Time-Resolved Magnetic Resonance Angiography in the Evaluation of Intracranial Vascular Lesions and Tumors: A Pictorial Essay of Our Experience.

Time-resolved magnetic resonance angiography (TR MRA) is a promising less invasive technique for the diagnosis of intracranial vascular lesions and hypervascular tumors. Similar to 4-dimensional computed tomographic angiography obtaining high frame rate images, TR MRA utilizes acceleration techniques to acquire sequential arterial and venous phase images for identifying, localizing, and classifying vascular lesions. Because of the good agreement with digital subtraction angiography for grading brain arteriovenous malformations with the Spetzler-Martin classification and the good sensitivity for visualizing arteriovenous fistulas, studies have suggested that TR MRA could serve as a screening or routine follow-up tool for diagnosing intracranial vascular disorders. In this pictorial essay, we report on the use of TR MRA at 3.0 T to diagnose intracranial vascular lesions and hypervascular tumors, employing DSA as the reference technique.

A composite score based on cardiovascular parameters can predict the mortality risk of patients with newly diagnosed interstitial lung disease: A prospective observational study.

BACKGROUND: It is crucial to identify factors that can predict the risk of mortality in patients newly diagnosed with interstitial lung disease (ILD). This study sought to develop and assess a composite scoring system for mortality prediction among ILD patients based on cardiovascular parameters, which were previously reported as predictors of survival. METHODS: We prospectively enrolled patients with newly diagnosed ILD and monitored their survival status for 24 months. Surviving and deceased patients were compared regarding their baseline characteristics including clinical, pulmonary, and cardiovascular parameters. A system of composite scores was established based on significant cardiovascular parameters and the Gender-Age-Physiology (GAP) score. Receiver operating characteristic curves were generated to identify their optimal cut-off values. Univariate as well as multiple multivariate regression models were built to investigate the mortality prediction of different individual and combined parameters. RESULTS: Ninety-six patients newly diagnosed with ILD underwent cardiovascular evaluation. In univariate analysis, three cardiovascular parameters were identified as significant predictors of mortality risk in ILD patients, either individually or as a combination of composite scores: tricuspid regurgitation velocity > 3.1 m/s; N-terminal pro-B-type natriuretic peptide level > 300 pg/ml and computed tomography pulmonary artery/ascending aorta diameter ratio > 0.9. In multivariate analysis, a composite score of those parameters [hazard ratio (HR) = 2.37 (confidence interval [CI]:1.06-5.33); p = 0.037; Score 1] and GAP score [HR = 1.62 (CI: 1.11-2.36); p = 0.012] were the most significant predictors for mortality among ILD patients. Combination of Score 1 and GAP score (Score 2) can increase the accuracy of survival predictions (area under the curve 0.83; p < 0.001). CONCLUSIONS: A composite score based on cardiovascular parameters and the GAP score can be used to predict the risk of mortality of patients with ILD. Such a score achieved better diagnostic accuracy than the GAP score alone. Nevertheless, further larger-scale randomized controlled trials are required for evaluation of the newly proposed score and confirmation of our results.

A Summed Score From Cardiopulmonary Exercise Test Parameters Predicts 1-Year Mortality in Newly Diagnosed Interstitial Lung Disease.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is a unique diagnostic tool that assesses the functional capacity of the heart, lungs, and peripheral oxidative system in an integrated manner. However, the clinical utility of CPET for evaluating interstitial lung disease (ILD) remains uncertain. The objective of this study was to determine the predictive value of CPET for mortality in subjects with ILD. METHODS: We prospectively enrolled subjects with ILD who underwent CPET at a tertiary medical center in Taiwan and followed up their survival status for 12 months. Mortality prediction was based on comparing CPET parameters between subjects who survived and those who died. We further analyzed CPET parameters that showed significant differences using receiver operating characteristic curves to identify their optimal cutoff values. RESULTS: A total of 106 newly diagnosed subjects with ILD underwent CPET, and the 1-y mortality rate was 7.5%. Six CPET variables were found to be significant predictors of mortality: peak oxygen consumption, oxygen pulse, end-tidal partial pressure of carbon dioxide, heart rate recovery 1 min after CPET, minute ventilation to carbon dioxide output slope, and functional aerobic impairment. We calculated a summed score by adding the number of CPET variables that exceeded their cutoff values. Subjects with a summed score of 6 had a 1-y survival rate of only 25%, whereas subjects with scores of 0-5 had a survival rate of 98%. CONCLUSIONS: In conclusion, the summed score represents a useful tool for screening patients with ILD who can undergo a CPET to determine their prognosis.

