Caspase inhibitors prevent endothelial apoptosis and cerebral vasospasm in dog model of experimental subarachnoid hemorrhage.

Apoptosis in the endothelium of major cerebral arteries may play a role in the initiation and maintenance of cerebral vasospasm after subarachnoid hemorrhage (SAH). We tested the therapeutic effect of caspase inhibitors on endothelial apoptosis and on cerebral vasospasm in an established dog double-hemorrhage model. Thirty-one mongrel dogs were divided into five groups: control; SAH; SAH treated with vehicle [DMSO]; SAH treated with Ac-DEVD-CHO [a specific caspase-3 inhibitor]; and SAH treated with Z-VAD-FMK [a broad caspase inhibitor]. The inhibitors (100 microM) were injected into the cisterna magna daily from Day 0 through Day 3. Angiography was performed on Day 0 and Day 7. Histology, TUNEL staining, and immunohistochemistry were conducted on basilar arteries collected on Day 7 after SAH. Positive staining of TUNEL, poly(ADP)-ribose polymerase (PARP), caspase-3, and caspase-8 was observed in the endothelial cells of the spastic arteries. Double fluorescence labeling demonstrated co-localization of TUNEL with caspase-3 and TNFalpha receptor-1 (TNFR1). Ac-DEVD-CHO and Z-VAD-FMK prevented endothelial apoptosis and reduced angiographic vasospasm. The mechanism of apoptosis in endothelial cells involves TNFR1 and the caspase-8 and caspase-3 pathways. Caspase inhibitors may have potential in the treatment of cerebral vasospasm.     

法舒地尔与尼莫地平对脑血管痉挛后脑脊液S100蛋白、血清NSE水平变化分析

目的探讨颅内动脉瘤(ICA)患者术中应用法舒地尔与尼莫地平对脑血管痉挛(CVS)的预防及治疗作用。方法选取2014年1月至2016年1月在本院神经外科接受显微外科夹闭手术的62例ICA患者采用抽签法随机分为研究组和对照组各31例,研究组给予法舒地尔联合尼莫地平,对照组仅给予尼莫地平,对比两组患者手术前后夹闭血管血流速度、脑脊液(CSF)中S100蛋白、血清神经元特异化烯醇化酶(NSE)水平等变化。结果术前,研究组和对照组患者的夹闭动脉瘤近心端、远心端的血流速度、MCA的血流速度、CSF S100、血清NSE水平差异无统计学意义(P>0.05);术后7d,研究组的夹闭动脉瘤近心端、远心端的血流速度均高于对照组(P<0.05),两组患者的MCA血流速度差异无统计学意义(P>0.05);术后,研究组的CSFS100、血清NSE水平均显著的低于对照组(P<0.05);术后28d,研究组的愈显率80.65%显著的高于对照组的58.06%(P<0.05);研究组的总有效率96.77%与对照组的90.23%差异无统计学意义(P>0.05)。结论 ICA患者术中应用法舒地尔联合尼莫地平能够更好的预防和治疗CVS,减少脑损伤,有利于提高临床治疗效果。     

Catecholamine levels in plasma and CSF in migraine.

There is clinical and pharmacological evidence of the existence of sympathetic dysfunction in migraine. Adrenaline and noradrenaline concentrations were determined in plasma and CSF of patients during attacks of common or classic migraine, comparing them with controls suffering from stress. Plasma noradrenaline levels were significantly lower in the patients with common migraine than in controls (p < 0.05). Other catecholamine levels in plasma and CSF in both migraine groups were only slightly lower than in controls. Our results suggest that central sympathetic dysfunction exists in patients with migraine.     

Bilirubin production and oxidation in CSF of patients with cerebral vasospasm after subarachnoid hemorrhage.

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.     

Normal CSF oxytocin and NPY levels in OCD.

