[Reference Intervals for total triiodothyronine (TT3), free thyroxine (FT4), and thyrotropin (TSH) by chemiluminescence immunoassay in children younger than six years old from northeastern Mexico]. / Valores de referencia de triyodotironina total (TT3), tiroxina libre (FT4) y tirotropina (TSH) obtenidos por quimioluminiscencia en niños menores de seis años del noreste de México.

BACKGROUND: Reference values according to age groups for each population are needed for the diagnosis and follow-up of pediatric patients with thyroid diseases. Such values are unknown for Mexican infants and children younger than six years. OBJECTIVE: To determine the reference values of total TT3, FT4 and TSH by chemiluminescence immunoassay in infants and children younger than six year old in Northeastern Mexico. MATERIAL AND METHODS: Thyroid hormone serum levels were determined by chemiluminescence immunoassay in healthy infants and children younger than six years old. RESULTS were analyzed according to gender in seven age groups: Newborns (NB), 1 to 6, 7 to 12, 13 to 18, 19 to 23, 24 to 35, and 36 to 71 months. RESULTS: A total of 405 infants and children were included, 209 male and 196 female, 1.6 ± 1.4 years of age (4 days to 5.6 years). Thyroid hormones: Although there were not significant differences according to gender, in NB TSH and FT4 serum levels were higher (p = 0.001 and p = 0.000, respectively) and TT3 levels were lower (p = 0.000). CONCLUSIONS: Serum levels of TSH and TT4 were higher and TT3 lower in newborns, which has been previously reported even for other measurement methods and other populations. These results allow counting with reference values of these hormones for this region.

Leptin and leptin receptor polymorphisms are associated with poor outcome (death) in patients with non-appendicular secondary peritonitis.

INTRODUCTION: Leptin (LEP) and its receptor (LEPR) participate in the immunological response during infection. LEP serum levels rise during sepsis. In patients with peritonitis, an insufficient elevation in serum LEP is associated with an increased risk of death. As gene variants of LEP and LEPR have been associated with diverse pathologic conditions, we explored the association of genetic polymorphisms of LEP or LEPR with death in patients with secondary peritonitis. METHODS: A case control study was undertaken. LEP Gene -2548G > A and the LEPR Gene 223A > G polymorphism were determined in 74 patients. The odds ratio of genotype and allele distribution in survival (control) versus death (case) among patients was calculated. Serum LEP, interleukin (IL)-6, tumour necrosis factor alpha, C-reactive protein (C-RP), IL-10 and IL-13 levels were analyzed in 34 patients. RESULTS: There were significant differences in genotype and allele distribution between survivors and non-survivors for -2548G > A and 223A > G polymorphisms. The presence of the mutant allele A, in -2548, had an odds ratio of 4.64 (95% CI 1.22, 17.67) with significance (P = 0.017) in the risk of death. The presence of mutant allele G, in 223, had an odds ratio of 3.57 (95% CI 1.06, 12.01) with significance in the risk of death (P = 0.033). The presence of allele A in the -2548 polymorphism was associated with differences in serum LEP (P = 0.013), and IL-10 (P = 0.0001). The presence of allele G in 223 polymorphism was likewise correlated with differences in serum LEP (P < 0001), C-RP (P = 0.033), and IL-10 (P = 0.043). CONCLUSIONS: The polymorphisms studied are associated with death in patients with peritonitis of non-appendicular origin. This association is stronger than many known risk-factors related to peritonitis severity, and is independent of body mass. The physiopathologic mechanism is possibly related to an insufficient increase in the elevation of serum LEP levels, and is unrelated to body mass.

[Risk factors associated with neurocysticercosis in a public hospital in Mexico]. / Factores de riesgo asociados a neurocisticercosis en un hospital público de México.

OBJECTIVE: A case-control study was carried out to determine risk factors associated with neurocysticercosis in a public hospital in Mexico. METHODS: The following factors were analyzed: Socioeconomic, sociodemographic, hygiene, eating habits, and family history of neurocysticercosis in 85 cases and 170 controls. Cases were patients with cranial computed tomography images compatible with neurocysticercosis. The densitometric analysis (Hounsfield units) allowed us to distinguish normal tissue from physiological and pathological calcifications, and other types of lesions. Controls were admitted for neurocysticercosis but findings were not compatible with initial diagnosis. Statistical analysis was done using SPSS and Epi-info 2002. RESULTS: The most common clinical manifestation in patients was epileptic seizures OR=4.2 (IC 95% 2.40-9.67). With regards to risk factors, consumption of street food OR=2.33 (IC 95% 1.25-4.38), and family history of neurocysticercosis OR= 2.37 (IC 95% 1.11-5.04) were found to be associated with neurocysticercosis. In the north central region of Mexico where this study was performed, the disease was more frequent among urban populations.

