One-stage Stent-assisted Coil Embolization for Rupture-side-unknown Bilateral Vertebral Artery Dissecting Aneurysms in an Acute Stage: A Case Report

Bilateral vertebral artery dissecting aneurysms (VADAs) with subarachnoid hemorrhage (SAH) are rare and their management is still challenging. In this report, we successfully performed one-stage stent-assisted coil embolization (SAC) for bilateral VADAs with SAH in an acute stage, because the ruptured side could not be diagnosed. A 47-year-old woman presented with a sudden onset of headache without laterality, and left-side dominant SAH with bilateral VADAs was noted on computed tomography (CT) scans. The size of aneurysmal dome and neck was similar between the two VADAs, and a bleb was observed only on the right VADA. In computational fluid dynamics (CFD) simulations, findings of wall shear stress (WSS), normalized WSS, and WSS gradient suggested that the left VADA was ruptured, while the oscillatory shear index and aneurysm formation indicator suggested the opposite-side one to be ruptured. Thus, we could not determine which VADA was ruptured by clinical data and CFD analyses. Therefore, we performed simultaneous treatment for the bilateral VADAs by using SAC technique 8 h after the onset under dual antiplatelet and anticoagulation therapies. There was no evidence of rebleeding and stent thrombosis. Stent thrombosis was monitored by duplex color-coded ultrasonography after the intervention. She was discharged without neurological deficits, and 6-month follow-up cerebral angiography demonstrated no recanalization of VADAs. This is the first report showing bilateral VADAs with SAH treated by one-stage SAC within 24 h of SAH, and the potential risks are discussed.

[Pontine Hemorrhage Suspected due to Dural Arteriovenous Fistula at the Craniocervical Junction:A Case Report]

Dural arteriovenous fistulas occurring at the craniocervical junction(CCJd-AVF)are uncommon; however, they demonstrate a wide range of clinical presentations. We describe the case of a patient with pontine hemorrhage suspected due to CCJd-AVF. A 68-year-old man presented to our hospital with a sudden onset of left hemiparesis. Cranial computed tomography(CT)revealed pontine and subarachnoid hemorrhage. Magnetic resonance imaging, as well as MR, CT, and left vertebral angiograms were performed and showed a CCJd-AVF in addition to a varix coincident with the hematoma cavities. The patient was successfully treated using surgical drainer clipping. A CCJd-AVF presenting concomitantly with a pontine hemorrhage is extremely rare. Careful assessment of the anatomical relationship between the skull base and the surrounding vascular structures is important to plan neurosurgical procedures for direct interruption of the draining vein. Three-dimensional CT angiography is a useful modality that facilitates visualization of complex and anomalous anatomical structures.

Increased metabolite production by deletion of an HDA1-type histone deacetylase in the phytopathogenic fungi, Magnaporthe oryzae (Pyricularia oryzae) and Fusarium asiaticum

Histone deacetylases (HDACs) play an important role in the regulation of chromatin structure and gene expression. We found that dark pigmentation of Magnaporthe oryzae (anamorph Pyricularia oryzae) ΔMohda1, a mutant strain in which an orthologue of the yeast HDA1 was disrupted by double cross-over homologous recombination, was significantly stimulated in liquid culture. Analysis of metabolites in a ΔMohda1 mutant culture revealed that the accumulation of shunt products of the 1,8-dihydroxynaphthalene melanin and ergosterol pathways were significantly enhanced compared to the wild-type strain. Northern blot analysis of the ΔMohda1 mutant revealed transcriptional activation of three melanin genes that are dispersed throughout the genome of M. oryzae. The effect of deletion of the yeast HDA1 orthologue was also observed in Fusarium asiaticum from the Fusarium graminearum species complex; the HDF2 deletion mutant produced increased levels of nivalenol-type trichothecenes. These results suggest that histone modification via HDA1-type HDAC regulates the production of natural products in filamentous fungi.

SIGNIFICANCE AND IMPACT OF THE STUDY

Natural products of fungi have significant impacts on human welfare, in both detrimental and beneficial ways. Although HDA1-type histone deacetylase is not essential for vegetative growth, deletion of the gene affects the expression of clustered secondary metabolite genes in some fungi. Here, we report that such phenomena are also observed in physically unlinked genes required for melanin biosynthesis in the rice blast fungus. In addition, production of Fusarium trichothecenes, previously reported to be unaffected by HDA1 deletion, was significantly upregulated in another Fusarium species. Thus, the HDA1-inactivation strategy may be regarded as a general approach for overproduction and/or discovery of fungal metabolites.

Mechanical Recanalization for Acute Embolic Occlusion at the Origin of the Superior Mesenteric Artery

Purpose:

We report a combined technique consisting of thrombectomy and thromboaspiration for the treatment of acute embolic occlusion of the superior mesenteric artery (SMA) at the origin.

Case:

A 90-year-old female with chronic atrial fibrillation had a sudden onset of abdominal pain and hematochezia due to acute embolic occlusion at the origin of the SMA. Computed tomographic findings showed reversible bowel wall ischemia. We performed mechanical thrombectomy using the Solitaire FR revascularization device, a self-expanding and fully retrievable stent-based thrombectomy system for acute intracranial large artery occlusion, combined with manual aspiration through a 6F guiding sheath placed at the SMA origin via a right brachial approach. Prompt and complete recanalization of the SMA was obtained without distal embolism, and intestinal necrosis was avoided.

Conclusion:

Combined endovascular procedures of mechanical thrombectomy using the Solitaire FR with thromboaspiration may allow prompt recanalization, clot removal, and prevention of distal embolism and therefore would be a new therapy for acute embolic occlusion at the origin of the SMA.

Simultaneous Spinal and Intracranial Chronic Subdural Hematoma Cured by Craniotomy and Laminectomy: A Video Case Report

Simultaneous spinal and intracranial chronic subdural hematoma (CSDH) is a rare entity. A 67-year-old man visited our hospital due to headache after diving into a river 2 weeks before. Non-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed bilateral intracranial CSDH. The bilateral CSDH was evacuated and his symptoms improved. Three days after craniotomy, he complained of sensory disturbance on his buttocks. Lumbar MRI showed a space-occupying lesion behind the thecal sac at L5. CT with myelography showed a subdural mass lesion; there was no communication with the subarachnoid space. Fourteen days after craniotomy, L5 laminectomy was performed and the dura mater was incised carefully. The video shows that a liquid hematoma similar to the intracranial CSDH flowed out, followed by cerebrospinal fluid. His symptoms improved after the operation and the hematoma did not recur. This is a rare condition of spinal CSDH demonstrated by neuroimaging and intraoperative video.

