Detection of soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in both cerebrospinal fluid and serum of patients after aneurysmal subarachnoid hemorrhage

OBJECT: The aim of this study was to explore whether levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are elevated in the cerebrospinal fluid (CSF) and serum of patients after aneurysmal subarachnoid hemorrhage (SAH). METHODS: This prospective clinical study focused on 21 patients who had recently suffered an SAH due to aneurysmal rupture and 15 control patients with hydrocephalus who had no other central nervous system disease. Cerebrospinal fluid and serum samples obtained within the first 3 days and on the 5th and 7th days of SAH were assayed for ICAM-1 and VCAM-1 by using quantitative enzyme-linked immunosorbent assays. Levels of soluble forms of ICAM-1 (p = 0.00001) and VCAM-1 (p = 0.009) in the patients' CSF and those of ICAM-1 (p = 0.00001) and VCAM-1 (p = 0.00001) in their serum were found to be elevated after SAH compared with levels in the CSF and serum of control patients with hydrocephalus. In addition, when the authors compared the increased levels of adhesion molecules in the CSF and serum of patients after SAH, the only statistically insignificant difference that they found was between the levels of VCAM-1 in serum obtained on Days 5 and 7 after SAH (p = 0.27). CONCLUSIONS: Adhesion molecules are a group of macromolecules that may participate in the inflammatory process, a common pathway leading to vasospasm after SAH. Leukocyte adherence to the vascular endothelium, which is induced by adhesion molecules, has been believed to be the initial signal of the development of vasospasm. The authors have demonstrated the synchronized elevation of two adhesion molecules in both CSF and serum following aneurysmal SAH. Blocking of ICAM-1 as well as VCAM-1 by monoclonal antibodies post-SAH may provide a beneficial effect on vasospasm.     

Markers for cell-mediated immune response are elevated in cerebrospinal fluid and serum after severe traumatic brain injury in humans

The brain is believed to be an immunologically privileged organ, sheltered from the systemic immunological defense by the blood-brain barrier (BBB). However, there is increasing evidence for a marked inflammatory response in the brain after traumatic brain injury (TBI). Markers for cellular immune activation, neopterin, beta2-microglobulin (beta2M), and soluble interleukin-2 receptor (sIL-2R), were measured for up to 3 weeks in cerebrospinal fluid (CSF) and serum of 41 patients with severe TBI in order to elucidate the time course and the origin of the cellular immune response following TBI. Neopterin gradually increased during the first posttraumatic week in both CSF and serum. Concentrations in CSF were generally higher than in serum, suggesting intrathecal release of this marker. beta2M showed similar kinetics but with higher serum than CSF concentrations. Nonetheless, intrathecal release as assessed by the beta2M index could be postulated for most of the patients. The mean levels of sIL-2R in both CSF and serum were elevated during the whole study period, serum concentrations being up to 2 x 10(4) times higher than in CSF. No significant intrathecal production of sIL-2R could be detected. The present data shows that severe TBI leads to a marked cell-mediated immune response within the brain and in the systemic circulation. In the intrathecal compartment the activated cells appear to be predominantly of the macrophage/microglia lineage, while the immune activation in the systemic circulation seems to involve mainly T-lymphocytes.     

Induction of cytosolic free calcium elevation in rat vascular smooth-muscle cells by cerebrospinal fluid from patients after subarachnoid hemorrhage

