Surveillance of osteoarticular infections caused by Staphylococcus aureus in a paediatric hospital in Mexico City.

Staphylococcus aureus is the main aetiologic agent of osteoarticular infections (OAIs) in paediatric patients. The aim of this prospective unicenter study was to describe the phenotypic and genotypic characteristics of S. aureus isolates obtained from OAIs in paediatric patients admitted to tertiary care hospital. Through a surveillance program called OsteoCode, a multidisciplinary team was created and we identified 27 patients with OAIs caused by S. aureus from 2019 to 2021. The susceptibility profile, virulence factors, biofilm formation, pulsed-field gel electrophoresis (PFGE), clonal complex (CC) and sequence type (ST) were determined. In addition, the clinical characteristics and evolution of the patients presented six months after the diagnosis of OAIs were described. Ninety-two percent of the isolates were methicillin-sensitive S. aureus (MSSA). In methicillin-resistant S. aureus (MRSA), SCCmec-II and SCCmec-V were detected. The pvl gene was only observed in MSSA (18.5%) and was associated with highest fever (p=0.015), multiple localization (p=0.017), and soft tissue sites of infection beyond the bone (pyomyositis, pulmonary abscess) (p=0.017). Biofilm formation was detected in 55.6% of isolates. The most common CC were CC5 and CC30 which represent the most common linages for bone and joint infections worldwide. The isolates were distributed in different STs, and ST672 was predominant. MRSA were associated with a longer duration of intravenous treatment and a prolonged hospital stay (p=0.023). Recurrent infection occurred in five children and orthopaedic complications in 33.3% of patients. This is the first study that reflects the epidemiology of S. aureus in OAIs in paediatric patients in Mexico; a clear predominance of MSSA distributed in different STs was observed. Our findings highlight that a multidisciplinary team is required for the diagnosis and treatment of OAIs.

Blood cytology in children with down syndrome.

INTRODUCTION: Down syndrome is associated with various congenital anomalies and metabolic alterations such as hematological alterations. Values for the major hematological indicators vary with age and sex, but these values have not been described for Mexican children with Down syndrome. OBJECTIVE: To describe the complete blood count (CBC) values of pediatric patients with Down syndrome in México and report the most common non-malignant hematological alterations. MATERIALS AND METHODS: The analysis includes data from 450 patients with Down syndrome, 55.5% ware males, aged 0-18 years who were patients at the Mexican National Institute of Pediatrics and whose clinical charts included CBC panel results for the period January 2008 through March 2018. RESULTS: A total of 3438 CBC panels were analyzed with descriptive statistics to find the values and statistical dispersion of the major indicators, with percentiles, and reported separately by sex and age group. The most common non-malignant hematological alterations found were macrocytic anemia, leukopenia, lymphopenia, and thrombocytosis. There were differences in values in all three series. CONCLUSIONS: The CBC panels and hematological alterations are summarized for patients with Down syndrome.

Prognostic Factors at Diagnosis Associated With Damage Accrual in Childhood-Onset Systemic Lupus Erythematosus Patients.

Objectives: To associate prognostic factors present at diagnosis with damage accrual in childhood-onset systemic lupus erythematosus (cSLE) patients. Methods: We designed a cohort study of eligible children age 16 or younger who fulfilled the 1997 American College of Rheumatology (ACR) classification criteria for SLE. Excluded were those with previous treatment of steroids or immunosuppressants. The diagnosis date was cohort entry. We followed up on all subjects prospectively for at least 2 years. Two experts assessed the disease activity with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Mexican-SLEDAI (MEX-SLEDAI) every 3-6 months. Damage was measured annually, applying Pediatric Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) to their last visit. We analyzed prognostic factors by relative risks (RR) and used logistic regression to construct the clinimetric table. Results: Ninety patients with a median age of 11.8 years at diagnosis had a SLEDAI score of 15.5 (2-40) and a MEX-SLEDAI score of 12 (2-29); and of them, forty-eight children (53%) had SDI ≥ 2. The associated variables to damage (SDI ≥ 2) are as follows: neurologic disease RR 9.55 [95% CI 1.411-64.621]; vasculitis RR 2.81 [95% CI 0.991-7.973], and hemolytic anemia RR 2.09 [95% CI 1.280-3.415]. When these three features are present at diagnosis, the probability of damage ascends to 98.97%. Conclusion: At diagnosis, we identified neurologic disease, vasculitis, and hemolytic anemia as prognostic factors related to the development of damage in cSLE. Their presence should lead to a closer follow-up to reduce the likelihood of damage development.