BACKGROUND: Attention has recently been focused on central nervous system neuropeptides as potential mediators of the symptom profile of obsessive-compulsive disorder (OCD). Increased CSF levels of the anxiolytic neuropeptide oxytocin have been reported in OCD. CSF levels of NPY, another anxiolytic neuropeptide, have not been studied. METHODS: We measured CSF oxytocin and NPY in 14 OCD patients and 26 healthy normal volunteers. RESULTS: There were no significant differences between the OCD patients and control subjects in CSF oxytocin or NPY levels. In both the OCD and control groups, women had significantly higher CSF oxytocin levels than men. CONCLUSIONS: These results do not support a prior finding of elevated CSF oxytocin in OCD patients and do not provide any evidence for an abnormality of NPY regulation in OCD.     

Protein C activity levels in endotoxin-induced disseminated intravascular coagulation in a dog model

The levels of protein C (PC) and other coagulation factors were monitored during endotoxin-induced disseminated intravascular coagulation (DIC) in the dog. Initial evaluation of the effectiveness of intradermal administration of bolus endotoxin quantities into the dog, demonstrated induction of DIC in the canine, without the severe side effects associated with bacterial sepsis. Quantitative determination of canine plasma protein C levels were performed using a multiple step amidolytic assay, that included a specific precipitation of the vitamin K-dependent proteins from citrated plasma, followed by thrombin activation (and neutralization) and subsequent measurement of the activated protein C (APC) by chromogen hydrolysis. This investigation demonstrated, that over a twenty-four hour interval, intradermal administration of endotoxin produces a gradual decrease in the PC activity levels, concomitant with a significant reduction in the Factor V, Factor VIII and fibrinogen levels and platelet count, and a prolongation of the Prothrombin Time and Partial Thromboplastin Time. During the first 6 hours, protein C levels fell below the pre-levels and remained significantly lower in the surviving dogs. Thus, this endotoxin-induced DIC animal model permits evaluation of various hemostatic parameters, yet diminishes the severe clinical findings associated with DIC.     

CSF phospho-tau correlates with behavioural decline and brain insoluble phospho-tau levels in a rat model of tauopathy

The aim of the present study was to identify the relationship between progressive neurobehavioural decline and phospho-tau levels (p-tau₁₈₁) in the cerebrospinal fluid (CSF) and the brain in transgenic rats expressing human truncated tau protein. Behavioural analyses, as quantified using the NeuroScale scoring method, revealed that the transgenic rats fell into two main groups based on the baseline behavioural functioning: (1) mild neurobehavioural impairment (MNI, score 3.3–26) and (2) severe neurobehavioural impairment (SNI, score 36–44). SNI transgenic rats showed a significant increase in brain sarkosyl insoluble p-tau₁₈₁ when compared to their MNI counterparts. In order to determine whether CSF phospho-tau reflects the behavioural decline and increase in sarkosyl insoluble tau in the brain, p-tau₁₈₁ was measured in the CSF in a longitudinal study. The study showed a significant increase in CSF p-tau₁₈₁ during the progression of the disease from MNI to SNI. Moreover, increased levels of p-tau₁₈₁ in CSF correlated with an increase in the sarkosyl insoluble p-tau₁₈₁ levels in the brain. The increase in the CSF level of p-tau₁₈₁ during progressive behavioural decline suggests that it may represent a useful surrogate biomarker for preclinical drug development and a potential surrogate endpoint for clinical trials of disease-modifying therapy for Alzheimer’s disease and related human tauopathies.     

Longitudinal stability of CSF tau levels in Alzheimer patients.

