Motoric cognitive risk syndrome and its association with falls: a secondary analysis of the Mexican Health and Aging Study.

OBJECTIVE: To reveal whether motoric cognitive risk syndrome (MCR) is associated with falls, recurrent falls, and complicated falls in older Mexican adults. MATERIALS AND METHODS: This is a secondary analysis of the Mexican Health and Aging Study. MCR was assessed in 2012 and included fall-related outcomes (recurrent [≥2], complicated [need for medical treatment] and number) in the 2018 follow-up. Competing risks analysis was performed, and subhazard ratios (sHRs) were estimated, adjusting for different variables. Negative binomial regression was used to estimate the incidence rate ratio (IRR) of the number of falls. RESULTS: A total of 1 929 participants were included, with a median age of 62 years and 58.3% female. The prevalence of MCR was 17.4% and was associated with falls sHR 1.11 (95%CI: 1.11, 1.12), recurrent falls sHR 1.16 (95%CI: 1.15, 1.16) and complicated falls sHR 1.25 (95%CI: 1.24, 1.25). The number of falls was also independently associated with baseline MCR (IRR 1.19; 95% CI 1.01, 1.40; p=0.039). CONCLUSION: MCR is independently associated with falls. Increasing the evidence on how MCR anticipates burdensome problems in older adults could lead to actions to halt them; therefore, including it in screening assessments could be clinically useful.

Minimally Invasive Surgery for Managing Grade IV and V Spondylolisthesis.

Surgical treatment of high-grade spondylolisthesis is controversial and aims at restoring the spinopelvic sagittal balance through complete or partial reduction of the listhesis. Nerve decompression and interbody fusion are necessary for patients presenting with neurological deficit, severe pain, lower limb asymmetry, or deformities. We present the case and the results of a patient with high-grade spondylolisthesis, in whom minimally invasive management was performed. A narrative review in this topic is also provided. We performed a literature review of high-grade spondylolisthesis to compare our technique to current surgical alternatives. We included articles from PubMed, Embase, Scopus, Ovid, and Science Direct published between 1963 and 2022 that were written in English, German, and Spanish. The terms used were the following: "high grade spondylolisthesis," "spondyloptosis," "surgical management," "interbody fusion," and "arthrodesis." In all, 485 articles were displayed, from which we filtered 112 by title and abstract. At the end, 75 references were selected for the review. Different interbody fusion techniques can be used to correct the lumbosacral kyphosis and restore the spinopelvic parameters. A complete reduction of the listhesis is not always required. The surgical procedure carried out in our patient corresponds to the first known case of minimally invasive circumferential arthrodesis with iliac screws and sacral fixation in a high-grade dysplastic spondylolisthesis. This approach guarantees the correction of the lumbosacral kyphosis and a complete reduction of the listhesis. Further studies are required to determine whether the results of this case can be extrapolated to other patients with high-grade spondylolisthesis.

Factores asociados al desarrollo de delírium en pacientes ancianos en el postoperatorio de cirugía por fractura de cadera / Factors Related to the Development of Delirium in Elderly Patients in the Postoperative Period of Hip Fracture Surgery / Fatores associados ao desenvolvimento de Delirium em pacientes idosos no pós-operatório de cirurgia de fratura de quadril

Introducción: durante el postoperatorio por cirugía de cadera, el delírium es la complicación más frecuente en los pacientes ancianos, con una alta incidencia y prevalencia, la cual lleva a una alta morbimortalidad en ellos. Objetivo: identificar los factores asociados con delírium en pacientes ancianos durante su posto-peratorio de cirugía por fractura de cadera. Materiales y métodos: se realizó un estudio observacional analítico de corte retrospectivo con pacientes hospitalizados por el grupo de Ortogeriatría en el Hospital Universitario San Ignacio en Bogotá (Colombia), entre enero de 2017 y septiembre de 2020. Resultados: se incluyeron 210 personas, en quienes se documentó una incidencia de delírium del 28.57 %. En el análisis bivariado, las variables con asociación estadísticamente significativa fueron edad, dependencia, demencia previa, malnutrición, polifarmacia y tipo de anestesia. Sin embargo, en el análisis multivariado, las dos variables con asociación estadísticamente significativa fueron edad (OR: 1.05; IC95 %: 1.01-1.10; p = 0.014) y demencia (OR: 2.83; IC95 %: 1.28-6.27; p = 0.010). Conclusión: las variables asociadas con delírium reportadas en el estudio concuerdan con la literatura ya publicada. Esto abre las puertas a futuras investigaciones no solo para identificar nuevos o más factores asociados, sino también para adoptar medidas en conjunto con los programas de ortogeriatría, a fin de intervenir estos factores y, de esta manera, poder disminuir la incidencia y prevalencia del delírium y, por ende, su morbimortalidad.