Growth charts for Mexican children with Down syndrome.

We present the results of a prospective, observational, descriptive, cross-sectional study performed on a Mexican population of 1867 children, aged 0-18 years, with Down syndrome (DS), observed between 2013 and 2019. A total of 9968 measurements of height, weight, and head circumference, as well as calculation of body mass index (BMI) were used to create growth charts and tables of percentiles. Growth curves were elaborated using Cole's LMS method. The mean weight and length at birth did not differ by sex: the weight was 2750 g for boys and 2710 g for girls (p > 0.05), and the length was 48.2 cm for boys and 47.9 cm for girls (p > 0.05). The mean final height at 18 years was different by sex: 149.6 cm for boys and 141.2 cm for girls. The average BMI at 18 years was 24.2 kg/m2 for boys and 21.9 kg/m2 for girls. In a comparison with U.S. growth charts, we find that the Mexican population has lower height and weight. These are the first growth curves for the Mexican population with DS. They can be used by health care providers to optimize preventive care by monitoring children with DS for the early identification of factors that affect individual growth.

Lipid profile of Mexican children with Down syndrome.

INTRODUCTION: Down syndrome (DS) is associated with various congenital anomalies and metabolic alterations, such as dyslipidemias, that can lead to cardiovascular disease in adulthood. This study was designed to describe the lipid concentrations and the frequency of dyslipidemias in children with DS. MATERIALS AND METHODS: The sample included 386 patients, 52.4% male. The study was carried out on children with DS, aged 2-18 years old, who were patients at the Mexican National Institute of Pediatrics between May 2016 and June 2017. Their height and weight were recorded, and their serum cholesterol, HDL cholesterol, and triglyceride levels were determined. RESULTS: Of the total patients included, 57.5% had some type of dyslipidemia, 32.6% isolated and 24.9% combined. The most common alteration, considering both isolated and combined dyslipidemias, was low HDL, in 45.9%, followed by hypertriglyceridemia, in 26.2%. Among those with combined dyslipidemia, high TG with low HDL-c was the most common, in 17.9%. A significant association was found between dyslipidemia and obesity, as well as between dyslipidemia and central obesity. The percentiles of lipid values are reported. CONCLUSION: The presence of an unfavorable lipid profile is common in pediatric patients with Down syndrome, especially low HDL cholesterol and high triglycerides.

Early clinical, histological, and immunohistochemical findings in suspected acute graft-versus-host disease and their association with patient outcomes.

BACKGROUND/OBJECTIVES: Acute graft-versus-host disease (aGVHD) is a serious condition after allogeneic hematopoietic stem cell transplantation (HSCT), frequently involving skin, gut, and liver. It can be difficult to diagnose early, yet this is vital for adequate management. We sought to identify initial clinical and histopathological features in children with suspected GVHD and the association with clinical course and outcomes. METHODS: Retrospective study of patients with skin biopsies for suspected aGVHD from 2006 to 2016. We collected demographic and clinical information, histologic, and immunohistochemical (IHC) findings, and outcomes during follow-up. Bivariate and multivariate analyses were done to identify risk factors associated with remission, development of severe/life-threatening aGVHD, and mortality. RESULTS: We included 42 patients, 15 females. Skin manifestations occurred 51 days (median) after HSCT. On biopsy, 76.2% had mild (stage 1-2) skin aGVHD; during the course of the disease, severity and systemic involvement increased to global grade III/IV in 66.6%. All patients received treatment; 15 are in remission from aGVHD and 23 have died. Histologic features were diagnostic in 83.3%. On bivariate and multivariate analysis, we identified initial clinical and histologic findings that were associated with the measured outcomes: odds of remission from aGVHD were increased when focal vacuolar changes were found on skin biopsy (OR 6.028; 95%CI:1.253-28.992) but decreased by initial hepatic aGVHD (OR 0.112; 95%CI: 0.017-0.748); severe/life-threatening aGVHD was associated with initial gastrointestinal aGVHD (OR 6.054; 95%CI:1.257-29.159); and odds of mortality were decreased with male donor (OR 0.056; 95%CI:0.004-0.804), nulliparous female donor (OR 0.076; 95%CI:0.009-0.669), and focal vacuolar changes on skin biopsy (OR 0.113; 95%CI:0.017-0.770). CONCLUSIONS: We found novel indicators predictive of remission, severity, and mortality in children with aGVHD. Further studies of this condition in children are needed.

