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result(s) for
"Marek, Lindsay"
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Rapidly Acquired Resistance to EGFR Tyrosine Kinase Inhibitors in NSCLC Cell Lines through De-Repression of FGFR2 and FGFR3 Expression
by
Hercule, Paula
,
Helfrich, Barbara A.
,
Marshall, Marianne E.
in
Analysis
,
Biology
,
Biotechnology
2010
Despite initial and sometimes dramatic responses of specific NSCLC tumors to EGFR TKIs, nearly all will develop resistance and relapse. Gene expression analysis of NSCLC cell lines treated with the EGFR TKI, gefitinib, revealed increased levels of FGFR2 and FGFR3 mRNA. Analysis of gefitinib action on a larger panel of NSCLC cell lines verified that FGFR2 and FGFR3 expression is increased at the mRNA and protein level in NSCLC cell lines in which the EGFR is dominant for growth signaling, but not in cell lines where EGFR signaling is absent. A luciferase reporter containing 2.5 kilobases of fgfr2 5' flanking sequence was activated after gefitinib treatment, indicating transcriptional regulation as a contributing mechanism controlling increased FGFR2 expression. Induction of FGFR2 and FGFR3 protein as well as fgfr2-luc activity was also observed with Erbitux, an EGFR-specific monoclonal antibody. Moreover, inhibitors of c-Src and MEK stimulated fgfr2-luc activity to a similar degree as gefitinib, suggesting that these pathways may mediate EGFR-dependent repression of FGFR2 and FGFR3. Importantly, our studies demonstrate that EGFR TKI-induced FGFR2 and FGFR3 are capable of mediating FGF2 and FGF7 stimulated ERK activation as well as FGF-stimulated transformed growth in the setting of EGFR TKIs. In conclusion, this study highlights EGFR TKI-induced FGFR2 and FGFR3 signaling as a novel and rapid mechanism of acquired resistance to EGFR TKIs and suggests that treatment of NSCLC patients with combinations of EGFR and FGFR specific TKIs may be a strategy to enhance efficacy of single EGFR inhibitors.
Journal Article
Traumatic brain injury: progress and challenges in prevention, clinical care, and research
by
Kent, Hope
,
Maas, Andrew I R
,
Steyerberg, Ewout W
in
Biomarkers
,
Blood pressure
,
Brain Injuries, Traumatic - drug therapy
2022
InTBIR studies have shown that measurement of blood-based biomarkers adds value to previously proposed clinical decision rules, holding the potential to improve efficiency while reducing radiation exposure. Advanced MRI, including diffusion tensor imaging and volumetric analyses, can identify additional injuries not detectable by visual inspection of standard clinical MR images. [...]the absence of CT abnormalities does not exclude structural damage—an observation relevant to litigation procedures, to management of mild TBI, and when CT scans are insufficient to explain the severity of the clinical condition. In the intensive care setting, automated analysis of blood pressure and intracranial pressure with calculation of derived parameters can help individualise management of TBI. TBI affects multiple domains of functioning, and outcomes are affected by personal characteristics and life-course events, consistent with a multifactorial bio-psycho-socio-ecological model of TBI, as presented in the US National Academies of Sciences, Engineering, and Medicine (NASEM) 2022 report.
Journal Article
Adjuvant Trastuzumab in HER2-Positive Breast Cancer
by
Lindsay, Mary-Ann
,
Press, Michael
,
Tabah-Fisch, Isabelle
in
Adjuvants
,
Anthracycline
,
Anthracyclines - adverse effects
2011
Trastuzumab added to a nonanthracycline regimen to treat HER2-positive breast cancer resulted in rates of disease-free and overall survival that were similar to those for an anthracycline-containing regimen, with lower rates of cardiac toxicity and secondary leukemia.
The HER2 gene encodes a tyrosine kinase receptor that mediates critical signaling functions in normal and malignant breast epithelial cells.
1
An acquired alteration consisting of amplification and overexpression of the gene product occurs in approximately 20 to 25% of human breast cancers.
2
,
3
HER2 overexpression is associated with an aggressive clinical phenotype that includes high-grade tumors, increased growth rates, early systemic metastasis, and decreased rates of disease-free and overall survival.
2
,
3
Preclinical data indicate that this adverse clinical picture results from fundamental changes in the biologic features of breast-cancer cells containing the alteration, including increased proliferation, suppression of apoptosis, increased . . .