The purpose of this study was to determine the effects of cerebrospinal fluid (CSF) from patients with subarachnoid hemorrhage (SAH) on cytosolic free calcium in cultured rat vascular smooth-muscle cells using the fluorescent intracellular calcium indicator fura-2/AM. Samples of CSF were collected from 12 patients (seven with and five without vasospasm) on Days 2, 6, 11, and 16 after SAH. Control CSF samples were obtained from five patients 6 to 9 months after they had undergone successful aneurysm surgery following an SAH. All CSF samples in both the non-vasospasm and vasospasm groups, regardless of the day of sampling after the SAH, induced significantly higher transient intracellular calcium elevations when compared to levels induced by control CSF. Furthermore, the addition of 2 mM ethyleneglycol-bis (beta-aminoethylether)-N,N'-tetra-acetic acid (EGTA) caused a slight reduction in the peak height in the CSF-induced intracellular calcium rise which declined more rapidly to basal levels than those studied without EGTA. In the non-vasospasm group, the intracellular calcium concentration remained stable after SAH throughout the study period. In contrast, in the vasospasm group, this concentration was highest on Day 2 post-SAH, but sharply decreased on Day 6 and rose again on Day 11. This result correlated with the clinical signs of vasospasm in these patients. These findings indicated that the intracellular calcium elevations induced by CSF obtained after SAH were due to the combination of the influx of extracellular calcium and the mobilization of intracellular calcium from storage sites. The changes in intracellular calcium concentrations in vascular smooth-muscle cells induced by CSF obtained from patients on successive days following SAH suggest that the substances that induce this repeat calcium elevation on Day 11 post-SAH may be the key spasmogens for vasospasm after SAH.     

Association of an endogenous inhibitor of nitric oxide synthase with cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage

OBJECT: Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) may be evoked by the decreased availability of nitric oxide (NO). Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl-L-arginine (ADMA), an endogenous inhibitor of NO synthase (NOS), have been associated with the course and degree of cerebral vasospasm in a primate model of SAH. In this study, the authors sought to determine if similar changes in CSF ADMA levels are observed in patients with SAH, and whether these changes are associated with NO and NOS metabolite levels in the CSF and the presence of cerebral vasospasm. METHODS: Asymmetric dimethyl-L-arginine, L-arginine, L-citrulline, and nitrite levels were measured in CSF and serum samples collected during the 21-day period after a single aneurysmal SAH in 18 consecutive patients. Samples were also obtained in a control group consisting of seven patients with Chiari malformation Type I and five patients with spontaneous intracerebral hemorrhage without SAH. Vasospasm, defined as a greater than 11% reduction in the anterior circulation vessel diameter ratio compared with the ratio calculated from the initial arteriogram, was assessed on cerebral arteriography performed around Day 7. RESULTS: In 13 patients with SAH, arteriographic cerebral vasospasm developed. Cerebrospinal fluid ADMA levels in patients with SAH were higher than in those in the control group (p < 0.001). The CSF ADMA level remained unchanged in the five patients with SAH without vasospasm, but was significantly increased in patients with vasospasm after Day 3 (6.2 +/- 1.7 microM) peaking during Days 7 through 9 (13.3 +/- 6.7 microM; p < 0.001) and then gradually decreasing between Days 12 and 21 (8.8 +/- 3.2 microM; p < 0.05). Nitrite levels in the CSF were lower in patients with vasospasm compared to patients without vasospasm (p < 0.03). Cerebrospinal fluid ADMA levels positively correlated with the degree of vasospasm (correlation coefficient [CC] = 0.88, p = 0.0001; 95% confidence interval [CI] 0.74-0.95) and negatively correlated with CSF nitrite levels (CC = -0.55; p = 0.017; 95% CI -0.81 to -0.12). CONCLUSIONS: These results support the hypothesis that ADMA is involved in the progression of cerebral vasospasm. Asymmetric dimethyl-L-arginine and its metabolizing enzymes may be a future target for treatment of cerebral vasospasm after SAH.     

The role of endothelin-1 in the origin of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage.

Plasma and cerebrospinal fluid (CSF) endothelin (ET)-1-like immunoactivity in 27 patients with aneurysmal subarachnoid hemorrhage (SAH) was measured serially by radioimmunoassay for 2 weeks after SAH onset. Mean ET-1-like immunoactivity levels in plasma of patients with SAH were highly elevated during the whole study period, while the levels in CSF of the same patients were not. Plasma ET-1-like immunoactivity levels in patients with SAH classified as Fisher computerized tomography (CT) Group 3 were higher than those in patients with SAH classified as Fisher CT Groups 1 and 2. There were no significant differences in plasma ET-1-like immunoactivity levels between the patient groups stratified by Hunt and Kosnik grade. In this series, plasma ET-1-like immunoactivity levels in the 12 patients with vasospasm were higher than those in the 15 patients without vasospasm during the 1st week; CSF ET-1-like immunoactivity levels in patients with vasospasm were in the normal range on Days 0 to 3 after SAH onset, then became elevated on Days 5 to 7 and remained high until the end of the 2nd week. In contrast, CSF ET-1-like immunoactivity levels in patients without vasospasm were within the normal range during the entire period of study. The time course of the occurrence of vasospasm and that of the increase in CSF ET-1-like immunoactivity coincided precisely. The possible role of endogenous ET-1 in the pathogenesis of vasospasm due to SAH is discussed.     