BACKGROUND: Antemortem levels of tau in the cerebrospinal fluid (CSF) of Alzheimer's disease (AD) patients have repeatedly been demonstrated to be elevated when compared to controls. Although CSF tau has been reported to be elevated even in very mild AD, it is unknown how tau levels change during the course of the disease. METHODS: We have followed 29 mild-to-moderately affected AD subjects over 2 years with repeated CSF taps. Clinical measures of dementia severity (Clinical Dementia Rating Scale, Global Deterioration Scale and Mini-Mental Status Examination) were obtained at the start and conclusion of the observation period, and CSF tau was measured with a standard enzyme-linked immunoabsorbent assay (ELISA) using two monoclonal antibodies. RESULTS: Despite significant changes in the clinical measures consistent with progression of the disease, no significant overall change in CSF tau levels (548 +/- 355 vs. 557 +/- 275 pg/mL, NS) was observed. None of the clinical variables was significantly correlated with either baseline measures of CSF tau or delta CSF tau (last-first). Similarly, CSF tau at baseline and changes over time were not significantly related to Apolipoprotein E (APO E) phenotype. CONCLUSIONS: These data suggest that CSF tau levels are stable over extended periods of time in a group of mild-to-moderately demented AD subjects and that CSF tau levels do not predict the severity or rate of progression of AD, at least not during the middle stages of the illness.     

Voltage-gated K+ channel dysfunction in myocytes from a dog model of subarachnoid hemorrhage.

Delayed cerebral vasospasm after subarachnoid hemorrhage is primarily due to sustained contraction of arterial smooth muscle cells. Its pathogenesis remains unclear. The degree of arterial constriction is regulated by membrane potential that in turn is determined predominately by K+ conductance (GK). Here, we identified the main voltage-gated K+ (Kv) channels contributing to outward delayed rectifier currents in dog basilar artery smooth muscle as Kv2 class through a combination of electrophysiological and pharmacological methods. Kv2 current density was nearly halved in vasospastic myocytes after subarachnoid hemorrhage (SAH) in dogs, and Kv2.1 and Kv2.2 were downregulated in vasospastic myocytes when examined by quantitative mRNA, Western blotting, and immunohistochemistry. Vasospastic myocytes were depolarized and had a smaller contribution of GK toward maintenance of their membrane potential. Pharmacological block of Kv current in control myocytes mimicked the depolarization observed in vasospastic arteries. The degree of membrane depolarization was found to be compatible with the amount of vasoconstriction observed after SAH. We conclude that Kv2 dysfunction after SAH contributes to the pathogenesis of delayed cerebral vasospasm. This may confer a novel target for treatment of delayed cerebral vasospasm.     

亚低温治疗对蛛网膜下腔出血继发性血管痉挛及脑脊液和血浆内皮素、降钙素基因相关肽的影响

目的 探讨亚低温治疗对蛛网膜下腔出血(SAH)继发性血管痉挛及脑脊液和血浆内皮素(ET)、降钙素基因相关肽(CGRP)水平的影响.方法 56例SAH患者随机分成亚低温组和对照组,两组在常规治疗的基础上,亚低温组增加局部亚低温治疗;检测两组入院时及治疗7 d、14 d脑脊液和血浆ET、CGRP水平,并比较两组脑血管痉挛的发病情况.结果 (1)脑脊液、血浆ET水平治疗7 d时亚低温组较对照组显著降低(均P＜0.05);14 d时差异更显著(均P＜0.01);两组CGRP水平治疗第7 d时降至最低,后渐升高,亚低温组较对照组变化幅度小,差异有统计学意义(P＜0.05～0.01).(2)亚低温组脑血管痉挛发病率为6.67%,较对照组的30.77%明显减少(P＜0.05).结论 亚低温治疗减少了SAH患者脑脊液和血浆中ET水平上升幅度及CGRP水平下降幅度,从而降低脑血管痉挛的发生率.     

Low levels of transthyretin in the CSF of depressed patients.

