[Group B streptococcal perinatal infection: A Global, Latin American and Mexican Overview]. / Infección perinatal por estreptococo del grupo B: panorama global, en América Latina y en México.

Group B streptococci (Streptococcus agalactiae) cause a number of infections in women during pregnancy and postpartum, such as urinary tract infection, chorioamnionitis and endometritis, consequently may affect the newborn. Group B streptococci is the most common cause of severe infections in newborns in developed countries. Studies on the epidemiology of group B streptococci infections in Latin America are still limited. This information is also unknown in Mexico, but studies carried out in the center of the country have found high rates of vaginal colonization in pregnant women and there are case series and case reports of newborns. Microbiological and molecular epidemiology studies in Mexico have shown that populations of group B streptococci have a clonal distribution and that there are clones with genetic and phenotypic characteristics of high virulence that appear to be responsible for most of perinatal pathology. However, the actual role of group B streptococci in perinatal pathology in Mexico is unknown. Consequently, whether to perform or not the screening for determining the group B streptococci colonization status in pregnant women, and the indication or not for intrapartum antibiotic prophylaxis to prevent neonatal group B streptococci infection in Mexico, are still controversial.

Gut microbiota in preterm infants receiving breast milk or mixed feeding.

BACKGROUND: Preterm birth is the leading cause of mortality in newborns, with very-low-birth-weight infants usually experiencing several complications. Breast milk is considered the gold standard of nutrition, especially for preterm infants with delayed gut colonization, because it contains beneficial microorganisms, such as Lactobacilli and Bifidobacteria. AIM: To analyze the gut microbiota of breastfed preterm infants with a birth weight of 1500 g or less. METHODS: An observational study was performed on preterm infants with up to 36.6 wk of gestation and a birth weight of 1500 g or less, born at the University Hospital Dr. José Eleuterio González at Monterrey, Mexico. A total of 40 preterm neonates were classified into breast milk feeding (BM) and mixed feeding (MF) groups (21 in the BM group and 19 in the MF group), from October 2017 to June 2019. Fecal samples were collected before they were introduced to any feeding type. After full enteral feeding was achieved, the composition of the gut microbiota was analyzed using 16S rRNA gene sequencing. Numerical variables were compared using Student's t-test or using the Mann-Whitney U test for nonparametric variables. Dominance, evenness, equitability, Margalef's index, Fisher's alpha, Chao-1 index, and Shannon's diversity index were also calculated. RESULTS: No significant differences were observed at the genus level between the groups. Class comparison indicated higher counts of Alphaproteobacteria and Betaproteobacteria in the initial compared to the final sample of the BM group (P < 0.011). In addition, higher counts of Gammaproteobacteria were detected in the final than in the initial sample (P = 0.040). According to the Margalef index, Fisher's alpha, and Chao-1 index, a decrease in species richness from the initial to the final sample, regardless of the feeding type, was observed (P < 0.050). The four predominant phyla were Bacteroidetes, Actinobacteria, Firmicutes, and Proteobacteria, with Proteobacteria being the most abundant. However, no significant differences were observed between the initial and final samples at the phylum level. CONCLUSION: Breastfeeding is associated with a decrease in Alphaproteobacteria and Betaproteobacteria and an increase of Gammaproteobacteria, contributing to the literature of the gut microbiota structure of very low-birth-weight, preterm.

Procalcitonin and C-reactive protein: markers in the early diagnosis of anastomotic leak.

OBJECTIVE: To determine the efficacy of serum procalcitonin (PCT) and C-reactive protein (CRP) in the early diagnosis of anastomotic leak (AL) in patients undergoing colorectal surgery. METHOD: Diagnostic test in a tertiary care hospital. Patients who did not have preoperative measurements of PCT and CRP were excluded. Those with postoperative infection not related to AL were eliminated. The diagnostic efficacy measures were sensitivity (Sn), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (LR+) and negative (LR-) likelihood ratios, and area under the receiver operating characteristic curve (AUROC). RESULTS: Thirty-nine patients were analyzed; six had AL (15.4%). PCT and CRP increased on the second postoperative day, only in patients with AL. The cut-off points at the second postoperative day were 1.55 ng/mL for PCT and 11.25 mg/L for CRP. The most efficacious test was PCR at second postoperative day (AUROC: 1.00; Sn: 100%; Sp: 96.7%; PPV: 85.7%; NPV: 100%; LR+: 33.0). CONCLUSIONS: CRP at second postoperative day was the most effective test in the early diagnosis of AL in patients undergoing colorectal surgery, with a cut-off point lower than that reported in the international literature.