Introduction: Post-operative delirium after hip surgery is the most common complication among the elderly, with a high incidence and prevalence, which leads to high morbidity and mortality rates among them. Objective: To identify the main factors associated with post-operative delirium after hip surgery among older adults. Materials and methods: a retrospective analytical observational study was conducted using data from patients hospitalized by the Orthogeriatric group at the San Ignacio University Hospital in Bogotá, Colombia, between January 2017 and September 2020. Results: 210 people were included in the study, with a documented incidence of delirium of 28.57% was documented. In the bivariate analysis, the variables with a statistically significant association with delirium were age, dependency, previous dementia, malnutrition, polypharmacy, and type of anesthesia used in the procedure. Nonetheless, in a multivariate analysis, the two variables with a statistically significant association were age (OR: 1.05; 95%CI: 1.01-1.10; p = 0.014) and dementia (OR: 2.83; 95% CI: 1.28-6.27; p = 0.010). Conclusion: the variables associated with postoperative delirium reported in our study align with the existing literature. This opens doors to future research not only to identify new or more risk factors, but also to adopt measures, jointly with the Orthogeriatric programs, to intervene such factors so that the incidence and prevalence of delirium can be reduced, and therefore, reduce the morbidity and mortality among the elderly.

Introdução: o delirium no pós-operatório de cirurgia de quadril é a complicação mais frequente em pacientes idosos, com alta incidência e prevalência, o que leva a alta morbimortalidade nos mesmos e, assim, o objetivo deste estudo foi identificar os fatores associados ao delirium em pacientes idosos no pós-operatório de cirurgia de fratura de quadril. Materiais e métodos: foi realizado um estudo observacional analítico retrospectivo com pacientes internados pelo grupo de Ortogeriatria do Hospital Universitário San Ignacio, em Bogotá, Colômbia, entre janeiro de 2017 e setembro de 2020. Resultados: foram incluídas 210 pessoas, nas quais foi documentado incidência de delirium de 28,57%. Na análise bivariada, as variáveis com associação estatisticamente significativa foram idade, dependência, demência prévia, desnutrição, polifarmácia e tipo de anestesia. Porém, na análise multivariada, as duas variáveis com associação estatisticamente significativa foram idade (or: 1,05; Ic 95% 1,01-1,10; p: 0,014) e demência (or: 2,83; Ic 95% 1,28-6,27, p: 0,010). Conclusão: as variáveis associadas ao delirium relatadas em nosso estudo concordam com a literatura publicada anteriormente. Isso abre as portas para pesquisas futuras não só para identificar novos ou mais fatores associados, mas também para adotar medidas em conjunto com programas de ortogeriatria para poder intervir nesses fatores e, assim, reduzir a incidência e prevalência de delirium e, portanto, a morbimortalidade

Muscular Function as an Alternative to Identify Cognitive Impairment: A Secondary Analysis From SABE Colombia.