The Role of Matricellular Proteins in Brain Edema after Subarachnoid Hemorrhage

Accumulated evidence suggests that blood-brain barrier disruption or brain edema is an important pathologic manifestation for poor outcome after aneurysmal subarachnoid hemorrhage. Many molecules may be involved, acting simultaneously or at different stages during blood-brain barrier disruption via multiple independent or interconnected signaling pathways. Matricellular protein is a class of nonstructural, secreted, and multifunctional extracellular matrix proteins, which potentially mediates brain edema formation. This study reviews the role of osteopontin and tenascin-C, representatives of matricellular proteins, in the context of brain edema formation after subarachnoid hemorrhage in both clinical and experimental settings.

Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Predictors for cerebral infarction, an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH), were examined. This study used data from the Prospective Registry of Subarachnoid Aneurysms Treatment (PRESAT) cohort, which included 579 patients whose ruptured aneurysms were treated with either clipping or coiling within 12 days of onset. Patient, clinical, radiographic, and treatment variables associated with cerebral infarction were determined. Ruptured aneurysms were clipped in 282 patients and coiled in 297 patients. Cerebral infarction occurred in 162 patients (28.0 %): 101 patients by cerebral vasospasm, 34 patients by clipping, and 33 patients by coiling. Univariate analyses showed that significant factors associated with cerebral infarction development were Fisher computed tomography (CT) group 3 on admission, premature aneurysm rupture during clipping procedure, cerebrospinal fluid drainage, symptomatic vasospasm, endovascular treatment for vasospasm, and shunt-dependent hydrocephalus. Multivariable logistic regression analyses showed that cerebral infarction was significantly associated with Fisher CT group 3 on admission, larger aneurysm dome size, ruptured posterior circulation aneurysms, premature aneurysm rupture during clipping procedure, symptomatic vasospasm, and infection, while endovascular treatment for vasospasm significantly decreased the development of cerebral infarction. The most important potentially treatable factor associated with cerebral infarction was symptomatic vasospasm.

Usefulness of arterial spin-labeling images in periictal state diagnosis of epilepsy

PURPOSE

Arterial spin-labeling (ASL) perfusion MRI, a noninvasive method of assessing cerebral blood flow, is becoming a diagnostic tool of epilepsy. This study was undertaken to evaluate the diagnostic validity of ASL in patients with status epilepticus (SE) in a periictal state.

METHOD

Twenty cases with SE were studied. Patients were imaged at a 3T MRI including ASL and diffusion-weighted imaging (DWI), and were also examined using electroencephalography (EEG). The abnormal findings of ASL were compared with those obtained from DWI and EEG.

RESULT

Focal hyperperfusion was found in the cortical territory of 13 cases (65%). In 10 of those 13 cases, the ASL hyperperfusion region corresponded to DWI high intensity and EEG abnormality. Two cases showed hyperperfusion corresponding to EEG abnormalities in ASL despite the absence of high intensity in DWI. The remaining single case showed hyperperfusion in ASL despite the absence of high intensity in DWI and EEG abnormalities. Hyperperfusion in the subcortical territory was observed in the ipsilateral thalamus in three cases and in the contralateral cerebellum in one case.

CONCLUSION

Our results suggest that ASL is a useful tool to diagnose status epilepticus and localization of the epilepsy focus.

Risk factors for vasospasm-induced cerebral infarct when both clipping and coiling are equally available

INTRODUCTION

Vasospasm-induced cerebral infarct is still a significant cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH).

MATERIALS AND METHODS

In 537 patients of the Prospective Registry of Subarachnoid Aneurysms Treatment cohort, ruptured aneurysms were treated either microsurgically or endovascularly judged by the attending neurosurgeon to be appropriate for the individual patient within 3 days of onset. Factors for vasospasm-induced cerebral infarct were examined.

RESULTS

Clipping (273 patients) was preferably performed for middle cerebral artery aneurysms, while coiling (264 patients) was preferred for larger, internal carotid artery and posterior circulation aneurysms. After aneurysmal obliteration, cerebrospinal fluid drainage was performed more in clipped patients, and antithrombotic treatment was performed more in coiled patients. Vasospasm-induced cerebral infarct occurred in 17.7 %, and multivariable logistic regression showed that vasospasm-induced cerebral infarct increased the odds of poor outcome by a factor of 5.2 (adjusted odds ratio, 5.2; 95 % confidence interval, 2.8-9.8; P < 0.001). Multivariate analyses showed that vasospasm-induced cerebral infarct was significantly associated with admission World Federation of Neurosurgical Societies grade IV-V, Fisher computed tomography (CT) group 3-4, and ruptured middle cerebral artery aneurysms.

CONCLUSIONS

New treatment strategies for vasospasm-induced cerebral infarct are needed, especially for ruptured middle cerebral artery aneurysm cases associated with massive SAH.

Tenascin-C is a possible mediator between initial brain injury and vasospasm-related and -unrelated delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

INTRODUCTION

Tenascin-C (TNC), a matricellular protein, exerts diverse functions, including tissue remodeling and apoptosis, and is induced in cerebrospinal fluid (CSF) after aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to examine the relationships among CSF TNC levels, initial brain injury, delayed cerebral ischemia (DCI), and vasospasm after SAH.

METHODS

CSF TNC levels were measured in 30 patients with aneurysmal SAH of Fisher computed tomography (CT) group III who were treated microsurgically or endovascularly with CSF drainage within 24 h of SAH. Admission World Federation of Neurosurgical Societies (WFNS) grade was supposed to indicate the severity of initial brain injury. Cerebral vasospasm was defined as narrowed (≥ 25 %) cerebral arteries demonstrated by angiography. DCI was defined as any neurological deterioration presumed related to ischemia that persisted for ≥ 1 h.

RESULTS

Higher CSF TNC levels were correlated with worse admission WFNS grades. Vasospasm was aggravated with higher TNC levels. DCI occurred regardless of the degree of vasospasm but was associated with TNC induction. Multivariate analyses showed that higher TNC levels and vasospasm were independent predictors of DCI occurrence.

