Background and purpose
Previous studies suggested that the overall burden of prior infections contributes to cardiovascular diseases and stroke. In the present study, the association between ...infectious burden (IB) and Alzheimer's disease (AD) was examined.
Methods
Antibody titers to common infectious pathogens including cytomegalovirus (CMV), herpes simplex virus type 1 (HSV‐1), Borrelia burgdorferi, Chlamydophila pneumoniae and Helicobacter pylori were measured by enzyme‐linked immunosorbent assay in 128 AD patients and 135 healthy controls. IB was defined as a composite serological measure of exposure to these common pathogens.
Results
Seropositivities toward zero−two, three and four−five of these pathogens were found in 44%, 40% and 16% of healthy controls but in 20%, 44% and 36% of AD patients, respectively. IB, bacterial burden and viral burden were independently associated with AD after adjusting for age, gender, education, APOE genotype and various comorbidities. Mini‐Mental State Examination scores were negatively correlated with IB in all cases. Serum beta‐amyloid protein (Aβ) levels (i.e. Aβ40, Aβ42 and total Aβ) and inflammatory cytokines (i.e. interferon‐γ, tumor necrosis factor α, interleukin‐1β and interleukin‐6) in individuals exposed to four−five infectious pathogens were significantly higher than those exposed to zero−two or three pathogens.
Conclusions
IB consisting of CMV, HSV‐1, B. burgdorferi, C. pneumoniae and H. pylori is associated with AD. This study supports the role of infection/inflammation in the etiopathogenesis of AD.
Click here to view the accompanying paper in this issue. Videocasts of this article are available in: English: http://player.polyv.net/videos/player.swf?vid=f6ee5715d9808c7a481b7ae727da00dd_f Mandarin: http://player.polyv.net/videos/f6ee5715d98ae743a9b0509d0900c91f_f.swf
In Alzheimer's disease (AD), neurodegenerative signals such as amyloid-beta (Aβ) and the precursors of neurotrophins, outbalance neurotrophic signals, causing synaptic dysfunction and ...neurodegeneration. The neurotrophin receptor p75 (p75NTR) is a receptor of Aβ and mediates Aβ-induced neurodegenerative signals. The shedding of its ectodomain from the cell surface is physiologically regulated; however, the function of the diffusible p75NTR ectodomain (p75ECD) after shedding remains largely not known. Here, we show that p75ECD levels in cerebrospinal fluid and in the brains of Alzheimer's patients and amyloid-beta precursor protein (APP)/PS1 transgenic mice were significantly reduced, due to inhibition of the sheddase-tumor necrosis factor-alpha-converting enzyme by Aβ. Restoration of p75ECD to the normal level by brain delivery of the gene encoding human p75ECD before or after Aβ deposition in the brain of APP/PS1 mice reversed the behavioral deficits and AD-type pathologies, such as Aβ deposit, apoptotic events, neuroinflammation, Tau phosphorylation and loss of dendritic spine, neuronal structures and synaptic proteins. Furthermore, p75ECD can also reduce amyloidogenesis by suppressing β-secretase expression and activities. Our data demonstrate that p75ECD is a physiologically neuroprotective molecule against Aβ toxicity and would be a novel therapeutic target and biomarker for AD.
Summary
Background
Acral melanoma (AM) is the most common histopathological subtype of malignant melanoma in Asians. However, differences in the mutational profiles underlying AM and nonacral ...cutaneous melanoma (NAM) in Asians are not well understood.
Objectives
To augment the understanding of the prevalence, patterns and associations of various mutations between different subtypes of melanoma.
Methods
We performed comprehensive genomic profiling of 409 cancer‐associated genes, using next‐generation sequencing, in 66 primary melanomas comprised of 45 AMs and 21 NAMs.