OBJECTIVE: Transthyretin plays an important role in the transport and distribution of thyroid hormone in the central nervous system (CNS). This study replicated and extended to patients with nonrefractory depressive illness a pilot study indicating that patients with refractory major depression have significantly lower levels of CSF transthyretin than do healthy comparison subjects. METHOD: Lumbar punctures were performed in drug-free subjects with DSM-III-R major depression (N = 18), DSM-III-R bipolar disorder, depressed phase (N = 1), and healthy comparison subjects (N = 24). CSF concentrations of transthyretin, determined by a quantitative dot-immunobinding assay, of the depressed patients and comparison subjects were compared by analysis of covariance (ANCOVA). The relationship between CSF transthyretin levels and Hamilton Depression Rating Scale scores was determined in a subset of the depressed patients. RESULTS: CSF concentrations of transthyretin were significantly lower in the depressed patients than in the comparison subjects by ANCOVA. Within the depressed group there was no significant overall correlation between CSF transthyretin levels and Hamilton depression scale scores, but there was a significant inverse correlation in male depressed patients (N = 8) between CSF transthyretin concentrations and Hamilton depression scores. CONCLUSIONS: Lower CSF transthyretin concentrations in depressed patients may reflect either a stable trait in this population or a state change secondary to depression or other factors. Lower CSF transthyretin concentrations may result in altered CNS thyroid hormone homeostasis. Such alteration could account for certain mood and neurovegetative symptoms of depression and might contribute to failure of standard antidepressant treatment.     

Improved rat model for cerebral vasospasm studies.

While the rat has been used extensively in subarachnoid hemorrhage (SAH)-cerebral vasospasm studies, concerns exist whether this animal represents a usable model because its time course and pattern of cerebral vasospasm following SAH is not comparable to that observed in man. At present, our knowledge of the rat model is based almost exclusively on studies using a 'single hemorrhage' method. Since there is a positive correlation between severity of cerebral vasospasm, and volume of subarachnoid blood, an obvious question is whether the rat will show modifications in vascular responses when insulted by a second SAH. Here, an SAH was produced in rats using a 'double hemorrhage' method. Following SAH, cerebral arteries showed pathological alterations, significant decreases in luminal perimeter, and increases in arterial wall thickness, over a 7-day post-SAH period. The above vascular features are considered to be indicative of cerebral vasospasm and their presence over a 7-day post-SAH period represents a significant time extension when compared to a single hemorrhage. These modified vascular responses made the double hemorrhaged rat a much-improved animal model.     

CSF hypocretin/orexin levels in narcolepsy and other neurological conditions.

OBJECTIVE: To examine the specificity of low CSF hypocretin-1 levels in narcolepsy and explore the potential role of hypocretins in other neurologic disorders. METHODS: A method to measure hypocretin-1 in 100 microL of crude CSF sample was established and validated. CSF hypocretin-1 was measured in 42 narcolepsy patients (ages 16-70 years), 48 healthy controls (ages 22-77 years,) and 235 patients with various other neurologic conditions (ages 0-85 years). RESULTS: As previously reported, CSF hypocretin-1 levels were undetectably low (<100 pg/mL) in 37 of 42 narcolepsy subjects. Hypocretin-1 levels were detectable in all controls (224-653 pg/mL) and all neurologic patients (117-720 pg/mL), with the exception of three patients with Guillain-Barré syndrome (GBS). Hypocretin-1 was within the control range in most neurologic patients tested, including patients with AD, PD, and MS. Low but detectable levels (100-194 pg/mL) were found in a subset of patients with acute lymphocytic leukemia, intracranial tumors, craniocerebral trauma, CNS infections, and GBS. CONCLUSIONS: Undetectable CSF hypocretin-1 levels are highly specific to narcolepsy and rare cases of GBS. Measuring hypocretin-1 levels in the CSF of patients suspected of narcolepsy is a useful diagnostic procedure. Low hypocretin levels are also observed in a large range of neurologic conditions, most strikingly in subjects with head trauma. These alterations may reflect focal lesions in the hypothalamus, destruction of the blood brain barrier, or transient or chronic hypofunction of the hypothalamus. Future research in this area is needed to establish functional significance.     

CSF and plasma GABA levels in Parkinson's disease

CSF gamma-aminobutyric acid (GABA) levels were reduced in patients with idiopathic Parkinson's disease when compared with age matched controls, but the difference was not significant. However, when the Parkinsonian patients were subdivided, CSF GABA levels were lower in the levodopa treated group than in the untreated group and the controls. There was no difference in plasma GABA levels between Parkinsonian patients and controls.