OBJETIVO: Determinar la eficacia de la procalcitonina (PCT) y la proteína C reactiva (PCR) séricas en el diagnóstico de fuga anastomótica (FA) en los pacientes sometidos a cirugía colorrectal. MÉTODO: Prueba diagnóstica en un hospital de tercer nivel. Se excluyeron los pacientes que no tuvieron mediciones preoperatorias de PCT y PCR. Se eliminaron los que cursaron con infección posoperatoria no relacionada con FA. Las medidas de eficacia diagnóstica fueron sensibilidad (S), especificidad (E), valores predictivos positivo (VPP) y negativo (VPN), razones de verosimilitud positiva (RV+) y negativa (RV−), y área bajo la curva característica operativa del receptor (AUROC). RESULTADOS: Se analizaron 39 pacientes, de los cuales 6 (15.4%) tuvieron FA. La PCT y la PCR aumentaron al segundo día posoperatorio solo en los pacientes con FA. Los puntos de corte al día 2 fueron 1.55 ng/ml para PCT y 11.25 mg/l para PCR. La prueba más eficaz fue la PCR al día 2 (AUROC: 1.00; S: 100%; E: 96.7%; VPP: 85.7%; VPN: 100%; RV+: 33.0). CONCLUSIONES: La PCR en el segundo día posoperatorio fue la prueba más eficaz en el diagnóstico temprano de FA en los pacientes sometidos a cirugía colorrectal, con un punto de corte inferior a lo reportado en la literatura internacional.

Frontal penetrating arrow injury: A case report.

BACKGROUND: Penetrating arrow injuries of the head and neck are exceedingly rare in pediatric patients. This pathology has high morbidity and mortality because of the presence of vital organs, the airway, and large vessels. Therefore, the treatment and removal of an arrow is a challenge that requires multidisciplinary management. CASE SUMMARY: A 13-year-old boy was brought to the emergency room after an arrow injury to the frontal region. The arrowhead was lodged in the oropharynx. Imaging studies showed a lesion of the paranasal sinuses without compromising vital structures. The arrow was successfully removed by retrograde nasoendoscopy without complications, and the patient was discharged. CONCLUSION: Although rare, maxillofacial arrow injuries have high morbidity and mortality and require multidisciplinary management to preserve function and aesthetics.

p16INK4a and pRb expression in laryngeal squamous cell carcinoma with and without infection by EBV or different genotypes of HPV: a retrospective study.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) represents one of the principal tumors of the head and neck. Human papillomavirus (HPV) and Epstein-Barr virus (EBV) are considered risk factors for the development and the clinical prognosis of LSCC. High levels of p16INK4a are suggested as a surrogate marker of HPV or EBV infection in some head and neck tumors but in LSCC is still controversial. Furthermore, pRb expression may be considered an additional biomarker but it has not been clearly defined. This work aimed to compare the expression of pRb and p16INK4a as possible biomarkers in tumor tissues with and without infection by EBV or different genotypes of HPV from patients with LSCC. METHODS: Tumor samples from 103 patients with LSCC were previously investigated for the presence and genotypes of HPV using the INNO-LiPA line probe assay and for the infection of EBV by qPCR. p16 INK4a and pRb expression was assessed by immunohistochemistry. RESULTS: Of the 103 tumor samples, expression of p16INK4a was positive in 55 (53.4%) and of this, 32 (56.1%) were positive for HPV whereas 11 (39.3%) were EBV positive but both without a significantly difference (p > 0.05). pRb expression was positive in 78 (75.7%) and a higher frequency of this expression was observed in HPV negative samples (87.0%) (p = 0.021) and in high-risk HPV negative samples (85.2%) (p = 0.010). No difference was observed when comparing pRb expression and EBV infection status (p > 0.05). CONCLUSION: Our results support the suggestion that p16INK4a is not a reliable surrogate marker for identifying HPV or EBV infection in LSCC. On the other hand, most of our samples had pRb expression, which was more frequent in tumors without HPV, suggesting that pRb could indicate HPV negativity. However, more studies with a larger number of cases are required, including controls without LSCC and evaluating other molecular markers to determine the real role of p16INK4a and pRb in LSCC.