Bilirubin as a cerebrospinal fluid marker of sentinel subarachnoid hemorrhage: a preliminary report in pigs

OBJECT: A model of subarachnoid hemorrhage (SAH) in pigs was developed to investigate bilirubin concentration in cerebrospinal fluid (CSF) as a potential marker of sentinel SAH. METHODS: Seven male Yorkshire pigs received a 250-microl injection of either whole autologous arterial blood (four animals) or isotonic saline (three animals) into the cisternae magna in an effort to produce volumetrically a model of sentinel SAH and a control injection model, respectively. Cerebrospinal fluid volumes of 100 microl were then collected from both the lumbar cistern and cisternae magna at 1 to 2-hour intervals for a total of 24 hours postinjection. The CSF was then tested for bilirubin. Mean concentrations of bilirubin (+/- standard deviation [SD]) obtained from the lumbar cistern 24 hours following the injection of blood or saline were 4.38 +/- 1.04 microM in the SAH animals and 1.02 +/- 0.05 microM in the controls. At 24 hours postinjection, mean concentrations (+/- SD) of cisternae magna bilirubin were 7.29 +/- 1.33 microM and 1.33 +/- 0.14 microM in the SAH animals and controls, respectively. In the SAH group, both the lumbar cistern and cisternae magna bilirubin concentrations differed significantly from baseline values 12 hours following SAH. CONCLUSIONS: Elevated concentrations of CSF bilirubin can be detected following a low-volume SAH, and the production of bilirubin occurred over a predictable time course. Twelve hours after hemorrhage, an elevated CSF bilirubin concentration was an indicator of hemolysis occurring in the subarachnoid spaces. The presence of bilirubin in CSF is a potential marker for differentiating SAHs from traumatic lumbar punctures in humans.     

In vitro and in vivo effects of probucol on hydrolysis of asymmetric dimethyl L-arginine and vasospasm in primates

OBJECT: Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl L-arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), are associated with delayed vasospasm after subarachnoid hemorrhage (SAH); however, the source, cellular mechanisms, and pharmacological inhibition of ADMA production following SAH are unknown. METHODS: In an in vitro experiment involving human umbilical vein endothelial cells (HUVECs), the authors examined mechanisms potentially responsible for increased ADMA levels during vasospasm and investigated whether this increase can be inhibited pharmacologically. In a second study, an in vivo experiment, the authors used probucol, which effectively inhibited ADMA increase in HUVEC cultures in vitro, in a randomized double-blind placebo-controlled experiment in a primate model of delayed cerebral vasospasm after SAH. Oxidized low-density lipids (OxLDLs; positive control; p < 0.02) and bilirubin oxidation products (BOXes; p < 0.01), but not oxyhemoglobin (p = 0.74), increased ADMA levels in HUVECs. Probucol inhibited changes in ADMA levels evoked by either OxLDLs (p < 0.001) or BOXes (p < 0.01). Comparable changes were observed in cell lysates. In vivo probucol (100 mg/kg by mouth daily) did not alter serum ADMA levels on Days 7, 14, and 21 after SAH compared with levels before SAH, and these levels were not different from those observed in the placebo group (p = 0.3). Despite achieving therapeutic levels in plasma and measurable levels in CSF, probucol neither prevented increased CSF ADMA levels nor the development of vasospasm after SAH. Increased CSF ADMA and decreased nitrite levels in both groups were strongly associated with the degree of delayed vasospasm after SAH (correlation coefficient [CC] 0.5, 95% confidence interval [CI] 0.19-0.72, p < 0.002 and CC -0.43, 95% CI -0.7 to -0.05, p < 0.03, respectively). CONCLUSIONS: Bilirubin oxidation products, but not oxyhemoglobin, increased ADMA levels in the HUVEC. Despite its in vitro ability to lower ADMA levels, probucol failed to inhibit increased CSF ADMA and decreased nitrite levels, and it did not prevent delayed vasospasm in a primate SAH model.     

