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Christoffersen Gammelgaard opublikował 1 rok, 3 miesiące temu
We propose that exposure to microbial amyloids in the gastrointestinal tract can accelerate αSyn aggregation and disease in the gut and the brain. © 2020, Sampson et al.Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons. © 2020, Moruno-Manchon et al.Although lifespan in mammals varies over 100-fold, the precise evolutionary mechanisms underlying variation in longevity remain unknown. Species-specific genetic changes have been observed in long-lived species including the naked mole-rat, bats, and the bowhead whale, but these adaptations do not generalize to other mammals. We present a novel method to identify associations between rates of protein evolution and continuous phenotypes across the entire mammalian phylogeny. Unlike previous analyses that focused on individual species, we treat absolute and relative longevity as quantitative traits and demonstrate that these lifespan traits affect the evolutionary constraint on hundreds of genes. Specifically, we find that genes related to cell cycle, DNA repair, cell death, the IGF1 pathway, and immunity are under increased evolutionary constraint in large and long-lived mammals. For mammals exceptionally long-lived for their body size, we find increased constraint in inflammation, DNA repair, and NFKB-related pathways. Strikingly, these pathways have considerable overlap with those that have been previously reported to have potentially adaptive changes in single-species studies, and thus would be expected to show decreased constraint in our analysis. This unexpected finding of increased constraint in many longevity-associated pathways underscores the power of our quantitative approach to detect patterns that generalize across the mammalian phylogeny. © 2020, Kowalczyk et al.Chronic Chagas heart disease has different clinical manifestations including arrhythmias, heart failure, and stroke. Chest pain is one of the most common symptoms and when associated with changes in the electrocardiogram, such as T-wave changes, electrically inactive areas, and segmental wall motion abnormalities, may lead to a misdiagnosis of acute coronary syndrome (ACS). Here, we describe two patients with Chagas heart disease and syncope due to sustained ventricular tachycardia who were misdiagnosed with ACS, and discuss the role of novel imaging modalities in the differential diagnosis and risk stratification.Zika virus (ZIKV) has recently been confirmed as endemic in Indonesia, but no congenital anomalies (CA) related to ZIKV infection have been reported. We performed molecular and serological testing for ZIKV and other flaviviruses on cord serum and urine samples collected in October 2016 to April 2017 during a prospective, cross-sectional study of neonates in Jakarta, Indonesia. Of a total of 429 neonates, 53 had CA, including 14 with microcephaly. These 53, and 113 neonate controls without evidence of CA, were tested by ZIKV-specific real-time reverse transcription polymerase chain reaction (RT-PCR), pan-flavivirus RT-PCR, anti-ZIKV and anti-DENV IgM ELISA, and plaque reduction neutralization test. There was no evidence of ZIKV infection among neonates in either the CA or non-CA cohorts, except in three cases with low titers of anti-ZIKV neutralizing antibodies. Further routine evaluation throughout Indonesia of pregnant women and their newborns for exposure to ZIKV should be a high priority for determining risk.In some areas of Argentina endemic for human T-lymphotropic virus type 1 (HTLV-1), tropical spastic paraparesis is frequent in subjects who lack antibodies against the virus; however, the relevance of this seronegative status in the country has not been investigated. In neighboring countries, HTLV-1-seronegative status has been described in patients with different diseases; however, data regarding features of seronegative HTLV-1 carriers are scarce. We investigated the seronegative status in 124 relatives of 28 HTLV-1-infected subjects from an endemic area in Northwest Argentina. Blood samples and clinical/epidemiological data were collected. Human T-lymphotropic virus type 1 infection was diagnosed by serology and LTR, env and tax gene detection. IgG anti-Tax HTLV-1 antibody, tax gene sequence, and DNA proviral load were also evaluated. Seventy-five percent of the 124 relatives were negative for HTLV-1/2 antibodies; 35.5% were also negative by molecular assays and 64.5% were negative for HTLV-1 LTR and env sequences, but positive for two sequences of HTLV-1 tax gene. Also, 35.7% of these subjects had IgG anti-Tax antibodies. The seronegative HTLV-1 status was significantly associated with male gender, youth, and sensory symptoms/autonomic nervous system dysfunction. High rates of seronegative symptomatic and asymptomatic HTLV-1 carriers in Argentina are described. The evidence highlights that HTLV-1 prevalence may be underestimated worldwide. Larger cohort studies are required to assess disease outcome in these seronegative subjects. Also, the findings emphasize the limitations of ongoing screening assays for diagnosis and blood safety. Therefore, algorithms for HTLV-1 diagnosis should include not only serological but also molecular assays.Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes of the genus Schistosoma. More than 220 million people worldwide were estimated to have active schistosomiasis in 2017, 90% of whom live on the African continent, but only 102 million were reported to have received treatment. Africa is also disproportionately burdened by HIV, with an estimated 26 million people living with HIV in 2017. Given these overlapping epidemics, we conducted a systematic review to ascertain the contribution of schistosomes to HIV acquisition risk, the contribution of HIV to schistosome acquisition, the impact of HIV on schistosomiasis-related morbidity, the impact of schistosomes on HIV disease progression and immune response, the impact of HIV on the efficacy of praziquantel treatment, and the impact of HIV on egg shedding. We reviewed studies of people living in sub-Saharan Africa coinfected with HIV and Schistosoma spp. between January 1996 and July 2018. We found that 1) infection with Schistosoma haematobium increases the risk of HIV acquisition, 2) there is currently a lack of data on whether HIV infection increases the risk of Schistosoma acquisition, 3a) HIV coinfection was not an accelerating factor for adverse Schistosoma outcomes, 3b) schistosomiasis may be an important contributor to immune activation in HIV coinfected people, 4) praziquantel use in coinfected people may improve immune reconstitution on antiretroviral therapy for HIV, and 5) there is evidence that HIV infection reduces egg excretion in individuals infected with Schistosoma mansoni.Eye-to-eye transmission of Chlamydia trachomatis, the causative agent of trachoma, may be plausibly interrupted if faces are kept free of ocular and nasal discharge. Between April and June 2018, 83 children aged 1-9 years with active trachoma were recruited from 62 households and allocated to a face cleaning protocol face washing with water, face washing with water and soap, or face wiping. Faces were examined for the presence of ocular and nasal discharge, and swabs were taken from faces and hands to test for C. trachomatis at baseline, immediately post protocol, and after 1, 2, and 4 hours (washing protocols). Washing with soap was more effective at removing ocular discharge than either washing with water (89% and 27% of discharge removed, respectively, P = 0.003) or wiping with a hand (42%, P = 0.013). The reduction in prevalence of ocular discharge was sustained for at least four hours. The prevalence of C. trachomatis on face swabs was reduced by all washing protocols. The importance of soap should not be overlooked during facial cleanliness promotion.Human liver fluke infection caused by Opisthorchis viverrini increases the risk of cholangiocarcinoma (CCA) reported along the Mekong basin including Thailand, Lao PDR, Cambodia, and Vietnam. The highest incidence of CCA has been reported in northeastern Thailand where liver fluke infection is prevalent. This study aimed to investigate the prevalence of O. viverrini infection in a northeastern-descendent community in rural Sa Kaeo Province, eastern Thailand, using stool examination and molecular technique. The Kato-Katz method was performed to determine eggs per gram (EPG) for infection intensity. Phosphate-buffered saline-ethyl acetate concentration was used to prepare specimens for polymerase chain reaction (PCR) and restriction fragment length polymorphism of the internal transcribed spacer 2 (ITS2) region of the ribosomal RNA. From 1,245 specimens, 105 (8.4%) samples were identified as Opisthorchis-like eggs from stool examination, and all positive specimens indicated light infection ( less then 1,000 EPG). From positive Opisthorchis-like egg samples, 55.2% (58/105) were identified as O. viverrini eggs from ITS2-PCR assay for which low infection intensity might result in a negative PCR result (44.8%). Using multiple logistic regression analysis, males were at 3.1 times higher risk of acquiring O. viverrini infection than females. From phylogenetic analysis, in eastern Thailand, nucleotide sequences of O. viverrini were grouped as a monoclade as those isolated from Greater Mekong, Vietnam, Myanmar, and west Siberia. The results revealed that the surveyed community is a low-grade endemic area of O. viverrini infection. Thus, data from this study can be used to improve health-promoting programs and activities to control the infection and its subsequent CCA.Zika virus (ZIKV) caused a public health threat in the United States in 2016, leading to rapid development and implementation of blood screening assays for ZIKV RNA. Several ZIKV sequences from clinical cases have been reported, but none from asymptomatic/pre-symptomatic infections. We isolated and sequenced ZIKV from asymptomatic/pre-symptomatic blood donor (ABD-ZIKV) samples and compared with reported clinical sequences. Twelve ABD-ZIKV isolates were produced from 67 cultivated samples, and isolates were genetically similar among themselves. Most isolates shared mutations with the clinical isolate PRVABC59 2015, whereas two ABD-ZIKV isolates shared specific mutations with U.S. clinical isolates from 2016. The ABD-ZIKV strains clustered into two distinct subclades one comprised mostly ABD-ZIKV from Puerto Rico, and another one comprised ABD-ZIKV from Florida and QTX-02 isolate (Puerto Rico). In this study, we showed the circulation of two slightly distinct virus strains among Puerto Rico blood donors, one of which was also reported in Florida.


