The Effect of Genetic Predisposition to Alzheimer's Disease and Related Traits on Recruitment Bias in a Study of Cognitive Aging.

The recruitment of participants for research studies may be subject to bias. The Prospective Imaging Study of Ageing (PISA) aims to characterize the phenotype and natural history of healthy adult Australians at high future risk of Alzheimer's disease (AD). Participants approached to take part in PISA were selected from existing cohort studies with available genomewide genetic data for both successfully and unsuccessfully recruited participants, allowing us to investigate the genetic contribution to voluntary recruitment, including the genetic predisposition to AD. We use a polygenic risk score (PRS) approach to test to what extent the genetic risk for AD, and related risk factors predict participation in PISA. We did not identify a significant association of genetic risk for AD with study participation, but we did identify significant associations with PRS for key causal risk factors for AD, IQ, household income and years of education. We also found that older and female participants were more likely to take part in the study. Our findings highlight the importance of considering bias in key risk factors for AD in the recruitment of individuals for cohort studies.

Associations of externalizing polygenic scores with externalizing disorders among Mexican youth.

Several studies have examined the association of externalizing polygenic scores (PGS) with externalizing symptoms in samples of European ancestry. However, less is known about the associations of externalizing polygenic vulnerability in relation to phenotypic externalizing disorders among individuals of different ancestries, such as Mexican youth. Here, we leveraged the largest genome-wide association study on externalizing behaviors that included over 1 million individuals of European ancestry to examine associations of externalizing PGS with a range of externalizing disorders in Mexican adolescents, and investigated whether adversity exposure in childhood moderated these associations. Participants (N = 1064; age range 12-17 years old; 58.8% female) were adolescents recruited for a general population survey on adolescent mental health in the Mexico City Metropolitan region and were genotyped. Childhood adversity exposure and externalizing disorders, specifically attention-deficit hyperactivity disorder (ADHD), conduct disorder, oppositional defiant disorder, and substance use disorder, were assessed via the computer-assisted World Mental Health Composite International Diagnostic Interview for adolescents. A greater externalizing PGS was associated with a greater odds of any externalizing disorder (OR = 1.29 [1.12, 1.48]; p < 0.01) and ADHD (OR = 1.40 [1.15, 1.70]; p < 0.01) in the whole sample, and in females in particular. There were no main effects of the externalizing PGS on conduct disorder, oppositional defiant disorder, or substance use disorder, nor did adversity exposure moderate these associations. Our results suggest that greater genetic propensity for externalizing disorders is associated with increased odds of any externalizing disorders and ADHD among Mexican adolescents, furthering our understanding of externalizing disorder manifestation in this population.

Achenbach's syndrome: a rare condition.

Achenbach's syndrome corresponds to a pathology characterized by the appearance of ecchymoses and bruises on the fingers of the hands and eventually on the feet. It is a benign and self-limited disease, which is accompanied by pain. It generates great concern because its sudden appearance leads women who are the most affected to consult the emergency services. At present, its pathophysiology is unknown and requires knowledge of the disease to diagnose it. It is a must for poorly trained professionals.

[The physicochemical and microbiological characteristics of saliva during and after pregnancy]. / Características fisicoquímicas y microbiológicas de la saliva durante y después del embarazo.

OBJECTIVES: Identify the changes in some physiological and microbiological parameters in the saliva from a group of women during and after their pregnancies. METHODS: Stimulated whole saliva was collected from a cohort of 35 women during their pregnancy and afterwards to determine each sample's physicochemical (secretion rate, pH and buffer capacity) and microbiological characteristics (acidogenic bacteria count). RESULTS: The pH and buffer capacity of saliva during pregnancy were lower than after pregnancy. There were no statistically significant changes regarding S. mutans and Lactobacillus spp. count, but a tendency towards increased values during pregnancy was noted. CONCLUSIONS: Changes occurring in the saliva of pregnant women can lead to an increase of risk of suffering disease affecting one's oral health, such as caries, gingivitis and periodontal disease; this could be prevented by appropriate diagnosis and dental follow-up, including education regarding pregnant women's oral health.

Tuberculosis among homeless population from Medellín, Colombia: associated mental disorders and socio-demographic characteristics.

Homeless people are highly susceptible to tuberculosis. It has been suggested that this population have high rates of mental disorders associated with tuberculosis. We assessed tuberculosis incidence, its transmission patterns and association with socio-demographic factors and mental disorders in Colombian homeless people. Prospective study which socio-demographic characteristics and mental disorders were assessed through interviews. Sputa from patients with respiratory symptoms were processed and clinical isolates analyzed by IS6110-RFLP. Multivariate analysis performed by logistic regression model. From 426 homeless studied, tuberculosis incidence found was 7.9 %. 44 % of isolates were clustering. It was found high risk of having tuberculosis associated with income from drugs trade (OR: 3.40 [95 % CI: 1.28-9.05]), dysthymia (OR: 2.54 [95 % CI: 1.10-5.86]) and receiving food from other homeless (OR: 2.47 [95 % CI: 1.16-5.25]). Tuberculosis incidence and degree of transmission are high in homeless studied. Implementing programs to better control tuberculosis among homeless population must consider socio-demographic factors and mental disorders associated with the disease.

Características fisicoquímicas y microbiológicas de la saliva durante y después del embarazo / The physicochemical and microbiological characteristics of saliva during and after pregnancy

Objetivo Identificar las variaciones producidas en algunos parámetros fisicoquímicos y microbiológicos de la saliva en un grupo de mujeres durante y después de la gestación. Materiales y Métodos Se recolectó saliva total estimulada en una cohorte de 35 mujeres embarazadas y después del parto. A cada muestra le fueron determinadas características fisicoquímicas (tasa de secreción, pH y capacidad amortiguadora) y microbiológicas (recuentos de bacterias acidogénicas). Resultados El pH y la capacidad amortiguadora de la saliva durante el embarazo fueron más bajos que en el posparto, mientras que la tasa de secreción salival fue más alta en el embarazo. Los recuentos de S. mutans y Lactobacillus spp. no presentaron cambios significativos estadísticamente, pero se observa una tendencia al aumento en los recuentos durante la gestación. Conclusión Los cambios ocurridos en la saliva de las gestantes pueden llevar a un aumento del riesgo de aparición de enfermedades bucales como caries, gingivitis y enfermedad periodontal, los cuales podrían disminuirse, mediante un adecuado diagnóstico y seguimiento odontológico, que incluya educación en salud oral a la gestante.

Objectives Identify the changes in some physiological and microbiological parameters in the saliva from a group of women during and after their pregnancies. Methods Stimulated whole saliva was collected from a cohort of 35 women during their pregnancy and afterwards to determine each sample's physicochemical (secretion rate, pH and buffer capacity) and microbiological characteristics (acidogenic bacteria count). Results The pH and buffer capacity of saliva during pregnancy were lower than after pregnancy. There were no statistically significant changes regarding S. mutans and Lactobacillus spp. count, but a tendency towards increased values during pregnancy was noted. Conclusions Changes occurring in the saliva of pregnant women can lead to an increase of risk of suffering disease affecting one's oral health, such as caries, gingivitis and periodontal disease; this could be prevented by appropriate diagnosis and dental follow-up, including education regarding pregnant women's oral health.