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The gastrointestinal (GI) system is affected in Alzheimer's disease (AD); however, it is currently unknown whether GI alterations arise as a consequence of central nervous system (CNS) pathology or play a causal role in the pathogenesis. GI mucus is a possible mediator of GI dyshomeostasis in neurological disorders as the CNS controls mucus production and secretion via the efferent arm of the brain−gut axis. The aim was to use a brain-first model of sporadic AD induced by intracerebroventricular streptozotocin (STZ-icv; 3 mg/kg) to dissect the efferent (i.e., brain-to-gut) effects of isolated central neuropathology on the GI mucus. Morphometric analysis of goblet cell mucigen granules revealed altered GI mucus secretion in the AD model, possibly mediated by the insensitivity of AD goblet cells to neurally evoked mucosal secretion confirmed by ex vivo cholinergic stimulation of isolated duodenal rings. The dysfunctional efferent control of the GI mucus secretion results in altered biochemical composition of the mucus associated with reduced mucin glycoprotein content, aggregation, and binding capacity in vitro. Finally, functional consequences of the reduced barrier-forming capacity of the mucin-deficient AD mucus are demonstrated using the in vitro two-compartment caffeine diffusion interference model. Isolated central AD-like neuropathology results in the loss of efferent control of GI homeostasis via the brain−gut axis and is characterized by the insensitivity to neurally evoked mucosal secretion, altered mucus constitution with reduced mucin content, and reduced barrier-forming capacity, potentially increasing the susceptibility of the STZ-icv rat model of AD to GI and systemic inflammation induced by intraluminal toxins, microorganisms, and drugs.

Accumulating evidence supports the involvement of the gastrointestinal (GI) system in Alzheimer's disease (AD), however, it is currently unknown whether GI alterations arise as a consequence of central nervous system (CNS) pathology or play a causal role in the pathogenesis of the disease. The GI mucus system is a possible mediator of GI dyshomeostasis in neurological disorders as CNS controls mucus production and secretion via the efferent arm of the brain-gut axis. The aim was to use a brain-first model of sporadic AD induced by intracerebroventricular streptozotocin (STZ-icv) to dissect the efferent (i.e. brain-to-gut) effects of isolated central neuropathology on the GI mucus system. Quantification and morphometric analysis of goblet cell mucigen granules revealed altered GI mucus secretion in the AD model possibly mediated by the insensitivity of AD goblet cells to neurally-evoked mucosal secretion confirmed by ex vivo cholinergic stimulation of isolated duodenal rings. The dysfunctional efferent control of the GI mucus secretion results in altered biochemical composition of the mucus associated with reduced glycoprotein aggregation and binding capacity in vitro. Finally, functional consequences of the reduced barrier-forming capacity of the AD mucus are demonstrated using the in vitro two-compartment caffeine diffusion interference model. Isolated central AD-like neuropathology results in the loss of efferent control of GI homeostasis via the brain-gut axis characterized by the insensitivity to neurally-evoked mucosal secretion, altered mucus constitution, and reduced barrier-forming capacity potentially increasing the susceptibility of STZ-icv rat model of AD to GI and systemic inflammation induced by intraluminal toxins, microorganisms, and drugs.

Evidence has raised concerns regarding the association between funding sources and doubtful data. Our main outcome was to analyze trends on funding sources in articles published from 1990 to 2020 in the more influential journals of internal and general medicine. In this meta-epidemiological study, we included peer-reviewed studies from the 10 highest impact journals in general and internal medicine published between January 1990 and February 2020 based on published original research according to the 2018 InCites Journal of Citation Reports, these consisted of the following: The New England Journal of Medicine, The Lancet, JAMA, BMJ, JAMA Internal Medicine, Annals of Internal Medicine, PLOS Medicine, Cachexia, BMC Medicine, and Mayo Clinic Proceedings. Two reviewers working in duplicate extracted data regarding year of publication, study design, and sources of funding. In total, 496 articles were found; of these, 311 (62.7%) were observational studies, 167 (33.7%) were experimental, and 16 (3.2%) were secondary analyses. Percentages of grant sources through the years were predominantly from government (60%), industry (23.83%), and non-governmental (16.06%) organizations. The percentage of industry subsidies tended to decrease, but this was not significant in a linear regression model (r=0.02, p≥0.05). Government and non-government funding sources showed a trend to decrease in the same univariate analysis with both significant associations (r=0.21, p≤0.001 and r=0.10, p≤0.001, respectively). The main funding source in medical research has consistently been government aid. Despite previous reported data, no association was found between the source of funding and statistically significant results favoring study authors’ hypothesis.

Objective Phaeohyphomycosis is an infection caused by pigmented fungi, which can be life-threatening in immunocompromised hosts and in disseminated disease. In adults with disseminated disease mortality is as high as 79%. Data in children is derived from case reports and series. We conducted this study to review the characteristics of phaeohyphomycoses in children. Methods We conducted this study following the PRISMA 2020 guideline for reporting systematic reviews. We performed a review of the reported cases of pediatric phaeohyphomycoses in core bibliographic databases published in the English and Spanish-language, between June 1977 and October 2021. We included all eligible cases in patients <18 years to determine the clinical characteristics, diagnosis, treatment, and outcomes. Results 130 cases were reviewed. Mean age was 8 years. The most common underlying conditions and risk factors included hematologic malignancies (32.5%), neutropenia (26.9%), steroid therapy (24.6%), trauma or surgery (23.1%), and children that received a transplant (14.6%). The most common presentation was localized infection (61.5%); skin and soft tissue infections were the most prevalent (25.4%). Exserohilum spp (20.8%) and Exophiala spp (17.7%) were the most common organisms isolated. Antifungal therapy remains as the most frequent treatment (87%). Overall mortality rate was 22.3% (localized 13.7% vs disseminated 37.3%). Conclusion The findings of this review suggest that phaeohyphomycoses in children has a better outcome compared to adults. We report a lower mortality rate in children when compared with adults in disseminated infection (37.3% vs 79%) and CNS infection (50% vs 60-70%). However, there is a wide variation in mortality rates according to infection site, treatment, and underlying conditions. Prospective studies are needed.