Prognostic importance of DNA from human papillomavirus in patients with oral squamous cell carcinoma

Background: Survival of patients with oral squamous cell carcinoma (OSCC) is generally low, with the likelihood of locoregional recurrence or disease progression (LR/DP). Knowledge of prognostic factors for survival is key to achieving an understanding and increased survival. The present study aimed to identify prognostic factors for patients with OSCC, especially the presence of DNA from human papillomavirus (HPV). Material and Methods: Retrospective cohort study including 119 patients with OSCC treated at the National Cancer Institute in Mexico City (2009-2013). Clinical information was obtained from patient records including LR/DP. Formalin-fixed, paraffin-embedded tissues were obtained and used for detecting DNA from different types of HPV. Potential prognostic factors for Overall Survival (OS) were analyzed using the Cox proportional hazards model. Results: After model adjustment, factors associated with longer OS were a pre-treatment platelet count above 400,000/mm3 (HR=0.09, p=0.026) and response to primary treatment (HR=0.26, p=0.001). HPV DNA was present in 23 (19.3%) of the patients and importantly, type 16 found in 19 of them. Although survival of HPV-positive patients was longer, difference was not significant. However, among patients with LR/DP, HPV positivity was significantly associated with increased survival (HR=0.23, p=0.034). Importantly, survival was significantly different for HPV-positive patients with LR/DP > 6 months (HR=0.20, p=0.002), had higher absolute lymphocyte count at start of treatment (HR=0.50, p=0.028) or had local rescue treatment (HR=0.24, p=0.019). Conclusions: Although HPV positivity was not associated with a longer OS of OSCC patients, a better prognosis was significantly associated with HPV positivity and recurring or progressing disease, particularly with HPV type 16.(AU)

Body Mass Index and Dental Caries, a Five-Year Follow-Up Study in Mexican Children.

There are conflicting reports on a possible association between body mass index (BMI) and caries. Given the ongoing worldwide increase in obesity, we undertook a 5-year follow-up study on 201 Mexican schoolchildren to analyse their BMI and dental caries experience. The children's weight and height were recorded, and their BMI was calculated using the WHO tables. Decayed, missing, and filled surfaces in both dentitions (dmf/DMFS) were assessed annually according to WHO criteria by two calibrated researchers (Kappa value 0.92 p < 0.001). The means, standard deviation, an ANOVA, and Student's t-test were calculated to analyse the relationship between the variables. At baseline, the children had an average of 6.5 ± 0.5 years, a BMI of 17.2 ± 3.1 (CI95% 16.8-17.6). Their weight's classifications were 61% normal, 19% obese, 17% overweight, and 3% showed thinness. At the end of the study, their BMI were 20.6 ± 4.4 (CI95% 19.8-21.5), 53% normal, 15% obese, 30% overweight, and 2% thin. The children's dmfs decreased from 5.8 ± 9.2 to 1.8 ± 3.4 and the DMFS increased from 0.07 ± 05 to 1.4 ± 2.3. In this population based on a 5-year follow-up, caries prevalence and incidence were not significantly associated with the BMI. However, schoolchildren with malnutrition had the highest caries indexes.

Stability of unstimulated and stimulated whole saliva flow rates in children.

OBJECTIVE: To analyze the stability of the unstimulated saliva flow rate (USFR) and the stimulated saliva flow rate (SSFR) in children followed from age 7 to 12 years old. METHODS: Longitudinal study. Whole saliva samples were collected from school children (50 girls and 50 boys). Forty-four girls and 32 boys remained in this cohort for 6 years (dropout rate 24%). Variables that could influence USFR or SSFR patterns were analyzed in a repeated-measures manova. RESULTS: Over a 6-year follow-up, the children's USFR ranged from 0.41 to 0.46 mL/min in the initial and final observation, respectively, and showed no significant differences (P = 0.4455) during the follow-up. The children consistently belonged to one of three distinct SSFR groups (P < 0.0001). A repeated-measures manova model showed that USFR and SSFR were not associated with sex, body mass index, or indoor temperature during sampling. CONCLUSION: These results indicate that USFR and SSFR patterns were stable from 7 to 12 years old. This finding may be useful in oral health prevention or treatment and in the search for biomarkers in saliva for screening or diagnostic purposes.

The PGRS Domain from PE_PGRS33 of Mycobacterium tuberculosis is Target of Humoral Immune Response in Mice and Humans.

