Publications by authors named "John Millar"

Combined antiretroviral therapy (cART) has greatly decreased mortality and morbidity among persons with HIV; however, neurologic impairments remain prevalent, in particular HIV-associated neurocognitive disorders (HANDs). White matter damage persists in cART-treated persons with HIV and may contribute to neurocognitive dysfunction as the lipid-rich myelin membrane of oligodendrocytes is essential for efficient nerve conduction. Because of the importance of lipids to proper myelination, we examined the regulation of lipid synthesis in oligodendrocyte cultures exposed to the integrase strand transfer inhibitor elvitegravir (EVG), which is administered to persons with HIV as part of their initial regimen.

View Article and Find Full Text PDF

It is important to determine if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and SARS-CoV-2 mRNA vaccinations elicit different types of antibodies. Here, we characterize the magnitude and specificity of SARS-CoV-2 spike-reactive antibodies from 10 acutely infected health care workers with no prior SARS-CoV-2 exposure history and 23 participants who received SARS-CoV-2 mRNA vaccines. We found that infection and primary mRNA vaccination elicit S1- and S2-reactive antibodies, while secondary vaccination boosts mostly S1 antibodies.

View Article and Find Full Text PDF

Repeated hypoglycemia exposure leads to impaired awareness of hypoglycemia (IAH) and the development of defective counterregulatory responses. To date, only pancreas or islet transplantation has demonstrated normalization of hypoglycemia awareness and the endogenous glucose production (EGP) response to defend against insulin-induced hypoglycemia in long-standing type 1 diabetes (T1D). This study aims to validate clinical metrics of IAH (Clarke score), hypoglycemia severity (HYPO score), glycemic lability (lability index), and continuous glucose monitoring (CGM) as predictors of absent autonomic symptom (AS) recognition and defective glucose counterregulation during insulin-induced hypoglycemia, thus enabling early identification of individuals with compromised physiologic defense against clinically significant hypoglycemia.

View Article and Find Full Text PDF

Background: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time.

View Article and Find Full Text PDF

High-density lipoprotein cholesterol (HDL-C) is thought to be atheroprotective yet some patients with elevated HDL-C levels develop cardiovascular disease, possibly due to the presence of dysfunctional HDL. We aimed to assess the metabolic fate of circulating HDL particles in patients with high HDL-C with and without coronary artery disease (CAD) using in vivo dual labeling of its cholesterol and protein moieties. We measured HDL apolipoprotein (apo) A-I, apoA-II, free cholesterol (FC), and cholesteryl ester (CE) kinetics using stable isotope-labeled tracers (D-leucine and C-acetate) as well as ex vivo cholesterol efflux to HDL in subjects with ( = 6) and without ( = 6) CAD that had HDL-C levels >90th percentile.

View Article and Find Full Text PDF

Genetic variants near the TRIB1 gene are highly significantly associated with plasma lipid traits and coronary artery disease. While TRIB1 is likely causal of these associations, the molecular mechanisms are not well understood. Here we sought to investigate how TRIB1 influences low density lipoprotein cholesterol (LDL-C) levels in mice.

View Article and Find Full Text PDF
Article Synopsis
  • Triglyceride-rich lipoproteins (TRLs) serve as important energy sources for tissues, with lipoprotein lipase (LPL) being the main enzyme responsible for breaking down triglycerides and clearing TRLs from circulation.
  • The study investigated the effects of endothelial lipase (EL) on TRL metabolism, focusing on humans and mice with genetic variations affecting EL function, leading to increased plasma triglycerides and impaired TRL clearance.
  • Findings indicate that EL works alongside LPL to enhance triglyceride breakdown, demonstrating its significant role in TRL metabolism which could have implications for understanding lipid-related conditions.
View Article and Find Full Text PDF

Some studies suggest that recent common coronavirus (CCV) infections are associated with reduced COVID-19 severity upon SARS-CoV-2 infection. We completed serological assays using samples collected from health care workers to identify antibody types associated with SARS-CoV-2 protection and COVID-19 symptom duration. Rare SARS-CoV-2 cross-reactive antibodies elicited by past CCV infections were not associated with protection; however, the duration of symptoms following SARS-CoV-2 infections was significantly reduced in individuals with higher common betacoronavirus (βCoV) antibody titers.

View Article and Find Full Text PDF

Recent common coronavirus (CCV) infections are associated with reduced COVID-19 severity upon SARS-CoV-2 infection, however the immunological mechanisms involved are unknown. We completed serological assays using samples collected from health care workers to identify antibody types associated with SARS-CoV-2 protection and COVID-19 severity. Rare SARS-CoV-2 cross-reactive antibodies elicited by past CCV infections were not associated with protection; however, the duration of symptoms following SARS-CoV-2 infections was significantly reduced in individuals with higher common betacoronavirus (βCoV) antibody titers.

View Article and Find Full Text PDF

Rationale: Single-nucleotide polymorphisms near the (inflammation and lipid regulator with ubiquitin-associated-like and NBR1 [next to gene 1 protein]-like domains) gene are genome-wide significantly associated with plasma lipid traits and coronary artery disease (CAD), but the biological basis of this association is unknown.

Objective: To investigate the role of ILRUN in plasma lipid and lipoprotein metabolism.