Results
Most of the AMs (n = 27/45; 60%), but only five of 21 (24%) NAMs, were triple wild‐type (triple‐WT) tumours. Compared with AMs, NAMs exhibited a significantly higher frequency of BRAF mutations. The frequencies of NRAS/KRAS mutations, cell‐cycle aberrations, copy number gains in BIRC2, BIRC3 and BIRC5, and gains of receptor tyrosine kinase genes were significantly higher in AMs. Ulceration was found at significantly higher rates in the AMs and NAMs with cell‐cycle aberrations and gains of receptor tyrosine kinase genes. Notably, cell‐cycle aberrations and copy number gains in BIRC2, BIRC3 and BIRC5 were significantly associated with poor melanoma‐specific survival in the 66 patients with melanoma and especially in the 45 patients with AM. Multivariate analysis showed that lymph node metastasis and cell‐cycle aberrations were independent prognostic factors of melanoma‐specific survival.
Conclusions
This study strengthens our understanding of the patterns and clinical associations of oncogenic mutations in AMs and NAMs in Asians.
What's already known about this topic?
Mutation frequencies of driver genes vary between melanoma subtypes.
Acral melanoma is the most common subtype of melanoma in Asians.
KIT mutations and copy number variations occur more frequently in the acral subtype of melanoma than in the nonacral subtype
What does this study add?
NRAS/KRAS mutations, cell‐cycle aberrations, copy number gains in BIRC2, BIRC3 and BIRC5, and amplifications of receptor tyrosine kinase genes were significantly enriched in acral melanoma and could be potential targets for treatment.
Melanomas with cell‐cycle aberrations and gains in receptor tyrosine kinase genes were significantly more likely to contain ulceration.
What is the translational message?
Cell‐cycle aberrations and copy number gains in BIRC2, BIRC3 and BIRC5 were significantly associated with poor melanoma‐specific survival.
These observations should be explored further for future drug development.
Linked Comment: Johansson. Br J Dermatol 2020; 182:1085.
Plain language summary available online
Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations ...have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.
Thioamides antithyroid‐drugs (ATDs) are important in hyperthyroid disease management. Identification of the susceptibility locus of ATD‐induced agranulocytosis is important for clinical management. ...We performed a genome‐wide association study (GWAS) involving 20 patients with ATD‐induced agranulocytosis and 775 healthy controls. The top finding was further replicated. A single‐nucleotide polymorphism (SNP), rs185386680, showed the strongest association with ATD‐induced agranulocytosis in GWAS (odds ratio (OR) = 36.4; 95% confidence interval (CI) = 12.8–103.7; P = 1.3 × 10‐24) and replication (OR = 37; 95% CI = 3.7–367.4; P = 9.6 × 10‐7). HLA‐B*38:02:01 was in complete linkage disequilibrium with rs185386680. High‐resolution HLA typing confirmed that HLA‐B*38:02:01 was associated with carbimazole (CMZ)/methimazole (MMI)‐induced agranulocytosis (OR = 265.5; 95% CI = 27.9–2528.0; P = 2.5 × 10‐14), but not associated with propylthiouracil (PTU). The positive and negative predictive values of HLA‐B*38:02:01 in predicting CMZ/MMI‐induced agranulocytosis were 0.07 and 0.999. Approximately 211 cases need to be screened to prevent one case. Screening for the risk allele will be useful in preventing agranulocytosis in populations in which the frequency of the risk allele is high.
