No abstract

Lipopolysaccharide (LPS) has been reported to contribute to a ruminal acidosis of cattle by affecting ruminal bacteria. The goal of this study was to determine how LPS affects the growth of pure cultures of ruminal bacteria, including those that contribute to ruminal acidosis. We found that dosing LPS (200,000 EU) increased the maximum specific growth rates of four ruminal bacterial species (Streptococcus bovis JB1, Succinivibrio dextrinosolvens 24, Lactobacillus ruminis RF1, and Selenomonas ruminantium HD4). Interestingly, all the species ferment sugars and produce lactate, contributing to acidosis. Species that consume lactate or ferment fiber were not affected by LPS. We found that S. bovis JB1 failed to grow in LPS as the carbon source in the media; growth of S. bovis JB1 was increased by LPS when glucose was present. Growth of Megasphaera elsdenii T81, which consumes lactate, was not different between the detoxified (lipid A delipidated) and regular LPS. However, the maximum specific growth rate of S. bovis JB1 was greater in regular LPS than detoxified LPS. Mixed bacteria from a dual-flow continuous culture system were collected to determine changes of metabolic capabilities of bacteria by LPS, and genes associated with LPS biosynthesis were increased by LPS. In summary, LPS was not toxic to bacteria, and lipid A of LPS stimulated the growth of lactate-producing bacteria. Our results indicate that LPS not only is increased during acidosis but also may contribute to ruminal acidosis development by increasing the growth of lactic acid-producing bacteria. IMPORTANCE Gram-negative bacteria contain lipopolysaccharide (LPS) coating their thin peptidoglycan cell wall. The presence of LPS has been suggested to be associated with a metabolic disorder of cattle—ruminal acidosis—through affecting ruminal bacteria. Ruminal acidosis could reduce feed intake and milk production and increase the incidence of diarrhea, milk fat depression, liver abscesses, and laminitis. However, how LPS affects bacteria associated with ruminal acidosis has not been studied. In this study, we investigated how LPS affects the growth of ruminal bacteria by pure cultures, including those that contribute to acidosis, and the functional genes of ruminal bacteria. Thus, this work serves to further our understanding of the roles of LPS in the pathogenesis of ruminal acidosis, as well as providing information that may be useful for the prevention of ruminal acidosis and reducetion of economic losses for farmers.

Alzheimer's disease (AD) is an age-related neurodegenerative pathology associated with accumulation of DNA damage. Inflammation and cell cycle alterations seem to be implicated in the pathogenesis of AD, although the molecular mechanisms have not been thoroughly elucidated to date. The aim of the present study was to evaluate whether peripheral blood mononuclear cells (PBMCs) of AD patients display alterations in gene expression profiles, focusing on finding markers that might improve the diagnosis of AD. Blood samples were collected from 22 AD patients and 13 healthy individuals to perform genome-wide mRNA expression. We found 593 differentially expressed genes in AD compared to controls, from which 428 were upregulated, and 165 were downregulated. By performing a gene set enrichment analysis, we observed pathways involved in inflammation, DNA damage response, cell cycle, and neuronal processes. Moreover, functional annotation analyses indicated that differentially expressed genes are strongly related to pathways associated with the cell cycle and the immune system. The results were compared with those of an independent study on hippocampus samples, and a number of genes in common between both studies were identified as potential peripheral biomarkers for AD, including DUSP1, FOS, SLC7A2, RGS1, GFAP, CCL2, ANGPTL4, and SSPN. Taken together, our results demonstrate that PBMCs of AD patients do present alterations in gene expression profiles, and these results are comparable to those previously reported in the literature for AD neurons, supporting the hypothesis that blood peripheral mononuclear cells express molecular changes that occur in the neurons of AD patients.

Background The use of telemedicine has become a fundamental tool in healthcare in recent years, especially at times of Covid-19 pandemic. Currently, there are several telemedicine tools that are simple, inexpensive, and effective means of communication. This article aims to describe indicators of feasibility including patient recruitment, attendance, discomfort (internet connection issues and/or noncompliant patient behavior), satisfaction, and travel time and cost savings of virtual telemedicine consultations for patients with dementia. Methods The study was conducted at the Geriatrics Department of Hospital Universitário Walter Cantídio (HUWC) in Fortaleza, Brazil, between May 1st and December 31, 2020. The eligibility criteria included previous diagnosis of dementia syndrome and receiving care at the hospital’s dementia outpatient clinic in face-to-face consultations in the preceding 12 months. Patients were excluded if they did not feel comfortable with virtual consultations, did not have the required communication technology available or their caregiver was not available to attend the remote consultation. The patients were recruited from the outpatient dementia clinic’s medical appointment scheduling list. The intervention was designed as a one-time consultation and it included treatment approaches and health promotion recommendations. Results Patient recruitment, attendance and discomfort rates were 85.5%, 97.7% and 9.4%, respectively. To attend face-to-face visits, they reported an average travel time (including the consultation) of 233.21 minutes and average total cost of 60.61 reais (around USD 11). The study intervention was well accepted among the patients and their caregivers with 97.6% being satisfied. Many were happy to avoid long waits in crowded medical waiting rooms and the risk of covid-19 contagion. Conclusions We found good recruitment, attendance, and acceptance rates of remote care for the follow-up of dementia patients as well as low discomfort rates. Trial registration Brazilian Trial Registry (REBEC) RBR-9xs978.