A new formula proposal for placing pH-impedance catheters in pediatric patients.

INTRODUCTION: Esophageal pH-impedance monitoring is a tool for diagnosing gastroesophageal reflux in children. The position of the pH catheter is essential for a reliable reading and the current formulas for calculating catheter insertion length are not completely accurate. The aim of the present study was to develop a new formula for adequate insertion of the pH catheter. MATERIAL AND METHODS: A cross-sectional study was conducted on children that underwent pH-impedance monitoring and later radiographic control, to calculate the correct catheter insertion length. The documented variables were age, sex, weight, height, naris to tragus distance, tragus to sternal notch distance, sternal notch to xiphoid process distance, and initial insertion length determined by the Strobel and height interval formulas. A multivariate regression analysis was carried out to predict the final insertion length. Regression ANOVA and Pearson's adjusted R-squared tests were performed. RESULTS: Forty-five pH-impedance studies were carried out, 53% of which were in males. The age and weight variables were not normally distributed. In the initial regression model, the variables that did not significantly correlate with the final insertion length were: sex (P 0.124), length determined by the Strobel or height interval formulas (P 0.078), naris to tragus distance (P 0.905), and tragus to sternal notch distance (P 0.404). The final equation: 5.6 + (height in cm * 0.12) + (sternal notch to xiphoid process distance * 0.57) produced an R2 of 0.93 (P 0.000). CONCLUSIONS: This formula can be considered a valid option for placement of the pH-impedance monitoring catheter in pediatrics.

A comparison of endoscopic procedures performed at a tertiary care hospital before and during the SARS-CoV-2 pandemic.

INTRODUCTION AND AIM: SARS-CoV-2 emerged in 2019 and had a huge impact on the world. The area of endoscopy suffered great changes, causing a reduction in the number of procedures and its indications. The aim of our study was to compare the quantity, indication, and type of procedures in 2019 with those in 2020. METHOD: A retrospective, observational, analytic, and cross-sectional study was conducted, obtaining information from the endoscopy registry. The STROBE checklist was employed. STATISTICAL ANALYSIS: The quantitative variables were analyzed with descriptive statistics (measures of central tendency and dispersion) and the categorical variables with frequencies and percentages. The quantitative variables were compared, using the Student's t test/Mann-Whitney U test, and the categorical variables with contingency tables, using the Fisher's exact test. RESULTS: In 2019, a total of 277 procedures were performed, compared with 139 in 2020. Mean patient age was 98.53 months (61.46 SD) in 2019 and 77.02 months (59.81 SD) in 2020; 352 diagnostic procedures and 136 therapeutic procedures were carried out in 2019, compared with 51 diagnostic procedures and 88 therapeutic procedures in 2020. The number of diagnostic and therapeutic procedures were inverted (72.1%-36.7% and 27.9%-63.3%, respectively) (p<0.0001). Esophageal varices, upper gastrointestinal bleeding (UGIB), and foreign body extraction were the indications, in order of predominance in 2019, compared with foreign body extraction (p<0.05), UGIB, and esophageal varices in 2020. There were no differences regarding colonoscopy. CONCLUSION: There was a clear difference in indication and type of procedure, with an increase in foreign body extraction in preschoolers.

Foreign body ingestion and associated factors in pediatric patients at a tertiary care center.

INTRODUCTION AND AIMS: Foreign body (FB) ingestion is a common problem in children under 5 years of age and is one of the main indications for endoscopy. The aim of the present study was to describe the clinical, radiographic, and endoscopic characteristics of patients with FB ingestion, as well as the factors associated with the anatomic location and the type of object ingested. MATERIALS AND METHODS: An analytic cross-sectional study was conducted on all patients with FB ingestion seen at the gastroenterology service from January 2013 to December 2018. The data were analyzed using the SPSS program, obtaining frequencies, percentages, medians, and interquartile ranges. Associations were assessed through the chi-square test. RESULTS: Eighty-five patients (52 males and 33 females) were included, with a median age of 4 years. The most common symptom was vomiting (29.4%). Two radiographic projections were carried out in 72.9% of the cases and the stomach was the site where the FB was most frequently visualized (32.9%). The objects most commonly ingested were coins (36%), with esophageal location (p<0.05), as well as objects with a diameter larger than 2cm (p<0.05). An endoscopic procedure was performed on 76 patients (89.4%) for FB extraction, with findings of erythema (28.9%), erosion (48.6%), ulcer (10.5%) and perforation (1.3%). CONCLUSIONS: Numerous factors should be taken into account in the approach to FB ingestion in pediatric patients, including type and size of the FB, time interval from ingestion to hospital arrival, and patient clinical status and age.