BACKGROUND: Identification of cognitive impairment is based traditionally on the neuropsychological tests and biomarkers that are not available widely. This study aimed to establish the association between motor function (gait speed and handgrip strength) and cognitive performance in the Mini-Mental State Examination, globally and by domains. A secondary goal was calculating a cut-off point for gait speed and handgrip strength to classify older adults as cognitively impaired. METHODS: This is a secondary analysis of SABE Colombia (Salud, Bienestar & Envejecimiento), a survey that was conducted in 2015 on health, wellbeing, and aging in Colombia. This study used linear regression models to search for an association between motor function and cognitive performance. The accuracy of motor function measurements in identifying cognitive impairment was assessed with receiver operating characteristic (ROC) curves. This study also analyzed other clinical and sociodemographical variables. RESULTS: Gait speed was associated with orientation (r 2 = 0.16), language (r 2 = 0.15), recall memory (r 2 = 0.14), and counting (r 2 = 0.08). Similarly, handgrip strength was associated with orientation (r 2 = 0.175), language (r 2 = 0.164), recall memory (r 2 = 0.137), and counting (r 2 = 0.08). To differentiate older adults with and without cognitive impairment, a gait speed cut-off point of 0.59 m/s had an area under the curve (AUC) of 0.629 (0.613-0.646), and a weak handgrip (strength below 17.5 kg) had an AUC of 0.653 (0.645-0.661). The cut-off points for handgrip strength and gait speed were significantly higher in male participants. CONCLUSIONS: Gait speed and handgrip strength are similarly associated with the cognitive performance, exhibiting the most extensive association with orientation and language domains of the Mini-Mental State Examination. Gait speed and handgrip strength can easily be measured by any clinician, and they prove to be useful screening tools to detect cognitive impairment.

Motoric Cognitive Risk Syndrome: Prevalence and Cognitive Performance. A cross-sectional study.

Background: Motoric Cognitive Risk Syndrome (MCR) is a predementia stage where slow gait speed and subjective memory complaints are present. The purpose of this study was to estimate the prevalence of MCR and assess its relationship with sociodemographic factors and chronic conditions. Methods: This is a secondary analysis of the SABE Colombia study conducted in 2015. The analytic sample consisted of 17·577 participants. After determining MCR prevalence, logistic regression was performed to examine the correlates of MCR. Findings: The prevalence of MCR was 10·71 %. The median age was 71 years and women composed 74·63 % of the MCR group. After adjusting for confounding variables MCR was associated with increasing age (OR 1·69, CI 1·43 - 1·92), no or low education (OR 1·99, CI 1·67- 2·37), MMSE (OR 0·93, CI 0·91 - 0·95) and chronic conditions such as mental disorders (OR 1·36, CI 1·11-1·67), history of myocardial infarction (OR 1·24, CI 1·04 - 1·47), hypertension (OR 1·23, CI 1·08 - 1·40) and diabetes (OR 1.18, CI 1.01 - 1.37). Interpretation: This study found a prevalence of 10·71 % of MCR in Colombian older adults. Additionally, MCR was associated with chronic conditions and sociodemographic factors identified in prior studies. These results increase the awareness of a novel predementia stage whose identification can be performed by clinicians in the outpatient clinic, minimizing the cost of a full neuropsychologic evaluation performed in a memory clinic. Funding: Funded by the Administrative Department of Science, Technology and Innovation (Colciencias) and the Ministry of Health and Social Protection of Colombia.

Life-space assessment and associated clinical factors: SABE Colombia / Avaliação do espaço de vida e fatores clínicos associados: SABE Colômbia

OBJECTIVES: Our aim was to assess whether an association exists between chronic diseases or multimorbidity and limited life space in older adults. METHODS: This is a secondary analysis of the SABE (Salud, Bienestar y Envejecimiento) Colombia Study. We assessed chronic diseases through self-report, and a limited life space was defined as any score ≤ 60 in the Life-Space Assessment scale. Multimorbidity was defined as having two or more coexisting diseases. We performed bivariate analyses and multivariate logistic regressions aiming to obtain odds ratios with 95% confidence intervals. RESULTS: The prevalence of limited life space was 2.95% with a mean score of 76.27 ± 19.34. Statistically significant associations were found between limited life space and mental disease (OR 1.45; 95%CI 1.15 ­ 1.82) and between limited life space and multimorbidity (OR 1.32; 95%CI 1.06 ­ 1.63). CONCLUSIONS: Mental disease and multimorbidity are associated with limited life space in older adults. Therefore, preventing, diagnosing, and treating mental illness should be sought in addition to the existing preventive and therapeutic approaches available for noncommunicable diseases.