The grade-response relation between severity of peritonitis and serum cytokine concentrations explains Mannheim Peritonitis Index threshold.

AIM: To explore the gradient between the acute-phase response (APR) and peritonitis of differing severity. METHODS: In 202 patients with peritonitis, we determined serum concentrations of interleukin (IL)-6, IL-10, IL-13, tumor necrosis factor (TNF)-alpha, and C-reactive protein (CRP). The severity of peritonitis was graded in accordance with the Mannheim Peritonitis Index (MPI). The grade-response relation between the severity of peritonitis and each analyte was explored. RESULTS: A statistically significant association was found between the medians of severity of peritonitis and IL-6 (p < 0.025), TNF-alpha (p < 0.01), CRP (p < 0.033), IL-10 (p < 0.0001), and IL-13 (p < 0.004). Both TNF-alpha and IL-10 had a direct, and IL-13 an indirect, relation to severity, whereas CRP and IL-6 tended toward linear behavior in equilibrium. A significant association persisted between individual MPI scores and IL-6 (p < 0.002), TNF-alpha (p < 0.002), CRP (p < 0.002), and IL-10 (p < 0.001), but not IL-13 (p = 0.646). CONCLUSION: Around the mean value of grade II peritonitis, the equilibrium between pro-inflammatory and anti-inflammatory cytokines is lost. This change coincides with the 26-point threshold for the MPI.

Genotypic resistance to lamivudine among hepatitis B virus isolates in Mexico.

BACKGROUND: Drug resistance of hepatitis B virus (HBV) is an increasing clinical problem. Resistance to lamivudine in HBV isolates in Mexico has been poorly explored. OBJECTIVES: To characterize the mutation patterns associated with genotypic resistance to lamivudine and their prevalence among HBV isolates in Mexico. MATERIAL AND METHODS: Thirty-nine Mexican HBV isolates were analysed by PCR and line probe assay for detection of genetic variants in the polymerase open reading frame domains B and C (INNO-LiPA HBV DR; INNOGENETICS N. V., Ghent, Belgium). This assay detects wild-type and mutations at codons 180, 204 and 207 of the HBV polymerase gene, and at codon positions 171, 172, 195, 196, 198 and 199 of the HBV surface antigen (HBsAg). HBV isolates were obtained from HBsAg-positive serum samples of 15 chronic hepatitis patients, two haemodialysis patients with chronic HBV carriage, 20 men found positive for HBsAg when seeking HIV testing and two AIDS patients with chronic HBV infection. None of the participants had received antiviral therapy. RESULTS: Overall, HBV wild-type was found in 37 (94.9%) out of the 39 isolates studied. Two (5.1%) out of the 39 isolates showed mixed wild-type and mutant populations. These mutations occurred in isolates from one hepatitis patient and one haemodialysis patient. The isolate from the hepatitis patient showed a double mutation at codon positions 180 (L180M) and 204 (M204V), thus a 2.6% prevalence of genotypic resistance to lamivudine was found. The isolate from the haemodialysis patient showed a single mutation at codon position 180 (L180M). The two HBV mutant isolates were further analysed for genotype and both isolates were genotype H. CONCLUSIONS: HBV genotypic resistance to lamivudine exists in Mexican isolates. The results highlight the importance of testing for HBV resistance before treatment and have implications for a more rational use of drugs.

Reacciones adversas asociadas a la vacunación con bacilo de Calmette y Guérin en una población infantil de la ciudad de Zacatecas, México / Adverse reactions in association with Bacillus Calmette-Guerin immunization in Mexican children

