Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many patients call the ENT emergency department because of vertigo and sudden hearing loss. The majority of cases are due to peripheral or neurootological reasons. A serious and ongoing problem is that life-threatening ischemic, hemorrhagic and inflammatory diseases of the central nervous system may cause identical symptoms, making it difficult to differentiate between them. On the basis of our own patients with cerebellar ischemia, basilar thrombosis, dissection of the vertebral artery, cerebellar abscess, brain tumor and cholesteatoma and on the basis of expert opinions, typical sets of symptoms in patients with neurootological symptoms of a central cause are defined. To ensure early detection of these rare differential diagnoses, physicians should place particular importance on modern imaging diagnostics and neurological, interdisciplinary cooperation.
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PMID:[Life-threatening differential diagnoses of vertigo and sudden hearing loss]. 1856 85

Non-invasive energy metabolism measurements in brain tumors in vivo are now performed widely as molecular imaging by positron emission tomography. This capability has developed from a large number of basic and clinical science investigations that have cross fertilized one another. Apart from precise anatomical localization and quantification, the most intriguing advantage of such imaging is the opportunity to investigate the time course (dynamics) of disease-specific molecular events in the intact organism. Most importantly, molecular imaging represents a key-technology in translational research, helping to develop experimental protocols that may later be applied to human patients. Common clinical indications for molecular imaging of primary brain tumors therefore contain (i) primary brain tumor diagnosis, (ii) identification of the metabolically most active brain tumor reactions (differentiation of viable tumor tissue from necrosis), and (iii) prediction of treatment response by measurement of tumor perfusion, or ischemia. The key-question remains whether the magnitude of biochemical alterations demonstrated by molecular imaging reveals prognostic value with respect to survival. Molecular imaging may identify early disease and differentiate benign from malignant lesions. Moreover, an early identification of treatment effectiveness could influence patient management by providing objective criteria for evaluation of therapeutic strategies for primary brain tumors. Specially, its novel potential to visualize metabolism and signal transduction to gene expression is used in reporter gene assays to trace the location and temporal level of expression of therapeutic and endogenous genes. The authors present here illustrative data of PET imaging: the thymidine kinase gene expression in experimentally transplanted F98 gliomas in cat brain indicates, that [(18)F]FHBG visualizes cells expressing TK-GFP gene in transduced gliomas as well as quantities and localizes transduced HSV-1-TK expression if the blood brain barrier is disrupted. The higher uptake of [(18)F]FLT in the wild-type compared to the transduced type may demonstrate the different doubling time of both tumor tissues suggesting different cytosolic thymidine kinase activity. Molecular imaging probes are developed to image the function of targets without disturbing them or as drug in oder to modify the target's function. This is transfer of gene therapy's experimental knowledge into clinical applications. Molecular imaging closes the gap between in vitro to in vivo integrative biology of disease.
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PMID:Molecular imaging of brain tumors personal experience and review of the literature. 1907 70

Rapid advances in the field of nanotechnology promise revolutionary improvements in the diagnosis and therapy of neuroinflammatory disorders. An array of iron oxide nano- and microparticle agents have been developed for in vivo molecular magnetic resonance imaging (mMRI) of cerebrovascular endothelial targets, such as vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and the glycoprotein receptor GP IIb/IIIa expressed on activated platelets. Molecular markers of glioma cells, such as matrix metalloproteinase-2 (MMP-2), and markers for brain tumor angiogenesis, such as alpha (v) beta (3) integrin (alpha(v)beta(3)), have also been successfully targeted using nanoparticle imaging probes. This chapter provides an overview of targeted, iron oxide nano- and microparticles that have been applied for in vivo mMRI of the brain in experimental models of multiple sclerosis (MS), brain ischemia, cerebral malaria (CM), brain cancer, and Alzheimer's disease. The potential of targeted nanoparticle agents for application in clinical imaging is also discussed, including multimodal and therapeutic approaches.
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PMID:Chapter 4 - Applications of nanotechnology in molecular imaging of the brain. 2030 29