The PE_PGRS33 protein is a member of the PE family, which encompasses the PE and the PE_PGRS subfamilies. Among PE_PGRS's, this protein is one of the most studied antigens and its immunomodulatory properties are influence by both PE and PGRS domains. However, the contribution of these domains to the host immune recognition of the PE_PGRS33 protein and their potential role in latent tuberculosis infection in humans is still unknown. In this study, the immunogenic properties of the complete PE_PGRS33 protein and each domain separately were evaluated in BALB/c mice and latent tuberculosis infected (LTBI) humans. In mice, PE_PGRS33 and its domains induced similar antibody production and secretion of IFN-γ. PE_PGRS33 and the PE domain stimulated higher CD4(+) and CD8(+) T-cell proliferation compared to the PGRS domain. This demonstrated that the principal difference in the immune recognition of the domains is the higher activation of T-cell subpopulations involved in the control of tuberculosis. In humans, the secretion of IFN-γ in response to PE_PGRS33 was detected in both LTBI and in non-infected vaccinated individuals. The same was observed for antibody response, which targets epitopes located in the PGRS domain but not in the PE domain. These observations suggest that T and B cell responses to PE_PGRS33 are induced by BCG vaccination and can be maintained for many years in non-infected individuals. This also indicates that the IFN-γ response detected might not be associated with latent tuberculosis infection. These results contribute to the elucidation of the role of the PE_PGRS33 protein and its PE and PGRS domains in the immune response against Mycobacterium tuberculosis.

Malocclusion and TMJ disorders in teenagers from private and public schools in Mexico City.

OBJECTIVE: To identify, among Mexican teenagers from public and private schools, the frequency, severity of malocclusion and orthodontic treatment needs, and their possible association with temporomandibular joint disorders. MATERIAL AND METHODS: Fifteen-year-old students were recruited from public and private schools. Clinical findings were registered as follows: oral hygiene status with the Oral Hygiene Index-Simplified, malocclusion using the Dental Aesthetic Index (DAI), and TMJ disorders following WHO criteria. Negative binomial and logistic regression models were constructed for data analysis. RESULTS: A total of 249 fifteen-year old students were included in the study (118 female 47.4%). 68% had a DAI score ≤ 25 (minor or no occlusal anomalies), 18% scored 26-30 (mild anomalies), 7% scored 31-35 (evident anomalies), and 6% scored ≥ 36 (major malocclusion). The most frequent anomalies were dental crowding in 50%, maxillary dental irregularity in 44.6%, mandible irregularity in 41.2% and excessive maxillary overjet in 37.8%. Among the students, 26.1% had clicking/muscle or TMJ pain, of these 12.3% showed pain during palpation. OHI-S > 1 was found in 34% of the participants. The negative binomial model showed an association between DAI score and TMJ disorders (P=0.041). Also the logistic regression model showed an association between malocclusion (DAI>25) and TMJ disorders (OR=2.58, p=0.002). Malocclusion was associated also with poor oral hygiene (OR=1.65, p=0.007), and with attendance to public schools (OR=1.97, p=0.039). CONCLUSIONS: TMJ disorders and DAI scores were significantly associated. Screening/Diagnostic programs for orthodontic and TMJ-disorders are needed, to identify and offer treatment to teenagers with major malocclusion and TMJ/muscle pain.

Clinical, salivary, and bacterial markers for caries risk assessment in schoolchildren: a 4-year follow-up.

BACKGROUND: In Mexico, there is a high prevalence of dental caries and large groups of children still show extensive untreated dental damage. AIM: This study aims to evaluate, in a cohort of 6-year-old Mexican children, the relationship between caries increment at 4 years and the following caries risk markers: fissure morphology, caries experience, salivary flow rate, Snyder test results, and mutans and lactobacilli counts. DESIGN: To predict new caries lesions in 110 schoolchildren, clinical, salivary, and bacteriological caries risk markers were used, including fissure morphology, caries experience, salivary flow rate, Snyder test, and Streptococcus mutans and lactobacilli counts. To determine the validity of these markers, the baseline data were compared with the caries increment after 4 years. RESULTS: The risk model's capacity to predict caries was moderate (specificity 79.6% and sensitivity 78.6%). Caries experience (P = 0.0001), Snyder test (P = 0.002), and fissure morphology (P = 0.024) had the strongest association with caries increment. Salivary flow rate, lactobacilli, and S. mutans counts did not contribute significantly to the prediction of caries lesions in these children. CONCLUSION: In addition to the initial caries experience, tooth morphology and Snyder test proved to be useful predictors for caries. These three risk markers may be particularly useful in targeting caries prevention efforts in developing countries.