Esophagogastric junction outflow obstruction in the differential diagnosis of post-fundoplication dysphagia in children.

INTRODUCTION AND AIMS: Post-fundoplication dysphagia is resolved with no therapeutic intervention in the majority of cases but it can persist in 5.3% of children that undergo the procedure. Among the differential diagnoses, esophagogastric junction outflow obstruction (EGJOO) is a disorder that should be suspected if there is a persistence of dysphagia. The aim of our study was to describe the clinical characteristics, treatment, and follow-up in a case series of patients diagnosed with post-fundoplication EGJOO. MATERIALS AND METHODS: The clinical records of patients diagnosed with EGJOO at a tertiary care hospital within the time frame of September 2015 to September 2019 were reviewed, with respect to manometry, etiology, treatment, and clinical course of the disease. RESULTS: Of the 213 high-resolution esophageal manometries performed, 4 patients met the criteria for post-fundoplication EGJOO. The primary symptom was dysphagia, presenting 15 days after the procedure. Esophageal dilations were carried out on all the patients but with no improvement. Symptoms related to the condition resolved spontaneously in three of the four patients. CONCLUSION: The management of children with post-fundoplication EGJOO continues to be a challenge. Even though more than half of the cases resolve with no intervention, optimum management of the motility disorder is still limited, given the scant experience with the condition in the pediatric population.

Foreign body ingestion and associated factors in pediatric patients at a tertiary care center. / Ingesta de cuerpo extraño en pacientes pediátricos en un hospital de tercer nivel y factores asociados.

INTRODUCTION AND AIMS: Foreign body (FB) ingestion is a common problem in children under 5 years of age and is one of the main indications for endoscopy. The aim of the present study was to describe the clinical, radiographic, and endoscopic characteristics of patients with FB ingestion, as well as the factors associated with the anatomic location and the type of object ingested. MATERIALS AND METHODS: An analytic cross-sectional study was conducted on all patients with FB ingestion seen at the gastroenterology service from January 2013 to December 2018. The data were analyzed using the SPSS program, obtaining frequencies, percentages, medians, and interquartile ranges. Associations were assessed through the chi-square test. RESULTS: Eighty-five patients (52 males and 33 females) were included, with a median age of 4 years. The most common symptom was vomiting (29.4%). Two radiographic projections were carried out in 72.9% of the cases and the stomach was the site where the FB was most frequently visualized (32.9%). The objects most commonly ingested were coins (36%), with esophageal location (p <0.05), as well as objects with a diameter larger than 2cm (p <0.05). An endoscopic procedure was performed on 76 patients (89.4%) for FB extraction, with findings of erythema (28.9%), erosion (48.6%), ulcer (10.5%) and perforation (1.3%). CONCLUSIONS: Numerous factors should be taken into account in the approach to FB ingestion in pediatric patients, including type and size of the FB, time interval from ingestion to hospital arrival, and patient clinical status and age.

Anorectal manometry in children with retentive fecal incontinence: What parameters should we evaluate? / Manometría anorrectal en niños con incontinencia fecal retentiva: ¿Qué parámetros debemos evaluar?

INTRODUCTION: Children with functional constipation frequently present with alterations in rectal compliance and the urge-to-defecate sensation that can be evaluated through anorectal manometry (ARM). In the present study, we evaluated the usefulness of the parameters obtained through ARM in children with retentive fecal incontinence (RFI). MATERIALS AND METHODS: Children with functional constipation, aged 4 to 17years, that underwent ARM were included in the study. RESULTS: Of the 35 children evaluated, 21 presented with functional constipation and 14 had functional constipation and RFI. The children with both constipation and RFI tolerated greater volumes of air insufflation for triggering the urge to defecate and reaching maximum tolerance of pain, compared with the children that did not have RFI. We identified the cutoff point of 135ml of air as the maximum tolerance sensation for distinguishing children with RFI. CONCLUSIONS: Maximum tolerance of pain was the most useful parameter for evaluating RFI in children with functional constipation.

Matching global and regional distribution models of the recluse spider Loxosceles rufescens: to what extent do these reflect niche conservatism?

The Mediterranean recluse spider, Loxosceles rufescens (Dufour, 1820) (Araneae: Sicariidae) is a cosmopolitan spider that has been introduced in many parts of the world. Its bite can be dangerous to humans. However, the potential distribution of this alien species, which is able to spread fairly quickly with human aid, is completely unknown. Using a combination of global and regional niche models, it is possible to analyse the spread of this species in relation to environmental conditions. This analysis found that the successful spreading of this species varies according to the region invaded. The majority of populations in Asia are stable and show niche conservatism, whereas in North America this spider is expected to be less successful in occupying niches that differ from those in its native region and that do not support its synanthropic way of living.

Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals.

To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.

Niche modelling of the Chilean recluse spider Loxosceles laeta and araneophagic spitting spider Scytodes globula and risk for loxoscelism in Chile.

In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile. Loxosceles laeta was found to be associated with high temperatures and low rates of precipitation, whereas although S. globula was also associated with high temperatures, its distribution was associated with a higher level of precipitation. The main variable associated with the distribution of L. laeta was the human footprint (48.6%), which suggests that this is a highly invasive species. Similarly to other species, the distribution of L. laeta reaches its southern limit at the Los Lagos region in Chile, which coincides with high levels of precipitation and low temperatures. The potential distribution of L. laeta in Chile corresponds to the distribution of cases of loxoscelism.

Spatio temporal population dynamics of the invasive diatom Didymosphenia geminata in central-southern Chilean rivers.

We document the distribution of Didymosphenia geminata in central-southern Chilean rivers and identify the chemical and physical factors associated with its presence/absence (p/a). Repeated surveys in five successive years provided evidence that D. geminata could be nearing a biogeographic equilibrium in the region. D. geminata databases from extensive biological and environmental surveys in 187 rivers, within ten catchments, south of 38°S commenced in November 2010 and ran through May 2013. In addition, data from two other field surveys were used. The sites evenly distributed latitudinally were climatically characterized. The recent sampling program, following a published species distribution model, was designed to explore D. geminata distribution within thirteen catchments (34°S-48°S). An extensive river survey in 2014 (spring-summer) and in 2015 (autumn) included the p/a, and relative abundance of D. geminata cells in phytobenthos and in the drift. These p/a results showed that the probability of re-encountering D. geminata cells at sites where the species was previously found was significantly high while the probability of finding D. geminata cells at sites previously without the species was significantly low. This suggests that the distribution of D. geminata cells among suitable habitats was nearing completion. The relative abundance of D. geminata cells in the phytobenthos versus in the drift indicates seasonality with higher proportion of cells in the phytobenthos during the spring-summer than during the autumn. During the final surveys, principal component analysis of chemical and physical characteristics of rivers showed significant differences between rivers with and without D. geminata. Based on our observations of the distribution of D. geminata cells among rivers with suitable habitat conditions and the fluctuating rate of spread between rivers, we conclude that D. geminata is probably in the ending stage of its spatial demographic expansion in Chile surmounting the different barriers of the invasive process.

Histopathologic findings in children diagnosed with cow's milk protein allergy.

BACKGROUND: Cow's milk protein allergy is the most common cause of food allergy. The challenge test, either open or doubled-blind with a placebo control, is regarded as the criterion standard. Endoscopy and histologic findings are considered a method that can aid in the diagnosis of this entity. AIMS: The aim of this study was to describe the histopathologic findings in children suspected of cow's milk protein allergy that were seen at our hospital. MATERIAL AND METHODS: A descriptive, observational study was conducted on 116 children clinically suspected of presenting with cow's milk protein allergy that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría. Upper endoscopy and rectosigmoidoscopy with biopsies were performed and the findings were described. RESULTS: Of the 116 patients, 64 (55.17%) were girls and 52 (44.83%) were boys. The rectum was the site with the greatest presence of eosinophils per field in both groups, followed by the duodenum. In general, more than 15 eosinophils were found in 46% of the patients. CONCLUSIONS: Between 40 and 45% of the cases had the histologic criterion of more than 15 to 20 eosinophils per field and the rectosigmoid colon was the most affected site. Therefore, panendoscopy and rectosigmoidoscopy with biopsy and eosinophil count are suggested.

Perinatal factors associated with the development of cow's milk protein allergy.

UNLABELLED: The prevalence of cow's milk protein allergy (CMPA) has increased in recent years, and is associated with antimicrobial use during the perinatal period, prematurity, the type of childbirth, and the decrease in breastfeeding. The aim of this study was to analyze whether there is any association between these factors and the development of CMPA. MATERIAL AND METHODS: A retrospective, comparative, cross-sectional, observational study was conducted by reviewing the case records of 101 children diagnosed with CMPA and seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría within the time frame of January 2012 and August 2013. The following variables were included: age, sex, weeks of gestation, history of maternal infection and antimicrobial use during the pregnancy, type of delivery, and feeding with human milk, and its duration. Likewise, the case records of 90 children were reviewed as a control group on not having CMPA or any other allergy. The chi-square test was used for proportions, and the Mann-Whitney U test was used for comparing means in the statistical analysis. RESULTS: The factors associated with CMPA were the use of antimicrobials during gestation and breastfeeding duration in months. Both factors were statistically significant (P<.001). No association was found between CMPA and gestational age or type of delivery. CONCLUSIONS: The statistically significant associated factors were breastfeeding duration and the use of antimicrobials during the gestational stage. These results underline the necessity for prospective studies.

