scholarly journals Modeling traumatic brain injury combined with hemorrhagic shock in rats: Neurological assessment and PET imaging with 18F-fluorodeoxyglucaric acid

2021 ◽  
Author(s):  
Hibah O Awwad ◽  
Andria Hedrick ◽  
Alex Mdzinarishvili ◽  
Hailey Houson ◽  
Kelly Standifer ◽  
...  

Traumatic brain injury (TBI)is a major cause of death and disability worldwide. Hemorrhagic shock (HS) aggravates tissue injury and complicates TBI recovery. We studied the combined insult of mild TBI and HS and investigated the impact of varying loss of blood volume on neurologic deficit and brain lesion volume. A novel positron emission tomography (PET) technique was employed to monitor tissue injury. Male Sprague Dawley rats received mTBI by controlled cortical impact (CCI) followed by withdrawal of 0%, 30-40%, 45%, or 50% of blood (mTBI, mTBI+HS≤40%, mTBI+HS45%, and mTBI+HS50%, respectively). Neurological deficit (mNSS= 5.6, 7.6, and 12.3) and mortality (2/12, 2/6, and 7/12) were higher in mTBI+HS≤40%, mTBI+HS45%, and mTBI+HS50%, than in mTBI alone rats (no death; mNSS=3.3). Histologic lesion size increased 3.5-fold in mTBI+HS50% compared to mTBI alone and the infarct-avid PET agent 18F-fluorodeoxyglucaric acid (FGA) proportionately detected tissue necrosis in mTBI+HS50% rats. Based on these results, we conclude that HS aggravates mTBI-induced neurological deficits, tissue injury and mortality. PET using 18F-FGA as an imaging marker can detect the extent of injury in a non-invasive manner.

2017 ◽  
Vol 83 (6) ◽  
pp. 1066-1073 ◽  
Author(s):  
Vahagn C. Nikolian ◽  
Patrick E. Georgoff ◽  
Manjunath P. Pai ◽  
Isabel S. Dennahy ◽  
Kiril Chtraklin ◽  
...  

Critical Care ◽  
2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Rita Campos-Pires ◽  
Haldis Onggradito ◽  
Eszter Ujvari ◽  
Shughoofa Karimi ◽  
Flavia Valeo ◽  
...  

Abstract Background Traumatic brain injury (TBI) is a major cause of morbidity and mortality, but there are no clinically proven treatments that specifically target neuronal loss and secondary injury development following TBI. In this study, we evaluate the effect of xenon treatment on functional outcome, lesion volume, neuronal loss and neuroinflammation after severe TBI in rats. Methods Young adult male Sprague Dawley rats were subjected to controlled cortical impact (CCI) brain trauma or sham surgery followed by treatment with either 50% xenon:25% oxygen balance nitrogen, or control gas 75% nitrogen:25% oxygen. Locomotor function was assessed using Catwalk-XT automated gait analysis at baseline and 24 h after injury. Histological outcomes were assessed following perfusion fixation at 15 min or 24 h after injury or sham procedure. Results Xenon treatment reduced lesion volume, reduced early locomotor deficits, and attenuated neuronal loss in clinically relevant cortical and subcortical areas. Xenon treatment resulted in significant increases in Iba1-positive microglia and GFAP-positive reactive astrocytes that was associated with neuronal preservation. Conclusions Our findings demonstrate that xenon improves functional outcome and reduces neuronal loss after brain trauma in rats. Neuronal preservation was associated with a xenon-induced enhancement of microglial cell numbers and astrocyte activation, consistent with a role for early beneficial neuroinflammation in xenon’s neuroprotective effect. These findings suggest that xenon may be a first-line clinical treatment for brain trauma.


2019 ◽  
Vol 20 (11) ◽  
pp. 2639 ◽  
Author(s):  
Mona Shehadeh ◽  
Eilam Palzur ◽  
Liat Apel ◽  
Jean Francois Soustiel

Experimental studies have shown that ligands of the 18 kDa translocator protein can reduce neuronal damage induced by traumatic brain injury by protecting mitochondria and preventing metabolic crisis. Etifoxine, an anxiolytic drug and 18 kDa translocator protein ligand, has shown beneficial effects in the models of peripheral nerve neuropathy. The present study investigates the potential effect of etifoxine as a neuroprotective agent in traumatic brain injury (TBI). For this purpose, the effect of etifoxine on lesion volume and modified neurological severity score at 4 weeks was tested in Sprague–Dawley adult male rats submitted to cortical impact contusion. Effects of etifoxine treatment on neuronal survival and apoptosis were also assessed by immune stains in the perilesional area. Etifoxine induced a significant reduction in the lesion volume compared to nontreated animals in a dose-dependent fashion with a similar effect on neurological outcome at four weeks that correlated with enhanced neuron survival and reduced apoptotic activity. These results are consistent with the neuroprotective effect of etifoxine in TBI that may justify further translational research.