OBJETIVO: Nosso objetivo foi avaliar se existe uma associação entre doenças crônicas ou multimorbidade e espaço de vida limitado em idosos. METODOLOGIA: Esta é uma análise secundária do Estudo SABE (Salud, Bienestar y Envejecimiento) Colômbia. Avaliamos as doenças crônicas por meio de autorrelato, e espaço de vida limitado foi definido como uma pontuação ≤ 60 na escala do Life-Space Assessment. Multimorbidade foi definida como a coexistência de duas ou mais doenças. Realizamos análises bivariadas e regressões logísticas multivariadas com o objetivo de obter odds ratios com intervalos de confiança de 95%. RESULTADOS: A prevalência de espaço de vida limitado foi de 2,95% com pontuação média de 76,27 ± 19,34. Associações estatisticamente significativas foram encontradas entre espaço de vida limitado e doença mental (OR 1,45; IC95% 1,15 ­ 1,82) e entre espaço de vida limitado e multimorbidade (OR 1,32; IC95% 1,06 ­ 1,63). CONCLUSÕES: A doença mental e a multimorbidade estão associadas ao espaço de vida limitado em idosos. Portanto, deve-se buscar formas de prevenir, diagnosticar e tratar doenças mentais além das abordagens preventivas e terapêuticas atualmente disponíveis para doenças não transmissíveis

The Role of Gait Speed in Dementia: A Secondary Analysis from the SABE Colombia Study.

INTRODUCTION: Gait speed (GS) is a predictor of negative outcomes in older adults and in those in risk to develop cognitive impairment; as such, it has been associated with dementia. Studies in Latin-American older adults showing this association are scarce. This study aimed to evaluate the relationship between GS and dementia in a representative sample of Colombian older adults. METHODS: This study is a secondary analysis from the Survey on Health, Well-Being, and Aging, SABE (from initials in Spanish: Salud, Bienestar & Envejecimiento) Colombia's survey conducted in 2015 with a sample of 23,694 elderly adults aged 60 years or older. RESULTS: A total of 19,470 participants from the SABE Colombia survey were available for analysis. The multivariate analysis shows that dementia was associated with slow GS (PR 2.39; CI 1.91-3.01) independently to the other variables (p < 0.001). Similarly, GS as a continuous variable shows a statistically significant association with dementia in the adjusted analysis (OR 0.06; CI 0.04-0.09; p < 0.001). CONCLUSION: Dementia was associated with slow GS. This finding provides evidence to include GS as a complementary parameter in the assessment of Colombian elderly adults.

Effect of antimicrobial peptides from Galleria mellonella on molecular models of Leishmania membrane. Thermotropic and fluorescence anisotropy study.

Antimicrobial peptides are molecules of natural origin, produced by organisms such as insects, which have focused attention as potential antiparasitic agents. They can cause the death of parasites such Leishmania by interacting with their membrane. In this study, additional information was obtained on how the anionic peptide 2 and cecropin D-like peptide derived from Galleria mellonella interact with liposomes that mimic the composition of the Leishmania membrane. In order to do this, lipid bilayers consisting of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylethanolamine, dimyristoylphosphatidylserine, and dimyristoylphosphatidylglycerol were constructed. The effect of the peptides on these membranes was evaluated using calorimetry analysis and fluorescence spectroscopy. The results obtained using differential scanning calorimetry indicated a concentration-dependent effect on membranes composed of phosphatidylserine and phosphatidylglycerol, showing a preference of both peptides for anionic lipids. The binding of the peptides drastically reduced the transition enthalpy in the phosphatidylserine and phosphatidylglycerol liposomes. The results suggest that the mode of action of anionic peptide 2 and cecropin D-like peptide is different, with a higher effect of cecropin D-like on the anionic lipids, which led to changes in the main transition temperature and a complete solubilization of the vesicles. Interactions between peptides and phosphatidylcholine, which is the most abundant lipid on the surface of Leishmania cells, were evaluated using isothermal titration calorimetry and the anisotropy of fluorescence of DPH. The peptides had a slight effect on the gel phase of the phosphatidylcholine, with changes in the anisotropy correlated with that observed by DSC. The results showed a selectivity of these peptides toward some lipids, which will direct the study of the development of new drugs.