Opportunistic screening with multiphase contrast-enhanced dual-layer spectral CT for osteoblastic lesions in prostate cancer compared with bone scintigraphy.

Our study aimed to compare bone scintigraphy and dual-layer detector spectral CT (DLCT) with multiphase contrast enhancement for the diagnosis of osteoblastic bone lesions in patients with prostate cancer. The patients with prostate cancer and osteoblastic bone lesions detected on DLCT were divided into positive bone scintigraphy group (pBS) and negative bone scintigraphy group (nBS) based on bone scintigraphy. A total of 106 patients (57 nBS and 49 pBS) was included. The parameters of each lesion were measured from DLCT including Hounsfield unit (HU), 40-140 keV monochromatic HU, effective nuclear numbers (Zeff), and Iodine no water (InW) value in non-contrast phase (N), the arterial phase (A), and venous phase (V). The slope of the spectral curve at 40 and 100 keV, the different values of the parameters between A and N phase (A-N), V and N phase (V-N), and hybrid prediction model with multiparameters were used to differentiate pBS from nBS. Receiver operating characteristic analysis was performed to compare the area under the curve (AUC) for differentiating the pBS group from the nBS group. The value of conventional HU values, slope, and InW in A-N and V-N, and hybrid model were significantly higher in the pBS group than in the nBS group. The hybrid model of all significant parameters had the highest AUC of 0.988, with 95.5% sensitivity and 94.6% specificity. DLCT with arterial contrast enhancement phase has the potential to serve as an opportunistic screening tool for detecting positive osteoblastic bone lesions, corresponding to those identified in bone scintigraphy.

Factors influencing long-term outcomes in fibrotic interstitial lung disease (F-ILD) diagnosed through multidisciplinary discussion (MDD): a prospective cohort study.

BACKGROUND: The diagnostic process for fibrotic interstitial lung disease (F-ILD) is notably intricate, necessitating a multidisciplinary discussion to achieve consensus based on both clinical and radiological features. This study investigated the shared and distinctive long-term mortality predictors among the two primary phenotypes of F-ILD, namely idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated interstitial lung disease (CTD-ILD). METHODS: We included patients with F-ILD diagnosed from December 2018 to December 2019 and conducted follow-up assessments until February 2023. Age, gender, usual interstitial pneumonia (UIP) pattern, gender-age-physiology (GAP) score, modified Medical Research Council (mMRC) dyspnea score, antifibrotic agent use, pulmonary function test parameters, and six-minute walking test (6MWT) parameters were recorded at baseline and used as mortality predictors in a multivariate Cox regression model. RESULTS: We enrolled 104 ILD patients. The survival rate of non-IPF patients was more than twice that of IPF patients (78.9% vs. 34%, p < 0.001), and the survival rate of patients with a GAP score of 0-2 was more than twice that of patients with a score of > 2 (93.2% vs. 36.6%, p < 0.001). Older age, male gender, definite UIP pattern, higher GAP score, higher mMRC dyspnea score, lower forced expiratory volume in one second/forced vital capacity (FEV1/FVC), shorter 6MWT distance, and lower initial and final SpO2 were also associated with higher long-term mortality (p < 0.05). In multivariable analysis, only a GAP score of > 2 (hazard ratio [HR]:16.7; 95% confidence interval [CI] 3.28-85.14; p = 0.001) and definite UIP pattern (HR: 4.08; 95% CI 1.07-15.5; p = 0.039) were significantly associated with overall mortality. CONCLUSION: The long-term mortality rate of IPF patients was higher than that of CTD-ILD patients. The GAP score and UIP patterns were significant mortality predictors for both IPF and CTD-ILD patients.