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Donglin Du ◽  
Wei Tang ◽  
Chao Zhou ◽  
Xiaochuan Sun ◽  
Zhengqiang Wei ◽  
...  

Background. Traumatic brain injury (TBI) can induce persistent fluctuation in the gut microbiota makeup and abundance. The present study is aimed at determining whether fecal microbiota transplantation (FMT) can rescue microbiota changes and ameliorate neurological deficits after TBI in rats. Methods. A controlled cortical impact (CCI) model was used to simulate TBI in male Sprague-Dawley rats, and FMT was performed for 7 consecutive days. 16S ribosomal RNA (rRNA) sequencing of fecal samples was performed to analyze the effects of FMT on gut microbiota. Modified neurological severity score and Morris water maze were used to evaluate neurobehavioral functions. Metabolomics was used to screen differential metabolites from the rat serum and ipsilateral brains. The oxidative stress indices were measured in the brain. Results. TBI induced significance changes in the gut microbiome, including the alpha- and beta-bacterial diversity, as well as the microbiome composition at 8 days after TBI. On the other hand, FMT could rescue these changes and relieve neurological deficits after TBI. Metabolomics results showed that the level of trimethylamine (TMA) in feces and the level of trimethylamine N-oxide (TMAO) in the ipsilateral brain and serum was increased after TBI, while FMT decreased TMA levels in the feces, and TMAO levels in the ipsilateral brain and serum. Antioxidant enzyme methionine sulfoxide reductase A (MsrA) in the ipsilateral hippocampus was decreased after TBI but increased after FMT. In addition, FMT elevated SOD and CAT activities and GSH/GSSG ratio and diminished ROS, GSSG, and MDA levels in the ipsilateral hippocampus after TBI. Conclusions. FMT can restore gut microbiota dysbiosis and relieve neurological deficits possibly through the TMA-TMAO-MsrA signaling pathway after TBI.


2010 ◽  
Vol 4 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Isaac A. Chang

Background: The estimation of lesion size is an integral part of treatment planning for the clinical applications of radiofrequency ablation. However, to date, studies have not directly evaluated the impact of different computational estimation techniques for predicting lesion size. In this study, we focus on three common methods used for predicting tissue injury: (1) iso-temperature contours, (2) Cumulative equivalent minutes, (3) Arrhenius based thermal injury. Methods: We created a geometric model of a multi-tyne ablation electrode and simulated thermal and tissue injury profiles that result from three calculation methods after 15 minutes exposure to a constant RF voltage source. A hybrid finite element technique was used to calculate temperature and tissue injury. Time-temperature curves were used in the assessment of iso-temperature thresholds and the method of cumulative equivalent minutes. An Arrhenius-based formulation was used to calculate sequential and recursive thermal injury to tissues. Results: The data demonstrate that while iso-temperature and cumulative equivalent minute contours are similar in shape, these two methodologies grossly over-estimate the amount of tissue injury when compared to recursive thermal injury calculations, which have previously been shown to correlate closely with in vitro pathologic lesion volume measurement. In addition, Arrhenius calculations that do not use a recursive algorithm result in a significant underestimation of lesion volume. The data also demonstrate that lesion width and depth are inadequate means of characterizing treatment volume for multi-tine ablation devices. Conclusions: Recursive thermal injury remains the most physiologically relevant means of computationally estimating lesion size for hepatic tumor applications. Iso-thermal and cumulative equivalent minute approaches may produce significant errors in the estimation of lesion size.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Glenn K. Wakam ◽  
Ben E. Biesterveld ◽  
Manjunath P. Pai ◽  
Michael T. Kemp ◽  
Rachel L. O’Connell ◽  
...  