Common bile duct diameter by age groups in adult patients without bile duct pathology.

OBJECTIVE: To determine the average value of the diameter of the common bile duct by age group in adult patients without bile duct pathology. METHOD: A cross-sectional, observational, descriptive and prospective study in adults without bile duct pathology who underwent abdominal ultrasound. The internal diameter of the common bile duct was measured after questioning. In the descriptive analysis, absolute frequencies, percentages, mean and standard deviation were used in the inferential Student's t test and Pearson's correlation. RESULTS: 608 patients without bile duct pathology were included, the mean diameter of the common bile duct was 4.04 ± 1.11 mm; with a minimum of 1.9 mm and a maximum of 8.8 mm. The mean for the population under 30 years was 3.8 ± 0.87, for the 30-39 years group it was 4.27 ± 0.89, for the 40-49 years group it was 4.39 ± 0.83, for the 50-59 years 4.86 ± 1, for the 60-69 years group it was 5.4 ± 0.95, and for those over 70 years it was 6.9 ± 0.8. CONCLUSIONS: The diameter of the common bile duct in adult patients without biliary pathology is greater at older age.

OBJETIVO: Determinar el valor promedio del diámetro del conducto colédoco por grupos de edad en pacientes adultos sin patología de la vía biliar. MÉTODO: Estudio transversal, observacional, descriptivo y prospectivo en adultos sin patología de vía biliar que acudieron a la realización de ultrasonografía abdominal. Se realizó la medición del diámetro interno del colédoco después de un interrogatorio. En el análisis descriptivo se utilizaron frecuencias absolutas, porcentajes, media y desviación estándar; en el inferencial, prueba t de Student y correlación de Pearson. RESULTADOS: Se incluyeron 608 pacientes sin patología de vía biliar. La media del diámetro del colédoco fue de 4.04 ± 1.11 mm, con un mínimo de 1.9 mm y un máximo de 8.8 mm. La media para la población menor de 30 años fue de 3.84 ± 0.87, para el grupo de 30-39 años fue de 4.27 ± 0.89, para el de 40-49 años fue de 4.39 ± 0.83, para el de 50-59 años fue de 4.86 ± 1, para el de 60-69 años fue de 5.4 ± 0.95 y para el de mayores de 70 años fue de 6.9 ± 0.8. CONCLUSIONES: El diámetro del conducto colédoco en pacientes adultos sin patología biliar es mayor conforme avanza la edad.

[Prevalencia y genotipos del virus del papiloma humano en muestras de tejido laríngeo de pacientes con cáncer de laringe del noreste de México]. / Prevalence and genotypes of the human papillomavirus in laryngeal tissue samples of patients with laryngeal cancer from Northeastern Mexico.