CONCLUSIONS

SAH (initial brain injury) that is more severe induces more TNC, which may cause the subsequent development of both vasospasm and vasospasm-unrelated secondary brain injury, leading to DCI.

Effects of tenascin-C on early brain injury after subarachnoid hemorrhage in rats

BACKGROUND AND PURPOSE

We previously reported that tenascin-C (TNC), a matricellular protein, was involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH), but the role of TNC in early brain injury (EBI) is unknown. This study assessed whether inhibition of TNC upregulation in brain by imatinib mesylate (imatinib), an inhibitor of the tyrosine kinases of platelet-derived growth factor receptors, prevents EBI after experimental SAH.

METHODS

Rats were assigned to sham, SAH plus vehicle, and SAH plus imatinib groups (n = 4 per group). Imatinib (50 mg/kg body weight) was administered intraperitoneally to rats undergoing SAH by endovascular perforation, and EBI was evaluated using terminal deoxynucleotidyl transferase-mediated uridine 5-triphosphate-biotin nick end-labeling staining at 24 h after SAH. Imatinib-treated SAH rats were also treated by a cisternal injection of recombinant TNC.

RESULTS

SAH upregulated TNC and caused EBI. Imatinib treatment suppressed both TNC upregulation and EBI at 24 h. Recombinant TNC reinduced EBI in imatinib-treated SAH rats.

CONCLUSIONS

TNC may be involved in the pathogenesis of EBI after SAH.

Vasoconstrictive effect of tenascin-C on cerebral arteries in rats

BACKGROUND AND PURPOSE

The authors have reported that tenascin-C (TNC), a matricellular protein, is induced after subarachnoid hemorrhage (SAH), associated with cerebral vasospasm. In this study, we examined whether TNC alone causes cerebral vasospasm-like constriction of the intracranial internal carotid arteries (ICAs) in rats, focusing on the p38 mitogen-activated protein kinase (MAPK)-mediated mechanisms.

METHODS

First, we injected 10 μg of TNC into the cisterna magna of healthy rats and studied morphologically whether TNC caused constriction of the left ICA at 24-72 h after administration. Second, we examined the effect of SB203580 (a p38 MAPK inhibitor) on the vessel diameter of the left ICA in healthy rats at 24 h. Third, we evaluated the effect of SB203580 on TNC-induced constriction of the left ICA in healthy rats at 24 h.

RESULTS

TNC significantly induced cerebral vasospasm-like angiographic constriction of the left ICAs, which continued at least for 72 h. SB203580 itself had no effect on the diameter of normal ICAs, but abolished the TNC-induced vasoconstrictive effect on the left ICA.

CONCLUSION

These findings show that TNC causes left ICA constriction via activation of p38 MAPK, resembling post-SAH vasospasm, and suggest the possible involvement of TNC in the pathogenesis of cerebral vasospasm.

Effects of acivicin on growth, mycotoxin production and virulence of phytopathogenic fungi

Acivicin is an inhibitor of γ-glutamyl transpeptidase and glutamine amidotransferase. When grown on a synthetic minimal agar medium, acivicin strongly inhibited the growth of Magnaporthe oryzae and Alternaria brassicicola, and to a lesser extent, Botrytis cinerea. However, only partial or marginal growth inhibition was observed with regard to Fusarium sporotrichioides and Fusarium graminearum. The growth retardation caused by acivicin was significantly alleviated by cultivating the fungus on a nutrient-rich medium. The inhibition of M. oryzae growth caused by 1 μmol l(-1) of acivicin on minimal agar medium was subdued by the addition of specific single amino acids, including His, a branched-chain amino acid (Leu, Ile or Val), an aromatic amino acid (Trp, Tyr or Phe), Met or Gln, at a concentration of 0·4 mmol l(-1). Trichothecene production by F. graminearum in trichothecene-inducing liquid medium was reduced significantly in the presence of acivicin despite its inability to inhibit growth in the trichothecene-inducing liquid medium. Foliar application of conidia in the presence of acivicin reduced the severity of rice blast disease caused by M. oryzae. These results suggest the usefulness of this modified amino acid natural product to mitigate agricultural problems caused by some phytopathogenic fungi. Significance and impact of the study: Fusarium head blight or scab disease and rice blast, caused by Fusarium graminearum and Magnaporthe oryzae, respectively, are major diseases of cereal crops that cause a significant loss of yield and deterioration in the quality of the grain. The present study investigated the effects of acivicin, a glutamine amino acid analog, on the physiology of various phytopathogenic fungi. Application of acivicin to a fungal culture and conidial suspension reduced mycotoxin production by the wheat scab fungus and the severity of rice blast, respectively. These results suggest the possibility that acivicin may serve as a lead compound to develop agricultural chemicals for the control of some plant diseases.

Neuromelanin magnetic resonance imaging in Parkinson's disease and multiple system atrophy

Pigmented neurons in the substantia nigra pars compacta (SNc) and locus coeruleus (LC) show decreased numbers differentially in Parkinson's disease (PD) and multiple system atrophy (MSA). Recent reports have described that fast spin-echo T1-weighted magnetic resonance imaging (MRI) by a 3-tesla machine can visualize neuromelanin-related contrast of the noradrenergic and dopaminergic neurons respectively in the LC and the SNc. Using neuromelanin MRI at 3 T, we investigated possible alterations of these catecholaminergic neurons in 32 PD and 9 MSA patients, and compared the results with those of 23 normal volunteers. The contrast ratio of the LC and SNc was decreased in MSA and PD patients, most prominently in the LC in MSA patients. The contrast ratio of the SNc was correlated with the Hoehn-Yahr stage of PD and the severity of neuroradiological abnormalities in MSA. These results indicate a potential diagnostic value of neuromelanin MRI to distinguish MSA patients from normal and PD patients.