Multidisciplinary-derived clinical score for accurate prediction of long-term mortality in fibrotic lung disease patients.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) stands out as one of the most aggressive forms of interstitial lung diseases (ILDs), currently without a definitive cure. Multidisciplinary discussion (MDD) is now considered a cornerstone in diagnosing and differentiating ILD subtypes. The Gender-Age-Physiology (GAP) score, developed to assess IPF prognosis based on sex, age, forced vital capacity, and diffusion capacity for carbon monoxide (DLCO), is limited in not considering dyspnea and functional impairment during the walking test. We proposed a MDD-based clinical score for mortality prediction among those patients. METHODS: From December 2018 to December 2019, we enrolled ILD patients with IPF and non-IPF and followed-up them till December 2020. Based on DLCO, modified Medical Research Council (mMRC) Dyspnea Scale, and six-minute walking test (6MWT) distance, a functional score was developed for mortality prediction. RESULTS: We enrolled 104 ILD patients, 12 (11.5%) died by the one-year follow-up. In receiver operating characteristic (ROC) curve analysis, DLCO (% predicted) was the most accurate variable predicting one-year mortality with an area under curve (AUC) of 0.88 (95% confidence interval [CI] = 0.80-0.94), followed by mMRC Dyspnea Score (AUC = 0.82 [95% CI = 0.73-0.89]), 6MWT distance (AUC = 0.80 [95% CI = 0.71-0.88]), and GAP score (AUC = 0.77 [95% CI = 0.67-0.84]). Only the GAP score (hazard ratio [HR] = 1.55, 95% CI = 1.03-2.34, p = 0.0.37) and functional score (HR = 3.45, 95% CI = 1.11-10.73, p = 0.032) were significantly associated with one-year mortality in multivariable analysis. CONCLUSION: The clinical score composite of DLCO, mMRC Dyspnea Scale, and 6MWT distance could provide an accurate prediction for long-term mortality in ILD patients, laying out a helpful tool for managing and following these patients.

2024 multidisciplinary consensus on image-guided lung tumor ablation from the Taiwan Academy of Tumor Ablation.

In this article, the multidisciplinary team of the Taiwan Academy of Tumor Ablation, who have expertise in treating lung cancer, present their perspectives on percutaneous image-guided thermal ablation (IGTA) of lung tumors. The modified Delphi technique was applied to reach a consensus on clinical practice guidelines concerning ablation procedures, including a comprehensive literature review, selection of panelists, creation of a rating form and survey, and arrangement of an in-person meeting where panelists agreed or disagreed on various points. The conclusion was a final rating and written summary of the agreement. The multidisciplinary expert team agreed on 10 recommendations for the use of IGTA in the lungs. These recommendations include terms and definitions, line of treatment planning, modality, facility rooms, patient anesthesia settings, indications, margin determination, post-ablation image surveillance, qualified centers, and complication ranges. In summary, IGTA is a safe and feasible approach for treating primary and metastatic lung tumors, with a relatively low complication rate. However, decisions regarding the ablation technique should consider each patient's specific tumor characteristics.

Feasibility of Computed Tomography-guided Percutaneous Renal Cryoablation Under Local Anesthesia: A Single Center Experience in Taiwan.

