Biomedica : revista del Instituto Nacional de Salud最新文献

Introduction. During the development of the SARS-CoV-2 pandemic in Antioquia, we experienced epidemiological peaks related to the α, ɣ, β, ƛ, and δ variants. δ hadthe highest incidence and prevalence. This lineage is of concern due to its clinical manifestations and epidemiological characteristics. A total of 253 δ sublineages have been reported in the PANGOLIN database. The sublineage identification through genomic analysis has made it possible to trace their evolution and propagation.Objective. To characterize the genetic diversity of the different SARS-CoV-2 δ sublineages in Antioquia and to describe its prevalence.Materials and methods. We collected sociodemographic information from 2,675 samples, and obtained 1,115 genomes from the GISAID database between July 12th, 2021, and January 18th, 2022. From the analyzed genomes, 515 were selected because of their high coverage values (>90%) to perform phylogenetic analysis and to infer allele frequencies of mutations of interest.Results. We characterized 24 sublineages. The most prevalent was AY.25. Mutations of interest as L452R, P681R, and P681H were identified in this sublineage, comprising a frequency close to 0.99.Conclusions. This study identified that the AY.25 sublineage has a transmission advantage compared to the other δ sublineages. This attribute may be related to the presence of the L452R and P681R mutations associated in other studies with higher evasion of the immune system and less efficacy of drugs against SARS-CoV-2.

Introduction: Vitamin D is required for bone and mineral metabolism and participates in the regulation of the immune response. It is also linked to several chronic diseases and conditions, usually in populations of European descent. Brazil presents a high prevalence of vitamin D deficiency and insufficiency despite the widespread availability of sunlight in the country. Thus, it is important to investigate the role of vitamin D as a risk factor for disease and to establish causal relationships between vitamin D levels and health-related outcomes in the Brazilian population.

Objective: To examine genetic variants identified as determinants of serum vitamin D in genome-wide association studies of European populations and check whether the same associations are present in Brazil. If so, these single nucleotide polymorphisms (SNPs) could be developed locally as proxies to use in genetically informed causal inference methods, such as Mendelian randomization.

Materials and methods: We extracted SNPs associated with vitamin D from the genomewide association studies catalog. We did a literature search to select papers ascertaining these variants and vitamin D concentrations in Brazil.

Results: GC was the gene with the strongest association with vitamin D levels, in agreement with existing findings in European populations. However, VDR was the most investigated gene, regardless of its non-existing association with vitamin D in the genomewide association studies.

Conclusions: More research is needed to validate sound proxies for vitamin D levels in Brazil, for example, prioritizing GC rather than VDR.

Introduction: Although Chagas disease causes high levels of morbidity, the muscle function and tolerance to physical activity in Chagas disease patients are still not completely understood.

Objective: To compare health-related fitness of patient groups with acute Chagas disease versus chronic Chagas disease.

Materials and methods: We conducted a cross-sectional study involving 18 patients. The data were obtained from patient´s records, and functional capacity was measured with the sixminute walk test, the peripheral muscle strength with handgrip strength, and respiratory muscle strength using the maximum inspiratory pressure and the maximum expiratory pressure.

Results: The 18 patients were divided in two groups: acute Chagas disease (n=9) and chronic Chagas disease (n=9). The distance walked in the six-minute walk test was lower than the predicted distance walked in both groups (p < 0.0001). The maximum expiratory pressure was lower than the predicted one (p = 0.005), and statistically significant for chronic Chagas disease patients (p = 0.02). Heart rate increased faster in the chronic Chagas disease group within the first two minutes of the six-minute walk test (p = 0.04). The sixminute walk test in the acute Chagas disease group presented a strong correlation with peripheral muscle strength (p = 0.012) and maximum inspiratory pressure (p = 0.0142), while in the chronic Chagas disease group, only peripheral muscle strength and maximum inspiratory pressure were correlated (p = 0.0259).

Conclusion: The results suggest lowered functional capacity and reduced respiratory and peripheral muscle strength in patients with Chagas disease, although no differences were observed between groups. The early increase in heart rate during exercise in the chronic Chagas disease group implies a greater myocardial overload.

Introduction: The multifactorial etiology of gastroenteritis emphasizes the need for different laboratory methods to identify or exclude infectious agents and evaluate the severity of diarrheal disease.

