A model of metformin mitochondrial metabolism in metachromatic leukodystrophy: first description of human Schwann cells transfected with CRISPR-Cas9.

Metachromatic leukodystrophy is a neurological lysosomal deposit disease that affects public health despite its low incidence in the population. Currently, few reports are available on pathophysiological events related to enzyme deficiencies and subsequent sulfatide accumulation. This research aims to examine the use of metformin as an alternative treatment to counteract these effects. This was evaluated in human Schwann cells (HSCs) transfected or non-transfected with CRISPR-Cas9, and later treated with sulfatides and metformin. This resulted in transfected HSCs showing a significant increase in cell reactive oxygen species (ROS) production when exposed to 100 µM sulfatides (p = 0.0007), compared to non-transfected HSCs. Sulfatides at concentrations of 10 to 100 µM affected mitochondrial bioenergetics in transfected HSCs. Moreover, these analyses showed that transfected cells showed a decrease in basal and maximal respiration rates after exposure to 100 µM sulfatide. However, maximal and normal mitochondrial respiratory capacity decreased in cells treated with both sulfatide and metformin. This study has provided valuable insights into bioenergetic and mitochondrial effects of sulfatides in HSCs for the first time. Treatment with metformin (500 µM) restored the metabolic activity of these cells and decreased ROS production.

Salivary markers of oxidative stress and periodontal pathogens in patients with periodontitis from Santander, Colombia. / Marcadores salivales de estrés oxidativo y agentes patógenos periodontales en pacientes con periodontitis en Santander, Colombia

INTRODUCTION: Periodontitis affects more than 20% of the Latin American population. Oxidative markers are associated with greater progression of periodontitis; therefore, its role in pathogenesis should be studied. OBJECTIVE: To determine the prevalence of the main oral bacteria and viruses associated with periodontitis and estimate the total antioxidant capacity and lipid peroxidation in saliva from patients with periodontitis. MATERIALS AND METHODS: We conducted systemically a cross-sectional study in 101 healthy subjects, 87 of whom had been diagnosed with periodontitis (P), according to the criteria of the Centers of Disease Control and Prevention and the American Academy of Periodontology, and 14 without periodontal pockets as controls (C). In subgingival samples, major viruses and dental pathogenic bacteria were identified using PCR techniques. The levels of total antioxidant capacity and malon-di-aldehyde (MDA) were determined by spectrophotometry in samples of unstimulated saliva. RESULTS: The mean of periodontal depth pocket and clinical attachment loss in patients with periodontitis was 5.6 ± 1.7 and 6.1 ± 3.1 mm, respectively. The most prevalent microorganisms were Aggregatibacter actinomycetemcomitans (32.5%) and Porphyromonas gingivalis (18.6%). The patients from rural areas showed a higher percentage of A. actinomycetemcomitans (urban: 17.9% vs. rural: 48.9%, p=0.0018). In patients with periodontitis, the frequency of EBV, HSV1 and 2, and HCMV genes was 2.3%. Periodontitis patients had higher levels of MDA (P: 2.1 ± 1.5; C: 0.46 ± 0.3 µmol/g protein; p=0.0001) and total antioxidant capacity (P: 0.32 ± 0.2; C: 0.15 ± 0.1 mM; p< 0.0036). Oxidative markers showed no modifications due to the presence of periodontopathic bacteria. CONCLUSIONS: Aggregatibacter actinomycetemcomitans was the most prevalent bacteria; its presence did not modify the levels of oxidative markers in the saliva of patients with periodontitis.