Efficacy and safety of an abbreviated perioperative care bundle versus standard perioperative care in children undergoing elective bowel anastomoses: A randomized, noninferiority trial.

PURPOSE: The aim was to evaluate if an abbreviated perioperative care bundle (APCB) is noninferior to the standard care, in terms of efficacy and safety, in pediatric patients undergoing bowel anastomoses. METHODS: A randomized, open, noninferiority trial with two parallel groups of equal size was carried out at the National Institute of Pediatrics in Mexico City, Mexico, from April 2016 to July 2018. The total number analyzed was 74 (37 per group). The APCB comprised same day admission, avoidance of mechanical bowel preparation, optimized antibiotic prophylaxis, and early feeding. Statistical analysis was done with Fisher's exact test or Chi2, and Student's T test. RESULTS: No significant differences were found for demographic variables and type of disease, either for the safety (anastomotic leakage, p 0.753; organ/space surgical site infection, p 0.500) or for some efficacy outcomes (ileus or bowel obstruction, p 0.693). Other efficacy outcomes were better in the study group, with shorter median times for feeding tolerance (19 h vs. 92 h, p < 0.001), for first bowel movement (15 h vs. 36 h, p < 0.001), and for discharge (1 vs. 6 days, p < 0.001). CONCLUSION: The abbreviated care bundle was proven to be as safe but more efficacious than the standard care. LEVEL OF EVIDENCE: I - randomized controlled trial with adequate statistical power.

[The prevalence of allergic diseases in children with short bowel syndrome]. / Prevalencia de enfermedades alérgicas en niños con síndrome de intestino corto.

BACKGROUND: Short bowel syndrome is the result of an extensive surgical resection that leaves the length of the small intestine at a critical value for the proper nutritional absorption. An increased risk of food allergy has been described in patients who suffer from this condition. OBJECTIVE: To describe the prevalence of allergic diseases in a group of patients with short bowel syndrome. METHODS: A descriptive, cross-sectional, and ambispective study was carried out; it included patients with short bowel syndrome who had attended the nephrology service of the National Institute of Pediatrics in a period of 18 months. Information about medical records, surgery history, diet history, and food tolerance was collected with prior authorization of parents or legal guardians. Likewise, there was questioning about history of atopy, and validated questionnaires for allergic diseases were applied in Spanish. The following tests were carried out: skin tests with allergen extracts, determination of four foods specific immunoglobulin E, patch test, and open oral food challenge. The protocol was authorized by the research ethics committee. RESULTS: Fifteen patients with a median age of 44 months (range of 8-128 months) and with a male/female ratio of 2:1 were included. The most common causes of SBS were necrotizing enterocolitis and intestinal atresia. 27% of the patients had a family history of atopy and 40 % of the patients had a personal history that suggested an allergy to cow's milk in infancy. Allergic diseases were found in 40 %. CONCLUSIONS: Allergic diseases seem to have high prevalence in patients with SBS. More studies in large populations are required in order to confirm this discovery.

