Abstract
Mosaic loss of chromosome Y (LOY) in immune cells is a male-specific mutation associated with increased risk for morbidity and mortality. The
CD99
gene, positioned in the pseudoautosomal ...regions of chromosomes X and Y, encodes a cell surface protein essential for several key properties of leukocytes and immune system functions. Here we used CITE-seq for simultaneous quantification of
CD99
derived mRNA and cell surface CD99 protein abundance in relation to LOY in single cells. The abundance of CD99 molecules was lower on the surfaces of LOY cells compared with cells without this aneuploidy in all six types of leukocytes studied, while the abundance of CD proteins encoded by genes located on autosomal chromosomes were independent from LOY. These results connect LOY in single cells with immune related cellular properties at the protein level, providing mechanistic insight regarding disease vulnerability in men affected with mosaic chromosome Y loss in blood leukocytes.
The Swedish Dementia Registry (SveDem) was developed with the aim to improve the quality of diagnostic work-up, treatment and care of patients with dementia disorders in Sweden.
SveDem is an internet ...based quality registry where several indicators can be followed over time. It includes information about the diagnostic work-up, medical treatment and community support (www.svedem.se). The patients are diagnosed and followed-up yearly in specialist units, primary care centres or in nursing homes.
The database was initiated in May 2007 and covers almost all of Sweden. There were 28 722 patients registered with a mean age of 79.3 years during 2007-2012. Each participating unit obtains continuous online statistics from its own registrations and they can be compared with regional and national data. A report from SveDem is published yearly to inform medical and care professionals as well as political and administrative decision-makers about the current quality of diagnostics, treatment and care of patients with dementia disorders in Sweden.
SveDem provides knowledge about current dementia care in Sweden and serves as a framework for ensuring the quality of diagnostics, treatment and care across the country. It also reflects changes in quality dementia care over time. Data from SveDem can be used to further develop the national guidelines for dementia and to generate new research hypotheses.
Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired ...mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.
Preserved functions of daily life and cognition are cornerstones of independent aging, which is crucial for maintaining a high quality of life. The aim of this study was to examine the impact of ...sarcopenia, and its underlying components, on independent ageing in a cohort study of very old men.
The presence of sarcopenia and independent ageing at a mean age of 87 was investigated in 287 men from the Uppsala Longitudinal Study of Adult Men. Five years later 127 men were re-evaluated for independent ageing. Sarcopenia was defined by two different definitions from the European Working Group on Sarcopenia in Older People. In the first definition sarcopenia was defined as skeletal muscle index < 7.26 kg/m
and either gait speed ≤0.8 m/s or hand grip strength < 30 kg. In the later up-dated definition, HGS < 27 kg and/or chair stand test > 15 s defines probable sarcopenia, which is confirmed by SMI < 7.0 kg/m
. Independent ageing was defined as a Mini-Mental State Examination score of ≥25 points, absence of diagnosed dementia, community-dwelling, independency in personal care and ability to walk outdoors alone.
Sarcopenia at baseline was observed in 21% (60/287) and 20% (58/287), respectively, due to definition. The prevalence of independent ageing was 83% (239/288) at baseline and 69% (87/127) five years later. None of the sarcopenia diagnoses were associated with independent ageing. In contrast, gait speed was both in cross-sectional (odds ratio (OR) per one standard deviation increase 2.15, 95% confidence interval (CI) 1.47-3.15), and in longitudinal multivariate analyses (OR 1.84, 95% CI 1.19-2.82). In the cross-sectional analysis also higher hand grip strength was associated with independent ageing (OR 1.58, 95% CI 1.12-2.22), while a slower chair stand test was inversely associated (OR 0.61, 95% CI 0.43-0.86). Muscle mass; i.e. skeletal muscle index, was not associated with independent ageing.
For very old men, especially a higher gait speed, but also a higher hand grip strength and a faster chair stand test, were associated with independent ageing, while skeletal muscle index alone, and the composite sarcopenia phenotype measured with two different definitions, were not.
Our aim was to evaluate the longitudinal associations of individual and multiple vascular risk factors with the subsequent development of dementia and Alzheimer's disease (AD).
The Uppsala ...Longitudinal Study of Adult Men started in 1970 when the 2,268 participants were 50 years old. Baseline investigations included determinations of blood pressure, fasting glucose, cholesterol, BMI and smoking status. Over a maximum follow-up of 40 years, 349 participants were diagnosed with dementia, out of which 127 had AD. Analyses were repeated using a re-examination of the cohort at 70 years of age as a baseline.
No associations between vascular risk factors and AD were found. For all-type dementia, the association between high systolic blood pressure and dementia was the most consistent. High fasting glucose was associated with increased risk of all-type dementia only when measured at 70 years. Individuals with both an APOE ε4 allele and vascular risk factors had the greatest dementia risk.
Vascular risk factors influence the future risk of dementia, in particular vascular and mixed-type rather than AD. The impact of vascular risk factors on dementia in a longitudinal study depends on the age at baseline and the length of follow-up.
Few studies with controls from the same cohort have investigated the impact of stroke on the ability to live an independent life at old age. We aimed to analyze how great an impact being a stroke ...survivor would have on cognition and disability. We also analyzed the predictive value of baseline cardiovascular risk factors.