It has been elucidated that cognitive dysfunction following cranial radiotherapy might be linked to the oxidative stress-induced impairment of hippocampal neurogenesis that is mediated by proliferating neural stem or progenitor cells. The novel free-radical scavenger edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) has been clinically used to reduce neuronal damage following ischemic stroke. Previously, we reported that the free-radical scavenger, edaravone, which is currently used to treat patients with brain ischemia, protected cultured human neural stem cells (NSCs) from radiation-induced cell death; the protective effect was observed more significantly in NSCs than in brain tumor cells. Here, in animal models, we demonstrate that edaravone protects neurons in the subgranular zone (SGZ) of the dentate gyrus of the hippocampus from cell death after irradiation. Moreover, edaravone protected spatial memory retention deficits as determined by Morris water maze tests. Our study may shed some light on the beneficial effects of free-radical scavengers in impaired neurogenesis following cranial radiation therapy.
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PMID:A free-radical scavenger protects the neural progenitor cells in the dentate subgranular zone of the hippocampus from cell death after X-irradiation. 2080 18

Motor evoked potentials (MEPs) elicited by both direct cortical stimulation (DCS) and transcranial electrical stimulation are used during brain tumor resection. Parallel use of direct cortical stimulation motor evoked potentials (DCS-MEPs) and transcranial electrical stimulation motor evoked potentials (TCeMEPs) has been practiced during brain tumor resection. We report that DCS-MEPs elicited by direct subdural grid stimulation, but not TCeMEPs, detected brain ischemia during brain tumor resection. Following resection of a brainstem high-grade glioma in a 21-year-old, the threshold of cortical motor-evoked-potentials (cMEPs) increased from 13 mA to 20 mA while amplitudes decreased. No changes were noted in transcranial motor evoked potentials (TCMEPs), somatosensory evoked potentials (SSEPs), auditory evoked potentials (AEPs), anesthetics, or hemodynamic parameters. Our case showed the loss of cMEPs and SSEPs, but not TCeMEPs. Permanent loss of DCS-MEPs and SSEPs was correlated with permanent left hemiplegia in our patient even when appropriate action was taken. Parallel use of DCS- and TCeMEPs with SSEPs improves sensitivity of intraoperative detection of motor impairment. DCS may be superior to TCeMEPs during brain tumor resection.
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PMID:Direct cortical stimulation but not transcranial electrical stimulation motor evoked potentials detect brain ischemia during brain tumor resection. 2198 37

Papilledema is a term generally reserved (at least in the English language use of the term) by neuro-ophthalmologists for optic disc edema due to increased intracranial pressure. The etiology for the intracranial hypertension may be known (e.g., brain tumor, meningitis, cerebral venous sinus thrombosis) or may be idiopathic (idiopathic intracranial hypertension [IIH]). IIH is a disorder that predominantly affects overweight women of childbearing age and these epidemiologic factors should offer clues to pathogenesis. The main morbidity of papilledema is visual loss and the major mechanism for permanent optic nerve damage is axoplasmic flow stasis and resultant intraneuronal ischemia. The current initial management of papilledema in IIH includes weight loss and medical therapy (e.g., acetazolamide or furosemide). Patients who fail, are intolerant to, or noncompliant with maximum tolerated medical therapy might require optic nerve sheath fenestration or cerebrospinal fluid diversion (i.e., shunting) procedures.
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PMID:Papilledema: are we any nearer to a consensus on pathogenesis and treatment? 2235 46

Improvements in cancer therapy have resulted in an expanding population of early-onset cancer survivors. In contrast to childhood and adolescent cancer survivors, there is still a lack of data concerning late morbidities among young adult (YA) cancer survivors. Thus, our aim was to investigate cardiac and vascular morbidity among early-onset cancer survivors with a special interest in YA cancer survivors. In a population-based setting, we explored the risk of cardiovascular disease in early-onset cancer survivors compared to healthy siblings. Patients diagnosed with cancer below 35 years of age since 1975 were identified from the Finnish Cancer Registry, and 5-year survivors were included in our study (N = 13,860). Information on cardiovascular morbidity was collected from the national hospital discharge registry. Compared to siblings, cancer survivors aged 0-19 and 20-34 at diagnosis had significantly elevated hazard ratios (HRs) for the studied outcomes: HR 13.5 (95% CI 8.9-20.4) and 3.6 (95% CI 2.8-4.6) for cardiomyopathy/cardiac insufficiency; HR 3.4 (95% CI 2.3-5.1) and 1.7 (95% CI 1.4-2.0) for atherosclerosis/brain vascular thrombosis; HR 3.3 (95% CI 1.7-6.5) and 1.8 (95% CI 1.5-2.1) for myocardial infarction/cardiac ischemia and HR 1.7 (95% CI 1.2-2.6) and 1.4 (95% CI 1.2-1.7) for cardiac arrhythmia. In both groups, depending on the outcome, the HR for adverse events was highest among lymphoma, brain tumor, leukemia and testicular malignancy survivors. Our results regarding late effects of childhood cancer survivors confirmed previous findings. Additionally, our study provides novel information concerning the YA cancer survivor population. Hence, our data may help in planning the risk-based long-term follow-up of early-onset cancer survivors.
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PMID:Cardiovascular morbidity in long-term survivors of early-onset cancer: a population-based study. 2385 51