Antecedentes: El síndrome de intestino corto es el resultado de una resección quirúrgica extensa que deja la longitud del intestino delgado en un valor crítico para una adecuada absorción nutricional. Se han descrito un incremento en el riesgo de alergia alimentaria en pacientes que sufren esta condición. Objetivo: Describir la prevalencia de enfermedades alérgicas en un grupo de pacientes con síndrome de intestino corto. Métodos: Se llevó a cabo un estudio descriptivo transversal y ambispectivo, en el cual se incluyeron pacientes con síndrome de intestino corto que acudieron al servicio de nefrología del Instituto Nacional de Pediatría en un período de 18 meses. Con previa autorización del padre o tutor se recabaron los expedientes médicos, los antecedentes de la cirugía, historial de alimentación y tolerancia a alimentos. De igual manera, se interrogaron antecedentes de atopia y se aplicaron cuestionarios validados en español para enfermedades alérgicas. Se realizaron pruebas cutáneas con extractos alergénicos, determinación de inmunoglobulina E específica para cuatro alimentos, prueba del parche y reto oral abierto con alimentos. El protocolo fue autorizado por el comité de ética e investigación. Resultados: Se incluyeron 15 pacientes con una mediana de 44 meses (rango 8-128 meses) y la relación hombre/mujer fue de 2:1. Las causas más frecuentes de síndrome de intestino corto fueron enterocolitis necrozante y atresia intestinal. El 27 % tenía historia familiar de atopia y 40 % antecedentes personales sugestivos de alergia a las proteínas de la leche de vaca en la infancia. Se encontraron enfermedades alérgicas en 40 %. Conclusiones: Las enfermedades alérgicas parecen tener una alta prevalencia en pacientes con síndrome de intestino corto. Se requieren más estudios en poblaciones extensas para confirmar este hallazgo.

High depression rates among pediatric renal replacement therapy patients: A cross-sectional study.

Depression is common in pediatric chronic kidney disease (CKD) patients. Depression is associated with inferior long-term outcomes. There is a paucity of studies that evaluate depression and possible associated factors in children and adolescents requiring renal replacement therapy (RRT). Cross-sectional study using Children`s Depression Inventory in a cohort from a large urban center. Forty-seven pediatric RRT patients (26 female, 12 peritoneal dialysis (PD), 17 hemodialysis (HD), 18 after successful kidney transplantation (KTX)) with a mean age at the time of assessment of 13.9 ± 2.3 years. Symptoms of depression were found in 30 (64%, 11KTX, 11HD, 8PD) patients. We found no association with age, sex, renal function, dialysis adequacy markers, anemia, electrolytes, socioeconomical status, IQ, educational status of the child including school attendance and distance from the house to the hospital among HD patients. Significant differences only applied for age at diagnosis of CKD, RRT vintage and deceased donor for KTX. The group with depression had a higher age at diagnosis of CKD and less time on RRT than the group without depression. There was also a high rate of depression in KTX patients. In this cohort, depression was a common comorbidity of RRT in children and adolescents with RRT and also for KTX patients, even though biomarkers of kidney function and time for RRT are much improved.

Effectiveness of an educational strategy to increase plain water consumption in children / Efectividad de una estrategia educativa para incrementar el consumo de agua simple en niños

Abstract: Objective: We tested the effectiveness of the I prefer plain water educational strategy used to increase water consumption in elementary school children. Materials and methods: A community intervention trial was performed in eight public elementary schools in Mexico City. The schools were randomized into an intervention (IG) and a control (CG) group. Each school was provided water dispensers inside the classrooms. The IG received the educational strategy. The strategy was considered effective if the students increased their water consumption by ≥220 ml. Results: Water consumption in the IG increased 167 ml vs. 37 ml in CG (p < 0.001). The goal of the educational strategy for water consumption was achieved in 166/413 children in the IG and 95/364 children in the CG (p < 0.001). Conclusions: I prefer plain water, associated with free access to water inside the classrooms, proved to be effective to increase water consumption.

Resumen: Objetivo: Evaluar la efectividad de la estrategia Prefiero agua simple para incrementar el consumo de agua en niños de escuelas primarias públicas. Material y métodos: Ensayo de intervención comunitaria en ocho escuelas en la Ciudad de México. Las escuelas se aleatorizaron en grupo de intervención (GI) y de control (GC). Se instalaron dispensadores de agua dentro de las aulas. Implementamos la estrategia al GI. Consideramos efectiva la estrategia si los estudiantes incrementaron su consumo de agua en ≥220 ml. Resultados: El incremento global en el consumo de agua del GI fue de 167 ml vs. 37 ml en GC (p <0.001). La efectividad de la estrategia para el consumo de agua se logró en 166/413 niños del GI y en 95/364 niños del GC (p <0.001). Conclusiones: Prefiero agua simple, asociada con libre acceso al agua dentro de las aulas, demostró ser efectiva para incrementar el consumo de agua.