Estreptococos cariogénicos predominantes, niveles de infección e incidencia de caries en un grupo de escolares: estudio exploratorio / Predominant cariogenic Streptococcus, infection level and caries incidence in a group of schoolchildren: en exploratory study

Objetivo: Estudiar la distribución de estreptococos cariogénicos, niveles de infección y su asociación con la incidencia de caries. Metodología: Sesenta escolares (8 y 10 años), seguidos durante 18 meses. Se registró caries, niveles bacterianos de estreptococos en muestras de placa; por medio de análisis bioquímico se hizo la tipificación bacteriana, se calculó la incidencia de caries en el molar muestreado. Resultados: El 80 por ciento de los estreptococos correspondieron al grupo mutans (40 por ciento S. sobrinus, 32 por ciento S. mutans, 5 por ciento S. rattus y 3 por ciento S. cricetus). El 20 por ciento restante correspondió a otros estreptococos (S. salivarius, S. mitis y S. sanguis). El 55 por ciento de los niños presentó conteos 105 ufc/mL en placa y el 30 por ciento desarrolló caries en el molar estudiado. Un modelo de regresión logística múltiple de pasos sucesivos mostró asociación entre la bacteria predominante y los niveles de infección (P < 0.01). No se demostró asociación entre bacteria predominante e incidencia de caries (P > 0.05). Sin embargo con el mismo modelo ponderado según los niveles de infección, mostró una asociación significativa (P < 0.0018). Conclusión: La asociación de cepas de estreptococos con la incidencia de caries en niños es dependiente del nivel de infección

Línea basal de factores de riesgo a caries en escolares / Baseline risk factors for caries in elementary school aged children

Resumen Introducción. El objetivo de este reporte es presentar las asociaciones iniciales de los factores de riesgo inmutable (género y edad) y los factores de riesgo biológico en la línea basal de un modelo diagnóstico de predicción de riesgo a caries. Material y métodos. Se registró en 110 niños entre 6 y 7 años que asisten a 2 escuelas públicas de la Ciudad de México, los siguientes indicadores: clínicos o dentales (morfología, índices de caries y lesiones activas); salivales (flujo salival estimulado y prueba de Snyder); y bacteriológicos (cuentas de Lactobacillus y Streptococcus mutans en saliva y placa dentobacteriana). Resultados. La experiencia de caries se asoció con los siguientes indicadores: morfología, prueba de Snyder y 3 de los indicadores bacteriológicos (ANOVA). Los puntos de corte de riesgo más altos en esta muestra fueron: conteo de S. mutans en saliva (0.96), prueba de Snyder (0.61) y experiencia de caries (0.58). Se usaron 3 modelos de ANOVA con y sin ponderación de los factores de riesgo inmutables, identificando que los indicadores: morfología, lesiones de caries activa y conteo de Lactobacillus salivales son los factores que se asocian de manera significativa con la experiencia de caries en los 3 modelos. Conclusión. El modelo que mejor explica la caries es el que pondera el género R² 62%.

Introduction. The objective of this report is to present the initial associations between age and gender and the biological risk factors at the baseline of a diagnostic model to predict the risk for caries. Material and methods. The following indicators were registered in 110 elementary school children between 6-7 years of age, who attended to 2 public schools in Mexico City: dental (morphology, caries indexes and active caries lesions); salivary (stimulated flow rate and Snyder test); and bacteriological (Streptococcus mutans and Lactobacillus counts in plaque and saliva). Results. Caries experience was associated with dental morphology, Snyder test and with 3 of the bacterial indicators (ANOVA). When the biological risk factors were analyzed by the cut off point for risk, the following variables were identified: salivary S. mutans counts (0.96), Snyder test (0.61) and history of caries (0.58) as highest. Three models of ANOVA were used with/without weighted immutable risk factors, identifying that the indicators: morphology, active lesions and salivary Lactobacillus counts as the factors significantly associated with the caries experience in the 3 models. Conclusion. The model that best explains the risk for caries is the 1 that weighted for gender R² 62%.

Sterilization of heat-resistant instruments with infrared radiation.