Introducción. La periodontitis afecta a más del 20 % de la población latinoamericana. La presencia de marcadores de estrés oxidativo se asocia con una mayor progresión de periodontitis, por lo que su rol en la patogenia debe estudiarse. Objetivo. Determinar la prevalencia de las principales bacterias y virus asociados con la periodontitis y estimar la capacidad antioxidante total y la peroxidación de lípidos en la saliva de los pacientes con periodontitis. Materiales y métodos. Se hizo un estudio transversal en 87 sujetos sanos diagnosticados con periodontitis (P) según los criterios de los Centers of Disease Control and Prevention y la American Academy of Periodontology y 14 sujetos sin enfermedad periodontal como grupo control (C). En las muestras subgingivales se identificaron los principales virus y bacterias mediante técnicas de PCR. Los niveles de capacidad antioxidante total y malon-di-aldehído (MDA) se establecieron mediante espectrofotometría en muestras de saliva no estimulada. Resultados. Las medias de profundidad del sondaje y del nivel de inserción clínico periodontal en pacientes con periodontitis fueron 5,6 ± 1,7 y 6,1 ± 3,1 mm, respectivamente. Los microorganismos más prevalentes fueron Aggregatibacter actinomycetemcomitans (32,5 %) y Porphyromonas gingivalis (18,6 %). Los pacientes de áreas rurales registraron un mayor porcentaje de A. actinomycetemcomitans (urbano: 17,9 % Vs. rural: 48,9 %; p=0,0018). La frecuencia de los genes EBV, HSV1 y 2, y HCMV fue de 2,3 %. En pacientes con periodontitis se evidenciaron mayores niveles de MDA (P: 2,1 ± 1,5; C: 0,46 ± 0,3 µmol/g proteína; p=0,0001) y capacidad antioxidante total (P: 0,32 ± 0,2; C: 0,15 ± 0,1 mM; p<0,0036). La presencia de bacterias periodontales patógenas no modificó los marcadores oxidativos. Conclusiones. Aggregatibacter actinomycetemcomitans fue el agente patógeno mas prevalente. Su presencia no modificó los niveles de marcadores oxidativos en la saliva de los pacientes con periodontitis.

Salivary markers of oxidative stress and periodontal pathogens in patients with periodontitis from Santander, Colombia / Marcadores salivales de estrés oxidativo y agentes patógenos periodontales en pacientes con periodontitis en Santander, Colombia

Introduction: Periodontitis affects more than 20% of the Latin American population. Oxidative markers are associated with greater progression of periodontitis; therefore, its role in pathogenesis should be studied. Objective: To determine the prevalence of the main oral bacteria and viruses associated with periodontitis and estimate the total antioxidant capacity and lipid peroxidation in saliva from patients with periodontitis. Materials and methods: We conducted systemically a cross-sectional study in 101 healthy subjects, 87 of whom had been diagnosed with periodontitis (P), according to the criteria of the Centers of Disease Control and Prevention and the American Academy of Periodontology, and 14 without periodontal pockets as controls (C). In subgingival samples, major viruses and dental pathogenic bacteria were identified using PCR techniques. The levels of total antioxidant capacity and malon-di-aldehyde (MDA) were determined by spectrophotometry in samples of unstimulated saliva. Results: The mean of periodontal depth pocket and clinical attachment loss in patients with periodontitis was 5.6 ± 1.7 and 6.1 ± 3.1 mm, respectively. The most prevalent microorganisms were Aggregatibacter actinomycetemcomitans (32.5%) and Porphyromonas gingivalis (18.6%). The patients from rural areas showed a higher percentage of A . actinomycetemcomitans (urban: 17.9% vs. rural: 48.9%, p=0.0018). In patients with periodontitis, the frequency of EBV, HSV1 & 2, and HCMV genes was 2.3%. Periodontitis patients had higher levels of MDA (P: 2.1 ± 1.5; C: 0.46 ± 0.3 µmol/g protein; p=0.0001) and total antioxidant capacity (P: 0.32 ± 0.2; C: 0.15 ± 0.1 mM; p< 0.0036). Oxidative markers showed no modifications due to the presence of periodontopathic bacteria. Conclusions: Aggregatibacter actinomycetemcomitans was the most prevalent bacteria; its presence did not modify the levels of oxidative markers in the saliva of patients with periodontitis.