Effectiveness of an educational strategy to increase plain water consumption in children.

OBJECTIVE: We tested the effectiveness of the I prefer plain water educational strategy used to increase water consumption in elementary school children. MATERIALS AND METHODS: A community intervention trial was performed in eight public elementary schools in Mexico City. The schools were randomized into an intervention (IG) and a control (CG) group. Each school was provided water dispensers inside the classrooms. The IG received the educational strategy. The strategy was considered effective if the students increased their water consumption by ≥220 ml. RESULTS: Water consumption in the IG increased 167 ml vs. 37 ml in CG (p < 0.001). The goal of the educational strategy for water consumption was achieved in 166/413 children in the IG and 95/364 children in the CG (p < 0.001). CONCLUSIONS: I prefer plain water, associated with free access to water inside the classrooms, proved to be effective to increase water consumption.

OBJECTIVE: Evaluar la efectividad de la estrategia Prefiero agua simple para incrementar el consumo de agua en niños de escuelas primarias públicas. MATERIALS AND METHODS: Ensayo de intervención comunitaria en ocho escuelas en la Ciudad de México. Las escuelas se aleatorizaron en grupo de intervención (GI) y de control (GC). Se instalaron dispensadores de agua dentro de las aulas. Implementamos la estrategia al GI. Consideramos efectiva la estrategia si los estudiantes incrementaron su consumo de agua en ≥220 ml. RESULTS: El incremento global en el consumo de agua del GI fue de 167 ml vs. 37 ml en GC (p < 0.001). La efectividad de la estrategia para el consumo de agua se logró en 166/413 niños del GI y en 95/364 niños del GC (p < 0.001). CONCLUSIONS: Prefiero agua simple, asociada con libre acceso al agua dentro de las aulas, demostró ser efectiva para incrementar el consumo de agua.

[Prevalence of allergic diseases in children with secondary renal tubular acidosis attending a tertiary care pediatric center]. / Prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria que acudieron a un hospital pediátrico de tercer nivel.

BACKGROUND: It has been suggested a high prevalence of allergic disease in children with RTA. OBJECTIVE: To describe the prevalence of allergic diseases in children with secondary RTA (renal tubular acidosis) in the nephrology department of the National Institute of Pediatrics (NIP), México. METHODS: An observational, prospective, cross-sectional, descriptive study. Children with secondary RTA < 18 years who attended the outpatient nephrology service in the NIP for 24 months, were included. ISAAC questionnaire and the EAACI guidelines were applied. To prove a suspected allergy, skin tests, total and specific IgE, patch testing and food challenge were performed. Using SPSS 19, frequency of allergic diseases was described. RESULTS: 113 patients were included. Age 8 to 168 months. Male: 53.9 %. RTA types: Distal (64.6 %), proximal (26.5 %), mixed (1.8 %) and undetermined (7 %). Age of onset between 1 and 96 months. Serum bicarbonate 10.1 to 20 mEq/L. Allergic diseases were found in 24.8 %: allergic rhinitis (18.4 %), food allergy (9.7 %), atopic dermatitis (8 %), asthma (8 %) and allergic conjunctivitis (6.1 %). Total IgE was increased in 9 patients. Positive skin tests in 14.2 %. Positive chemiluminescence in 18 children; positive open food challenge in 11 children and patch tests in 4. CONCLUSION: Secondary RTA is common in children attending tertiary care hospitals. The prevalence of allergic disease in children with secondary ATR, is similar to that described in the general population.