Objective: To diagnose the infectious etiology in diarrheic children and to evaluate some fecal markers associated with intestinal integrity.

Materials and methods: The study group comprised 45 children with diarrheal disease, tested for enteropathogens and malabsorption markers, and 76 children whose feces were used for fat evaluation by the traditional and acid steatocrit tests.

Results: We observed acute diarrhea in 80% of the children and persistent diarrhea in 20%. Of the diarrheic individuals analyzed, 40% were positive for enteropathogens, with rotavirus (13.3%) and Giardia duodenalis (11.1%) the most frequently diagnosed. Among the infected patients, occult blood was more evident in those carrying pathogenic bacteria (40%) and enteroviruses (40%), while steatorrhea was observed in infections by the protozoa G. duodenalis (35.7%). Children with diarrhea excreted significantly more lipids in feces than non-diarrheic children, as determined by the traditional (p<0.0003) and acid steatocrit (p<0.0001) methods. Moreover, the acid steatocrit method detected 16.7% more fecal fat than the traditional method.

Conclusions: Childhood diarrhea can lead to increasingly severe nutrient deficiencies. Steatorrhea is the hallmark of malabsorption, and a stool test, such as the acid steatocrit, can be routinely used as a laboratory tool for the semi-quantitative evaluation of fat malabsorption in diarrheic children.

Introduction: Metabolic bone disease of premature infants is a rare complication characterized by a lower mineral content in bone tissue.

Objective: To establish the incidence of metabolic bone disease in premature infants and to determine associated risk factors.

Materials and method: We conducted a descriptive prospective cohort study for one year in all newborns under 32 gestational weeks, or 1,500 g, at the Hospital Universitario de Santander to determine the incidence of metabolic bone disease. We collected demographic data and prenatal histories of the selected patients, and later, we measured serum alkaline phosphatase and serum phosphorus at the third week of birth, having as reference values for diagnosis less than 5.6 mg/dl for the first one and more than 500 UI/L for the second one. We applied statistical tools for data analysis, such as average proportions, dispersion, distribution and association measures, and binomial regression.

Results: From a total of 58 patients, 7 had a diagnosis of metabolic bone disease, with an incidence of 12%. The weight was reported as an independent variable for the development of the disease, being significant in children under 1,160 g, as well as prolonged parenteral nutrition for more than 24 days. When performing the multivariate analysis, low weight and short time of parenteral nutrition appeared as risk factors; in the same way, maternal age below 22 years is associated with a higher relative risk, even more than a newborn weight inferior to 1,160 g.

Conclusion: Establishing an early intervention in patients with metabolic bone disease enhancing risk factors, such as low weight and prolonged parenteral nutrition, is critical to prevent severe complications.

Paraquat®, or N,N′-dimethyl-4,4′-bipyridinium dichloride, is a bipyridyl compound used as a non-selective herbicide and desiccant that can cause acute poisoning through all routes of exposure. There is no known antidote, and the available treatments are based on avoiding its absorption and timely removing it, in adults and children. We describe a case series of 14 pediatric patients from the department of Cauca, Colombia, with acute intoxication after oral intake of paraquat. Patients were referred to a medium-high complexity hospital in southwestern Colombia and treated according to an institutional protocol for acute paraquat poisoning. Acute paraquat poisoning after oral ingestion is associated with a high mortality rate, even with timely medical attention, as the compound has no known antidote and quickly reaches systemic concentrations for fulminant poisoning. Based on the available literature, our center has proposed a clinical protocol including early standard management, immunosuppressive and antioxidant treatments, and systemic removal techniques. This protocol suggests an adequate approach to acute paraquat poisoning in the pediatric population.

Introduction. During the SARS-CoV-2 pandemic, many countries experienced decreased respiratory virus circulation, followed by an out-of-season outbreak. In a pediatric hospital in Colombia, we observed a surge in severe adenovirus infections, leading to concerns about the impact of eased public health restrictions and immune debt in children under five years old.Objective. To describe the clinical characteristics of patients with severe adenovirus infection in a pediatric hospital in Colombia.Materials and methods. We reviewed the data of 227 patients with severe adenovirus infection at the Fundación Hospital Pediátrico La Misericordia.Results. A total of 196 patients were included in this study. The median age was two years, and 62% were male. Adenoviruses were isolated from all patients’ samples. Ninetyseven percent were admitted to the pediatric intensive care unit, 94% required respiratory support, and the in-hospital lethality rate was 11%.Conclusion. In 2022, there was an outbreak of severe adenovirus infections, affecting mainly children under five years of age, with higher-than-usual mortality.