Introducción. La periodontitis afecta a más del 20 % de la población latinoamericana. La presencia de marcadores de estrés oxidativo se asocia con una mayor progresión de periodontitis, por lo que su rol en la patogenia debe estudiarse. Objetivo. Determinar la prevalencia de las principales bacterias y virus asociados con la periodontitis y estimar la capacidad antioxidante total y la peroxidación de lípidos en la saliva de los pacientes con periodontitis. Materiales y métodos. Se hizo un estudio transversal en 87 sujetos sanos diagnosticados con periodontitis (P) según los criterios de los Centers of Disease Control and Prevention y la American Academy of Periodontology y 14 sujetos sin enfermedad periodontal como grupo control (C). En las muestras subgingivales se identificaron los principales virus y bacterias mediante técnicas de PCR. Los niveles de capacidad antioxidante total y malon-di-aldehído (MDA) se establecieron mediante espectrofotometría en muestras de saliva no estimulada. Resultados. Las medias de profundidad del sondaje y del nivel de inserción clínico periodontal en pacientes con periodontitis fueron 5,6 ± 1,7 y 6,1 ± 3,1 mm, respectivamente. Los microorganismos más prevalentes fueron Aggregatibacter actinomycetemcomitans (32,5 %) y Porphyromonas gingivalis (18,6 %). Los pacientes de áreas rurales registraron un mayor porcentaje de A. actinomycetemcomitans (urbano: 17,9 % Vs. rural: 48,9 %; p=0,0018). La frecuencia de los genes EBV, HSV1 y 2, y HCMV fue de 2,3 %. En pacientes con periodontitis se evidenciaron mayores niveles de MDA (P: 2,1 ± 1,5; C: 0,46 ± 0,3 µmol/g proteína; p=0,0001) y capacidad antioxidante total (P: 0,32 ± 0,2; C: 0,15 ± 0,1 mM; p<0,0036). La presencia de bacterias periodontales patógenas no modificó los marcadores oxidativos. Conclusiones.Aggregatibacter actinomycetemcomitans fue el agente patógeno mas prevalente. Su presencia no modificó los niveles de marcadores oxidativos en la saliva de los pacientes con periodontitis.

Prevalence and molecular typing of rotavirus in children with acute diarrhoea in Northeastern Colombia.

After the introduction of the rotavirus vaccine, the number of rotavirus-associated deaths and the predicted annual rotavirus detection rate had slightly declined worldwide. Taking in account that in Colombia, Rotarix vaccine was introduced in 2009, the purpose of this study was to evaluate the presence of rotavirus A in children under five years who were treated for acute diarrhoea in Bucaramanga, Colombia and, moreover, to determine the genotypes of rotavirus present in those children. We performed an analytical cross-sectional study of rotavirus A in faecal samples from children up to five years of age. Stool samples were screened for rotavirus A using a lateral-flow immunochromatographic assay and confirmed using a VP6 sandwich ELISA. Genotyping of rotavirus A-positive samples was performed by PCR and sequencing of VP7 and VP4 genes. The overall prevalence of rotavirus was 30.53% (95% confidence interval [CI] 21.2 - 39.7). Most of the children with rotavirus (86.2%) had received two doses of the rotavirus vaccine. G3 strains accounted for the vast majority of cases (82.8%), followed by G12 strains (13.8%) and G3/G9 coinfections (3.4%). Among the P genotypes, P[8] was the most prevalent (69%), followed by P[9] (31%). The most common G[P] genotype combination was G3P[8], followed by G3P[9]. The main finding in this study was that rotavirus, in a Colombian region, is still an important pathogen in children under five years old, previously vaccinated. The results showed that different factors, such as kindergarten attendance, could explain the epidemiology and transmission of rotavirus in Bucaramanga.

Prevalence and molecular epidemiology of Canine parvovirus 2 in diarrheic dogs in Colombia, South America: A possible new CPV-2a is emerging?