Antecedentes: Se ha sugerido elevada prevalencia de enfermedades alérgicas en niños con acidosis tubular renal. Objetivos: Describir la prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria atendidos en el Servicio de Nefrología del Instituto Nacional de Pediatría, México. Métodos: Estudio observacional, prospectivo, transversal, descriptivo. Se incluyeron niños atendidos durante 24 meses. Se aplicó el cuestionario ISAAC y los criterios de la guía EAACI. Ante sospecha de alergia se realizaron pruebas cutáneas, IgE total y específica, pruebas del parche y reto alimentario. Resultados: Se incluyeron 113 pacientes con edades entre 8 y 168 meses; 53.9 % del sexo masculino. Tipos de acidosis tubular renal: distal (64.6 %), proximal (26.5 %), mixta (1.8 %) y no determinada (7 %). La edad de inicio osciló entre 1 y 96 meses. Se registró 10.1 a 20 mEq/L de bicarbonato sérico; 24.8 % mostró enfermedades alérgicas: 18.4 % rinitis alérgica, 9.7 % alergia alimentaria, 8 % dermatitis atópica, 8 % asma y 6.1 % conjuntivitis alérgica. Se observó IgE total elevada en 9 pacientes. En 14.2 % las pruebas cutáneas fueron positivas y la quimioluminiscencia en 18 niños; el reto abierto con alimentos fue positivo en 11 y las pruebas del parche en 4. Conclusiones: La prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria fue similar a la de la población general.

Real-Time Polymerase Chain Reaction-Based Detection of Bordetella pertussis in Mexican Infants and Their Contacts: A 3-Year Multicenter Study.

OBJECTIVES: To evaluate the usefulness of real-time polymerase chain reaction (RT-PCR) as a diagnostic method for the detection of Bordetella pertussis in hospitalized patients aged <1 year with a clinical diagnosis of whooping cough, as well as to identify the role of household contacts as a source of infection. STUDY DESIGN: This was a prospective, multicenter study of infants aged <1 year who were hospitalized with symptoms suggestive of whooping cough. Nasopharyngeal samples were obtained for culture and RT-PCR testing. The clinical and epidemiologic characteristics and outcomes were analyzed. B pertussis detection and symptoms in household contacts of patients diagnosed with pertussis were studied. RESULTS: A total of 286 patients were included; of these, 67.1% had B pertussis and 4.5% had Bordetella spp. Complications occurred in 20% of patients, and the mortality rate was 6.7%. Of 434 contacts studied, 111 were mothers of study infants, representing the most frequently B pertussis-infected group and the main symptomatic contact. CONCLUSION: The use of RT-PCR permits improved detection and diagnosis of pertussis and a better understanding of the epidemiology of sources of infection. The complications and mortality rate of pertussis continue to be high. Household contacts are confirmed as a frequent source of infection of B pertussis in young children.

Morphological study of bone cranial in athymic mice / Estudio morfológico de hueso craneal en ratones atímicos

The aim of our research was to create an osteogenic unit in the skulls of athymic mice; however, the first challenge we faced was to find sufficient and adequate data that would allow us to determine the morphological, immunohistochemical and microtopographical characteristics that could be used as normality standards in athymic mice skulls and, hence, a reference in the event of achieving the formation of de novo bone using the osteogenic unit we proposed. Knowing the normal bone morphology in the skull of athymic mice was a necessary precondition to develop subsequently an osteogenic unit possessing the Osteogenesis, Osteoinduction and Osteoconductivity that could be compared versus those in the normal bone during its formations and remodeling processes. Therefore, we conducted a pilot study to determine bone morphological characteristics in the skull of athymic mice by means of specific histological staining: hematoxylin-eosin and Von Kossa, for osteoid tissue and mineralized bone, and Masson Tri-chrome for ossified areas. We also use immunohistochemistry to detect bone formation markers: alkaline phosphatase resulting from osteoblastic activity stimulation, type 1 collagen a bonematrix structural protein; Osteopontine, a protein specifically synthesized by osteoblasts that favors cell proliferation and remodeling in bone defects; Osteocalcine, a peptide hormone produced by osteoblasts during bone formation; and, Runx 2, a transcription factor expressed by stem cells which stimulates bone differentiation. Likewise, we used electron microscopy on the newly formed tissue to determine the presence of organic deposits, such as calcium, phosphate and magnesium in bone tissue.