Interleukin-6 and Development of Vasospasm after Subarachnoid Haemorrhage

Summary  The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6).  Concentrations of interleukin-1β (IL-1 β), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs.  CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29±5% from pretreatment diameter at 8 hours. Prostaglandins E₂ and I₂ were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angioenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF.  IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.     

Association between cerebrospinal fluid levels of asymmetric dimethyl-L-arginine, an endogenous inhibitor of endothelial nitric oxide synthase, and cerebral vasospasm in a primate model of subarachnoid hemorrhage

OBJECT: Decreased availability of nitric oxide (NO) has been proposed to evoke delayed cerebral vasospasm after sub-arachnoid hemorrhage (SAH). Asymmetric dimethyl-L-arginine (ADMA) inhibits endothelial NO synthase (eNOS) and, therefore, may be responsible for decreased NO availability in cases of cerebral vasospasm. The goal of this study was to determine whether ADMA levels are associated with cerebral vasospasm in a primate model of SAH. METHODS: Twenty-two cynomolgus monkeys (six control animals and 16 with SAH) were used in this study. The levels of ADMA, L-arginine, L-citrulline, nitrites, and nitrates in cerebrospinal fluid (CSF) and serum were determined on Days 0, 7, 14, and 21 following onset of SAH. Cerebral arteriography was performed to assess the degree of vasospasm. Western blot analyses of the right and left middle cerebral arteries (MCAs) were performed to assess the expression of eNOS, type I protein-arginine methyl transferase (PRMT1) and dimethylarginine dimethylaminohydrolase (DDAH2). Cerebrospinal fluid levels of ADMA remained unchanged in the control group (six animals) and in animals with SAH that did not have vasospasm (five animals; p = 0.17), but the levels increased in animals with vasospasm (11 animals) on Day 7 post-SAH (p < 0.01) and decreased on Days 14 through 21 (p < 0.05). Cerebrospinal fluid levels of ADMA correlated directly with the degree of vasospasm (correlation coefficient = 0.7, p = 0.0001; 95% confidence interval: 0.43-0.83). Levels of nitrite and nitrate as well as those of L-citrulline in CSF were decreased in animals with vasospasm. Furthermore, DDAH2 expression was attenuated in the right spastic MCA on Day 7 post-SAH, whereas eNOS and PRMT1 expression remained unchanged. CONCLUSIONS: Changes in the CSF levels of ADMA are associated with the development and resolution of vasospasm found on arteriograms after SAH. The results indicate that endogenous inhibition of eNOS by ADMA may be involved in the development of delayed cerebral vasospasm. Inhibition of ADMA production may provide a new therapeutic approach for cerebral vasospasm after SAH.     

Free fatty acids in human cerebrospinal fluid following subarachnoid hemorrhage and their potential role in vasospasm: a preliminary observation

OBJECT: The mechanisms leading to vasospasm following subarachnoid hemorrhage (SAH) remain unclear. Accumulation in cerebrospinal fluid (CSF) of free fatty acids (FFAs) may play a role in the development of vasospasm; however, in no previous study have concentrations of FFAs in CSF been examined after SAH. METHODS: We collected samples of CSF from 20 patients with SAH (18 cases of aneurysmal SAH and two cases of spontaneous cryptogenic SAH) and used a high-performance liquid chromatography assay to determine the FFA concentrations in these samples. We then compared these findings with FFA concentrations in the CSF of control patients. All FFA concentrations measured 24 hours after SAH were significantly greater than control concentrations (p < 0.01 for palmitic acid and < 0.001 for all other FFAs). All measured FFAs remained elevated for the first 48 hours after SAH (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). After 7 days, a second elevation in all FFAs was observed (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). Samples of CSF collected within 48 hours after SAH from patients in whom angiography and clinical examination confirmed the development of vasospasm after SAH were found to have significantly higher concentrations of arachidonic, linoleic, and palmitic acids than samples collected from patients in whom vasospasm did not develop (p < 0.05). CONCLUSIONS: Following SAH, all FFAs are initially elevated. A secondary elevation occurs between 8 and 10 days after SAH. This study provides preliminary evidence of FFA elevation following SAH and of a potential role for FFAs in SAH-induced vasospasm. A prospective study is warranted to determine if CSF concentrations of FFAs are predictive of vasospasm.     