ANTECEDENTES: El cáncer de laringe representa el 21.7% de las neoplasias malignas de vías aerodigestivas superiores. La prevalencia del virus del papiloma humano (VPH) en el cáncer de laringe oscila entre el 0 y el 80%. MÉTODO: Se incluyeron 112 muestras de tejido laríngeo de pacientes con cáncer de laringe. Se amplificó el ADN y se analizó la presencia y el genotipo del VPH mediante hibridación reversa (INNO-LiPA®). Se realizaron pruebas de ji cuadrada, Fisher y t de Student no pareada. RESULTADOS: Se incluyeron muestras de 107 hombres (95.5%) y 5 mujeres (4.5%), con una edad de 65.3 ± 10.1 años, con antecedente de tabaquismo 108 (96.4%), alcoholismo 9 (8.0%) y carcinoma epidermoide moderadamente diferenciado queratinizante 96 (85.7%). Se identificó VPH en 60 (53.5%), VPH-11 en 51 (45.5%), VPH-52 en 27 (24.1%), VPH-16 en 9 (8.0%), VPH-45 en 3 (2.6%) y coinfección por más de un genotipo en 31 (27.6%). No hubo diferencia entre pacientes con y sin infección por VPH en cuanto a edad, sexo, localización, diagnóstico histopatológico, tabaquismo ni alcoholismo (p > 0.05). CONCLUSIONES: La prevalencia de infección por VPH en el cáncer de laringe fue del 53.5%, con coinfección por más de un genotipo en el 27.6%. El genotipo más frecuente fue el VPH-11, tipo de bajo riesgo, seguido por el VPH-52, de alto riesgo oncogénico. BACKGROUND: Laryngeal cancer represents 21.7% of malignancies of the upper aerodigestive tract. The prevalence of the Human Papillomavirus (HPV) in laryngeal cancer ranges 0 to 80%. METHODS: We included 112 laryngeal tissue samples obtained from patients with laryngeal cancer. DNA was extracted and amplified by PCR. HPV presence and genotype were analyzed by the reverse hybridization INNO-LiPA® assay. Chi-square, Fisher's and unpaired Student t tests were used. RESULTS: Samples from 107 male (95.5%) and 5 female patients (4.5%) were evaluated, aged 65.3±10.1 years, 108 with smoking history (96.4%), 9 with alcoholism history (8.0%), and in 96 the histological diagnosis was moderately differentiated keratinizing squamous cell carcinoma (85.7%). HPV was detected in 60 samples (53.5%), HPV-11 in 51 (45.5%), HPV-52 in 27 (24.1%), HPV-16 in 9 (8.0%), HPV-45 in 3 (2.6%), and coinfection by more than one genotype in 31 (27.6%). There was no difference between patients with and without HPV infection with respect to age, sex, tumor location and histology, smoking and alcoholism history (p>0.05). CONCLUSIONS: The prevalence of HPV infection in laryngeal cancer was 53.5% with coinfection with more than one genotype in 27.6%. The most frequent genotype was HPV-11, an oncogenic low-risk genotype, followed by HPV-52, a high-risk genotype.

Infection and coinfection by human papillomavirus, Epstein-Barr virus and Merkel cell polyomavirus in patients with squamous cell carcinoma of the larynx: a retrospective study.

BACKGROUND: Human papillomavirus (HPV) is recognized as an important risk factor for laryngeal carcinogenesis. Although HPV-16 and 18 have been strongly implicated, the presence of other high-risk HPV (HR-HPV) genotypes or the coinfection with Epstein-Barr virus (EBV) or Merkel cell polyomavirus (MCPV) may increase the risk, but their etiological association has not been definitively established. METHODS: We characterized the genotype-specific HPV and the frequency of EBV and MCPV infections through the detection of their DNA in 195 laryngeal specimens of squamous cell carcinoma (SCC) histologically confirmed. RESULTS: HPV DNA was detected in 93 (47.7%) specimens. HPV-11 was the most frequent with 68 cases (73.1%), and HPV-52 was the most frequently HR-HPV found with 51 cases, which corresponds to 54.8% of all HPV-positive specimens. EBV DNA was detected in 54 (27.7%) tumor tissue specimens of which 25 (46.3%) were in coinfection with HPV. MCPV DNA was detected only in 11 (5.6%) cases of which 5 (45.4%) were in coinfection with an HR-HPV. No association between the presence of DNA of the three examined viruses and the patient smoking habits, alcohol consumption, age, the keratinization status, differentiation grade, or localization of the tumor in the larynx were found. DISCUSSION: HPV-52 was the most prevalent HR-HPV, which may suggest that this and other genotypes in addition to HPV-16 and 18 could be considered for prophylaxis. However, further studies including non-cancer larynx cases and the evaluation of other molecular markers and viral co-infection mechanisms are needed to determine the role of the different HR-HPV genotypes, EBV, and MCPV in the etiology of SCC of the larynx.