Propusimos la realización de una unidad osteogénica a desarrollar en cráneo de ratones atímicos, Sin embargo, nos enfrentamos al reto de encontrar datos que nos determinaran cuales eran las características morfológicas, inmunohistoquímicas y micro-topográficas del cráneo de estos ratones atímicos, que nos sirvieran como referencia de normalidad y tener un punto de comparación, en caso de que pudiéramos lograr la formación de hueso de novo, a partir de la unidad osteogénica que propusimos. El objetivo, de conocer la morfología del hueso normal de cráneo de ratones atímicos, fue desarrollar posteriormente una unidad osteogénica que reuniera las características de Osteogénesis, Osteoinducción y Osteoconducción, y, compararlas contra las que tiene dicho hueso normal durante su proceso de formación y remodelación. Así, realizamos un estudio piloto donde establecimos características morfológicas de hueso del cráneo de ratones atímicos, a través de tinciones histológicas específicas, con hematoxilina-eosina y von Kossa para buscar tejido osteoide y hueso mineralizado y Tricrómico de Massón para observar zonas osificadas. Además, analizamos el tejido óseo a través de inmunohistoquímica, con la finalidad de buscar marcadores de formación ósea como fosfatasa alcalina que es resultado del estímulo de la actividad osteoblástica; colágena 1, la cual es una proteína estructural de la matriz ósea; osteopontina, proteína sintetizada específicamente por osteoblastos que favorece la proliferación celular y la remodelación en defectos óseos; osteocalcina hormona peptídica producida por los osteoblastos durante la formación ósea y Runx 2 Factor de transcripción expresado por las células progenitoras que estimula la diferenciación ósea. Además, sometimos el tejido óseo a microscopía electrónica para determinar la presencia de depósitos de compuestos como calcio, fósforo y magnesio.

Consentimiento informado en grupos vulnerables: participación de niños y adolescentes en protocolos de investigación / Informed consent in vulnerable groups: participation of children and adolescents in research protocols

El consentimiento informado (Cl) es un proceso activo de comunicación, que incluye toma de decisiones y responsabilidades compartidas entre el médico y su paciente. Es un punto clave en la práctica clínica, que pretende proteger al paciente de otros posibles intereses. El asentimiento del menor, una vez que han consentido las personas que son responsables de él, y su derecho a preguntar y discutir son dos temas de gran relevancia en la investigación científica en la población infantil.

Informed consent is an active process of communication that includes decision making and shared responsibilities between physician and patient. It is a key point in clinical practice and aims to protect the patient from other potential interests. The assent of the child, once the responsible persons have consented, and the rights of the child to ask questions and to discuss are two issues of great significance in scientific research in children.

Efficacy of simvastatin in children with hyperlipidemia secondary to kidney disorders.

Children with hyperlipidemia secondary to renal disease develop premature atherosclerosis and glomerulosclerosis. The aims of this pilot study were to find the dosage and short-term efficacy of simvastatin and potential adverse events in children with chronic kidney diseases. This was a random, double-blind, placebo-controlled, cross-over clinical trial performed on children with hyperlipidemia secondary to kidney disorders. After being placed on a diet for 3 months, patients were randomly placed in one of two balanced group blocks and treated with diet plus placebo or simvastatin at doses of 5 mg for children weighing 30 kg or less and 10 mg for children weighing over 30 kg, for 1 month, and then doubled for two more months. After this treatment, patients were placed on a diet for a 3-month washout period. During the last trial phase, patients previously treated with simvastatin were administered a placebo, and vice versa. A total of 25 patients with ages ranging from 4 years to 17 years were included in the study. A significant decrease in the levels of serum cholesterol (26.4%), low-density lipoprotein (LDL) (35.4%) and triglycerides (23.1%) was noted during the study, primarily during the simvastatin treatments, in which case cholesterol, LDL and triglycerides decreased by 23.3%, 33.7% and 21%, respectively. High-density lipoprotein (HDL) levels increased moderately (10.7%) during the study but without differences during simvastatin treatment. No differences were found across groups with respect to adverse events. In the short-term the combination of diet and simvastatin was effective in lowering hyperlipidemia in children with renal disorders.