Since its identification in 1978, Canine parvovirus type 2 (CPV-2) has been considered a pathogen of great importance in the canine population because it causes severe enteritis with high mortality rates in pups. CPV-2 is a virus belonging to the family Parvoviridae. Currently, there are three described antigenic variants (CPV-2a, CPV-2b, and CPV-2c). CPV-2c is an emerging virus that is seen as a global health hazard. The objective of this work was to confirm the presence of CPV-2 in dogs with acute gastroenteritis compatible with parvovirus and to molecularly characterize the antigenic variants circulating in two regions of Colombia. An analytical cross-sectional study was conducted with fecal samples collected from 71 dogs showing signs of acute diarrhea. The samples were processed and polymerase chain reaction (PCR), restriction fragment length polymorphism analysis (RFLP), sequencing and phylogenetic analysis was performed to detect and characterize CPV. A total of 70.42% of the individuals were confirmed positive for CPV-2. Statistically differences were found in the presentation of CPV-2 between the evaluated regions. Phylogenetic analyses confirmed the presence of the antigenic variants CPV-2a/2b. Moreover, we found the presence of two conserved substitutions Asn428Asp and Ala514Ser in the VP2 protein suggesting the presence of a possible new CPV-2a variant circulating in Colombia. This study demonstrates the importance of the CPV 2a/2b in the region and highlights the importance of performing molecular studies for the early detection of new antigenic variants of CPV-2.

Low muscle strength is associated with metabolic risk factors in Colombian children: the ACFIES study.

PURPOSE: In youth, poor cardiorespiratory and muscular strength are associated with elevated metabolic risk factors. However, studies examining associations between strength and risk factors have been done exclusively in high income countries, and largely in Caucasian cohorts. The aim of this study was to assess these interactions in schoolchildren in Colombia, a middle income Latin American country. METHODS: We measured body mass index, body composition, handgrip strength (HG), cardiorespiratory fitness (CRF) and metabolic risk factors in 669 low-middle socioeconomic status Colombian schoolchildren (mean age 11.52±1.13, 47% female). Associations between HG, CRF and metabolic risk factors were evaluated. RESULTS: HG and CRF were inversely associated with blood pressure, HOMA index and a composite metabolic risk score (p<0.001 for all) and HG was also inversely associated with triglycerides and C-reactive protein (CRP) (both p<0.05). Associations between HG and risk factors were marginally weakened after adjusting for CRF, while associations between CRF and these factors were substantially weakened after adjusting for HG. Linear regression analyses showed inverse associations between HG and systolic BP (ß = -0.101; p = 0.047), diastolic BP (ß = -0.241; p> = 0.001), HOMA (ß = -0.164; p = 0.005), triglycerides (ß = -0.583; p = 0.026) and CRP (ß = -0.183; p = 0.037) but not glucose (p = 0.698) or HDL cholesterol (p = 0.132). The odds ratios for having clustered risk in the weakest quartile compared with the strongest quartile were 3.0 (95% confidence interval: 1.81-4.95). CONCLUSIONS: In Colombian schoolchildren both poorer handgrip strength/kg body mass and cardiorespiratory fitness were associated with a worse metabolic risk profile. Associations were stronger and more consistent between handgrip and risk factors than between cardiorespiratory fitness and these risk factors. Our findings indicate the addition of handgrip dynamometry to non-invasive youth health surveillance programs would improve the accuracy of the assessment of cardio-metabolic health.

Factores de virulencia del patógeno intestinal Entamoeba histolytica / Virulence factors of intestinal pathogen Entamoeba histolytica

Entamoeba histolytica es un protozoo entérico causante de la amebiasis intestinal y extraintestinal. Se calcula que 10% de la población mundial está infectada por el complejo Entamoeba histolytica/Entamoeba dispar. Según la OMS, hay 500 millones de nuevas infecciones por año y, aproximadamente, 70.000 a 100.000 muertes a causas de ellas. Este parásito cumple un proceso de invasión muy elaborado, en el cual se secretan y expresan proteínas que le permiten adherirse al epitelio, degradar la matriz extracelular y producir citólisis de las células epiteliales para penetrar dentro de la mucosa. El entendimiento de estos factores de virulencia ha generado múltiples estudios en diferentes áreas de las ciencias biomédicas, desde métodos diagnósticos cada vez más sensibles y específicos hasta candidatos para vacunas, lo que abre nuevas expectativas terapéuticas a raíz de estos estudios.

