Differentially methylated CpG regions analyzed by PCR-high resolution melting for monozygotic twin pair discrimination.

Discrimination between monozygotic (MZ) twins is a forensic limitation when using conventional DNA profiling techniques for human identification. Recent works based on epigenetics seem to open a new way to solve this issue due to methylation status of MZ twins change during their lifetime. Methylation analysis through BeadChip platforms allows the study up to 850 K CpG sites revealing that numerous differential methylation regions exist between MZ twins. However, this methodology is difficult to implement in forensic laboratories. On the contrary, PCR-HRM (High Resolution Melting) technology is one of the easiest methods for analyzing DNA methylation and it has been capable to discriminate between MZ twins. The purpose of this study is to contribute with new differential methylation regions in MZ twins to those that have been previously studied through PCR-HRM. Here, we have selected 6 CpG regions located at the ITGA2B, ASPA, PDE4C, ZIC5, USP11 and NOP14 loci that have shown methylation status variation during lifetime. The study has been carried out from saliva-derived DNA of 18 MZ twin pairs. The most discriminating regions were those located at ITGA2B, ASPA and ZIC5 loci showing significant within-pair differences in 44.4% of the cases. Non evidences of relation between age and significant differences between MZ twins were found, although the 50% of MZ twin pairs were discrimnated in the oldest age range (59-66 years old). These results support the use of these regions to increase the number of epigenetics age-related markers available to discriminate between MZ twins in a pair by PCR-HRM in forensic laboratories.

Obesity does not increase the risk of chronic low back pain when genetics are considered. A prospective study of Spanish adult twins.

BACKGROUND CONTEXT: Obesity is commonly investigated as a potential risk factor for low back pain (LBP); however, current evidence remains unclear. Limitations in previous studies may explain the inconsistent results in the field, such as the use of a cross sectional design, limitations in the measures used to assess obesity (eg, body mass index-BMI), and poor adjustment for confounders (eg, genetics and physical activity). PURPOSE AND DESIGN: To better understand the effects of obesity on LBP, our aim was to investigate in a prospective cohort whether obesity-related measures increase the risk of chronic LBP outcomes using a longitudinal design. We assessed obesity through measures that consider the magnitude as well as the distribution of body fat mass. A within-pair twin case-control analysis was used to control for the possible effects of genetic and early shared environmental factors on the obesity-LBP relationship. PATIENT SAMPLE AND OUTCOME MEASURES: Data were obtained from the Murcia Twin Registry in Spain. Participants were 1,098 twins, aged 43 to 71 years, who did not report chronic LBP at baseline. Follow-up data on chronic LBP (>6 months), activity-limiting LBP, and care-seeking for LBP were collected after 2 to 4 years. RISK FACTORS: The risk factors were BMI, percentage of fat mass, waist circumference, and waist-to-hip ratio. METHODS: Sequential analyses were performed using logistic regression controlling for familial confounding: (1) total sample analysis (twins analyzed as independent individuals); (2) within-pair twin case-control analyses (all complete twin pairs discordant for LBP at follow-up); and within-pair twin case-control analyses separated for (3) dizygotic and (4) monozygotic twins. RESULTS: No increase in the risk of chronic LBP was found for any of the obesity-related measures: BMI (men/women, odds ratio [OR]: 0.99; 95 % confidence interval [CI]: 0.86-1.14), % fat mass (women, OR: 0.87; 95% CI: 0.66-1.14), waist circumference (women, OR: 0.98; 95% CI: 0.74-1.30), and waist-to-hip ratio (women, OR: 1.05; 95% CI: 0.81-1.36). Similar results were found for activity-limiting LBP and care-seeking due to LBP. After the adjustment for genetics and early environmental factors shared by twins, the non-significant results remained unchanged. CONCLUSIONS: After 2 to 4 years, obesity-related measures did not increase the risk of developing chronic LBP or care-seeking for LBP with or without adjustment for familial factors such as genetics in Spanish adults.

