👤 Brian Hubbard

Mild traumatic brain injury can disrupt brain function and is associated with high morbidity and healthcare utilization. While many individuals recover from mild traumatic brain injury, a significant proportion experience long-term sequelae, collectively known as post-concussion syndrome. Symptoms of post-concussion syndrome include headache, dizziness, insomnia, cognitive processing difficulties and mental health disturbances. The disease burden is augmented by the current lack of objective measures to accurately predict long-term symptoms and deficits, providing an opportunity to utilize biomarkers in biofluids. A large proportion of available diagnostic clinical tools are subjective symptom scores. This review aims to explore current fluid biomarkers, grouped by clinical symptoms. With the available literature, we have discovered a wide range of fluid biomarkers that have been investigated for predicting post-traumatic headache, including neuropeptides; sleep disturbances, such as cortisol and melatonin; vestibular disturbances, including interleukin-6 and neurone-specific enolase; and vomiting, such as S100B. Along with physical symptoms, biomarkers investigated for predicting cognitive disturbances include inflammatory markers, S100B, neurofilament light chain, tau, microRNA and hormones. Biomarkers to predict mental health disturbances may include brain-derived neurotrophic factor, tau and cortisol. By utilizing such biomarkers, there is capacity to adopt a personalized medicine approach to facilitate early interventions for those most in need while also identifying individuals with a favourable prognosis who can safely return to their normal activities. Show less

FGFR alterations are known to be driver alterations in several tumor types. We aimed to assess the efficacy of pemigatinib, an oral FGFR1-3 inhibitor, in patients with metastatic or unresectable colorectal cancer whose tumors harbored FGF/FGFR alterations. The ACCRU-GI-1701 is a single-arm phase II trial which enrolled patients with previously treated FGF/FGFR-altered metastatic colorectal cancer to receive oral pemigatinib daily in 21-day cycles. The primary endpoint is objective response. Secondary endpoints include clinical benefit, progression-free survival, overall survival, quality of life, and adverse events (AEs). This trial was registered with ClinicalTrials.gov (NCT04096417). Of the 14 patients included in the interim analysis, the objective response rate as well as clinical benefit rate were 0%. Given these results, the trial closed to enrollment after stage one due to futility. A total of 42.9% of patients had at least one grade 3 or higher AE, the most common being anemia and fatigue. Pemigatinib monotherapy did not lead to objective responses in patients with chemorefractory metastatic colorectal cancer harboring FGF/FGFR alterations, although it was overall relatively well tolerated with no new safety signals. Notably, 93% (n = 13) of patients had only FGF/FGFR mutations and amplifications; one patient had an FGFR3-WHSC1 fusion at a low cfDNA percentage (0.02%). Show less

Apolipoprotein A5 (APOA5) regulates the metabolisms of triglyceride and HDL. APOA5 variants have been linked to coronary artery disease (CAD), but their causal roles are not well studied yet. This study aims to identify the causal effects of APOA5 variants on premature CAD. Sequencing analysis of APOA5 in 128 premature, familiar CAD patients from GeneQuest identified 11 genomic variants, including p.S19W (rs3135506). SKAT analysis showed that all sequenced variants, in aggregate, significantly increased the risk of premature CAD (P-skat = 0.037). Individually, the p.S19W variant was significantly associated with risk of premature CAD (OR = 2.30, P = 0.008) in an independent set of 342 premature CAD patients and 537 controls after adjusting for covariates of sex, age, hypertension, body mass index, triglycerides (TGs), and total, LDL-, and HDL-cholesterol levels. Meanwhile, p.S19W significantly correlated with HDL-C levels (P = 0.048) and TG levels (P = 0.025). Mediation analysis yielded a mediation effect of p.S19W on risk of premature CAD through HDL-C (OR = 0.98, P = 0.040) and TG (OR = 0.98, P = 0.042), suggesting a causal relationship between p.S19W and premature CAD partially through its effects on HDL-C and TG levels. These results suggest that APOA5 variation regulates TG and HDL levels, thus displaying a causal role in the development of CAD. Show less

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. We enrolled 39 participants in a fixed-sequence, double-blind study of the effects of anacetrapib on the metabolism of apoB and high-density lipoproteins. Twenty-nine patients were randomized to atorvastatin 20 mg/d, plus placebo for 4 weeks, and then atorvastatin plus anacetrapib (100 mg/d) for 8 weeks. The other 10 subjects were randomized to double placebo for 4 weeks followed by placebo plus anacetrapib for 8 weeks. We examined the mechanisms of Lp(a) lowering in a subset of 12 subjects having both Lp(a) levels >20 nmol/L and more than a 15% reduction in Lp(a) by the end of anacetrapib treatment. We performed stable isotope kinetic studies using Anacetrapib reduces Lp(a) levels by decreasing its production. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00990808. Show less