BACKGROUND/AIM: To survey the safety and efficacy of percutaneous cryoablation for renal tumors under local anesthesia and pain control by using the -40°C lethal isotherm of the ice ball to cover the tumor margin as well as the coaxial cryoablation technique. PATIENTS AND METHODS: All procedures were performed between February 2014 and November 2021 with computed tomography (CT) guidance. All tumors were ablated by following the aforementioned plan, according to which tumor margins were covered by the -40°C lethal isotherm. Hydrodissection and coaxial cryoablation were performed in some cases to avoid organ injury and massive bleeding. 2% xylocaine was used for local anesthesia and 50 mg of pethidine (meperidine) was injected intramuscularly for pain control and sedation. The complications were evaluated and the Kaplan-Meier method was used to estimate local recurrence-free survival (LRFS). RESULTS: Sixty-five tumors [49 renal cell carcinomas (RCC) and 16 angiomyolipomas] were ablated in 55 patients (median Charlson Comorbidity Index=5.0). Local recurrence occurred in three of the 49 RCC cases. Two received a second cryoablation. LRFS at three and five years were both 91%. LRFS at three and five years reached 100% in tumors <3 cm. A large tumor (≥3 cm) was observed in the recurrence group. Hemorrhage was the most common complication (76.9%). Two patients who needed blood transfusion did not receive coaxial cryoablation. Three (4.6%) major complications (Clavien-Dindo grade ≥3) occurred. CONCLUSION: By using -40°C as the pre-plan tumor coverage, with the aid of coaxial cryoablation and multiplanar reconstruction method, CT-guided percutaneous renal cryoablation under local anesthesia is a safe and effective procedure in patients with many comorbidities.

Elevated levels of serum glial fibrillary acidic protein breakdown products in mild and moderate traumatic brain injury are associated with intracranial lesions and neurosurgical intervention.

STUDY OBJECTIVE: This study examines whether serum levels of glial fibrillary acidic protein breakdown products (GFAP-BDP) are elevated in patients with mild and moderate traumatic brain injury compared with controls and whether they are associated with traumatic intracranial lesions on computed tomography (CT) scan (positive CT result) and with having a neurosurgical intervention. METHODS: This prospective cohort study enrolled adult patients presenting to 3 Level I trauma centers after blunt head trauma with loss of consciousness, amnesia, or disorientation and a Glasgow Coma Scale (GCS) score of 9 to 15. Control groups included normal uninjured controls and trauma controls presenting to the emergency department with orthopedic injuries or a motor vehicle crash without traumatic brain injury. Blood samples were obtained in all patients within 4 hours of injury and measured by enzyme-linked immunosorbent assay for GFAP-BDP (nanograms/milliliter). RESULTS: Of the 307 patients enrolled, 108 were patients with traumatic brain injury (97 with GCS score 13 to 15 and 11 with GCS score 9 to 12) and 199 were controls (176 normal controls and 16 motor vehicle crash controls and 7 orthopedic controls). Receiver operating characteristic curves demonstrated that early GFAP-BDP levels were able to distinguish patients with traumatic brain injury from uninjured controls with an area under the curve of 0.90 (95% confidence interval [CI] 0.86 to 0.94) and differentiated traumatic brain injury with a GCS score of 15 with an area under the curve of 0.88 (95% CI 0.82 to 0.93). Thirty-two patients with traumatic brain injury (30%) had lesions on CT. The area under these curves for discriminating patients with CT lesions versus those without CT lesions was 0.79 (95% CI 0.69 to 0.89). Moreover, the receiver operating characteristic curve for distinguishing neurosurgical intervention from no neurosurgical intervention yielded an area under the curve of 0.87 (95% CI 0.77 to 0.96). CONCLUSION: GFAP-BDP is detectable in serum within an hour of injury and is associated with measures of injury severity, including the GCS score, CT lesions, and neurosurgical intervention. Further study is required to validate these findings before clinical application.

Ubiquitin C-terminal hydrolase is a novel biomarker in humans for severe traumatic brain injury.