Tenascin-C induces prolonged constriction of cerebral arteries in rats

Tenascin-C (TNC), a matricellular protein, is induced in association with cerebral vasospasm after subarachnoid hemorrhage. The aim of this study was to assess the vasoconstrictive effects of TNC and its mechanisms of action on cerebral arteries in vivo. Two dosages (1 and 10μg) of TNC were administered intracisternally to healthy rats, and the effects were evaluated by neurobehavioral tests and India-ink angiography at 24, 48, and 72h after the administration. Western blotting and immunohistochemistry were performed to explore the underlying mechanisms on constricted cerebral arteries after 24h. The effects of toll-like receptor 4 (TLR4) antagonists (LPS-RS), c-Jun N-terminal kinase (JNK), and p38 inhibitors (SP600125 and SB203580) on TNC-induced vasoconstriction were evaluated at 24h. Higher dosages of TNC induced more severe cerebral arterial constriction, which continued for more than 72h. TNC administration also upregulated TLR4, and activated JNK and p38 in the smooth muscle cell layer of the constricted cerebral artery. LPS-RS blocked TNC-induced TLR4 upregulation, JNK and p38 activation, and vasoconstrictive effects. SP600125 and SB203580 abolished TNC-induced TLR4 upregulation and vasoconstrictive effects. TNC may cause prolonged cerebral arterial constriction via TLR4 and activation of JNK and p38, which may upregulate TLR4. These findings suggest that TNC causes cerebral vasospasm and provides a novel therapeutic approach against it.

Matricellular protein: a new player in cerebral vasospasm following subarachnoid hemorrhage

INTRODUCTION

Matricellular protein (MCP) is a class of nonstructural and secreted extracellular matrix proteins that exert diverse functions, but its role in vascular smooth muscle contraction has not been investigated.

MATERIAL AND METHODS

First, rat subarachnoid hemorrhage (SAH) models were produced by endovascular perforation and examined for tenascin-C (TNC) and osteopontin (OPN) induction (representatives of MCPs) in vasospastic cerebral arteries using immunostaining. Second, recombinant TNC (r-TNC), recombinant OPN (r-OPN), or both were injected into a cisterna magna in healthy rats, and the effects on the diameter of basilar arteries were determined using India ink angiography.

RESULTS

In SAH rats, TNC immunoreactivity was markedly induced in the smooth muscle cell layers of spastic cerebral arteries on day 1 but not in control animals. The TNC immunoreactivity decreased on day 3 as vasospasm improved: OPN immunoreactivity, on the other hand, was more induced in the arterial wall on day 3. r-TNC injections caused prolonged contractions of rat basilar arteries, which were reversed by r-OPN, although r-OPN itself had no effect on the vessel diameter.

CONCLUSIONS

MCPs, including TNC and OPN, may contribute to the pathophysiology of cerebral vasospasm and provide a novel therapeutic approach against it.

Role of platelet-derived growth factor in cerebral vasospasm after subarachnoid hemorrhage in rats

BACKGROUND AND PURPOSE

The role of platelet-derived growth factor (PDGF) remains unknown in cerebral vasospasm after subarachnoid hemorrhage (SAH). In this study, we examined the effects of PDGF receptor (PDGFR) inactivation on cerebral vasospasm in the endovascular perforation model of SAH in rats.

METHODS

Rats were assigned to sham, SAH plus vehicle, and SAH plus imatinib mesylate (imatinib) groups (n = 4 per group). Imatinib (50 mg/kg body weight), an inhibitor of the tyrosine kinases of PDGFR, or vehicle was administered intraperitoneally 30 min post-SAH. Vasospasm was evaluated in the left (perforation-sided) internal carotid artery by means of neurobehavioral tests, India ink angiography, and immunohistochemistry at 24 h after SAH.

RESULTS

Imatinib significantly inhibited post-SAH PDGFR activation in the left internal carotid artery, in which vasospasm was significantly prevented. Animal's neurobehavior also showed a tendency to improve by imatinib treatment.

CONCLUSIONS

PDGF may play an important role in the pathogenesis of vasospasm after SAH.

Neck clipping of paraclinoid small aneurysms

Paraclinoid small aneurysms with a diameter less than 5 mm may be difficult to handle intraoperatively. We have encountered 9 such aneurysms among 375 cases. The most frequent location was the ophthalmic segment (n = 6) followed by the anterior wall (n = 3) of the internal carotid artery (ICA). The endovascular procedure was not suitable for this particular lesion because of the difficulty in deploying the coil across such small aneurysms. One patient with an ophthalmic segment aneurysm underwent endovascular treatment first; however, the procedure was aborted because of mechanical vasospasm. Finally the patient underwent craniotomy, and the aneurysm was successfully clipped. Two patients with anterior wall aneurysms presented with subarachnoid hemorrhage, and the blood blister-like aneurysms were clipped without sacrifice of the ICA. Five patients with unruptured aneurysms of the ophthalmic segment and one such case of the anterior wall of ICA were all clipped uneventfully. The operative procedure for these small aneurysms is deemed straightforward: (1) high attention should be paid to avoid premature rupture; (2) both the internal carotid artery and optic nerve are mobilized and the anterior clinoid process and falciform ligament are removed, then the aneurysmal neck is created; (3) the neck of the aneurysm is created by pushing the wall of the ICA slightly away during clip application; this is called the "nip on method." Although neck clipping of small aneurysms can be difficult, no efforts should be spared to accomplish direct neck clipping.

Astrocytic neuroprotection through induction of cytoprotective molecules; a proteomic analysis of mutant P301S tau-transgenic mouse

Hyperphosphorylated tau protein constitutes a significant portion of intracellular inclusions in some neurodegenerative diseases. In addition, mutations in tau protein cause familial forms of frontotemporal dementia (FTD), indicating that dysfunction of tau protein is responsible for neurodegeneration and dementia. P301S tau-transgenic (Tg) mouse expressing human mutant tau in neurons exhibits similar features of human tauopathies including neuronal degeneration and filament accumulation consisted of hyperphosphorylated tau protein. In the present study, we attempted to characterize protein expression profiles in P301S tau-Tg mouse by using two-dimensional differential in-gel electrophoresis (2D-DIGE) coupled by peptide mass fingerprinting (PMF). As a result, we identified four upregulated proteins; heat shock protein 27 (Hsp27), peroxiredoxin 6 (Prdx6), apolipoprotein E (ApoE), and latexin (LTXN), all of which may function as a neuroprotective mechanism against tau toxicity. In immunohistochemistry, these four proteins were increased invariably in astrocytes, and these astrocytes infiltrated the area in which there are numerous accumulations of hyperphosphorylated tau and neuronal loss. Therefore, these results may indicate that astrocytes provide a neuroprotective mechanism against tau toxicity.