Journal Article
Clustering identifies endotypes of traumatic brain injury in an intensive care cohort: a CENTER-TBI study
2022
Background
While the Glasgow coma scale (GCS) is one of the strongest outcome predictors, the current classification of traumatic brain injury (TBI) as ‘mild’, ‘moderate’ or ‘severe’ based on this fails to capture enormous heterogeneity in pathophysiology and treatment response. We hypothesized that data-driven characterization of TBI could identify distinct endotypes and give mechanistic insights.
Methods
We developed an unsupervised statistical clustering model based on a mixture of probabilistic graphs for presentation (< 24 h) demographic, clinical, physiological, laboratory and imaging data to identify subgroups of TBI patients admitted to the intensive care unit in the CENTER-TBI dataset (
N
= 1,728). A cluster similarity index was used for robust determination of optimal cluster number. Mutual information was used to quantify feature importance and for cluster interpretation.
Results
Six stable endotypes were identified with distinct GCS and composite systemic metabolic stress profiles, distinguished by GCS, blood lactate, oxygen saturation, serum creatinine, glucose, base excess, pH, arterial partial pressure of carbon dioxide, and body temperature. Notably, a cluster with ‘moderate’ TBI (by traditional classification) and deranged metabolic profile, had a worse outcome than a cluster with ‘severe’ GCS and a normal metabolic profile. Addition of cluster labels significantly improved the prognostic precision of the IMPACT (International Mission for Prognosis and Analysis of Clinical trials in TBI) extended model, for prediction of both unfavourable outcome and mortality (both
p
< 0.001).
Conclusions
Six stable and clinically distinct TBI endotypes were identified by probabilistic unsupervised clustering. In addition to presenting neurology, a profile of biochemical derangement was found to be an important distinguishing feature that was both biologically plausible and associated with outcome. Our work motivates refining current TBI classifications with factors describing metabolic stress. Such data-driven clusters suggest TBI endotypes that merit investigation to identify bespoke treatment strategies to improve care.
Trial registration
The core study was registered with ClinicalTrials.gov, number
NCT02210221
, registered on August 06, 2014, with Resource Identification Portal (RRID: SCR_015582).
Journal Article
Understanding the relationship between cognitive performance and function in daily life after traumatic brain injury
2021
ObjectiveCognitive impairment is a key cause of disability after traumatic brain injury (TBI) but relationships with overall functioning in daily life are often modest. The aim is to examine cognition at different levels of function and identify domains associated with disability.Methods1554 patients with mild-to-severe TBI were assessed at 6 months post injury on the Glasgow Outcome Scale—Extended (GOSE), the Short Form-12v2 and a battery of cognitive tests. Outcomes across GOSE categories were compared using analysis of covariance adjusting for age, sex and education.ResultsOverall effect sizes were small to medium, and greatest for tests involving processing speed (ηp 2 0.057–0.067) and learning and memory (ηp 2 0.048–0.052). Deficits in cognitive performance were particularly evident in patients who were dependent (GOSE 3 or 4) or who were unable to participate in one or more major life activities (GOSE 5). At higher levels of function (GOSE 6–8), cognitive performance was surprisingly similar across categories. There were decreases in performance even in patients reporting complete recovery without significant symptoms. Medium to large effect sizes were present for summary measures of cognition (ηp 2 0.111), mental health (ηp 2 0.131) and physical health (ηp 2 0.252).ConclusionsThis large-scale study provides novel insights into cognitive performance at different levels of disability and highlights the importance of processing speed in function in daily life. At upper levels of outcome, any influence of cognition on overall function is markedly attenuated and differences in mental health are salient.
Journal Article
Traumatic brain injury: integrated approaches to improve prevention, clinical care, and research
by
Schneider, Kathryn J
,
Tibboel, Dick
,
Maas, Andrew I R
in
Aging
,
Alzheimer's disease
,
Brain Injuries - etiology
2017
[...]it might also be possible to specifically target individuals to address their patterns of risk-taking behaviour.183 Irrespective of the target population, information campaigns should employ a range of measures to raise awareness of key issues in prevention and care for TBI. Since awareness of child abuse has increased and family risk factors have been elucidated, local programmes have been developed in the USA and other countries to educate parents about the dangers and long-term effects of brain injury, and to provide caregiver relief and advice on coping skills for stress. The GCS42 is the most commonly used approach to quantify the clinical severity of TBI358 (figure 2), but this is relatively crude and does not reflect different pathoanatomical subsets of TBI. [...]the increasing use of prehospital sedation and tracheal intubation often confounds assessment with the GCS and has reduced its usefulness as a metric of injury severity.359 Existing International Classification of Diseases codes360 also do not adequately capture severity of TBI.361 Alternative TBI coding taxonomies-including the Abbreviated Injury Scale (AIS), which categorises severity of intracranial and extracranial injury,362 and the Marshall classification system, which is based on head CT findings363-are anatomically oriented and summarise the type, location, and severity of injuries. [...]current management strategies are based on guidelines that favour a one-size-fits-all approach, and the care of patients with TBI is therefore poorly individualised (section 5). [...]despite investment of many billions of dollars by pharmaceutical companies, no effective drugs exist for treatment in the acute setting-a failing due, in part, to insufficient targeting of therapies to patients in whom the relevant mechanism is active.