Introducción. La vacuna BCG (bacilo de Calmette y Guérin) previene formas graves de tuberculosis, los efectos adversos son poco frecuentes: abscesos locales, linfadenopatías, lesiones músculo-esqueléticas y enfermedad diseminada; manifestándose meses posteriores y persistiendo varias semanas, asociados con la técnica de aplicación, dosis, edad del niño y estados de inmuno-supresión. Métodos. Mediante un estudio retrospectivo, se evaluó la frecuencia de manifestaciones clínicas secundarias a BCG en niños atendidos durante el período de 8 años y 5 meses en una clínica pública de la ciudad de Zacatecas, México. Además, se determinaron las características demográficas, clínicas, perinatales y antropométricas. Resultados. Se identificaron 22 casos, con una frecuencia de eventos adversos de 1.47 x 10-3 (intervalo de confianza de 95% [IC95%): 0.8, 2.1 x 0-3); 12 fueron del sexo masculino. La manifestación más común fue linfadenopatía (10 casos), seguido por pústula persistente (5), nódulo persistente (4) y úlcera (2 casos), en 4 casos se identificaron factores de inmunosupresión. Conclusiones. La prevalencia de reacciones secundarias es baja, no hubo asociación con sexo, peso y talla al nacimiento, ni con antecedentes maternos. La mayor frecuencia fue de linfadenopatías (IC95%: 22.4, 68.5%). La secuela postratamiento más importante fue la hiperqueratosis. Se observaron bajos eventos adversos, y cuando éstos se presentaron fueron bien resueltos, médica y quirúrgicamente, sin secuelas de importancia.

Introduction. The vaccine BCG (bacillus Calmette and Guerin) prevents severe forms of tuberculosis. Adverse effects are rare and such as local abscesses, lymphadenopathy, skeletal muscle injury and disseminated disease; they usually occur months later and persist for several weeks. Adverse effects are related to technical implementation, doses, age and state of immunosuppression. Methods. A retrospective study assessed the frequency of clinical manifestations secondary to BCG, in children attended over 5 years and 8 months in a government clinic in the city of Zacatecas, Mexico. Demographic, clinical, perinatal, and anthropometric characteristics were determined. Results. Twenty-two cases were identified with an adverse event frequency of 1.47 x 10-3 (IC95%: 0.8, 2.1 x 10-3), 12 male/ 10 female children. The most frequent event was lymphadenopathy (10 cases), followed by persistent pustules (5), persistent nodule (4) and ulcer (2 cases). Immunosuppression was identified in 4 cases. Conclusions. The prevalence of adverse effects is low. There was no association with sex, height or weight at birth, neither with maternal background. The most frequent event was lymphadenopathy (IC95%: 22.4). Hyperkeratosis was the most important post-treatment sequela. BCG is a vaccine with few adverse events; they are clinically well resolved with no important sequelae.

Factores de riesgo asociados a neurocisticercosis en un hospital público de México / Risk factors associated with neurocysticercosis in a public hospital in Mexico

Objetivo: Determinar los factores de riesgo asociados con neurocisticercosis en un hospital público de México. Material y métodos: Se analizaron factores socioeconómicos, demográficos, patrones higiénicos, dietéticos y antecedentes familiares asociados en 85 casos y 170 controles. La muestra se tomó de pacientes que acudieron al estudio de tomografía de cráneo. Los casos presentaron calcificaciones en cráneo compatibles con neurocisticercosis y de acuerdo con la densitometría (Unidades Hounsfield) se definió el tejido normal, las calcificaciones fisiológicas, patológicas así como otras lesiones. Los controles compartían la misma demanda de atención, sin presentar el evento en estudio. Para el análisis estadístico se utilizaron los paquetes computacionales SPSS v 11® y Epi-Info 2002®. Resultados: Las principales manifestaciones clínicas fueron las crisis convulsivas RM 4.2 (IC95% 2.40-9.67); se consideraron factores de riesgo: ingerir alimentos en vía pública RM 2.33 (IC95% 1.25-4.38) y tener antecedentes familiares de neurocisticercosis RM2.37 (IC95% 1.11-5.04), predominó en la población urbana, en la región centro norte de la República Mexicana.

OBJECTIVE: A case-control study was carried out to determine risk factors associated with neurocysticercosis in a public hospital in Mexico. METHODS: The following factors were analyzed: Socioeconomic, sociodemographic, hygiene, eating habits, and family history of neurocysticercosis in 85 cases and 170 controls. Cases were patients with cranial computed tomography images compatible with neurocysticercosis. The densitometric analysis (Hounsfield units) allowed us to distinguish normal tissue from physiological and pathological calcifications, and other types of lesions. Controls were admitted for neurocysticercosis but findings were not compatible with initial diagnosis. Statistical analysis was done using SPSS and Epi-info 2002. RESULTS: The most common clinical manifestation in patients was epileptic seizures OR=4.2 (IC 95% 2.40-9.67). With regards to risk factors, consumption of street food OR=2.33 (IC 95% 1.25-4.38), and family history of neurocysticercosis OR= 2.37 (IC 95% 1.11-5.04) were found to be associated with neurocysticercosis. In the north central region of Mexico where this study was performed, the disease was more frequent among urban populations.