OBJECTIVE: Ubiquitin C-terminal hydrolase (UCH-L1), also called neuronal-specific protein gene product (PGP 9.3), is highly abundant in neurons. To assess the reliability of UCH-L1 as a potential biomarker for traumatic brain injury (TBI) this study compared cerebrospinal fluid (CSF) levels of UCH-L1 from adult patients with severe TBI to uninjured controls; and examined the relationship between levels with severity of injury, complications and functional outcome. DESIGN: This study was designed as prospective case control study. PATIENTS: This study enrolled 66 patients, 41 with severe TBI, defined by a Glasgow coma scale (GCS) score of < or =8, who underwent intraventricular intracranial pressure monitoring and 25 controls without TBI requiring CSF drainage for other medical reasons. SETTING: : Two hospital system level I trauma centers. MEASUREMENTS AND MAIN RESULTS: Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, 120, 144, and 168 hrs following TBI and analyzed for UCH-L1. Injury severity was assessed by the GCS score, Marshall Classification on computed tomography and a complicated postinjury course. Mortality was assessed at 6 wks and long-term outcome was assessed using the Glasgow outcome score 6 months after injury. TBI patients had significantly elevated CSF levels of UCH-L1 at each time point after injury compared to uninjured controls. Overall mean levels of UCH-L1 in TBI patients was 44.2 ng/mL (+/-7.9) compared with 2.7 ng/mL (+/-0.7) in controls (p <.001). There were significantly higher levels of UCH-L1 in patients with a lower GCS score at 24 hrs, in those with postinjury complications, in those with 6-wk mortality, and in those with a poor 6-month dichotomized Glasgow outcome score. CONCLUSIONS: These data suggest that this novel biomarker has the potential to determine injury severity in TBI patients. Further studies are needed to validate these findings in a larger sample.

Biochemical, structural, and biomarker evidence for calpain-mediated cytoskeletal change after diffuse brain injury uncomplicated by contusion.

Calpain-mediated degradation of the cytoskeletal protein alpha-II-spectrin has been implicated in the pathobiology of experimental and human traumatic brain injury (TBI). Spectrin proteolysis after diffuse/widespread TBI uncomplicated by either subtle or overt contusion and/or mass lesions, (i.e. mild to moderate TBI), has not been previously evaluated. To determine the spatiotemporal pattern and cellular localization of calpain-mediated spectrin proteolysis after diffuse/widespread TBI and the extent to which parenchymal changes in calpain-mediated spectrin proteolysis are reflected in the cerebrospinal fluid, adult rats were subjected to a moderate midline fluid percussion injury and allowed to survive for 3 hours to 7 days postinjury. Light and electron microscopic immunocytochemical and Western blot analyses were performed to identify the calpain-specific 145-kDa breakdown product of alpha-II-spectrin (SBDP145). After diffuse TBI, enhanced levels of SBDP145 immunoreactivity were observed in the neocortex, subcortical white matter, thalamus, and hippocampus, peaking between 24 and 48 hours postinjury. Immunoreactivity was localized almost exclusively to damaged axons and axonal terminal debris. Heightened levels of SBDP145 were also observed in the cerebrospinal fluid at 24 hours postinjury. These results confirm the widespread occurrence of calpain-mediated spectrin proteolysis after diffuse TBI without contusion and support the potential utility of SBDPs as biomarkers of a diffusely injured brain.

Multiple alphaII-spectrin breakdown products distinguish calpain and caspase dominated necrotic and apoptotic cell death pathways.