The enteric protozoan parasite Entamoeba histolytica is a human pathogen that causes widespread morbidity and mortality. It is estimated that 10% of the world’s population is infected with the complex Entamoeba histolytica/ Entamoeba dispar. According to the WHO there are 500 million new infections per year and it is the cause of approximately 70,000 - 100,000 deaths. This parasite has a very elaborate process of invasion, where there are expressed and secreted proteins that allow the parasite to adhere to the epithelium, to degrade extracellular matrix and to penetrate epithelial cells within the mucosa. Numerous studies have been carried out to understand how virulence factors work in diverse areas of biomedical sciences. The studies have proposed diagnostic tests to increase the sensitivity and specificity and to find vaccine candidates, which are an opening way to new therapeutic expectations.

Producción de anticuerpos policlonales IgG contra una proteína con actividad de óxido nítrico sintetasa de Toxoplasma gondii recombinante (NOS-Tg-r) y marcación inmunológica en taquizoítoso / Production of Polyclonal Antibodies against Toxoplasma gondii Recombinant protein with Nitric Oxide Synthase activity and immunologic marking in Tachyzoites

La enzima óxido nítrico sintetasa ha sido estudiada en mamíferos; en los últimos años se ha descrito que existe también en protozoos, pero se desconocen aspectos importantes de su función. Se logró producir anticuerpos policlonales contra la proteína recombinante con actividad de óxido nítrico sintetasa (NOS-Tg-r) de Toxoplasma gondii y realizar marcación inmunológica en taquizoítos. Se usaron dos conejos Nueva Zelanda (Oryctolagus cuniculus)que se inmunizaron por vía intramuscular con NOS-Tg-r, y dos tipos de adyuvantes, hidróxido de aluminio y adyuvante de Freund. Se comprobó la presencia de anticuerpos policlonales con la técnica de ensayo inmunoenzimático indirecto. Los resultados obtenidos mostraron que a NOS-Tg-r con adyuvante de Freund indujo mayor respuesta inmune que la de la NOS-Tg-r con hidróxido aluminio p 0,005). Para verificar si había reacción cruzada, se realizó una prueba ELISA utilizando como antígenos: metaloproteasa de T. gondii recombinante, cisteína proteasa 5 de Entamoeba histolytica recombinante, albúmina al 2%, hidróxido de aluminio y adyuvante de Freund. Los valores obtenidos con sueros preinmunes y contra proteínas alternas no superaron el punto de corte (0,069), lo cual indica que los anticuerpos policlonales obtenidos son específicos para NOS-Tg-r. Se realizó marcación inmunológica en taquizoítos de Toxoplasma gondii con inmunofluorescencia indirecta que mostró una marcación difusa a nivel de citoplasma y confirmó la presencia de esta proteína en los taquizoítos.

The nitric oxide synthase (NOS)is an enzyme well described on mammals but little is known about the role of these enzymes on pathogenic parasites. We produced polyclonal antibodies against a recombinant NOS enzyme from Toxoplasma gondii nd e lso er formed n mmunol locali zation of the enzyme on tachyzoites. We used two New Zealand rabbits (Oryctolagus cuniculus) to perform intramuscular immunization and we used two types of adjuvant: aluminum hydroxide and Freund ’s adjuvant. We tested the generation of polyclonal antibodies by an indirect ELISA assay. The results showed that levels of antibodies were higher in rabbits immunized with Freund ’s adjuvant than with aluminum hydroxide (p =0.005). In order to test cross reactions, we used a recombinant Toxoplasma metallooprotease, a recombinant cysteine protease from Entamoeba histolytica, albumin 2%, hydroxide aluminium and Freund ’s adjuvant as antigens on indirect ELISA assays for the polyclonal serum antibodies. No serum showed absorbances higher than the cutoff level with these antigens, indicating that the polyclonal antibodies were specific for recombinant Toxoplasma NOS. Additionally, we performed immunodetection of the enzyme on Toxoplasma gondii tachyzoites and we obtained a diffuse labeling of the parasite.