Role of osteopontin in early brain injury after subarachnoid hemorrhage in rats

BACKGROUND

Subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) contributes to delayed ischemic neurological deficits, one of whose key pathologic manifestation is the blood-brain barrier (BBB) disruption. Although post-SAH BBB breakdown is a self-repairable phenomenon, the molecular pathways are unknown. We determined the role of osteopontin (OPN), a pleiotropic extracellular matrix glycoprotein, in the post-SAH BBB disruption in rats.

METHOD

First, we produced the endovascular perforation model of SAH and studied if OPN is induced in the brain after SAH. Secondly, we examined the effects of blockage of endogenous OPN induction on neurological impairments and BBB disruption. Thirdly, we evaluated the effects of exogenous OPN on neurological impairments, brain edema and BBB disruption, and the related protein expression levels.

FINDINGS

OPN was significantly induced and peaked at 72 h after SAH, in the recovery phase of EBI. OPN small interfering RNA significantly aggravated neurological impairment and BBB disruption 72 h after SAH. Exogenous OPN significantly prevented neurological impairment, brain edema and BBB disruption associated with the deactivation of nuclear factor-κB activity, the inhibition of matrix metalloproteinase (MMP)-9 induction and tissue inhibitor of MMP-1 reduction, and the consequent preservation of cerebral microvessel basal lamina protein laminin and tight junction protein zona occludens-1.

CONCLUSIONS

These findings suggest the protective effects of OPN against BBB disruption after SAH, a finding which should provide a novel therapeutic approach for post-SAH EBI.

STA-MCA bypass for the treatment of ischemic stroke

It is considered controversial whether superficial temporal artery (STA)-middle cerebral artery (MCA) bypass affects the outcome of patients with ischemic stroke. This prospective study was undertaken to demonstrate the effect of STA-MCA bypass on the cerebral blood flow and neurological status of the patients with ischemic stroke. Seventy-five patients underwent unilateral or bilateral STA-MCA bypass surgery. The selection of the patients closely adhered to the criteria of the Japan EC-IC Bypass Trial (JET). Cerebral blood flow (CBF) before and after Diamox administration was measured by single photon emission computed tomography (SPECT) using iodine-123-N-isopropyl-p-iodoamphetamine (IMP). MRI, contrast-enhanced 3D CT scans, and angiography were performed on each patient pre- and postoperatively. Bypass surgery was successfully done in all patients. CBF was significantly increased after STA-MCA bypass (P < 0.05). In addition, reservation of CBF was significantly improved after STA-MCA bypass (P < 0.05). Patients with transient ischemic attack (TIA) did not experience recurrence of such episodes after STA-MCA bypass. The neurological deficit was unchanged in patients with complete stroke after bypass surgery. However, the NIH stroke scale was significantly improved after bypass surgery (P < 0.01). In addition, the satisfaction rate of treatment as assessed by the patients themselves was very high after STA-MCA bypass (>90%) compared to the conservative treatment group (<50%). STA-MCA bypass still plays a limited role in the treatment of ischemic stroke, but may become a bright hope in depressed patients after cerebral ischemia.

Mitogen-activated protein kinases in cerebral vasospasm after subarachnoid hemorrhage: a review

BACKGROUND

Mitogen-activated protein kinases (MAPKs) have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage. The goal of this review is to bring together recent diverse data concerning the roles of MAPKs in cerebral vasospasm and to consider the future research.

METHOD

A review of publications in the National Library of Medicine and National Institutes of Health database was conducted in August 2009 using specific keyword search terms pertaining to subarachnoid hemorrhage and MAPKs.

FINDINGS

There are nine in vitro studies and 17 in vivo studies published. Most of previous studies used MAPK inhibitors or their upstream molecule inhibitors, and showed that MAPK inhibitions prevented vasospasm. The MAPK cascade appears to interact with other signaling molecules, and MAPK may be an important final common pathway for the signaling transduction during cerebral vasospasm. However, the mechanism by which MAPK causes sustained vascular smooth muscle contraction remains unclear. In addition, the role of endogenous MAPK inhibitors, MAPK phosphatases, has not been investigated in cerebral vasospasm.

CONCLUSIONS

The experimental data support the causative role of MAPK in cerebral vasospasm and warrant further research.

Recombinant osteopontin in cerebral vasospasm after subarachnoid hemorrhage

OBJECTIVE

Osteopontin (OPN), a pleiotropic extracellular matrix glycoprotein, has been reported to be protective against ischemic lesions, but effects of OPN on vascular functions have not been investigated. The aim of this study was to assess whether recombinant OPN (r-OPN) could prevent cerebral vasospasm after subarachnoid hemorrhage (SAH) in rats.

METHODS

r-OPN was administered intraventricularly to rats undergoing SAH by endovascular perforation, and its protective effects were evaluated by measuring the diameter of cerebral arteries and neurobehavioral testing. Western blotting and immunofluorescence were performed to explore the underlying mechanisms. An integrin receptor antagonist GRGDSP or mitogen-activated protein kinase (MAPK) phosphatase (MKP)-1 small interfering RNA (siRNA) was also administered to r-OPN-treated SAH rats, and those effects were evaluated.

RESULTS

Pre-SAH administration of r-OPN prevented vasospasm and neurological impairments at 24-72 hours post-SAH. r-OPN enhanced an endogenous MAPK inhibitor, MKP-1, and suppressed the phosphorylation of MAPKs, caldesmon, and heat shock protein 27 in the spastic cerebral arteries at 24 hours post-SAH. Immunofluorescence revealed that MKP-1 was induced in the arterial smooth muscle layer. GRGDSP prevented r-OPN-induced MKP-1 upregulation, and MKP-1 siRNA abolished both MAPK inactivation and anti-vasospastic effects by r-OPN. Post-SAH r-OPN treatment also prevented vasospasm.

INTERPRETATION

r-OPN induced MKP-1 in the spastic cerebral arteries via binding to L-arginyl-glycyl-L-aspartate-dependent integrin receptors and prevented vasospasm after SAH. Therapeutic induction of MKP-1 may be a novel approach for the prevention and treatment of cerebral vasospasm.