Apoptosis and oncotic necrosis in neuronal and glial cells have been documented in many neurological diseases. Distinguishing between these two major types of cell death in different neurological diseases is needed in order to better reveal the injury mechanisms so as to open up opportunities for therapy development. Accumulating evidence suggests apoptosis and oncosis epitomize the extreme ends of a broad spectrum of morphological and biochemical events. Biochemical markers that can distinguish between the calpain and caspase dominated types of cell death would help in this process. In this study, three chemical agents, maitotoxin (MTX), staurosporine (STS) and thylenediaminetetraacetic acid (EDTA), were used to induce different types of cell death in PC12 neuronal-like cells. MTX-induced necrosis, as determined by the increased levels of calpain-specific cleaved fragments of spectrin by antibodies specific to the calpain-cleaved 150 kDa alphaII-spectrin breakdown product (SBDP150) and 145 kDa alphaII-spectrin breakdown product (SBDP145). In this paradigm, there were no detectable SBDP150i and SBDP120 fragments as determined by antibodies specific to the caspase-cleaved specific fragments similar to those seen in the EDTA-mediated apoptotic PC-12 cells. In contrast to the calpain specific MTX necrosis treatment and the caspase EDTA apoptotic treatment is the STS treatment which induced both proteases as shown by the increase in all the SBDP fragments. Furthermore, compared to SBDP150, SBDP145 appears to be a more specific and sensitive biomarker for calpain activation. Taken together, our results suggested calpains and caspases which dominate the two major types of cell death could be independently discriminated by specifically examining the multiple alphaII-spectrin cleavage breakdown products.

Dicyclomine, an M1 muscarinic antagonist, reduces biomarker levels, but not neuronal degeneration, in fluid percussion brain injury.

Recent studies indicate that alphaII-spectrin breakdown products (SBDPs) have utility as biological markers of traumatic brain injury (TBI). However, the utility of SBDP biomarkers for detecting effects of therapeutic interventions has not been explored. Acetylcholine plays a role in pathological neuronal excitation and TBI-induced muscarinic cholinergic receptor activation may contribute to excitotoxic processes. In experiment I, regional and temporal changes in calpain-mediated alpha-spectrin degradation were evaluated at 3, 12, 24, and 48 h using immunostaining for 145-kDa SBDP. Immunostaining of SBDP-145 was only evident in the hemisphere ipsilateral to TBI and was generally limited to the cortex except at 24 h when immunostaining was also prominent in the dentate gyrus and striatum. In Experiment II, cerebral spinal fluid (CSF) samples were analyzed for various SBDPs 24 h after moderate lateral fluid percussion TBI. Rats were administered either dicyclomine (5 mg/kg i.p.) or saline vehicle (n = 8 per group) 5 min prior to injury. Injury produced significant increases (p < 0.001) of 300%, 230%, and >1000% in SBDP-150, -145, and -120, respectively in vehicle-treated rats compared to sham. Dicyclomine treatment produced decreases of 38% (p = 0.077), 37% (p = 0.028), and 63% (p = 0.051) in SBDP-150, -145, and -120, respectively, compared to vehicle-treated injury. Following CSF extraction, coronal brain sections were processed for detecting degenerating neurons using Fluoro-Jade histofluorescence. Stereological techniques were used to quantify neuronal degeneration in the dorsal hippocampus CA2/3 region and in the parietal cortex. No significant differences were detected in numbers of degenerating neurons in the dorsal CA2/3 hippocampus or the parietal cortex between saline and dicyclomine treatment groups. The percent weight loss following TBI was significantly reduced by dicyclomine treatment. These data provide additional evidence that, as TBI biomarkers, SBDPs are able to detect a therapeutic intervention even in the absence of changes in neuronal cell degeneration measured by Fluoro-jade.

Adult-to-adult living donor liver transplantation preoperative survey using MDCT, a single medical center experience in Taiwan.