Implicit constitutive relations for nonlinear magnetoelastic bodies.

Implicit constitutive relations that characterize the response of elastic bodies have greatly enhanced the arsenal available at the disposal of the analyst working in the field of elasticity. This class of models were recently extended to describe electroelastic bodies by the present authors. In this paper, we extend the development of implicit constitutive relations to describe the behaviour of elastic bodies that respond to magnetic stimuli. The models that are developed provide a rational way to describe phenomena that have hitherto not been adequately described by the classical models that are in place. After developing implicit constitutive relations for magnetoelastic bodies undergoing large deformations, we consider the linearization of the models within the context of small displacement gradients. We then use the linearized model to describe experimentally observed phenomena which the classical linearized magnetoelastic models are incapable of doing. We also solve several boundary value problems within the context of the models that are developed: extension and shear of a slab, and radial inflation and extension of a cylinder.

Identificación, establecimiento in vitro y análisis fitoquímico preliminar de especies silvestres de ñame (Dioscorea spp.) empleadas con fines medicinales / Identification, in vitro establishment and preliminary phytochemical analysis of wild yam (Dioscorea spp.) used for medicinal purposes

Tubérculos del género Dioscorea comercializados con fines medicinales, fueron recolectados con el propósito de lograr su establecimiento a condiciones in vitro. Previamente se lograron identificar taxonómicamente las especies y por medio de análisis fitoquímicos demostrar su potencial farmacéutico. El material recolectado fue identificado como Dioscorea coriacea, D. lehmannii, D. meridensis, D. polygonoides y una especie comestible D. trifida. Tubérculos recolectados de centros de acopio y traídos de campo fueron lavados, desinfectados, asperjados con Ácido Giberélico (AG3) y sembrados en sustrato BM-2®, en invernadero a 18°C día y 10°C noche. Los tubérculos completos o por secciones fueron almacenados en bolsas herméticas a temperatura ambiente. Posteriormente se desinfectó material vegetal de las especies D. coriacea, D. lehmannii, D. meridensis y D polygonoides, seleccionando explantes de brotes sanos (D. coriacea / laboratorio) para su establecimiento. Se evaluaron tres medios de cultivo para establecimiento, el que presentó los mejores resultados fue Medio Murashige & Skoog (1962) suplementado con BAP 1 mL/L, AG3 1 mL/L y Putrescina 2 mL/L. Para la extracción y análisis de metabolitos secundarios se utilizaron tubérculos de D. coriacea, D. lehmannii y D. polygonoides, empleando como solvente de extracción metanol. Se encontró mayor concentración de extracto vegetal en D. coriacea (54%), y mediante cromatografía en capa delgada (CCD), se confirmó la presencia de saponinas, que resultó mayor en comparación con D. polygonoides especie reconocida por su alto contenido de saponinas. Estos resultados permitirán realizar análisis más avanzados de los compuestos presentes y plantear su propagación masiva en condiciones in vitro.

Wild tubers of the genus Dioscorea sold for medicinal use were collected for the purpose of achieving its establishment under in vitro conditions. First we taxonomically identified the species and through phytochemical analysis demonstrated pharmaceutical potential. The material collected was identified as Dioscorea coriacea, D. lehmannii, D. meridensis, D. polygonoides and the edible species D. trifida. Tubers collected from wholesale distributors and from the field were washed, disinfected, sprayed with Gibberellic Acid (GA3) and planted in substrate BM-2®, in a greenhouse at 18 ° C during the day and 10 ° C overnight. Whole tubers or sections thereof were stored in sealed bags at room temperature. Subsequently plant material of the species D. coriacea, D. lehmannii, D. meridensis and D. polygonoides was disinfected and healthy buds (D. coriacea / laboratory) were selected for in vitro establishment. Three different culture media were evaluated for establishment; that which presented the best results was the Murashige & Skoog (1962) medium, supplemented with BAP 1 mL / L, GA3 1 mL / L and Putrescin 2 mL / L. For the collection and analysis of secondary metabolites, tubers of D. coriacea, D. lehmannii and D. polygonoides were used, using methanol as the extraction solvent. The highest concentration of plant extract, 54%, was found in D. coriacea, a higher value than that of D. polygonoides, which had been reported previously; the presence of saponins was confirmed by thin layer chromatography (TLC). These results will enable more advanced analysis of the present compounds and enhance their mass propagation under in vitro conditions.