Introduction: A specialized service for antifungal blood level determination is not available in Colombia. This service is essential for the proper follow-up of antifungal therapies.

Objective: To standardize and validate a simple, sensitive, and specific protocol based on high-performance liquid chromatography with a diode array detector for voriconazole blood level quantification.

Materials and methods: We used an Agilent HPLC™ series-1200 equipment with a UVdiode array detector with an analytical column Eclipse XDB-C18 and pre-column Eclipse- XDB-C18 (Agilent). We used voriconazole as the primary control and posaconazole as an internal control. We performed the validation following the Food and Drug Administration (FDA) recommendations.

Results: The best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detection at 256 nm for voriconazole and 261 nm for posaconazole (internal standard); 50 μl of injection volume, 0,8 ml/min volume flow, 10 minutes of run time, and mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 for voriconazole and 5.16 minutes for posaconazole. Quantification range varied from 0.125 μg/ml to 16 μg/ml.

Conclusion: The selectivity and chromatographic purity of the obtained signal, the detection limits, and the standardized quantification make this method an excellent tool for the therapeutic monitoring of patients treated with voriconazole.

Introduction. Monoclonal B-cell lymphocytosis generally precedes chronic lymphocytic leukemia, affecting about 12% of the healthy adult population. This frequency increases in relatives of patients with chronic B-cell lymphoproliferative disorders.Objective. To determine the frequency of monoclonal B-cell lymphocytosis in relatives of patients with chronic B-cell lymphoproliferative disorders, their immunophenotypic/cytogenetic characteristics, a possible relationship with infectious agents, and short-term follow-up in the Colombian population.Materials and methods. Fifty healthy adults with a family history of chronic B-cell lymphoproliferative disorders were studied using multiparametric flow cytometry,cytogenetic/serological testing, lifestyle survey, and 2-year follow-up.Results. The frequency of monoclonal B-cell lymphocytosis found was 8%, with a predominance of female gender and advanced age, increasing to 12.5% for individuals witha family history of chronic lymphocytic leukemia. Three out of four individuals presented chronic lymphocytic leukemia-type immunophenotype, all with low counts. In turn, a significantly higher number of cells/μl is observed in these individuals in T lymphocyte subpopulations, together with a greater predisposition to the disease. The described clonal populations increase over time in a non-significant manner.Conclusions. The frequency and behavior of monoclonal B-cell lymphocytosis in patients with family history of chronic B-cell lymphoproliferative disorders are like those found in related studies, which suggests that there is no involvement of more relevant genes that can trigger uncontrolled clonal proliferation, but that generates immunological deregulation that could justify a greater risk of serious infection in these individuals.

Introduction. The OLGA system has been proved to be useful in Asia and Europe as a risk marker of gastric cancer. However, its usefulness in high-risk populations in Colombia is still unknown.Objective. To assess potential associations between the OLGA staging system and an increased risk of gastric cancer and dysplasia in a high-risk Colombian population and to establish diagnostic capacity of the scale to assess the risk.Materials and methods. We carried out a multicenter study including patients with cancer and dysplasia (cases) and patients with atrophy and intestinal metaplasia (controls). A total of 506 patients were recruited from three centers in an area with a high risk population in Colombia. The endoscopic and histopathologic studies were evaluated according to the Sydney system and the OLGA staging system proposed by Rugge. The effect of each variable on the disease (gastric cancer and dysplasia) was evaluated using bivariate and multivariate models. Statistical significance was set considering a p value inferior to 0.05.Results. Advanced stages of the OLGA system (III-IV) were associated with a higher risk of dysplasia and gastric cancer (adjusted OR = 8.71; CI95% = 5.09-14.9; p=0.001), sensitivity=54.9%, specificity=89.3% and positive likelihood ratio=5.17.Conclusions. The OLGA staging system is a risk marker for gastric cancer and dysplasia in the studied population. We recommend its implementation to improve the timelydiagnosis and follow-up of patients with the highest cancer risk.