In this multicentre study, we examined 60 cases of Type II enteropathy-associated T-cell lymphoma (EATL) from the Asia-Pacific region by histological review, immunohistochemistry and molecular ...techniques. Patients were mostly adult males (median age: 58 years, male:female 2.6:1), presenting with abdominal pain (60%), intestinal perforation (40%) and weight loss (28%). None had a history of coeliac disease and the median survival was only 7 months. Histologically, these tumours could be divided into (i) central tumour zone comprising a monotonous population of neoplastic lymphocytes, (ii) peripheral zone featuring stunted villi and morphologically atypical lymphocytes showing epitheliotropism, and (iii) distant mucosa with normal villous architecture and cytologically normal intra-epithelial lymphocytes (IELs). Characterized by extensive nuclear expression of Megakaryocyte-associated tyrosine kinase (MATK) (87%) and usually a CD8(+)CD56(+) (88%) cytotoxic phenotype, there was frequent aberrant expression of CD20 (24%). T-cell receptor (TCR) expression was silent or not evaluable in 40% but of the remainder, there was predominant expression of TCRαβ over TCRγδ (1.6:1). In keeping with the normal ratio of IEL subsets, CD8(+) cases showed predominant CD8αα homodimer expression (77%), regardless of TCR lineage. These tumours constitute a distinct entity from classical EATL, and the pathology may reflect tumour progression from IEL precursors, remnants of which are often seen in the distant mucosa.
The amyloid-β protein (Aβ) protein plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). It is believed that Aβ deposited in the brain originates from the brain tissue itself. ...However, Aβ is generated in both brain and peripheral tissues. Whether circulating Aβ contributes to brain AD-type pathologies remains largely unknown. In this study, using a model of parabiosis between APPswe/PS1dE9 transgenic AD mice and their wild-type littermates, we observed that the human Aβ originated from transgenic AD model mice entered the circulation and accumulated in the brains of wild-type mice, and formed cerebral amyloid angiopathy and Aβ plaques after a 12-month period of parabiosis. AD-type pathologies related to the Aβ accumulation including tau hyperphosphorylation, neurodegeneration, neuroinflammation and microhemorrhage were found in the brains of the parabiotic wild-type mice. More importantly, hippocampal CA1 long-term potentiation was markedly impaired in parabiotic wild-type mice. To the best of our knowledge, our study is the first to reveal that blood-derived Aβ can enter the brain, form the Aβ-related pathologies and induce functional deficits of neurons. Our study provides novel insight into AD pathogenesis and provides evidence that supports the development of therapies for AD by targeting Aβ metabolism in both the brain and the periphery.
Diabetes mellitus is a common comorbidity of atrial fibrillation (AF), which can complicate the management of AF. The pharmacology of oral anticoagulants (OACs) have been implicated in pathogenesis ...of diabetes, but the relationship between different OACs and risk of diabetes remains unexamined. This study aimed to evaluate the risk of diabetes with use of different OACs in AF patients.
Population-based retrospective cohort study using an electronic healthcare database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with AF from 2014 through 2018 and prescribed OACs were included and followed till December 31, 2019. Inverse probability of treatment weighting based on the propensity score (PS) is used to address potential bias due to nonrandomized allocation of treatment. The risks ofdiabetes were compared between different new OAC users using propensity score-weighted cumulative incidence differences (CID).
There were 13,688 new users of OACs (warfarin: n = 3454; apixaban: n = 3335; dabigatran: n = 4210; rivaroxaban: n = 2689). The mean age was 75.0 (SD, 11.2), and 6,550 (47.9%) were women. After a median follow-up of 0.93 years (interquartile range, 0.21-1.92 years), 698 incident diabetes cases were observed. In Cox-regression analysis, dabigatran use was significantly associated with reduced risk of diabetes when compared with warfarin use HR 0.69 (95% CI 0.56-0.86; P < 0.001), with statistically insignificant associations observed for use of apixaban and rivaroxaban. The corresponding adjusted CIDs at 2 years after treatment with apixaban, dabigatran, and rivaroxaban users when compared with warfarin were - 2.06% (95% CI - 4.08 to 0.16%); - 3.06% (95% CI - 4.79 to - 1.15%); and - 1.8% (- 3.62 to 0.23%). In head-to-head comparisons between women DOAC users, dabigatran was also associated with a lower risk of diabetes when compared with apixaban and rivaroxaban.
Among adults with AF receiving OACs, the use of dabigatran had the lowest risk of diabetes when compared with warfarin use.
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