Conventional knowledge considered apoptosis as the sole form of programmed cell death during development, homeostasis and diseases, whereas necrosis was regarded as an unregulated and uncontrollable process. Recent revelations suggest that necrosis can also occur in a regulated, caspase-independent manner and shares characteristics with both necrosis and apoptosis. The major cell death processes namely apoptosis, autophagy and necrosis are interlinked and contain many common regulatory mechanisms. Mounting evidence indicates that necroptosis contributes to the pathogenesis of various diseases, including ischemic stroke, traumatic brain injury, neurodegenerative disorders and brain tumor. We present here an overview of the molecular mechanisms governing necroptosis and its connection with apoptosis and autophagy processes. Further, the necroptosis mechanisms underlying the neurodegeneration during ischemia reperfusion (I/R) injury are described, with an emphasis on the key proteins involved in this type of cell death. Knowledge regarding programmed cell death (PCD) with relevance to necroptosis may play a significant role in debilitating brain disorders.
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PMID:Necroptosis: who knew there were so many interesting ways to die? 2415 29

Patients with cerebral ischemia or brain tumor have been reported to exhibit an increase of deoxygenated hemoglobin (deoxy-Hb) together with an increase of oxygenated hemoglobin (oxy-Hb). However, the physiological mechanisms underlying this hemodynamic response pattern are unclear. In this study, we performed a simulation using the balloon model (Buxton et al., Magn Reson Med 39:855-864, 1998). We hypothesized that the oxygen extraction rate during the rest period (E 0) in the patients is larger than in normal subjects, because the cerebral blood flow and the speed at which the blood passes through the brain tissues are lower in the patients. The simulation result showed an increase of deoxy-Hb as well as oxy-Hb, especially when E 0 is extremely high. Thus, the results of our simulation suggest that the increase of deoxy-Hb during activation in patients with ischemia or brain tumor is caused by an increased oxygen extraction rate at rest, compared with that of healthy adults.
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PMID:Physiological mechanism of increase in deoxy-hemoglobin concentration during neuronal activation in patients with cerebral ischemia: a simulation study with the balloon model. 2472 37

Despite widespread applications of multiphoton microscopy in microcirculation, its small field of view and inability to instantaneously quantify cerebral blood flow velocity (CBFv) in vascular networks limit its utility in investigating the heterogeneous responses to brain stimulations. Optical Doppler tomography (ODT) provides 3D images of CBFv networks, but it suffers poor sensitivity for measuring capillary flows. Here we report on a new method, contrast-enhanced ODT with Intralipid that significantly improves quantitative CBFv imaging of capillary networks by obviating the errors from long latency between flowing red blood cells (low hematocrit ~20% in capillaries). This enhanced sensitivity allowed us to measure the ultraslow microcirculation surrounding a brain tumor and the abnormal ingrowth of capillary flows in the tumor as well as in ischemia triggered by chronic cocaine in the mouse brain that could not be detected by regular ODT. It also enabled significantly enhanced sensitivity for quantifying the heterogeneous CBFv responses of vascular networks to acute cocaine exposure. Inasmuch as lipid emulsions are widely used for parenteral nutrition the Intralipid contrast method has translational potential for clinical applications.
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PMID:Ultrasensitive detection of 3D cerebral microvascular network dynamics in vivo. 2519 54


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