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Jong Youl Kim ◽  
Nuri Kim ◽  
Meshell Johnson ◽  
Midoir A. Yenari

Inflammation which accompanies traumatic brain injury (TBI) can exacerbate neurological deficits. Thus, anti-inflammatory treatments have the potential to improve outcome. Angiotensin II receptor type 1 (ART1) mediates vasoconstriction, and its inhibition has been widely used to treat hypertension. However, recent work has suggested that it may also modulate apoptosis, and neuroinflammation. Thus, treatment with already available ART1 blockers may have additional neuroprotective value. We explore the contribution of ART1 to neuroprotection and brain hemorrhage in a model of TBI. Male, wildtype (Wt) and ART1 knockout (Ko) mice were subjected to TBI using controlled cortical impact (CCI). This model leads to reproducible traumatic brain injury with disruption of motor function and hemorrhage into the area of injury. Sensorimotor function (adhesive removal & elevated body swing tests), brain hemorrhage and lesion size were assessed at 3, 7 and 14 days. To explore the clinical relevance of ART1 in brain injury, we also gave Wt mice an ATR1 inhibitor (candesartan, 0.1mg/kg IP). We found that ATR1 deficient mice were protected from CCI as evidenced by decreased lesion and hemorrhage volumes (decreases of ∼40% in lesion size amongst Ko mice, n=6/group, p<0.05), improved neurobehavioral outcomes (n=6/group, p<0.05) and fewer activated microglia in Ko mice (p<0.05). This was also associated with decreased cytokine expression relative to Wt. Candesartan similarly protected against brain injury and improved neurological outcome out to 14 days post CCI (n=6/group, p<0.05). These data are consistent with the notion that ART1 contributes negatively to traumatic brain injury, and its inhibition or deficiency leads to improved outcomes and decreased immune responses. Considering the clinical availability of ART1 inhibitors, this approach may be a promising novel therapeutic target against TBI and related conditions including stroke.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eric Eyolfson ◽  
Glenn R Yamakawa ◽  
Yannick Griep ◽  
Reid Collins ◽  
Thomas Carr ◽  
...  

Abstract While the physical and behavioral symptomologies associated with a single mild traumatic brain injury (mTBI) are typically transient, repetitive mTBIs (RmTBI) have been associated with persisting neurological deficits. Therefore, this study examined the progressive changes in behavior and the neuropathological outcomes associated with chronic RmTBI through adolescence and adulthood in male and female Sprague Dawley rats. Rats experienced 2 mTBIs/week for 15 weeks and were periodically tested for changes in motor behavior, cognitive function, emotional disturbances, and aggression. Brain tissue was examined for neuropathological changes in ventricle size and presentation of Iba1 and GFAP. We did not see progressively worse behavioral impairments with the accumulation of injuries or time, but did find evidence for neurological and functional change (motor disturbance, reduced exploration, reduced aggression, alteration in depressive-like behavior, deficits in short-term working memory). Neuropathological assessment of RmTBI animals identified an increase in ventricle size, prolonged changes in GFAP, and sex differences in Iba1, in the corpus callosum, thalamus, and medial prefrontal cortex. Telomere length reduced exponentially as the injury load increased. Overall, chronic RmTBI did not result in accumulating behavioral impairment, and there is a need to further investigate progressive behavioral changes associated with repeated injuries in adolescence and young adulthood.


2012 ◽  
Vol 33 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Lesley M Foley ◽  
Alia M Iqbal O'Meara ◽  
Stephen R Wisniewski ◽  
T Kevin Hitchens ◽  
John A Melick ◽  
...  

Secondary insults such as hypotension or hemorrhagic shock (HS) can greatly worsen outcome after traumatic brain injury (TBI). We recently developed a mouse combined injury model of TBI and HS using a controlled cortical impact (CCI) model and showed that 90 minutes of HS can exacerbate neuronal death in hippocampus beneath the contusion. This combined injury model has three clinically relevant phases, a shock, pre hospital, and definitive care phases. Mice were randomly assigned to four groups, shams as well as a CCI only, an HS only, and a CCI + HS groups. The CCI and HS reduced cerebral blood flow (CBF) in multiple regions of interest (ROIs) in the hemisphere ipsilateral and contralateral to injury. Hemorrhagic shock to a level of ~30 mm Hg exacerbated the CCI-induced CBF reductions in multiple ROIs ipsilateral to injury (hemisphere and thalamus) and in the hemisphere contralateral to injury (hemisphere, thalamus, hippocampus, and cortex, all P < 0.05 versus CCI only, HS only or both). An important effect of HS duration was also seen after CCI with maximal CBF reduction seen at 90 minutes ( P < 0.0001 group-time effect in ipsilateral hippocampus). Given that neuronal death in hippocampus is exacerbated by 90 minutes of HS in this model, our data suggest an important role for exacerbation of posttraumatic ischemia in mediating the secondary injury in CCI plus HS. In conclusion, the serial, non invasive assessment of CBF using ASL-MRI (magnetic resonance imaging with arterial spin labeling) is feasible in mice even in the complex setting of combined CCI + HS. The impact of resuscitation therapies and various mutant mouse strains on CBF and other outcomes merits investigation in this model.


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