The effect of subarachnoid hemorrhage on blood and CSF atrial natriuretic factor

Atrial natriuretic factor (ANF) is a diuretic natriuretic peptide hormone produced by both the heart and brain which has been postulated to play a role in the hemodynamic and sodium instability that frequently follows subarachnoid hemorrhage (SAH). Levels of ANF were measured in 12 patients with nontraumatic SAH and nine control patients with unruptured cerebral aneurysms. At surgery, the mean plasma ANF level (+/- standard deviation) of the SAH group was significantly higher than that of the control group (158.1 +/- 83.8 vs. 57.8 +/- 45.3 pg/ml, respectively; p = 0.01). There was no significant difference in serum sodium concentration, blood pressure, or central venous pressure between these groups. Nine patients with SAH due to aneurysm rupture had plasma ANF levels similar to those in three patients with SAH due to other causes. Four patients with moderate to severe SAH had significantly higher mean cerebrospinal fluid (CSF) ANF values (17.7 +/- 12.8 pg/ml) than five patients with minimal SAH (0.6 +/- 0.9 pg/ml) or the control group of nine patients (3.7 +/- 1.3 pg/ml) (p less than 0.05). Five patients with moderate to severe SAH had significantly higher plasma ANF values (202.6 +/- 72.2 pg/ml) than five with minimal SAH (86.8 +/- 29.2 pg/ml) or the control group (57.8 +/- 45.3 pg/ml) (p less than 0.05). Plasma ANF values were substantially higher than CSF ANF content in the SAH group (p less than 0.01) and in the control group (p = 0.05). From these data it is concluded that: 1) plasma ANF is elevated significantly after SAH; 2) this rise appears unrelated to the cause of hemorrhage, serum sodium concentration, blood pressure, or central venous pressure, but is related to the extent of the hemorrhage; 3) ANF concentrations in the CSF are significantly lower than in plasma, and are elevated after moderate to severe SAH; and 4) the source of CSF ANF is probably the plasma, and the source of plasma ANF is likely the heart.     

Intrathecal and systemic concentration of NT-proBNP in patients with severe traumatic brain injury

Outcome of patients suffering from traumatic brain injury (TBI) depends on the development of secondary brain damage. In this context, recent studies underlined the role of the natriuretic peptides- atrial natriuretic peptide and brain natriuretic peptide (BNP)-in aneurysmatic subarachnoidal hemorrhage (SAH). Especially BNP correlates with intracranial pressure and clinical outcome after SAH. Since its role in TBI remains unclear, the intracranial and systemic concentrations of N-terminal (NT)-proBNP were analyzed in patients suffering from severe TBI. We measured NT-proBNP levels in cerebrospinal fluid (CSF) and serum of 14 patients suffering from severe TBI (GCS15 mm Hg (n=6), the serum (800+/-150 pg/mL) and CSF levels (55+/-9 pg/mL) of NT-proBNP were significantly increased after 24 h, as compared to patients with ICP15 mm Hg. Further studies are currently performed to elucidate the physiologic role of NT-proBNP in TBI.     