Prognostic factors in children with membranoproliferative glomerulonephritis type I.

The clinical outcome of patients with membranoproliferative glomerulonephritis (MPGN) varies, with some patients progressing to end-stage renal disease. The aim of this retrospective study was to analyze the initial clinical signs and laboratory test results associated with an MPGN prognosis. The study cohort consisted of 47 patients with idiopathic MPGN Type I treated at the National Institute of Pediatrics, Mexico City, between 1971 and 2001. The median follow-up was 3 years. The three different outcomes of interest were death, renal failure, and nephrotic syndrome. The patients' ages ranged between 4 and 16 years. All patients had different degrees of proteinuria, hyperlipidemia, and microscopic/macroscopic hematuria, and 85.1% of them showed hypocomplementemia. Clinical outcomes varied, however, the most common was nephrotic syndrome, either alone or combined with other syndromes, which accounted for 74.5% of all cases. Fifteen patients died. Treatment with methylprednisolone improved the patient's condition, while the use of chloroquine or cyclophosphamide worsened it. Twenty-two patients had some degree of renal failure; glomerular filtration rate (GFR) levels and albumin values were negatively associated to renal failure, while treatment with methylprednisolone decreased the probability of renal failure. Nephrotic syndrome persisted in 18 patients; hemolytic complement and hemoglobin values were negatively associated with nephrotic syndrome, while macroscopic hematuria was positively associated with it. Signs that suggested a poor prognosis during diagnosis were low GFR, low albumin, low hemolytic complement, and macroscopic hematuria. Treatment with methylprednisolone seemed to improve prognosis, however, this needs to be confirmed with randomized studies.

Hyper-IgE syndrome and autoimmunity in Mexican children.

Hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by recurrent skin abscesses, recurrent pneumonia with pneumatocele formation, eczema, eosinophilia, and elevated levels of serum IgE. Patients with the autosomal recessive (AR) form of HIES appear to be prone to developing autoimmune diseases. We present two cases of HIES with autoimmune complications; one case was a product of a consanguineous marriage, the other one was a sporadic case. The first patient presented with recurrent episodes of erythema nodosum, warts, bronchiolitis obliterans and thrombocytopenia. The second patient developed glomerulonephritis resulting in endstage renal failure. She later developed malar rash, oral ulcers, cerebral infarcts with vasculitis and positive ANA, anti-dsDNA, and antiphospholipid antibodies. We discuss the dilemma in treating patients who present with both primary immunodeficiency and autoimmunity.

Eritropoyetina en el tratamiento de la anemia en niños en hemodiálisis / Erythropoietin in the treatment of anemic children in hemodialysis

La anemia de la insuficiencia renal tiene origen multifactorial; el más importane es la disminución de la producción de eritropoyetina por las células renales peritubulares. La administración de esta hormona permite corregir la anemia. Se trató la anemia de siete niños en hemodiálisis con eritropoyetina recombinante humana. La dosis inicial fue de 150-250 U/kg/semana y la dosis de mantenimiento 100-200 U/kg/semana. La hemoglobina se elevó de 5.8 g/dL a 10 g/dL en promedio; tres pacientes presentaron ferropenia y falta de respuesta transitoria a la hormona a pesar del uso profiláctico de hierro. Mejoró la calidad de vida al corregirse la anemia y los pacientes no requirieron transfusiones después de 20 semanas. Tres pacientes desarrollaron trombosis en el sitio del acceso vascular; no hubo otros efectos colaterales. La eritropoyetina es útil en el tratamiento de la anemia de la insuficiencia renal con pocos efectos colaterales en niños

Transplante de órganos y parasitosis / Organ trasplant and parasitosis

La infección es una de las complicaciones graves en los pacientes sometidos a trasplante de órganos y la causa más frecuente de muerte en los trasplantados de riñon. En nuestro medio el control profiláctico de las infecciones bacterianas y virales se realiza de manera estricta, no así de las infecciones parasitarias. El presente artículo tiene como fin alertar al médico y señalar los lineamientos que deben seguirse para prevenir infecciones parasitarias en los enfermos que reciban un trasplante