Methods And Results: encodes a protein that contains a ubiquitin-associated-like domain, suggesting that it may interact with ubiquitinylated proteins.

View Article and Find Full Text PDF

Objectives: Masson tumor or intravascular papillary endothelial cell proliferation was first described in 1923. Only a few cases of intracranial Masson tumor have been reported following stereotactic radiosurgery (SRS). We report a series of 6 cases, age range 28-56 years, with intracranial Masson tumor following SRS for treatment of an intracranial arteriovenous malformation (AVM).

View Article and Find Full Text PDF

Purpose: The purpose of this paper is to present a detailed case study of the evaluation strategies of a complex, multi-faceted response to a public health emergency: drug-related overdose deaths. It sets out the challenges of evaluating such a complex response and how they were overcome. It provides a pragmatic example of the rationale and issues faced to address the what, the why and particularly the how of the evaluation.

View Article and Find Full Text PDF

Background: Apo (apolipoprotein) M mediates the physical interaction between high-density lipoprotein (HDL) particles and sphingosine-1-phosphate (S1P). Apo M exerts anti-inflammatory and cardioprotective effects in animal models.

Methods: In a subset of PHFS (Penn Heart Failure Study) participants (n=297), we measured apo M by Enzyme-Linked ImmunoSorbent Assay (ELISA).

View Article and Find Full Text PDF

Background: Bariatric surgery is associated with improved cardiovascular outcomes and also affects lipid levels, but few studies have compared the effects of Roux-en-Y gastric bypass (RYGB) surgery with those of laparoscopic sleeve gastrectomy (LSG) on serum fatty acid levels. The present study compares the effects of RYGB and LSG surgeries on serum fatty acid levels.

Methods: The study participants were women who were undergoing either RYGB or LSG and body mass index (BMI)-matched controls.

View Article and Find Full Text PDF

The originally published version of the Supplementary Information file associated with this Article contained an error in Supplementary Figure 3. Panel b was inadvertently replaced with a duplicate of panel a. The error has now been fixed and the corrected version of the Supplementary Information PDF is available to download from the HTML version of the Article.

View Article and Find Full Text PDF

Nitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, metagenomics, and in vitro assays.

View Article and Find Full Text PDF

Background: The outcomes of microsurgery of previously coiled aneurysms have been poorly described, and little is known about the factors predictive of poor outcome. Here we aimed to identify predictors of poor outcome following microsurgery for previously coiled recurrent aneurysms.

Methods: In this retrospective cohort study of a prospectively maintained vascular database, we reviewed presentations, recurrent aneurysm measurements, surgery, and outcomes of microsurgical clipping of recurrent previously coiled intracranial aneurysms.

View Article and Find Full Text PDF

Purpose Of Review: Cholesterol metabolism has been the object of intense investigation for decades. This review focuses on classical and novel methods assessing in vivo cholesterol metabolism in humans. Two factors have fueled cholesterol metabolism studies in the last few years: the renewed interest in the study of reverse cholesterol transport (RCT) as an atheroprotective mechanism and the importance of the gut microbiome in affecting cholesterol metabolism.

View Article and Find Full Text PDF

Objective: To gain mechanistic insights into the role of (lipase A), the gene encoding LAL (lysosomal acid lipase) protein, in human macrophages.

Approach And Results: We used CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) technology to knock out in human induced pluripotent stem cells and then differentiate to macrophage (human-induced pluripotent stem cells-derived macrophage [IPSDM]) to explore the human macrophage loss-of-function phenotypes. was abundantly expressed in monocyte-derived macrophages and was markedly induced on IPSDM differentiation to comparable levels as in human monocyte-derived macrophage.

View Article and Find Full Text PDF

Recent large-scale genetic sequencing efforts have identified rare coding variants in genes in the triglyceride-rich lipoprotein (TRL) clearance pathway that are protective against coronary heart disease (CHD), independently of LDL cholesterol (LDL-C) levels. Insight into the mechanisms of protection of these variants may facilitate the development of new therapies for lowering TRL levels. The gene APOC3 encodes apoC-III, a critical inhibitor of triglyceride (TG) lipolysis and remnant TRL clearance.

View Article and Find Full Text PDF

Background: Long-term outcomes following occlusion of spinal dural arteriovenous fistula (SDAVF) are poorly understood and are based on small series reporting predominantly short-term outcomes. The degree and duration of improvement remain unclear. In this study, we analyzed long-term outcomes following occlusion in a cohort of patients with SDAVF.

View Article and Find Full Text PDF

Objective: Recovery of oculomotor nerve palsy after microsurgical and endovascular treatment has been studied in numerous small series of predominantly ruptured aneurysms. Little consideration has been given to the distinction between ruptured and unruptured aneurysms. This study examines the influence of treatment modality on oculomotor palsy recovery as a result of unruptured posterior communicating artery aneurysms.

View Article and Find Full Text PDF

Objective: Lp(a) [lipoprotein (a)] is composed of apoB (apolipoprotein B) and apo(a) [apolipoprotein (a)] and is an independent risk factor for cardiovascular disease and aortic stenosis. In clinical trials, anacetrapib, a CETP (cholesteryl ester transfer protein) inhibitor, causes significant reductions in plasma Lp(a) levels. We conducted an exploratory study to examine the mechanism for Lp(a) lowering by anacetrapib.

View Article and Find Full Text PDF