Effect of experimental subarachnoid hemorrhage on CSF eicosanoids in the rat

A simple and inexpensive experimental model of subarachnoid hemorrhage (SAH) was developed in the rat. Based on accumulating data indicating the important role of arachidonic acid metabolites in the etiology of delayed cerebral vasospasm, we investigated changes induced by SAH on cerebrospinal fluid (CSF) levels of prostaglandin E2 (PGE2), F2 alpha (PGF2 alpha), and thromboxane B2 (TXB2). SAH was produced by the cisternal injection of blood via percutaneous suboccipital puncture. SAH rats (n = 200) were injected with 300 microliters of fresh autologous arterial blood; Control rats (n = 100) received the same volume of mock CSF. In 60 additional animals, no injections were made. To follow the changes induced by SAH on both the spectrum and time course of CSF eicosanoids, cisternal CSF samples were collected under basal conditions, 6, 12, and 36 after cisternal injection. PGE2, PGF2 alpha, and TXB2 were assayed in aliquots of CSF obtained by pooling samples from each experimental group. Eicosanoids were assayed using radioimmunoassay techniques. Arterial spasm was verified in parallel groups of SAH and control rats by comparison of the angiographic diameters of the basilar arteries (BA) and middle cerebral arteries (MCA) to that of the stapedial artery. CSF levels of all three eicosanoids were significantly higher in the SAH groups compared to both noninjected and mock-CSF injected control rats. These increases in concentrations of eicosanoids were accompanied by a decrease in the mean vascular diameter (77.5-82.0% of control) on day 2 following cisternal injection. We conclude that marked elevations of spasmogenic eicosanoids in the CSF are associated with experimental SAH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased concentrations of the monoamine metabolities homovanillic acid and 5-hydroxyindoleacetic acid in lumbar and central CSF and of 3-methoxy-4-hydroxyphenylglycol in lumbar CSF after subarachnoid haemorrhage

Summary The concentrations of the dopamine metabolite homovanillic acid (HVA), the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MOPEG) were determined in cerebrospinal fluid (CSF) from patients with subarachnoid haemorrhage (SAH) using a mass fragmentographic method.In a first group of 24 patients lumbar CSF was collected during the first 10 days after SAH. The concentrations of HVA and 5-HIAA showed a several-fold increase in the majority of subjects while that for MOPEG was less pronounced in comparison to controls.In a second group of 12 SAH-patients, CSF was collected in 10 ml fractions during surgical clipping of aneurysms. The mean concentrations of HVA, 5-HIAA and MOPEG in lumbar CSF was 469,275 and 39 pmol/l, respectively, whereas central CSF concentrations were 1,212, 499 and 48 pmol/ml, respectively. Compared to healthy controls, both HVA and 5-HIAA showed increased levels (pl 0,01) but MOPEG was within the normal range.No correlation between the concentrations of the monoamine metabolites, the neurological condition or the cerebral vascular diameter was observed in neither of the two groups.It is suggested that the accumulation of HVA and 5-HIAA in SAH patients is explained by a disturbance of the active transport mechanism.This study was supported by grants from Karolinska Institutet.     

不同时间浅低温对蛛网膜下腔出血犬脑血管痉挛的影响

目的 探讨不同时间浅低温对蛛网膜下腔出血犬脑血管痉挛的影响.方法 成年健康犬30只,雌雄不拘,体重14～20 kg,采用枕骨大孔二次注血法制备犬蛛网膜下腔出血模型.随机分为5组(n=6),人工脑脊液组(ACSF组):枕骨大孔处注入ACSF 0.5 ml/ks;蛛网膜下腔出血组(SAH组):制备蛛网膜下腔出血模型,维持直肠温度38～39℃;不同时间浅低温组(H_(1～3)组):在第2次注血后分别立即实施8、16和32 h浅低温(33.5℃),随后复温至38～39℃.于第1次注血或注入ACSF前和第2次注血或注入ACSF 5、12和19 d时行整体功能分级(OPC),并采用ELISA法和硝酸还原酶法分别测定血浆和脑脊液内皮素-1(ET-1)和一氧化氮(NO)代谢产物NO_2~-/NO_3~-的浓度,采用CT血管造影动态测量脑基底动脉直径.结果 与ACSF组比较,SAH组和H_1,2组OPC分级升高,血浆和脑脊液ET-1浓度升高,NO_2~-/NO_3~-浓度降低,基底动脉直径减小(P＜0.05),H_3组上述指标差异无统计学意义(P＞0.05);与SAH组比较,H_2,3组OPC分级降低,血浆和脑脊液ET-1浓度降低,NO_2~-/NO_3~-浓度升高,基底动脉直径增大(P＜0.05),H_1组各时点上述指标差异无统计学意义(P＞0.05);与H_2组比较,H_3组血浆和脑脊液ET-1浓度降低,NO_2~-/NO_3~-浓度升高,基底动脉直径增大(P＜0.05).结论 浅低温16～32 h可缓解蛛网膜下腔出血犬脑血管痉挛,且随浅低温时间延长该作用增强,其机制可能与降低全身和脑组织ET-1水平,升高NO水平,调节脑血管收缩-舒张平衡有关.     