This study evaluated multi-detector computed tomography (MDCT) scans performed on potential living donors for adult-to-adult liver transplantation (LDLT), with the aim of identifying significant findings that could be used to exclude potential transplantation donors. We retrospectively reviewed the medical records of 151 consecutive potential adult donors for LDLT from May 2007 to January 2015. Liver parenchyma steatosis, focal hepatic mass or intraabdominal malignancy, vascular variations, and donor liver volume were evaluated via MDCT. Grounds for excluding potential donors were also recorded and analyzed. Of the 151 potential donors, nine (6.0%) had moderate to severe fatty liver, 37 (24.5%) had hepatic arterial variants, 22 (14.6%) had significant portal venous variants, and more than half were found to have right accessory inferior hepatic vein. No intraabdominal malignancies were found. Eighty-eight potential donors were rejected, with the most common cause being insufficient recipient volume or remnant donor volume (47.7%), moderate to severe parenchymal steatosis (10.2%), and recipient expiration prior to transplantation (8.0%). An additional 16 potential donors were excluded by the surgical team due to the complexity of their portal venous variations. The rate of exclusion by pre-transplant imaging evaluation with MDCT was 33.8%. MDCT can provide accurate quantification of donor liver volume and steatosis severity along with precise demonstration of vascular variants, which are crucial for the preoperative evaluation of LDLT. However, MDCT may be ineffective for evaluating the biliary system without hepatobiliary-excreted contrast agent and has the disadvantage of ionizing radiation.

Clinical significance of alphaII-spectrin breakdown products in cerebrospinal fluid after severe traumatic brain injury.

Following traumatic brain injury (TBI), the cytoskeletal protein alpha-II-spectrin is proteolyzed by calpain and caspase-3 to signature breakdown products. To determine whether alpha -II-spectrin proteolysis is a potentially reliable biomarker for TBI in humans, the present study (1) examined levels of spectrin breakdown products (SBDPs) in cerebrospinal fluid (CSF) from adults with severe TBI and (2) examined the relationship between these levels, severity of injury, and clinical outcome. This prospective case control study enrolled 41 patients with severe TBI, defined by a Glasgow Coma Scale (GCS) score of < or =8, who underwent intraventricular intracranial pressure monitoring. Patients without TBI requiring CSF drainage for other medical reasons served as controls. Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, and 120 h following TBI and analyzed for SBDPs. Outcome was assessed using the Glasgow Outcome Score (GOS) 6 months after injury. Calpain and caspase-3 mediated SBDP levels in CSF were significantly increased in TBI patients at several time points after injury, compared to control subjects. The time course of calpain mediated SBDP150 and SBDP145 differed from that of caspase-3 mediated SBDP120 during the post-injury period examined. Mean SBDP densitometry values measured early after injury correlated with severity of injury, computed tomography (CT) scan findings, and outcome at 6 months post-injury. Taken together, these results support that alpha -II-spectrin breakdown products are potentially useful biomarker of severe TBI in humans. Our data further suggests that both necrotic/oncotic and apoptotic cell death mechanisms are activated in humans following severe TBI, but with a different time course after injury.

Comparing calpain- and caspase-3-mediated degradation patterns in traumatic brain injury by differential proteome analysis.

A major theme of TBI (traumatic brain injury) pathology is the over-activation of multiple proteases. We have previously shown that calpain-1 and -2, and caspase-3 simultaneously produced alphaII-spectrin BDPs (breakdown products) following TBI. In the present study, we attempted to identify a comprehensive set of protease substrates (degradome) for calpains and caspase-3. We further hypothesized that the TBI differential proteome is likely to overlap significantly with the calpain- and caspase-3-degradomes. Using a novel HTPI (high throughput immunoblotting) approach and 1000 monoclonal antibodies (PowerBlottrade mark), we compared rat hippocampal lysates from 4 treatment groups: (i) naïve, (ii) TBI (48 h after controlled cortical impact), (iii) in vitro calpain-2 digestion and (iv) in vitro caspase-3 digestion. In total, we identified 54 and 38 proteins that were vulnerable to calpain-2 and caspase-3 proteolysis respectively. In addition, the expression of 48 proteins was down-regulated following TBI, whereas that of only 9 was up-regulated. Among the proteins down-regulated in TBI, 42 of them overlapped with the calpain-2 and/or caspase-3 degradomes, suggesting that they might be proteolytic targets after TBI. We further confirmed several novel TBI-linked proteolytic substrates, including betaII-spectrin, striatin, synaptotagmin-1, synaptojanin-1 and NSF (N-ethylmaleimide-sensitive fusion protein) by traditional immunoblotting. In summary, we demonstrated that HTPI is a novel and powerful method for studying proteolytic pathways in vivo and in vitro.