Mutations Related to Antiretroviral Resistance Identified by Ultra-Deep Sequencing in HIV-1 Infected Children under Structured Interruptions of HAART.

Although Structured Treatment Interruptions (STI) are currently not considered an alternative strategy for antiretroviral treatment, their true benefits and limitations have not been fully established. Some studies suggest the possibility of improving the quality of life of patients with this strategy; however, the information that has been obtained corresponds mostly to studies conducted in adults, with a lack of knowledge about its impact on children. Furthermore, mutations associated with antiretroviral resistance could be selected due to sub-therapeutic levels of HAART at each interruption period. Genotyping methods to determine the resistance profiles of the infecting viruses have become increasingly important for the management of patients under STI, thus low-abundance antiretroviral drug-resistant mutations (DRM's) at levels under limit of detection of conventional genotyping (<20% of quasispecies) could increase the risk of virologic failure. In this work, we analyzed the protease and reverse transcriptase regions of the pol gene by ultra-deep sequencing in pediatric patients under STI with the aim of determining the presence of high- and low-abundance DRM's in the viral rebounds generated by the STI. High-abundance mutations in protease and high- and low-abundance mutations in reverse transcriptase were detected but no one of these are directly associated with resistance to antiretroviral drugs. The results could suggest that the evaluated STI program is virologically safe, but strict and carefully planned studies, with greater numbers of patients and interruption/restart cycles, are still needed to evaluate the selection of DRM's during STI.

[Intra and inter-observer reliability of electroencephalogram interpretation in pediatric patients with neurological alterations]. / Confiabilidad intra e interobservador de la lectura del EEG en pacientes pediátricos con alteraciones neurológicas.

BACKGROUND: Interpreting an electroencephalogram (EEG) is a subjective process which involves various obstacles to reach an agreement. If the interobserver agreement of a diagnostic process is poor, that process cannot be considered accurate. The aim of this study was to evaluate the intra and interobserver agreement of the EEG reading in pediatric patients. METHODS: 108 EEGs of children under 16 years of age were included. EEGs were interpreted by two pediatric neurologists. Observer number one performed three readings on three different moments to assess intraobserver agreement, while the third reading was blind for the diagnosis. Interobserver agreement was assessed with a single blind reading for the diagnosis of the two observers. Agreement was measured with the kappa index. RESULTS: Intraobserver agreement to differentiate if the EEG was normal or abnormal was substantial when the three readings were compared (kappa index: 0.66-0.78). The highest agreement rate corresponded to the readings of those who had knowledge of the diagnosis. The interobserver agreement assessing between abnormal or normal EEG was slight (k = 0.12). CONCLUSIONS: Since the EEG is a subjective interpreter dependent study, it is necessary to establish a consensus to standardize the criteria for its interpretation in order to increase the interobserver agreement.

Introducción: interpretar un electroencefalograma (EEG) es un proceso subjetivo que involucra diversos obstáculos para llegar a un acuerdo. Si la concordancia interobservador de un proceso diagnóstico es pobre, ese proceso no puede considerarse certero. El objetivo de este estudio fue valorar la concordancia intra e interobservador de la lectura del EEG en pacientes pediátricos. Métodos: se incluyeron 108 EEG de niños menores de 16 años, los cuales fueron interpretados por dos neurólogos pediatras. Para evaluar la concordancia intraobservador, el observador número uno realizó tres lecturas en tres tiempos distintos; la tercera lectura fue ciega para el diagnóstico. La concordancia interobservador fue evaluada por medio de una lectura ciega para el diagnóstico de los dos observadores. Se midió el índice kappa. Resultados: la concordancia intraobservador para diferenciar si el EEG era normal o anormal fue substancial en las tres lecturas (kappa 0.66-0.78). La concordancia más alta correspondió a las lecturas con conocimiento del diagnóstico. La concordancia interobservador para evaluar si el EEG era anormal o normal fue leve (k = 0.12). Conclusiones: el EEG es un estudio subjetivo que depende del interpretador. Es necesario establecer un consenso para uniformar los criterios para su interpretación y así aumentar la concordancia.