Mechanisms of osteopontin-induced stabilization of blood-brain barrier disruption after subarachnoid hemorrhage in rats

BACKGROUND AND PURPOSE

Osteopontin (OPN) is an inducible, multifunctional, extracellular matrix protein that may be protective against blood-brain barrier (BBB) disruption after subarachnoid hemorrhage (SAH). However, the protective mechanisms remain unclear.

METHODS

We produced the endovascular perforation model of SAH in rats and studied the time course of OPN induction in brains by Western blotting and immunofluorescence (n=50). Then, 34 rats were randomly assigned to sham (n=3), sham+OPN small interfering RNA (siRNA, n=3), SAH+negative control siRNA (n=14), and SAH+OPN siRNA (n=14) groups, and 109 rats were allocated to sham+vehicle (n=17), sham+recombinant OPN (n=17), SAH+vehicle (n=33), SAH+recombinant OPN (n=31), and SAH+recombinant OPN+L-arginyl-glycyl-L-aspartate motif-containing hexapeptide (n=11) groups. The effects of OPN siRNA or recombinant OPN on BBB disruption and related proteins were studied.

RESULTS

OPN was significantly induced in reactive astrocytes and capillary endothelial cells, peaking at 72 hours after SAH, during the recovery phase of BBB disruption. Blockage of endogenous OPN induction exacerbated BBB disruption and was associated with a reduction of angiopoietin-1 and mitogen-activated protein kinase (MAPK) phosphatase-1 (an endogenous MAPK inhibitor), activation of MAPKs, and induction of vascular endothelial growth factor-A at 72 hours after SAH, whereas recombinant OPN treatment improved it and was associated with MAPK phosphatase-1 induction, MAPK inactivation, and vascular endothelial growth factor-A reduction, which was blocked by L-arginyl-glycyl-L-aspartate motif-containing hexapeptide at 24 hours after SAH. Vascular endothelial growth factor-B and angiopoietin-2 levels were unchanged.

CONCLUSIONS

OPN may increase MAPK phosphatase-1 that inactivates MAPKs, upstream and downstream of vascular endothelial growth factor-A, by binding to L-arginyl-glycyl-L-aspartate-dependent integrin receptors, suggesting a novel mechanism of OPN-induced post-SAH BBB protection.

Granulocyte-colony stimulating factor inhibits apoptotic neuron loss after neonatal hypoxia-ischemia in rats

Neonatal hypoxia-ischemia (HI) is an important clinical problem with few effective treatments. Granulocyte-colony stimulating factor (G-CSF) is an endogenous peptide hormone of the hematopoietic system that has been shown to be neuroprotective in focal ischemia in vivo and is currently in phase I/II clinical trials for ischemic stroke in humans. We tested G-CSF in a rat model of neonatal hypoxia-ischemia in postnatal day 7 unsexed rat pups. Three groups of animals were used: hypoxia-ischemia (HI, n=67), hypoxia-ischemia with G-CSF treatment (HI+G, n=65), and healthy control (C, n=53). G-CSF (50 microg/kg, subcutaneous) was administered 1 h after HI and given on four subsequent days (five total injections). Animals were euthanized 24 h, 1, 2, and 3 weeks after HI. Assessment included brain weight, histology, immunohistochemistry, and Western blotting. G-CSF treatment was associated with improved quantitative brain weight and qualitative Nissl histology after hypoxia-ischemia. TUNEL demonstrated reduced apoptosis in group HI+G. Western blot demonstrated decreased expression of Bax and cleaved caspase-3 in group HI+G. G-CSF treatment was also associated with increased expression of STAT3, Bcl-2, and Pim-1, all of which may have participated in the anti-apoptotic effect of the drug. We conclude that G-CSF ameliorates hypoxic-ischemic brain injury and that this may occur in part by an inhibition of apoptotic cell death.

An Arabidopsis sigma factor (SIG2)-dependent expression of plastid-encoded tRNAs in chloroplasts

A eubacteria-type RNA polymerase (PEP) plays crucial roles for chloroplast development in higher plants. The core subunits are encoded on plastid DNA (rpo genes) while the regulatory sigma factors are encoded on the nuclear DNA (SIG genes). However, the definite gene specificity of each sigma factor is unknown. We recently identified an Arabidopsis recessive pale-green mutant abc1 in which T-DNA is inserted in SIG2 (sigB). In this mutant, almost normal etioplasts were developed under dark conditions while the small chloroplasts with poor thylakoid membranes and stacked lamellar were developed under light conditions. The sig2-1 mutant was deficient in accumulating enough photosynthetic and photosynthesis-related proteins as well as chlorophyll. However, mRNAs of their structural genes were not significantly reduced. Further analyses revealed that several plastid-encoded tRNAs including trnE-UUC that has dual function for protein and ALA biosyntheses were drastically reduced in the sig2-1 mutant. In contrast, nucleus-encoded T7 phage-type RNA polymerase (NEP)-dependent gene transcripts were steadily accumulated in the mutant. These results indicate that progress of chloroplast development requires SIG2-dependent expression of plastid genes, particularly some of the tRNA genes.

Splitting and penetration of the optic nerve by an aneurysm arising from the anterior wall of internal carotid artery: case report

Aneurysms arising from the anterior wall of the internal carotid artery (ICA) are uncommon. There have not been any reports demonstrating the anatomical relation of such aneurysms to the optic nerve. An aneurysm arising from the anterior wall of the ICA splitting and penetrating the optic nerve is reported. A 73 year old woman presented with severe headache due to subarachnoid haemorrhage. She had never experienced a visual disturbance. At surgery, the aneurysm was shown to arise from the anterior wall of the left internal carotid artery and to split and penetrate the left optic nerve. The aneurysm was not related to arterial bifurcation of any branches and was safely neck clipped. Given the evidence of a split and penetration of the optic nerve, the pathogenesis of such an aneurysm may be due to the persistence of an embryonic vessel.