We included 1147 men, free from stroke, dementia, and disability, from the Uppsala Longitudinal Study of Adult Men, between 69-74 years of age. Follow-up data were collected between the ages of 85-89 years and were available for 481 of all 509 survivors. Data on stroke diagnosis were obtained through national registries. Dementia was diagnosed through a systematic review of medical charts and in accordance with the current diagnostic criteria. The primary outcome, preserved functions, was a composite outcome comprising four criteria: no dementia, independent in personal activities of daily living, ability to walk outside unassisted, and not living in an institution.
Among 481 survivors with outcome data, 64 (13%) suffered a stroke during the follow-up. Only 31% of stroke cases, compared to 72% of non-stroke cases (adjusted OR 0.20 95% CI 0.11-0.37), had preserved functions. The chance of being free of dementia was 60% lower in the stroke group, OR 0.40 95% CI 0.22-0.72. No cardiovascular risk factors were independently able to predict preserved functions among stroke cases.
Stroke has long lasting consequences for many aspects of disability at very high age.
Alzheimer's disease is a neurodegenerative disorder accounting for more than 50% of cases of dementia. Diagnosis of Alzheimer's disease relies on cognitive tests and analysis of amyloid beta, protein ...tau, and hyperphosphorylated tau in cerebrospinal fluid. Although these markers provide relatively high sensitivity and specificity for early disease detection, they are not suitable for monitor of disease progression. In the present study, we used label-free shotgun mass spectrometry to analyse the cerebrospinal fluid proteome of Alzheimer's disease patients and non-demented controls to identify potential biomarkers for Alzheimer's disease. We processed the data using five programs (DecyderMS, Maxquant, OpenMS, PEAKS, and Sieve) and compared their results by means of reproducibility and peptide identification, including three different normalization methods. After depletion of high abundant proteins we found that Alzheimer's disease patients had lower fraction of low-abundance proteins in cerebrospinal fluid compared to healthy controls (p<0.05). Consequently, global normalization was found to be less accurate compared to using spiked-in chicken ovalbumin for normalization. In addition, we determined that Sieve and OpenMS resulted in the highest reproducibility and PEAKS was the programs with the highest identification performance. Finally, we successfully verified significantly lower levels (p<0.05) of eight proteins (A2GL, APOM, C1QB, C1QC, C1S, FBLN3, PTPRZ, and SEZ6) in Alzheimer's disease compared to controls using an antibody-based detection method. These proteins are involved in different biological roles spanning from cell adhesion and migration, to regulation of the synapse and the immune system.
Milk and fermented milk consumption has been linked to health and mortality but the association with Parkinson's disease (PD) is uncertain. We conducted a study to investigate whether milk and ...fermented milk intakes are associated with incident PD. This cohort study included 81,915 Swedish adults (with a mean age of 62 years) who completed a questionnaire, including questions about milk and fermented milk (soured milk and yogurt) intake, in 1997. PD cases were identified through linkage with the Swedish National Patient and Cause of Death Registers. Multivariable-adjusted hazard ratios were obtained from Cox proportional hazards regression models. During a mean follow-up of 14.9 years, 1251 PD cases were identified in the cohort. Compared with no or low milk consumption (<40 mL/day), the hazard ratios of PD across quintiles of milk intake were 1.29 (95% CI 1.07, 1.56) for 40-159 mL/day, 1.19 (95% CI 0.99, 1.42) for 160-200 mL/day, 1.29 (95% CI 1.08, 1.53) for 201-400 mL/day, and 1.14 (95% CI 0.93, 1.40) for >400 mL/day. Fermented milk intake was not associated with PD. We found a weak association between milk intake and increased risk of PD but no dose-response relationship. Fermented milk intake was not associated with increased risk of PD.
Computerized cognitive tests have the potential to cost-effectively detect and monitor cognitive impairments and thereby facilitate treatment for these conditions. However, relatively few of these ...tests have been validated in a variety of populations. Brain on Track, a self-administered web-based test, has previously been shown to have a good ability to differentiate between healthy individuals and patients with cognitive impairment in Portuguese populations. The objective of this study was to validate the differential ability and evaluate the usability of Brain on Track in a Swedish memory clinic setting. Brain on Track was administered to 30 patients with mild cognitive impairment/mild dementia and 30 healthy controls, all scheduled to perform the test from home after one week and after three months. To evaluate the usability, the patient group was interviewed after completion of the testing phase. Patients scored lower than healthy controls at both the first (median score 42.4 vs 54.1, p<0.001) and the second test (median score 42.3 vs 55.0, p<0.001). The test-retest intra-class correlation was 0.87. A multiple logistic regression model accounting for effects of age, gender and education rendered an ability of Brain on Track to differentiate between the groups with an area under the receiver operation characteristics curve of 0.90 for the first and 0.88 for the second test. In the subjective evaluation, nine patients left positive comments, nine were negative whereas five left mixed comments regarding the test experience. Sixty percent of patients had received help from relatives to log on to the platform. In conclusion, Brain on Track performed well in differentiating healthy controls from patients with cognitive impairment and showed a high test-retest reliability, on par with results from previous studies. However, the substantial proportion of patients needing help to log in could to some extent limit an independent use of the platform.
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