Auditory steady-state response in cochlear implant patients.

INTRODUCTION AND OBJECTIVE: Auditory steady state responses to continuous amplitude modulated tones at rates between 70 and 110Hz, have been proposed as a feasible alternative to objective frequency specific audiometry in cochlear implant subjects. The aim of the present study is to obtain physiological thresholds by means of auditory steady-state response in cochlear implant patients (Clarion HiRes 90K), with acoustic stimulation, on free field conditions and to verify its biological origin. METHODS: 11 subjects comprised the sample. Four amplitude modulated tones of 500, 1000, 2000 and 4000Hz were used as stimuli, using the multiple frequency technique. The recording of auditory steady-state response was also recorded at 0dB HL of intensity, non-specific stimulus and using a masking technique. RESULTS: The study enabled the electrophysiological thresholds to be obtained for each subject of the explored sample. There were no auditory steady-state responses at either 0dB or non-specific stimulus recordings. It was possible to obtain the masking thresholds. A difference was identified between behavioral and electrophysiological thresholds of -6±16, -2±13, 0±22 and -8±18dB at frequencies of 500, 1000, 2000 and 4000Hz respectively. CONCLUSIONS: The auditory steady state response seems to be a suitable technique to evaluate the hearing threshold in cochlear implant subjects.

Identification and evaluation of Galleria mellonella peptides with antileishmanial activity.

Leishmaniasis is a neglected disease, World Health Organization (WHO) declared it as high priority worldwide. Colombia is one of the 98 countries in which the disease caused more than 17.000 cases per year. There is a need to explore novel therapies to reduce the side effects of the current treatments. For this reason, this study was aimed to evaluate Galleria mellonella hemolymph for potential peptides with anti-parasitic activity. Larvae were challenged with Leishmania (V) panamensis promastigotes and hemolymph was analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), reversed-phase chromatography (RP-HPLC), two-dimensional gel electrophoresis and liquid chromatography-mass spectroscopy (LC/MS). The immunological response of Galleria mellonella was followed by SDS-PAGE, immunized hemolymph was fractionated by RP-HPLC where fractions 5 and 11 showed the highest antileishmanial activity. From these fractions 15 spots were isolated by 2D gel electrophoresis and evaluated by LC/MS to identify the peptides present in the spots. After the analysis Moricin-B, Moricin-C4, Cecropin-D and Anionic Peptide 2 were identified due to the immune challenge with Leishmania promastigotes. Anionic peptide 2 and Cecropin-D were synthesized and evaluated for antileishmanial activity. The results showed that Anionic peptide 2 presented more anti-parasitic activity. This study showed for the first time the anti-parasitic potential of peptides derived from hemolymph of Galleria mellonella.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface.

PURPOSE: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). METHODS: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. RESULTS: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. CONCLUSIONS: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface / Efeitos da fumaça de incêndios na superfície ocular em Buenos Aires, Argentina

Purpose: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). Methods: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. Results: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. Conclusions: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode. .

Objetivo: Avaliar os efeitos agudos da fumaça do episódio de incêndio violento ocorrido em 2008, sobre a superfície ocular de sujeitos que vivem na Região Metropolitana de Buenos Aires (MABA). Métodos: Um total de 86 indivíduos foram avaliados: Grupo 1: pacientes de um hospital público de oftalmologia (N=35) e Grupo 2: voluntários saudáveis (N=51). Todos os participantes responderam a um questionário sobre os sintomas oculares e foram submetidos a exame oftalmológico (hiperemia conjuntival bulbar, teste de fluoresceína, corante rosa bengala, tempo de ruptura do filme lacrimal (TBUT), teste de Schirmer I, lisozima lacrimal e citologia de impressão) durante e após o episódio agudo. As concentrações de monóxido de carbono, dióxido de nitrogênio e partículas (PM) foram medidas antes, durante e após o episódio agudo. Resultados: Ambos os grupos apresentaram aumento estatisticamente significativo dos sintomas oculares, hiperemia conjuntival bulbar, e diminuição estatisticamente significativa no tempo de ruptura do filme lacrimal durante o episódio agudo. Grupo 1 apresentou maior intensidade dos sintomas e aumento estatisticamente significativo no teste de fluoresceína e rosa bengala durante o episódio agudo. Encontramos uma correlação negativa significativa entre os sintomas oculares e tempo de ruptura do filme lacrimal. Durante o episódio agudo de 2008, os níveis de CO, NO2 e PM na Região Metropolitana de Buenos Aires foram 4 vezes maiores do que os níveis médios habituais para o mesmo período de 2007 e 2009. Conclusões: O aumento da poluição do ar a partir da queima de biomassa está associado a uma diminuição da estabilidade do filme lacrimal (TBUT) gerando zonas da exposição da superfície ocular, que podem ser a causa do aumento da sensação de irritação. Grupo 1 foi mais afetado por não ter superfície ocular saudável e, portanto, consultaram um oftalmologista. Mudanças citológicas da conjuntiva não foram observadas e isso poderia ser devido ...