Prevalencia de VIH entre las personas de ocho ciudades españolas que se realizan la serología tras exposiciones heterosexuales, 1992-2003 / HIV prevalence among individuals having had serology performed in eight spanish cities following heterosexual exposure, 1992-2003

Fundamento: La epidemia de infecciones por el virus de la inmunodeficiencia humana (VIH) en España se caracterizó durante los primeros años por el predominio de casos en personas usuarias de drogas inyectadas, pero en la actualidad todo parece apuntar a un progresivo predominio de la transmisión sexual. El objetivo de este trabajo es describir la evolución en la prevalencia de VIH en varios grupos de población heterosexual y caracterizar las situaciones en las que se produjeron las infecciones. Métodos: Estudio descriptivo de las personas que se realizaron la prueba por primera vez en nueve centros de diagnóstico de VIH entre 1992 y 2003 por exposiciones heterosexuales de riesgo, excluyéndose a los usuarios de drogas inyectadas. Resultados: El número de personas en las que se determinó la serología fue de 47.870. La prevalencia de VIH en la población estudiada descendió del 3,2% al 1,0% (p<0,001). En las personas con pareja con diagnóstico de infección por VIH la prevalencia se mantuvo en torno al 10%, en hombres usuarios de prostitución descendió del 1,9% al 1,0% (p=0,049), en las mujeres que ejercen la prostitución del 1,4% al 0,7% (p=0,008), y en el resto de heterosexuales disminuyó del 1,6% al 1,0% en hombres (p=0,014) y del 1,1% al 0,7% en mujeres (p=0,012). Conclusiones: Los resultados indican avances en el control de la transmisión heterosexual del VIH, principalmente en mujeres, aunque todavía se requiere insistir en la prevención (AU)

Background: The human immunodeficiency virus (HIV) epidemic in Spain was characterized throughout the first few years by the predominance of infections among injected drug users (IDU's), but everything currently points to a progressive predominance of sexual transmission. This study is aimed at describing the trend in HIV infection among several heterosexual populations groups and at characterizing the situations in which the infections occurred. Methods: Descriptive study of the individuals who had the test conducted for the first time at nine HIV diagnosis centres within the 1992-2003 period due to high-risk heterosexual exposures, not including injected drug users. Results: A total of 47,870 individuals had serology performed during the period under study. The HIV prevalence among the population under study dropped from 3.2% to 1.0% (p< 0.001). Among the individuals with an HIV infected partners, the prevalence remained at around 10%, the male users of prostitution having dropped from 1.9% to 1.0% (p=0.049); among women involved in prostitution, from 1.4% to 0.7% (p=0.008); and among all other heterosexuals, having dropped from 1.6% to 1.0% among males (p=0.014) and from 1.1% to 0.7% among women (p=0.012). Conclusions: The results indicate advances in the control of heterosexual human immunodeficiency virus transmission, mainly among women, although it is necessary to still continue stressing prevention (AU)

[HIV prevalence among individuals having had serology performed in eight Spanish cities following heterosexual exposure, 1992-2003]. / Prevalencia de VIH entre las personas de ocho ciudades Españolas que se realizan la serología tras exposiciones heterosexuales, 1992-2003.

BACKGROUND: The human immunodeficiency virus (HIV) epidemic in Spain was characterized throughout the first few years by the predominance of infections among injected drug users (IDU's), but everything currently points to a progressive predominance of sexual transmission. This study is aimed at describing the trend in HIV infection among several heterosexual populations groups and at characterizing the situations in which the infections occurred. METHODS: Descriptive study of the individualls who had the test conducted for the first time at nine HIV diagnosis centres within the 1992-2003 period due to high-risk heterosexual exposures, not including injected drug users. RESULTS: A total of 47,870 individuals had serology performed during the period under study. The HIV prevalence among the population under study dropped from 3.2% to 1.0% (p< 0.001). Among the individuals with an HIV infected partners, the prevalence remained at around 10%, the male users of prostitution having dropped from 1.9% to 1.0% (p=0.049); among women involved in prostitution, from 1.4% to 0.7% (p=0.008); and among all other heterosexuals, having dropped from 1.6% to 1.0% among males (p=0.014) and from 1.1% to 0.7% among women (p=0.012). CONCLUSIONS: The results indicate advances in the control of heterosexual human immunodeficiency virus transmission, mainly among women, although it is necessary to still continue stressing prevention.