Rapid Induction of Meningeal Collagen Synthesis in the Cerebral Cisternal and Ventricular Compartments after Subarachnoid Hemorrhage

Summary. Procollagen propeptides in the lumbar CSF increase after subarachnoid hemorrhage (SAH), and elevated concentrations have been detected as early as on day 8. We studied here the timing and localization of the induction of meningeal collagen synthesis during the first week after SAH by analysing cisternal and ventricular CSF samples. We obtained 29 cisternal and 10 ventricular CSF samples at operation from patients with SAH between days 1 and 9 after onset. The carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP) were measured using radio-immunoassays. The concentrations of PICP and PIIINP in the cisternal CSF were elevated as early as on day 2 after SAH. PICP increased in a sigmoidal fashion (R²=0.39, p<0.001), while PIIINP increased linearly (R²=0.28, p=0.003) and was approximately 3-fold higher on day 9 than initially. PICP was twice as high (p=0.02) in the cisternal than in the ventricular CSF after SAH and PIIINP was 4-times higher (p=0.007). Interestingly, the concentrations were similar in a patient with intraventricular bleeding. The cisternal compartment contributed to the propeptides in the CSF more than did the ventricular compartment, but the latter also appeared to have a definite potential for fibroproliferative reaction. Meningeal collagen synthesis was induced rapidly within the first few days after SAH suggesting that therapeutic attempts to inhibit the fibroproliferative reaction should be started as early as possible.     

Increased concentration of hypoxanthine in human central cerebrospinal fluid after subarachnoid haemorrhage

Summary The adenine nucleotide metabolites hypoxanthine, xanthine and uric acid were determined by high performance liquid chromatography in cerebrospinal fluid (CSF) from 25 patients with subarachnoid haemorrhage (SAH) and from 26 control subjects. In addition, the haemoglobin and protein levels in the CSF of the patients were determined.In 13 subjects, from which lumbar CSF was collected three, six and nine days after SAH, there was a gradual increase in 8 patients for hypoxanthine and in 3 of the 13 patients for xanthine and uric acid. The mean concentrations were not significantly higher than the controls. In 12 SAH patients, consecutive CSF fractions of 10 ml were collected peroperatively during surgical clipping of aneurysms. The hypoxanthine concentrations increased continously from lumbar to central CSF samples. Hypoxanthine levels were 6.5±1.0 M in lumbar CSF compared to 11.8±2.3 M in central CSF (p<0.001), while xanthine, uric acid, haemoglobin and protein levels were equally distributed. Furthermore, the SAH patients showed about 3 times higher concentrations of central CSF hypoxanthine (p<0.01) and xanthine (p<0.05) while that for uric acid was similar compared to all control subjects. Also, an in vitro study showed that the increased concentrations of the adenine nucleotide metabolites could not be caused by degradation of blood components in the subarachnoid space.It is presumed that the increased central CSF concentrations of hypoxanthine that were demonstrated in patients after SAH could be a sensitive marker for brain tissue ischaemia. However, since there was no correlation between the hypoxanthine levels, clinical condition or cerebral vascular diameter, other factors have to be excluded before ischaemia alone could explain the elevated central hypoxanthine levels in patients without major clinical dysfunction after SAH.This study was supported by grants from Karolinska Institutet, the Swedish National Society against Heart and Chest disease, The Swedish Society of Medical Sciences, Wibergs Foundation, Boehringer Ingelheim and the Swedish Medical Research Council (proj. no. 7485).     