OBJECTIVE: To evaluate the lethality profile of an infrared radiation (IR) prototype sterilizer. METHOD: Simulated use and D value tests were conducted with Bacillus subtilis spores American Type Culture Collection-9372. A spore suspension (1.06 +/- 0.03 x 10(6)) in 5% bovine serum albumin was air dried on stainless steel instruments. IR cycles were completed and the instruments were immersed in tryptic soy broth for 120 hours at 37 degrees C. Direct enumeration of survivors was performed to evaluate IR death. Instrument loads contained carriers laden with spores (1.06 +/- 0.3 x 10(6)). The spores were seeded on tryptic soy agar and survivors were counted after 120 hours of incubation at 37 degrees C. RESULTS: All instruments exposed to IR (n = 50) were culture negative. In contrast, all unprocessed instruments (n = 30) showed B. subtilis growth. The prototype's D value was 0.56, and the death rate's slope was -1.76 (r = -0.99741; P < .0001). The 10(6) sterility assurance level was reached after 8 minutes and 40 seconds of exposure, from cold start. CONCLUSIONS: IR destroys B. subtilis spores. Instrument sterilization with IR may provide another technology for infection control.

El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico dental / Benzalkonium chloride is unacceptable to sterilize o disinfect medical or dental instruments

Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB) con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM). Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl) sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37§C. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado). El glutaraldehído al 2 por ciento destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

Verificación biológica de los ciclos de esterilización / Biologic verification of the sterilization cycles

En 55 meses se realizaron 2,920 pruebas con IB en 91 consultorios dentales de la República Mexicana. El 71.4 por ciento (n=2,084) de los ciclos de esterilización fue en vapor de agua a presión, el 9.4 por ciento (n=274) vapor químico a presión, y el 19.2 por ciento (n=562) en calor seco. El 67.6 por ciento (n=1974) de las pruebas se realizó en forma semanal, el 16.9 por ciento (n=493) quincenal y el 15.5 por ciento (n=453) mensual. Se detectaron fallas en 7.6 por ciento (n=223) de todos los ciclos de esterilización. El 7.5 por ciento (n=156) en vapor de agua a presión, el 7.7 por ciento (n=21) en vapor químico a presión y el 8.2 por ciento (n=46) de los ciclos de calor seco. Todos los métodos de esterilización empleados fallaron con frecuencias similares (X = 0.307, P mayor 0.8)

Análisis de algunos indicadores biológicos disponibles comercialmente en México / Analysis of some biological markers available in Mexico

El objetivo de esta investigación fue comparar, mediante las pruebas descriptas en la farmacopea de los Estados Unidos Mexicanos, diversos indicadores biológicos (IB) contra las cepas de Bacillus subtilis 9372 y B. stearothermophilus 7953 del catálogo de la ATCC. Se observó que las cepas ATCC y los IB provenientes de fabricantes extranjeros cumplen con las características morfológicas, bioquímicas y de cultivo estipuladas por la FEUM. De hecho, los fabricantes extranjeros establecen que sus productos están elaborados con las cepas ATCC. Por el contrario, algunos IB de fabricación nacional no son elaborados con las cepas ATCC. El aislado de B. subtilis, para verificar la esterilización por calor seco, se comporta como la cepa ATCC-9372, mientras que los indicadores para vapor a presión, supuestamente B. stearothermophilus, se comportan como B. subtilis sin pigmento. El fabricante de IB deberá documentar la veracidad de sus afirmaciones y proporcionar información que permita al usuario la selección de productos adecuados. Las instrucciones de uso deberán ser precisas

Inmunización contra la caries / Inmunization against caries

Hay dos grandes líneas de pensamiento sobre la etiología de la caries dental. Mientras que algunos afirman que se debe a un desequilibrio de la microflora bucal normal, como consecuencia de un alto consumo de carbohidratos, la mayoría de los investigadores dentales coincide en que la caries es una enfermedad infecciosa y transmisible. El Streptococus mutans (caries) coloniza la cavidad bucal del ser humano sólo después de la erupción dentaria, pues para crecer requieren de superficies duras. Su identificación por la tipificación de sus bacteriocinas y plásmidos señala que en el ser humano, la madre es el reservorio primario de la infección y el contagio ocurre si su saliva, o la de otro individuo con caries, llega a la boca del infante. Existen dos estrategias globales para el desarrollo de vacunas contra la caries. Dos grupos de investigadores británicos exploran la inmunización por vía subcutánea, mientras que las vacunas administrables por vía entérica están bajo estudio en cuatro laboratorios de los Estados Unidos, además grupos suecos, franceses y japoneses participan en la búsqueda de una vacuna eficaz; se anotan los avances en cuanto a la inmunización parenteral, inmunización gingival, inmunización pasiva local, vacunas entéricas y presentación de antígenos como partículas y uso de adyuvantes