Cristalización y predicción de la estructura tridimensional de la proteína homóloga del receptor activado para la quinasa c (lack) de leishmania / Crystallization and prediction of three-dimensional structure of the homologue protein of the receptor for activated c-kinase (lack) from leishmania / Cristalização e predição da estrutura tridimensional da proteína homologa do receptor ativado para a quinasa c (lack) de leishmania

Los parásitos del género Leishmania son los causantes de la enfermedad conocida como Leishmaniasis. Esta enfermedad es endémica en 98 países. Veinte especies de Leishmania sp han sido descritas como patógenos en humanos y varias de ellas presentan manifestaciones clínicas diferentes. No se dispone de vacuna, a pesar del considerable esfuerzo de muchos grupos de investigación. Las alternativas para descubrir nuevos medicamentos están basadas en el diseño de compuestos que interaccionen con blancos específicos, principalmente, proteínas encargadas de procesos metabólicos o celulares del patógeno, e.g. la parasitación de las células del huésped vertebrado. La eficiente parasitación del huésped vertebrado por Leishmania depende de la expresión de diferentes proteínas, incluyendo la proteína Lack. Parásitos deficientes de Lack no sobreviven internalizados en las células de los vertebrados. Este artículo presenta las condiciones de renaturalización, purificación y cristalización de la proteína Lack del patógeno humano Leishmania (Viannia) panamensis. Además, los resultados de modelación estructural de esta proteína muestran una conformación proteica similar a un ventilador organizado en 7 aspas, cada una compuesta de 4 hojas β. La estructura de la proteína Lack resultó similar a la proteína asociada a ribosoma RACK1 de Trypanosoma brucei y Saccharomyces cerevisiae, y a la de otros eucariotas. Las características estructurales de la proteína Lack podrían ser usadas para la exploración de nuevos.

Leishamnia parasites are the causative agents of the leishmaniasis disease. Due to its broad distribution, parasites are endemic in approximately 98 countries. Twenty species of Leishmaniasp has been described as human pathogens and several of them present different clinical manifestations. This feature poses a significant challenge to the general goals of parasite control and erradication. There is no a protective vaccine for humans, despite substantial efforts by many research teams. Alternatives to discover new drugs are based on the design of new compounds that bind selected targets. Mainly, the targets are proteins involved in key metabolic or cellular processes of the pathogen, e.g. parasitization of vertebrate host cells. The efficient parasitization of the vertebrate host by Leishmania parasites depends on the expression of different molecules including Lack protein. The knockout parasites fail to survive inside the vertebrate host cells. In this article we highlight the conditions to perform the refold, purification, and crystallizing of the Lack protein of the human pathogen Leishmania (Viannia) panamensis. Moreover, we present structure modelling analysis which shows a protein conformation like a fan organized in 7 blades, each one composed of 4 b sheets. Furthermore, the structure of Lack protein was found to be similar to RACK1-ribosome associated protein from Trypanosoma brucei and Saccharomyces cerevisiae and other eukaryotes. The structural characteristics of Lack protein could be used for exploration of new drugs.