Alterations of monoamine metabolites and of tryptophan in the basal cisternal CSF of patients after subarachnoid haemorrhage

Summary Homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and tryptophan (TRP) were measured in the CSF obtained from the basal cistern of 20 patients, who had undergone surgical obliteration of bleeding aneurysms within 3 days after subarachnoid haemorrhage (SAH). The concentrations of these substances, which were assayed by high performance liquid chromatography (HPLC), were the highest on days 3 or 4, and thereafter showed a gradual decrease with an increase in time. The cisternal CSF in patients who had severe pre-operative clinical grades of SAH or vasospasm contained relatively higher concentrations of HVA, 5-HIAA and TRP than those contained in patients who did not. It is proposed that SAH stimulates the release of monoamines from the brain with the resultant extracellular accumulation of their metabolites and their diffusion into CSF during the acute stage. This stimulatory effect of SAH on the brain monoamine system may be consistent with those previously reported in cases of cerebral haemorrhage or infarction.     

Role of adenosine 5'-triphosphate in vasospasm after subarachnoid hemorrhage: human investigations

OBJECTIVE: Adenosine 5'-triphosphate (ATP) is a vasoactive compound found in high concentrations inside erythrocytes. This compound may contribute to vasospasm after subarachnoid hemorrhage (SAH). We assessed the hypothesis that ATP contributes to vasospasm in humans. METHODS: ATP and hemoglobin concentrations were measured in cerebrospinal fluid (CSF) from humans with SAH and in blood incubated in vitro. The vasoactivity of the human CSF samples and of fractionated (fractions with molecular weight greater than or less than 10 kDa) and unfractionated blood incubated in vitro was assessed by application of samples to canine basilar artery segments under isometric tension. RESULTS: ATP in human CSF declined within 72 hours of SAH to concentrations too low to contract cerebral arteries. Vasoactivity of human CSF correlated with the concentration of hemoglobin. The vasoactivity of incubated erythrocyte hemolysates remained high despite a decline in ATP concentrations. Fractionation of incubated erythrocyte hemolysates showed that for incubation periods up to 7 days, all vasoactivity was in a fraction of molecular weight greater than 10 kDa. CONCLUSION: ATP is unlikely to contribute to vasospasm because the concentrations in CSF after SAH in humans are not high enough to cause vasospasm after 72 hours. The vasoactivity of erythrocyte hemolysate is not related to the ATP or ferrous hemoglobin content but may be related to the total hemoglobin content. Therefore, ATP is unlikely to be a major cause of clinically significant delayed vasospasm.     

Increased levels of somatomedins in human lumbar and central cerebrospinal fluid after subarachnoid haemorrhage

Summary The somatomedins, multitargit growth-promoting peptide hormones, were measured with radio receptor assay in cerebrospinal fluid (CSF) after subarachnoid haemorrhage (SAH) in 21 patients and after head injury in 2 patients.In the first group of 10 patients, lumbar (n=8) or central (n=2) CSF was collected on days three, six and nine after SAH. 6 of the 8 patients with SAH showed an increase in somatomedin concentrations ranging between 0.52–1.26 U/ml while 2 patients fell within the normal range between 0.19–0.48 U/ml. In the 2 patients with head injury, the somatomedin concentrations were scarcely detectable.In the second group of 13 patients with SAH, CSF was collected peroperatively during surgical clipping of an aneurysm. These patients fell into two groups: 6 patients who had CSF somatomedin levels within the normal range and 7 patients with pathologically increased somatomedin concentrations ranging between 0.38–1.26 U/ml. Neither the neurological condition nor the cerebral vascular diameter correlated with the somatomedin concentrations. It is suggested that the increased somatomedin levels in CSF after SAH could be a compensatory response in order to stimulate cerebral anabolism after injury.This work was supported by grants from Karolinska Institutet, the Swedish Medical Research Council, Sävstaholmsföreningen, and Loo and Hans Osterman Research Fund.