Dissection of the functional and structural domains of phosphorelay histidine kinase A of Bacillus subtilis

The initiation of sporulation in Bacillus subtilis results primarily from phosphoryl group input into the phosphorelay by histidine kinases, the major kinase being kinase A. Kinase A is active as a homodimer, the protomer of which consists of an approximately 400-amino-acid N-terminal putative signal-sensing region and a 200-amino-acid C-terminal autokinase. On the basis of sequence similarity, the N-terminal region may be subdivided into three PAS domains: A, B, and C, located from the N- to the C-terminal end. Proteolysis experiments and two-hybrid analyses indicated that dimerization of the N-terminal region is accomplished through the PAS-B/PAS-C region of the molecule, whereas the most amino-proximal PAS-A domain is not dimerized. N-terminal deletions generated with maltose binding fusion proteins showed that an intact PAS-A domain is very important for enzymatic activity. Amino acid substitution mutations in PAS-A as well as PAS-C affected the in vivo activity of kinase A, suggesting that both PAS domains are required for signal sensing. The C-terminal autokinase, when produced without the N-terminal region, was a dimer, probably because of the dimerization required for formation of the four-helix-bundle phosphotransferase domain. The truncated autokinase was virtually inactive in autophosphorylation with ATP, whereas phosphorylation of the histidine of the phosphotransfer domain by back reactions from Spo0F~P appeared normal. The phosphorylated autokinase lost the ability to transfer its phosphoryl group to ADP, however. The N-terminal region appears to be essential both for signal sensing and for maintaining the correct conformation of the autokinase component domains.

Prognostic significance of p53 and p21WAF1/CIP1 immunoreactivity and tumor micronecrosis for recurrence of meningiomas

Recurrence is an important factor for prognosis of meningioma patients, this also occurring with some lesions diagnosed histopathologically as benign. To analyze their relationships with clinicopathological factors, p53 and p21WAF1/CIP1 immunoreactivity, 80 meningiomas were classified into four groups with regard to the World Health Organization (WHO) histological classification and recurrence: 40 cases of Group I (typical type)-NR (no recurrence); five cases of Group I-R (recurrence); 20 cases of Group II (atypical or anaplastic type)-NR and 15 cases of Group II-R. Micronecrosis was detected in 25% of Group II-NR and 73.3% of Group II-R (P = 0.007, odds ratio (OR) = 8.25, 95% confidence interval (CI) = 1.79-38.01). Patients receiving radiation therapy had a lower risk of recurrence (P = 0.041, OR = 0.20, 95% CI = 0.05-0.85). Immunoreactivity for p53 protein was positive in 22% of Group I and 54% or Group II (P = 0.005), and in 80% of Group I-R and 15% of Group I-NR (P = 0.006, OR = 22.7, 95% CI = 2.15-239.4). p21WAF1/CIP1 protein was detected in 22% of Group I and 48% of Group II (P = 0.017), but with no link to recurrence. Multivariate analysis also showed p53 immunoreactivity in Group I (benign lesions) and micronecrosis in Group II (atypical/anaplastic meningiomas) to be strong prognostic factors for recurrence (P < 0.05). These results indicate that p53 immunoreactivity and micronecrosis can help predicting recurrence of meningiomas.

Chloroplast development in Arabidopsis thaliana requires the nuclear-encoded transcription factor sigma B

Development of plastids into chloroplasts, the organelles of photosynthesis, is triggered by light. However, little is known of the factors involved in the complex coordination of light-induced plastid gene expression, which must be directed by both nuclear and plastid genomes. We have isolated an Arabidopsis mutant, abc1, with impaired chloroplast development, which results in a pale green leaf phenotype. The mutated nuclear gene encodes a sigma factor, SigB, presumably for the eubacterial-like plastid RNA polymerase. Our results provide direct evidence that a nuclear-derived prokaryotic-like SigB protein, plays a critical role in the coordination of the two genomes for chloroplast development.

Regulation of virulence factors of enterohemorrhagic Escherichia coli O157:H7 by self-produced extracellular factors

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes serious diarrhea and hemolytic uremic syndrome in humans. The expressions of EspD and intimin by O157:H7 have now been shown to be down-regulated by medium conditioned by O157:H7 grown at stationary phase. Preparation of conditioned medium showing the effect on the amount of EspD was not dependent on temperature or growth medium, but was dependent on growth phase. Inhibition of EspD and intimin expression was also induced by medium conditioned by E. coli K-12 strains and homoserine lactone, a signal molecule of the quorum-sensing system in gram-negative bacteria. These results suggest the possibility that the quorum-sensing system mediated by self-produced extracellular factors plays an important role in control of colonization of EHEC O157:H7.

SdiA, an Escherichia coli homologue of quorum-sensing regulators, controls the expression of virulence factors in enterohaemorrhagic Escherichia coli O157:H7

The quorum-sensing system in bacteria is a well-known regulatory system that controls gene expression in a cell density-dependent manner. A transcriptional regulator (LuxR homologue), signal synthase (LuxI homologue) and autoinducer (acyl homoserine lactone) are indispensable for this system in most Gram-negative bacteria. In this study, we found that SdiA, an Escherichia coli LuxR homologue, is a negative regulator of the expression of virulence factors EspD and intimin in enterohaemorrhagic E. coli (EHEC) O157:H7. The expression of EspD and intimin was inhibited at the RNA level upon SdiA overexpression. SdiA has a DNA-binding motif in its C-terminal part and can bind to the promoter regions of the esp and eae genes in vitro. Extracellular factors, which accumulate in culture supernatants of O157:H7 at the stationary phase of growth and inhibit EspD and intimin synthesis, bind to the N-terminal part of SdiA in vivo and in vitro. O157:H7 overproducing the N-terminal part of SdiA exhibited hypertranscription of EspD and intimin, suggesting that the overproduced N-terminal part had inhibited the activity of intact SdiA through titration of the extracellular factors. These results indicate that a quorum-sensing system including the SdiA protein controls colonization by O157:H7.

Chloroplast targeting, distribution and transcriptional fluctuation of AtMinD1, a Eubacteria-type factor critical for chloroplast division

In Arabidopsis thaliana, a mature mesophyll cell contains approximately 100 chloroplasts. Although 12 arc mutants (accumulation and replication of chloroplasts) and two chloroplast division genes homologous to eubacterial ftsZ have been isolated from A. thaliana, the molecular mechanism underlying the chloroplast division is still unclear. We characterized AtMinD1, a eubacterial minD homolog, for chloroplast division in A. thaliana. AtMinD1-green fluorescent protein targeted to the chloroplasts and possibly associated with the envelope membranes in vivo. During the seed germination, the AtMinD1 transcripts were accumulated twice, just after release from cold treatment and at the beginning of rapid greening, in similar fashion to AtFtsZs. Furthermore the transcript level in a severest chloroplast division mutant, arc6, was 3-5-fold higher than that in wild-type.

