Low platelet iPLA2 activity predicts conversion from mild cognitive impairment to Alzheimer’s disease: a 4-year follow-up study

Reduced phospholipase A₂ (PLA₂) activity has been reported in the brain and in blood cells of patients with Alzheimer’s disease (AD). Individuals with mild cognitive impairment (MCI) are at increased risk of developing AD. In the present study, we determined the activity of distinct PLA₂ subgroups (iPLA₂, sPLA₂ and cPLA₂) in older adults with MCI as compared to patients with mild dementia due to AD and to cognitively healthy controls. We investigated whether decreased PLA₂ activity at baseline is associated with the progression of MCI to AD upon follow-up during a period of 4 years. The activity of PLA₂ subgroups was determined in platelets from 169 elderly adults. Progression of MCI to AD was ascertained by standard clinical criteria for AD upon follow-up. At baseline, iPLA₂ activity was significantly decreased (p = 0.001) in patients with AD and MCI as compared to controls. Patients with MCI who progressed to AD during follow-up showed significantly lower iPLA₂ activity at baseline as compared to patients with MCI who did not progress to AD (p = 0.009). Moreover, subjects from the control group at baseline who progressed to MCI during follow-up had lower sPLA₂ and cPLA₂ (p = 0.014 and p = 0.009, respectively). Our findings suggest that low platelet iPLA₂ activity may be a risk marker for AD in subjects with MCI. Moreover, low sPLA₂ and cPLA₂ were related to cognitive decline in healthy controls, suggesting a relationship with the very early stages of the disease.     

T-cells producing multiple combinations of IFNγ, TNF and IL10 are associated with mild forms of dengue infection

Multifunctional interleukin 10 (IL10)⁺Th1 cells have been implicated in favorable evolution of many infectious diseases, promoting an efficacious immune response while limiting immunopathology. Here, we investigated the presence of multifunctional CD4⁺ and CD8⁺ T-cells that expressed interferon gamma (IFNγ), IL10 and tumor necrosis factor (TNF), or its combinations during dengue infection. Peripheral blood mononuclear cells (PBMCs) from outpatients with dengue (mild dengue forms) and hospitalized patients (or patients with dengue with warning signs and severe dengue) were cultured in the presence of envelope (ENV) or NS3 peptide libraries of DENV during critical (hospitalization period) and convalescence phases. The production of IFNγ, IL10 and TNF by CD4⁺ and CD8⁺ T-cells was assessed by flow cytometry. Our data show that patients with mild dengue, when compared with patients with dengue with warning signs and severe dengue, presented higher frequencies of multifunctional T-cells like NS3-specific IFNγ/IL10-producing CD4⁺ T-cells in critical phase and NS3- and ENV-specific CD8⁺ T-cells producing IFNγ/IL10. In addition, NS3-specific CD8⁺ T-cells producing high levels of IFNγ/TNF and IFNγ/TNF/IL10 were also observed in the mild dengue group. We observed that multifunctional T-cells produced higher levels of cytokines as measured by intracellular content when compared with single producer T-cells. Importantly, multifunctional CD4⁺ and CD8⁺ T-cells producing IFNγ, TNF and IL10 simultaneously displayed positive correlation with platelet levels, suggesting a protective role of this population. The presence of IL10⁺Th1 and IL10⁺Tc1 multifunctional cells was associated with mild dengue presentation, suggesting that these cells play a role in clinical evolution of dengue infection.     

Sociodemographic,sexual, and reproductive variables associated with pregnancy among adolescents from low socioeconomic background

Adolescent pregnancy remains a public health concern in both developed and developing countries. Portugal and Brazil represent some of the best examples of this phenomenon. The present study aimed to identify sociodemographic, sexual, and reproductive health-related variables associated with adolescent pregnancy among students from low socioeconomic backgrounds in both countries. The sample included 984 female adolescents, among whom 215 became pregnant. Living with a partner and lack of information about sex and contraception from the family were the best explicative factors for pregnancy occurrence in both countries. Country-specific variables were also identified. Our results may contribute to developing global preventive interventions, addressing the school as an ideal setting for primary intervention and considering culture-specific characteristics of high-risk populations.     

Perceived Associations between Excessive Sugar Intake and Health Conditions

Excessive sugar intake represents an increased risk of developing non-communicable diseases (e.g., obesity, cardiometabolic diseases, and dental diseases). Still, it is unclear whether people are aware of these adverse health outcomes. The current study systematically examined the extent to which people associate health conditions with excessive sugar intake. Participants (N = 1010 Portuguese volunteers) freely reported all health conditions they associated with excessive sugar consumption and rated the strength of these associations for eight specific health conditions. All participants reported health conditions associated with excessive sugar intake, with the most frequent being risk factors for cardiometabolic diseases (e.g., diabetes), cardiovascular diseases, oral problems, oncological and mental health conditions. Moreover, participants considered diabetes, overweight/obesity, and oral problems as being the conditions most related to excessive sugar intake. Women, participants with children in the household, and experts in health/nutrition rated excessive sugar intake as being more strongly linked to some of the health conditions. The identification of the health conditions that people associate with excessive sugar consumption may inform policymakers, educators, and health professionals and support interventions targeting the general public or specific groups (e.g., overweight people) in raising awareness of potential adverse health outcomes and, ultimately, contribute to reducing sugar intake.