Os parasitas do gênero Leishmania são os agentes causadores da doença conhecida como Leishmaniasis. Esta doença é endêmica em 98 países. Vinte espécies de Leishmania sp têm sido descritas como patógenos em humanos e várias delas apresentam manifestações clínicas diferentes. Não se dispõe de vacina, apesar do considerável esforço de muitos grupos de pesquisa. As alternativas para descobrir novos medicamentos estão baseadas no desenho de compostos que interajam com alvos específicos, principalmente, proteínas encarregadas de processos metabólicos ou celulares do patógeno, e.g. a parasitação das células do hóspede vertebrado. A eficiente infestação do hóspede vertebrado por Leishmania depende da expressão de diferentes proteínas, incluindo a proteína Lack. Parasitas deficientes de Lack não sobrevivem internalizados nas células dos vertebrados. Este artigo apresenta as condições de regeneração, purificação e cristalização da proteína Lack do patogénico humano Leishmania (Viannia) panamensis. Além disso, resultados de modelação estrutural desta proteína mostram uma conformação protéica similar a um ventilador, organizado em 7 pás, cada uma composta de 4 folhas β. A estrutura da proteína Lack resultou similar a proteína associada ao ribossomo RACK1 de Trypanosoma brucei y Saccharomyces cerevisiae, e à de outros eucariotas. As características estruturais da proteína Lack poderiam ser usadas para a pesquisa de novos fármacos.

Bacilos gramnegativos no fermentadores (BGNNF) aislados en un laboratorio hospitalario / Non fermentative gramnegative bacilli (NFGNB) isolated in a hospital laboratory

Se realizó un estudio prospectivo de los BGNNF, excluyendo Pseudomonas aeruginosa, aislados en el Laboratorio del Hospital "Dr. Julio C. Perrando" de la ciudad de Resistencia (Argentina) con el objeto de conocer su frecuencia y susceptibilidad antimicrobiana. La identificación bacteriana fue realizada mediante pruebas bioquímicas. El mayor porcentaje de BGNNF aislados procedía de sangre (25 por ciento), secreciones respiratoria y orina (23,9 por ciento), siendo Acinetobacter baumannii (34,7 por ciento), Pseudomonas fluorescens/P putida (15,2 por ciento), Stenotrophomonas maltophllia (9,7 por ciento) y Burkholderia cepacia (8,7 por ciento) las especies aisladas con más frecuencia. Se estudió además la distribución de las distintas cepas según el producto patológico y área de hospitalización, realizándose pruebas de sensibilidad a los antimicrobianos a cepas con mayor porcentaje de aislamiento. Se concluye que: 1- los BGNNF son aislados con mayor frecuencia de pacientes internados y comprometidos que de los ambulatorios y 2- la antibioticoterapia debiera ser administrada según el informe del laboratorio de bacteriología

Bacilos gramnegativos no fermentadores (BGNNF) aislados en un laboratorio hospitalario / Non fermentative gramnegative bacilli (NFGNB) isolated in a hospital laboratory

Se realizó un estudio prospectivo de los BGNNF, excluyendo Pseudomonas aeruginosa, aislados en el Laboratorio del Hospital "Dr. Julio C. Perrando" de la ciudad de Resistencia (Argentina) con el objeto de conocer su frecuencia y susceptibilidad antimicrobiana. La identificación bacteriana fue realizada mediante pruebas bioquímicas. El mayor porcentaje de BGNNF aislados procedía de sangre (25 por ciento), secreciones respiratoria y orina (23,9 por ciento), siendo Acinetobacter baumannii (34,7 por ciento), Pseudomonas fluorescens/P putida (15,2 por ciento), Stenotrophomonas maltophllia (9,7 por ciento) y Burkholderia cepacia (8,7 por ciento) las especies aisladas con más frecuencia. Se estudió además la distribución de las distintas cepas según el producto patológico y área de hospitalización, realizándose pruebas de sensibilidad a los antimicrobianos a cepas con mayor porcentaje de aislamiento. Se concluye que: 1- los BGNNF son aislados con mayor frecuencia de pacientes internados y comprometidos que de los ambulatorios y 2- la antibioticoterapia debiera ser administrada según el informe del laboratorio de bacteriología (AU)