Understanding the genetic basis of airflow obstruction and smoking behaviour is key to determining the pathophysiology of chronic obstructive pulmonary disease (COPD). We used UK Biobank data to study the genetic causes of smoking behaviour and lung health. We sampled individuals of European ancestry from UK Biobank, from the middle and extremes of the forced expiratory volume in 1 s (FEV1) distribution among heavy smokers (mean 35 pack-years) and never smokers. We developed a custom array for UK Biobank to provide optimum genome-wide coverage of common and low-frequency variants, dense coverage of genomic regions already implicated in lung health and disease, and to assay rare coding variants relevant to the UK population. We investigated whether there were shared genetic causes between different phenotypes defined by extremes of FEV1. We also looked for novel variants associated with extremes of FEV1 and smoking behaviour and assessed regions of the genome that had already shown evidence for a role in lung health and disease. We set genome-wide significance at p<5 × 10(-8). UK Biobank participants were recruited from March 15, 2006, to July 7, 2010. Sample selection for the UK BiLEVE study started on Nov 22, 2012, and was completed on Dec 20, 2012. We selected 50,008 unique samples: 10,002 individuals with low FEV1, 10,000 with average FEV1, and 5002 with high FEV1 from each of the heavy smoker and never smoker groups. We noted a substantial sharing of genetic causes of low FEV1 between heavy smokers and never smokers (p=2.29 × 10(-16)) and between individuals with and without doctor-diagnosed asthma (p=6.06 × 10(-11)). We discovered six novel genome-wide significant signals of association with extremes of FEV1, including signals at four novel loci (KANSL1, TSEN54, TET2, and RBM19/TBX5) and independent signals at two previously reported loci (NPNT and HLA-DQB1/HLA-DQA2). These variants also showed association with COPD, including in individuals with no history of smoking. The number of copies of a 150 kb region containing the 5' end of KANSL1, a gene that is important for epigenetic gene regulation, was associated with extremes of FEV1. We also discovered five new genome-wide significant signals for smoking behaviour, including a variant in NCAM1 (chromosome 11) and a variant on chromosome 2 (between TEX41 and PABPC1P2) that has a trans effect on expression of NCAM1 in brain tissue. By sampling from the extremes of the lung function distribution in UK Biobank, we identified novel genetic causes of lung function and smoking behaviour. These results provide new insight into the specific mechanisms underlying airflow obstruction, COPD, and tobacco addiction, and show substantial shared genetic architecture underlying airflow obstruction across individuals, irrespective of smoking behaviour and other airway disease. Medical Research Council. Show less

Clozapine and its two major metabolites, N-desmethylclozapine and clozapine N-oxide were quantified using a high-performance liquid chromatographic method with UV detection in dog plasma following a single dose of clozapine. The analysis was performed on a 5-micrometer Hypersil CN (CPS-1; 250x4.6 mm) column. The mobile phase consisted of acetonitrile-water-1 M ammonium acetate (50:49:1, v/v/v), which was adjusted to pH 5.0 with acetic acid. The detection wavelength was 254 nm. A liquid-liquid extraction technique was used to extract clozapine and its metabolites from dog plasma. The recovery rates for clozapine, N-desmethylclozapine, and the internal standard (I.S.) were close to 100% using this method. The recovery rate for clozapine N-oxide (62-66%) was lower as expected because it is more polar. The quantitation limits for clozapine, clozapine N-oxide, and N-desmethylclozapine were 0.11, 0.05 and 0.05 microM, respectively. Intra-day reproducibility for concentrations of 0.1, 1.0 and 5.0 microM were 10.0, 4.4 and 4.2%, respectively, for N-oxide; 11.2, 4.3 and 4.9%, respectively, for N-desmethylclozapine; and 10.8, 2.2 and 4.9%, respectively, for clozapine. Inter-day reproducibility was <15% for clozapine N-oxide, <8% for N-desmethylclozapine and <19% for clozapine. This simple method was applied to determine the plasma concentration profiles of clozapine, N-desmethylclozapine and clozapine N-oxide in dog following administration of a 10 mg/kg oral dose of clozapine. Show less