Journal Article
Radiofrequency therapy improves exercise capacity of mice with emphysema
2021
Emphysema is a common phenotype of chronic obstructive pulmonary disease (COPD). Although resection of emphysematous tissue can improve lung mechanics, it is invasive and fraught with adverse effects. Meanwhile, radiofrequency (RF) treatment is an extracorporeal method that leads to tissue destruction and remodeling, resulting in “volume reduction” and overall improvement in lung compliance of emphysematous lungs. Whether these changes lead to improved exercise tolerance is unknown. Here, we investigated the effectiveness of RF treatment to improve the exercise capacity of mice with emphysema. Fifty-two mice (7 weeks of age) were used in this experiment. A bilateral emphysema model was created by intratracheally instilling porcine pancreatic elastase (PPE) (1.5U/100 g body weight). RF treatment (0.5 W/ g body weight) was administered extracorporeally 14 days later and mice were sacrificed after another 21 days. The exercise capacity of mice was measured using a treadmill. Treadmill runs were performed just before PPE instillation (baseline), before RF treatment and before sacrifice. Following sacrifice, lung compliance and mean linear intercept (Lm) were measured and fibrosis was assessed using a modified Ashcroft score. There were 3 experimental groups: controls (instilled with saline, n = 12), emphysema (instilled with porcine pancreatic elastase, PPE, n = 11) and emphysema + treatment (instilled with PPE and given RF, n = 9). At endpoint, the maximum velocity of the emphysema + treatment group was significantly higher than that of the emphysema group, indicating improved exercise tolerance (86.29% of baseline vs 61.69% of baseline, p = 0.01). Histological analysis revealed a significant reduction in emphysema as denoted by Lm between the two groups (median 29.60 µm vs 35.68 µm, p = 0.03). The emphysema + treatment group also demonstrated a higher prevalence of lung fibrosis (≧Grade 3) compared with the emphysema group (11.7% vs 5.4%, p < 0.01). No severe adverse events from RF were observed. RF treatment improved the exercise capacity of mice with emphysema. These data highlight the therapeutic potential of RF treatment in improving the functional status of patients with COPD.
Journal Article
Early systemic insults following traumatic brain injury: association with biomarker profiles, therapy for intracranial hypertension, and neurological outcomes—an analysis of CENTER-TBI data
by
Tibboel, Dick
,
Graziano, Francesca
,
Esser, Patrick
in
Biomarkers
,
Brain
,
Calcium-binding protein
2024
PurposeWe analysed the impact of early systemic insults (hypoxemia and hypotension, SIs) on brain injury biomarker profiles, acute care requirements during intensive care unit (ICU) stay, and 6-month outcomes in patients with traumatic brain injury (TBI).MethodsFrom patients recruited to the Collaborative European neurotrauma effectiveness research in TBI (CENTER-TBI) study, we documented the prevalence and risk factors for SIs and analysed their effect on the levels of brain injury biomarkers [S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), neurofilament light (NfL), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and protein Tau], critical care needs, and 6-month outcomes [Glasgow Outcome Scale Extended (GOSE)].ResultsAmong 1695 TBI patients, 24.5% had SIs: 16.1% had hypoxemia, 15.2% had hypotension, and 6.8% had both. Biomarkers differed by SI category, with higher S100B, Tau, UCH-L1, NSE and NfL values in patients with hypotension or both SIs. The ratio of neural to glial injury (quantified as UCH-L1/GFAP and Tau/GFAP ratios) was higher in patients with hypotension than in those with no SIs or hypoxia alone. At 6 months, 380 patients died (22%), and 759 (45%) had GOSE ≤ 4. Patients who experienced at least one SI had higher mortality than those who did not (31.8% vs. 19%, p < 0.001).ConclusionThough less frequent than previously described, SIs in TBI patients are associated with higher release of neuronal than glial injury biomarkers and with increased requirements for ICU therapies aimed at reducing intracranial hypertension. Hypotension or combined SIs are significantly associated with adverse 6-month outcomes. Current criteria for hypotension may lead to higher biomarker levels and more negative outcomes than those for hypoxemia suggesting a need to revisit pressure targets in the prehospital settings.
Journal Article