Molecular detection of cryptic Y-chromosomal material in patients with Turner syndrome.

A systematic search for a hidden Y-chromosome mosaicism, in Turner syndrome (TS) patients is justified by the evaluation of the risk of development of germ cell tumors. In this study, we analyzed cryptic Y-chromosome derivatives by polymerase chain reaction (PCR) coupled with fluorescence in situ hybridization (FISH) using Y-specific sequences in patients with TS, and validated this methodology. Unrelated patients with TS (n=32) of Mexican mestizo ethnic origin were diagnosed using cytogenetic analysis. Clinical assessment, endocrine evaluation, karyotyping, FISH and PCR analysis of the Y-chromosomal loci were performed. We found that 9.4% (3 out of 32) patients with TS had Y-chromosome material. Two patients showed Y-chromosome by conventional cytogenetics. One patient had no Y-chromosome by initial karyotyping (45, X) but was positive by lymphocyte PCR DNA analysis of the Y-sequence-specific sex-determining region Y (SRY) gene. Our results suggest that the detection of the Y-chromosome material using sensitive methods, such as PCR coupled with FISH, should be carried out in all patients with TS and should not be limited to TS patients with cytogenetically identifiable Y-chromosome and/or virilization.

Expression of CCR5, CXCR4 and DC-SIGN in Cervix of HIV-1 Heterosexually Infected Mexican Women.

BACKGROUND: A number of studies have demonstrated that receptor and co-receptor expression levels which may affect viral entry, promoting cervical HIV infection. The aim was to evaluate the expression levels of CCR5, CXCR4and DC-SIGN mRNA in a sample of heterosexually HIV infected Mexican women. METHODS: We enrolled twenty-six HIV heterosexual infected women attending a local infectious diseases medical unit.RNA was isolated from the cervix and gene expression analysis was performed using real-time PCR. RESULTS: Expression rates for mRNA of CCR5 (median 1.82; range 0.003-2934) were higher than those observed for CXCR4 (0.79; 0.0061-3312) and DC-SIGN (0.33; 0.006-532) receptors (p < 0.05). A high correlation was found between the mRNA expression levels of these three receptors (rs = 0.52 to 0.85, p < 0.01). CONCLUSION: Levels of expression of the tested chemokine receptors in the cervix are different from each other and alsovary from woman to woman, and seem to support the suggestion that chemokine receptor expression in genital tissues may be playing a role in the HIV transmission.

Drug resistance mutations during structured interruptions of HAART in two HIV-1-infected children.

Information concerning structured treatment interruptions (STI) of the Highly Active Antiretroviral Therapy (HAART) and their risk for selecting antiretroviral drug resistance in children is scarce. In this study, we searched for antiretroviral drug resistance mutations at the end of five viral rebounds of two children with HIV and a chronically undetectable viral load (VL) who underwent an STI program. The HAART was interrupted for 4 weeks and then restarted and continued for 12 weeks for three cycles. VL, CD4+/CD8+ lymphocytes, and clinical status were evaluated at the end of each STI and at 6 and 12 weeks after HAART was resumed. Treatment of both the patients based on zidovudine+lamivudine+ritonavir remained identical during the study. The reverse transcriptase (RT)- and protease (PR)-coding regions were sequenced at the end of each viral rebound. One patient experienced progressively lower viral rebounds (269000-31300 at the first and third rebounds, respectively), while the other patient did not experience such a reduction, and the VL of both the patients fell to undetectable levels during therapy. In the five viral rebounds examined, no mutations for resistance to protease inhibitors (PIs) were found and the analysis indicated susceptibility to all PIs currently in clinical use. Although the mutation K103R associated with non-nucleoside reverse transcriptase inhibitor resistance was found in two viral rebounds of one patient, the analysis indicated the absence of resistance to RT inhibitors. As no mutation related to antiretroviral drug resistance was found, our results suggest that the STI program evaluated may have a low risk of selecting antiretroviral drug resistance. Nevertheless, further studies evaluating larger cohorts over longer periods are required before definitive conclusions about the safety of STI of HAART in children may be drawn.