Air Pollution Particulate Matter Exposure and Chronic Cerebral Hypoperfusion and Measures of White Matter Injury in a Murine Model

BACKGROUND: Exposure to ambient air pollution particulate matter (PM) is associated with increased risk of dementia and accelerated cognitive loss. Vascular contributions to cognitive impairment are well recognized. Chronic cerebral hypoperfusion (CCH) promotes neuroinflammation and blood–brain barrier weakening, which may augment neurotoxic effects of PM. OBJECTIVES: This study examined interactions of nanoscale particulate matter (nPM; fine particulate matter with aerodynamic diameter [Formula: see text]) and CCH secondary to bilateral carotid artery stenosis (BCAS) in a murine model to produce white matter injury. Based on other air pollution interactions, we predicted synergies of nPM with BCAS. METHODS: nPM was collected using a particle sampler near a Los Angeles, California, freeway. Mice were exposed to 10 wk of reaerosolized nPM or filtered air (FA) for 150 h. CCH was induced by BCAS surgery. Mice (C57BL/6J males) were randomized to four exposure paradigms: a) FA, b) nPM, c) [Formula: see text] , and d) [Formula: see text]. Behavioral outcomes, white matter injury, glial cell activation, inflammation, and oxidative stress were assessed. RESULTS: The joint [Formula: see text] group exhibited synergistic effects on white matter injury (2.3× the additive nPM and [Formula: see text] scores) with greater loss of corpus callosum volume on T2 magnetic resonance imaging (MRI) (30% smaller than FA group). Histochemical analyses suggested potential microglial-specific inflammatory responses with synergistic effects on corpus callosum C5 immunofluorescent density and whole brain nitrate concentrations (2.1× and 3.9× the additive nPM and [Formula: see text] effects, respectively) in the joint exposure group. Transcriptomic responses (RNA-Seq) showed greater impact of [Formula: see text] than individual additive effects, consistent with changes in proinflammatory pathways. Although nPM exposure alone did not alter working memory, the [Formula: see text] cohort demonstrated impaired working memory when compared to the [Formula: see text] group. DISCUSSION: Our data suggest that nPM and CCH contribute to white matter injury in a synergistic manner in a mouse model. Adverse neurological effects may be aggravated in a susceptible population exposed to air pollution. https://doi.org/10.1289/EHP879

Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia

Saw palmetto (SP), a botanical extract with antiandrogenic properties, has gained commercial popularity for its purported benefits on hair regrowth. To summarize published evidence on the efficacy, safety, and tolerability of supplements containing SP in the treatment of alopecia, we conducted a PubMed, Google Scholar, and Cochrane database search using the following terms: (saw palmetto and hair loss), (saw palmetto and androgenetic alopecia), and (saw palmetto and natural supplement and alopecia). Five randomized clinical trials (RCTs) and 2 prospective cohort studies demonstrated positive effects of topical and oral supplements containing SP (100-320 mg) among patients with androgenetic alopecia (AGA) and telogen effluvium. Sixty percent improvement in overall hair quality, 27% improvement in total haircount, increased hair density in 83.3% of patients, and stabilized disease progression among 52% were noted with use of various topical and oral SP-containing supplements. SP was well tolerated and not associated with serious adverse events in alopecia patients. Although robust high-quality data are lacking, supplements containing SP may be a treatment option for patients with AGA, telogen effluvium, and self-perceived hair thinning. Further large-scale RCTs focusing on the sole contribution of SP to hair growth outcomes are needed to confirm efficacy and determine long-term adverse events

The Effects of Smoking on Hair Health: A Systematic Review.

Smoking is not only a preventable cause of significant systemic disease but also affects the follicular growth cycle and fiber pigmentation. Ambient tobacco smoke exposure results in nicotine accumulation in hair follicles and the hair shaft. This review summarizes the evidence on the association between smoking and hair health, as denoted by alopecia and premature hair graying (PHG). In July 2020, a review of the literature using PubMed/MEDLINE and CINAHL databases identified 32 studies investigating the relationship between smoking, PHG, and alopecia (androgenetic alopecia and frontal fibrosing alopecia). The prevalence of hair loss and PHG is more prevalent in smokers than nonsmokers. Smoking is associated with negative effects on hair health as evidenced in PHG and alopecia. Smoking status should be assessed in patients who are presenting to their dermatologist for evaluation of alopecia and PHG

Encephaloduroarteriosynangiosis Operative Technique and Intraoperative Anesthesia Management: Treatment From Both Sides of the Curtain.

BACKGROUND: Encephaloduroarteriosynangiosis (EDAS) is a form of indirect revascularization for cerebral arterial steno-occlusive disorders. EDAS has gained growing interest as a technique applicable to pediatric and adult populations for several types of ischemic cerebral steno-occlusive conditions. OBJECTIVE: To present a team-oriented, multidisciplinary update of the EDAS technique for application in challenging adult cases of cerebrovascular stenosis/occlusion, successfully implemented in more than 200 cases. METHODS: We describe and demonstrate step-by-step a multidisciplinary-modified EDAS technique, adapted to maintain uninterrupted intensive medical management of patients\u27 stroke risk factors and anesthesia protocols to maintain strict hemodynamic control. RESULTS: A total of 216 EDAS surgeries were performed in 164 adult patients, including 65 surgeries for patients with intracranial atherosclerotic disease and 151 operations in 99 patients with moyamoya disease. Five patients with intracranial atherosclerotic disease had recurrent strokes (3%), and there was one perioperative death. The mean clinical follow-up was 32.9 mo with a standard deviation of 31.1. There was one deviation from the surgical protocol. There were deviations from the anesthesia protocol in 3 patients (0.01%), which were promptly corrected and did not have any clinical impact on the patients\u27 condition. CONCLUSION: The EDAS protocol described here implements a team-oriented, multidisciplinary adaptation of the EDAS technique. This adaptation resides mainly in 3 points: (1) uninterrupted administration of intensive medical management, (2) strict hemodynamic control during anesthesia, and (3) meticulous standardized surgical technique

Nanoparticulate matter exposure results in neuroinflammatory changes in the corpus callosum.

Epidemiological studies have established an association between air pollution particulate matter exposure (PM2.5) and neurocognitive decline. Experimental data suggest that microglia play an essential role in air pollution PM-induced neuroinflammation and oxidative stress. This study examined the effect of nano-sized particulate matter (nPM) on complement C5 deposition and microglial activation in the corpus callosum of mice (C57BL/6J males). nPM was collected in an urban Los Angeles region impacted by traffic emissions. Mice were exposed to 10 weeks of re-aerosolized nPM or filtered air for a cumulative 150 hours. nPM-exposed mice exhibited reactive microglia and 2-fold increased local deposition of complement C5/ C5α proteins and complement component C5a receptor 1 (CD88) in the corpus callosum. However, serum C5 levels did not differ between nPM and filtered air cohorts. These findings demonstrate white matter C5 deposition and microglial activation secondary to nPM exposure. The C5 upregulation appears to be localized to the brain