etiológico, perfil de sensibilidad y respuesta al tratamiento empírico de una población pediátrica. Métodos: Estudio descriptivo, retrospectivo realizado en el Hospital Pablo Tobón Uribe (HPTU), Medellín (Colombia), entre enero de 2010 y diciembre de 2011. Resultados: Se incluyeron 144 pacientes, con una relación hombre: mujer de 1:2.06. El 79.9% consultó por fiebre objetiva y el 31.3% había tenido un episodio de ITU previa. El 72.0% presentó leucocituria y el gram de gota de orina sin centrifugar fue positivo en el 86.0% (77.8% de bacilos con tinción de gram negativos). Los uropatógenos más frecuentes fueron Escherichia coli y Klebsiella pneumoniae. Escherichia coli tuvo una sensibilidad mayor al 90% para la mayoría de antibióticos, excepto en el de trimetropín sulfametoxazol, con una resistencia del 42.6% y del 45.5% a la ampicilina sulbactam. Se usó la amikacina como tratamiento empírico en el 66.0%. En 17 de 90 pacientes se encontró algún grado de reflujo vesicoureteral (RVU). Conclusión: La elección del tratamiento empírico precoz debe basarse en el conocimiento de la epidemiología y el perfil de sensibilidad y resistencia de cada institución. En este estudio se encontró elevado porcentaje de resistencia de la E. coli y otros uropatógenos a trimetropín sulfametoxazol y ampicilina sulbactam.

Diastereoselective synthesis of C60/steroid conjugates.

The design and synthesis of fullerene-steroid hybrids by using Prato's protocol has afforded new fullerene derivatives endowed with epiandrosterone, an important naturally occurring steroid hormone. Since the formation of the pyrrolidine ring resulting from the 1,3-dipolar cyloaddition reaction takes place with generation of a new stereogenic center on the C2 of the five-membered ring, the reaction proceeds with formation of a diastereomeric mixture [compounds 6 and 7 in 70:30 ratio, 8 and 9 in 26:74 ratio (HPLC)] in which the formation of the major diasteroisomers 6 and 9 is consistent with an electrophilic attack of [60]fullerene on the Re face of the azomethine ylide directed by the steroidic unit. The chiroptical properties of these conjugates reveal typical Cotton effects in CD spectra that have been used to assign the absolute configuration of the new fulleropyrrolidines. The electrochemical study of the new compounds reveals the presence of four quasi-reversible reduction waves which are cathodically shifted in comparison with the parent C60, thus ascertaining the proposed structures.

Varicela visceral en paciente pediátrico, reporte de un caso clínico / Visceral varicella in pediatric patients, clinical case report

Se presenta el caso de un paciente pediátrico de 10 años, inmunosuprimido con corticosteroides y metotrexato por enfermedad reumatológica de base, que presentó varicela visceral con manifestaciones atípicas tales como compromiso pulmonar, hepático y alteraciones hematológicas. Inicialmente, no tuvo manifestaciones cutáneas, las cuales desarrolló a los ocho días de evolución, por lo cual requirió apoyo en la unidad de cuidados intensivos pediátricos y manejo multidisciplinario. La varicela es una enfermedad exantemática frecuente, considerada benigna con presentación leve y de resolución espontánea, en pacientes sin compromiso inmunitario. Por el contrario, la infección por este virus en pacientes inmunosuprimidos es una entidad que amenaza potencialmente la vida, principalmente cuando se presenta con compromiso visceral. Se debe considerar la posibilidad de infección por el virus varicela zóster en pacientes con disfunción hepática inexplicable asociada a dolor abdominal o lumbar, bajo condiciones de inmunosupresión, aun en ausencia de exposición viral o compromiso en piel; tanto la complicación hepática como la de los otros sistemas se han relacionado con alta morbimortalidad. Un alto índice de sospecha de varicela grave en el paciente inmunosuprimido, es importante para el diagnóstico y manejo oportuno.

We report the case of a 10 years old pediatric patient immunosuppressed with steroids and methotrexate for rheumatological disease who presents atypical varicella with visceral involvement such as lung, liver and blood disorders, without skin manifestations initially which development to the 8-day, requiring support in pediatric intensive care unit and multidisciplinary management. Chickenpox is a common rash illness, considered benign with a mild and limited in immunocompetent patients. By contrast, infection with this virus in immunosuppressed patients is an entity that potentially life threatening, especially when presented with visceral involvement. Infection with varicella-zoster virus should be considered in patients with unexplained liver dysfunction associated with abdominal or back pain under conditions of immunosuppression, even in the absence of viral exposure or skin compromise, The hepatic involvement as both of the other systems has been associated with high morbidity and mortality. A high index of suspicion of severe varicella in immunosuppressed patients is important for diagnosis and timely management.

Vertical self-assembly of modified multiwalled carbon nanotubes on gold surfaces induced by chitosan and Tween.

Multiwalled carbon nanotubes modified with 2-aminoethanethiol (MWNT-AET) were vertically self-assembled on gold electrodes with the assistance of chitosan and Tween. According to AFM and cyclic voltammetric determinations the best results were achieved using chitosan.