Elevation of cytoskeletal protein breakdown in aged Wistar rat brain.

Previous studies indicated there is an overall increase of proteolysis in aging rat brains. We monitored the potential degradation of cytoskeletal proteins in neuronal tissue taken from cerebral cortex and cerebellum of young (3 month) and aging (17, 21 and 23.5 month) Wistar rats. We found significant age-dependent proteolysis of cytoskeletal proteins (alphaII-spectrin and microtubule-associated protein MAP-2A/B) in the cerebral cortex and the cerebellum. The pattern of alphaII-spectrin breakdown shows a marked increase in 150- and 145-kDa fragments (SBDP150 and SBDP145, respectively), but we did not detect the caspase-3-mediated 120-kDa fragment (SBDP120) in aged rat brains, suggesting the involvement of the calpain proteases. The pattern of MAP-2A/B breakdown in aged rat brains mirrors that produced by in vitro calpain digestion of 3-month control rat brain MAP-2A/B. In aged rat brains, there is no significant increase in pro-caspase-3 processing; rather, there is a moderate reduction in pro-caspase-3 protein and caspase-3 hydrolytic activity in the cortex. These results point to selective susceptibility of cytoskeletal proteins to calpain-mediated degradation, but not caspase-3 in aging rat brains.

Ecstasy toxicity: a comparison to methamphetamine and traumatic brain injury.

Ecstasy use is a growing problem in the United States. Techniques to demonstrate and characterize the toxicity associated with its use have been limited and employed infrequently. In this study, we compare the deleterious effects of ecstasy use in rats with that of methamphetamine and traumatic brain injury. Specifically, we investigate the degradation of structural proteins alphaII-spectrin and tau by the pro-necrotic calpain and pro-apoptotic caspase systems. Ecstasy-induced neurotoxicity is shown after 24 hours, although to a much lesser extent than that of methamphetamine or traumatic brain injury. Neurotoxicity is still evident after 72 hours. Furthermore, apoptosis of the liver is seen 72 hours after ecstasy use. Use of protease inhibitors may be useful in preventing ecstasy-induced toxicity.

Proteomic identification of biomarkers of traumatic brain injury.

Traumatic brain injury (TBI) is a major national health problem without a US Food and Drug Administration-approved therapy. This review summarizes the importance of discovering relevant TBI protein biomarkers and presents logical rationale that neuroproteomic technologies are uniquely suited for the discovery of otherwise unnoticed TBI biomarkers. It highlights that one must make careful decisions when choosing which paradigm (human vs. animal models) and which biologic samples to use for such proteomic studies. It further outlines some of the desirable attributes of an ideal TBI biomarker and discusses how biomarkers discovered proteomically are complementary to those identified by traditional approaches. Lastly, the most important sequela of any proteomically identified TBI biomarker is validation in preclinical or clinical samples.

Concurrent calpain and caspase-3 mediated proteolysis of alpha II-spectrin and tau in rat brain after methamphetamine exposure: a similar profile to traumatic brain injury.

Neurotoxicity in rat cortex and hippocampus following acute methamphetamine administration was characterized and compared to changes following traumatic brain injury. Doses of 10, 20, and 40 mg/kg of methamphetamine produced significant increases in calpain- and caspase-cleaved alpha II-spectrin and tau protein fragments, suggesting cell injury or death. Changes in proteolytic products were significantly increased over vehicle controls. Use of fragment specific biomarkers detected prominent calpain-mediated protein fragments in the cortex and hippocampus while caspase-mediated protein fragments were also detected in the hippocampus. Remarkably, proteolytic product increases at the 40 mg/kg dose after 24 h were as high as those observed in experimental traumatic brain injury. Use of calpain and caspase proteolytic inhibitors may be useful in preventing methamphetamine-induced neurotoxicity.