Efficient sonochemical synthesis of alkyl 4-aryl-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate derivatives.

A facile, efficient and environment-friendly protocol for the synthesis of 6-chloro-5-formyl-1,4-dihydropyridine derivatives has been developed by the convenient ultrasound-mediated reaction of 2(1H)pyridone derivatives with the Vilsmeier-Haack reagent. This method provides several advantages over current reaction methodologies including a simpler work-up procedure, shorter reaction times and higher yields.

Clinical and epidemiological characteristics of pediatric patients with positive serology for Mycoplasma pneumoniae, treated in the third level hospital from 2006 to 2008 / Características clínicas y epidemiológicas de pacientes pediátricos con serología positiva para Mycoplasma pneumoniae, atendidos en un hospital de tercer nivel durante el período 2006-2008

Introduction: Infection by Mycoplasma pneumoniae is becoming more frequent at younger ages. It appears as a generally benign and unspecific clinical condition of respiratory symptoms and sometimes responsible for a broad spectrum of extrapulmonary manifestations.Objective: To describe demographic, clinical, laboratory, and treatment characteristics of pediatric-age patients with positive serology for M. pneumoniae diagnosed at the Pablo Tobón Uribe Hospital (HPTU) during the 2006-2008 period.Materials and methods: Observational, retrospective study, which describes the demographic, clinical, laboratory, and treatment characteristics of patients from 1 month to 14 years of age with positive IgM for M. pneumoniae seen at HPTU during September 2006 and November 2008.Results: We reviewed 305 clinical charts of patients with positive IgM for M. pneumoniae. The average age was 5.15 years ± 3.62 SD. Cough (87.5%), fever (65.9%), rhinorrea (39.3%), and respiratory difficulty (38%) were the most frequent clinical findings. Extrapulmonary compromise was mainly manifested in the skin (12.8%), the central nervous system (CNS) (3.6%), and osteomuscular system (3.9%). Auscultation and thoracic X-ray were normal in 33.1% and 30.8% of the patients, respectively. Episodes of asthma exacerbation were related to infection by Mycoplasma in 35% of the cases. A total of 51% of the patients required hospitalization with an average stay of seven days. All the patients received antibiotic treatment; clarithromycin (75.8%) was the antibiotic of choice.Conclusion: Infection by M. pneumoniae has a broad range of clinical manifestations, requiring a high index of clinical suspicion and an active search for extrapulmonary compromise given that in our realm there is no specific diagnostic method for the acute infection.

Introducción: La infección por Mycoplasma pneumoniae es cada vez más frecuente a edades tempranas. Se presenta como un cuadro clínico de síntomas respiratorios generalmente benigno e inespecífico y en ocasiones es reponsable de un amplio espectro de manifestaciones extrapulmonares.Objetivo: Describir las características demográficas, clínicas, de laboratorio y el tratamiento de pacientes en edad pediátrica con serología positiva para M. pneumoniae diagnosticados en el Hospital Pablo Tobón Uribe (HPTU) durante el período 2006-2008.Materiales y métodos: Estudio observacional, retrospectivo, que describe las características demográficas, clínicas, de laboratorio y tratamiento de pacientes de 1 mes a 14 años de edad con IgM positiva para M. pneumonie atendidos en el HPTU entre septiembre de 2006 y noviembre de 2008.Resultados: Se revisaron 305 historias clínicas de pacientes con IgM positiva para M. pneumoniae. La edad promedio fue 5.15 años ± 3.62 DE. La tos (87.5%), fiebre (65.9%), rinorrea (39.3%) y dificultad respiratoria (38%) fueron los hallazgos clínicos más frecuentes. El compromiso extrapulmonar se manifestó sobre todo en piel (12.8%), sistema nervioso (3.6%) y sistema osteomuscular (3.9%). La auscultación y la radiografía de tórax fueron normales en 33.1% y 30.8% respectivamente. Los episodios de exacerbación del asma se relacionaron con infección por Mycoplasma en 35% de los casos. Del total de niños, 51% necesitó hospitalización con un promedio de estancia de 7 días. Todos los pacientes recibieron tratamiento antibiótico, siendo el de elección claritromicina (75.8%).Conclusión: La infección por M. pneumoniae posee una amplia gama de manifestaciones clínicas que requiere un alto índice de sospecha clínica y una búsqueda activa de compromiso extrapulmonar porque en Colombia no se cuenta con un método diagnóstico específico para la infección aguda.

Ultrasound-assisted one-pot, four component synthesis of 4-aryl 3,4-dihydropyridone derivatives.

The condensation of Meldrum's acid, aromatic aldehydes, alkyl acetoacetates and ammonium acetate in glacial acetic acid under ultrasound irradiation at room temperature results in the formation of 3,4-dihydropyridone derivatives (4a-p) in 85-96% yields. Compared with conventional methods, the main advantages of the present procedure are milder conditions, shorter reaction times and higher yields.