Chronic hydrocephalus presenting with bilateral ptosis after minor head injury: case report

OBJECTIVE AND IMPORTANCE

Some patients with hydrocephalus may exhibit various signs of oculomotor dysfunction. However, ptosis has not previously been described in chronic hydrocephalus patients.

CLINICAL PRESENTATION

We report a 50-year-old woman who was diagnosed with chronic hydrocephalus based on an evaluation for bilateral ptosis after a minor head injury. She exhibited bilateral ptosis and upward gaze paralysis, but other oculomotor functions were normal. Neuroimages revealed chronic hydrocephalus with no traumatic abnormalities.

INTERVENTION

The eyelid dysfunction resolved after placement of a right ventriculoperitoneal shunt with a programmable pressure valve.

CONCLUSION

The resolution of eyelid dysfunction by cerebrospinal fluid diversion suggests that chronic hydrocephalus was involved in the development of ptosis after the minor head injury. A mild but sudden cerebrospinal fluid pressure change at the time of minor head injury might induce functional impairment at the level of vulnerable periaqueductal structures, which barely withstood the longstanding ventriculomegaly, resulting in the clinical features observed in our patient.

Isolation and characterization of mini-Tn5Km2 insertion mutants of enterohemorrhagic Escherichia coli O157:H7 deficient in adherence to Caco-2 cells

Adherence of enterohemorrhagic Escherichia coli (EHEC) to intestinal epithelium is essential for initiation of the infection. To identify genes involved in adherence, an EHEC O157:H7 strain (O157Sakai) was mutagenized by mini-Tn5Km2, where Km refers to kanamycin resistance, and 4,677 insertion mutants were screened for their ability to form microcolonies (MC) on Caco-2 cells. The less adherent mutants were divided into three groups: those with no adherent ability (designated as class 1 mutants, n = 10), those less adherent than the wild type (class 2 mutants, n = 16), and those unable to form MC but which adhered in a diffuse manner (class 3 mutants, n = 1). The sites of insertion in class 1 mutants were all found within genes of the locus for enterocyte effacement (LEE) thought to be required for type III protein secretion. Indeed, the class 1 mutants failed to secrete type III secreted proteins such as EspA and Tir into the culture medium. The insertions in class 2 mutants were outside the LEE, and all the mutants except one were able to secrete type III proteins into the culture medium. The class 3 mutant had the insertion in the tir gene in the LEE and was deficient in Tir and intimin expression, suggesting that in the absence of intimin-Tir, O157Sakai can still adhere to Caco-2 cells but in a diffused manner. This was confirmed by construction of a nonpolar eae (encoding intimin) mutant. Examination of the eae mutant together with O157Sakai and one of the class 1 mutants for the ability to form MC revealed that EHEC initially adhered diffusely at 1.5 h after infection. Following washing out of the nonadherent bacteria, while wild-type EHEC bacteria developed MC for another 2 to 3 h on Caco-2 cells, the eae mutant diffusely adhered throughout the infection without forming MC. MC with O157Sakai but not the diffusely adherent eae mutant could evoke F-actin condensation beneath the bacterium. Our results suggest that EHEC encodes additional adherence-associated loci and that the type III secreted proteins are involved in the initial diffuse adherence, while the intimin-Tir interaction is required for the subsequent development of MC.

Three new nuclear genes, sigD, sigE and sigF, encoding putative plastid RNA polymerase sigma factors in Aarabidopsis thaliana

Three new nuclear genes (sigD, sigE and sigF) of Arabidopsis thaliana, encoding putative plastid RNA polymerase sigma factors, were identified and analyzed. Phylogenetic analysis revealed that higher plant sigma factors fell into at least four distinct subgroups within a diverse protein family. In addition, Arabidopsis sig genes contained conserved chromosomal intron sites, indicating that these genes arose by DNA duplication events during plant evolution. Transcript analyses revealed two alternatively spliced transcripts generated from the sigD region, one of which is predicted to encode a sigma protein lacking the carboxy-terminal regions 3 and 4. Finally, the amino-terminal sequence of the sigF gene product was shown to function as a plastid-targeting signal using green fluorescent protein fusions.

[Heme oxgenase-1 gene induction and the mechanism in the rat vasospasm model]

Using fluorescent differential display and quantitative reverse-PCR, we found in the rat vasospasm model that heme oxygenase-1 messenger RNA was induced in basilar artery. Intracistemal injection of antisense OH-1 oligodeoxynucleotide significantly reduced HO-1 mRNA and HO-1 protein levels and enhanced angiographic vasospasm. Thus, we demonstrate that HO-1 induction may play a important role in the resolution of delayed vasospasm after subarachnoid hemorrhage.

Plastidic RNA polymerase sigma factors in Arabidopsis

In plant cells, plastid DNA is transcribed by at least two types of RNA polymerase, plastid-encoded RNA polymerase (PEP) and nuclear-encoded RNA polymerase (NEP). PEP is homologous to eubacterial transcription machinery, but its regulatory subunit, sigma (sigma) factor, is not encoded on the plastid DNA. We previously cloned the three nuclear-encoded sigma factor genes from Arabidopsis thaliana and designated them as sigA, sigB, and sigC. By means of RFLP mapping, sigA and sigB were mapped on chromosome I and sigC on the chromosome III. Based on comparison of the genomic structure of the three sig genes, intron sites in the 3' half of the genes were shown to be identical between sigB and sigC but divergent in sigA, consistent with the phylogenetic relevance of the three gene products. A transient expression assay of GFP fusions in Arabidopsis protoplasts showed that the N-termini of all three sig gene products functioned as chloroplast-targeting signals. We also constructed transgenic Arabidopsis lines harboring the sigA-promoter or the sigB-promoter uidA fusion. Both the sigA- and sigB-promoters were similarly activated at cotyledons, hypocotyls, rosette leaves, cauline leaves, sepals, and siliques but not at roots, seeds, or other flower organs. In addition, the two promoters were repeatedly activated in young seedlings under continuous light, possibly in an oscillated fashion.

Heme oxygenase-1 gene induction as an intrinsic regulation against delayed cerebral vasospasm in rats

Delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) causes cerebral ischemia and infarction. To date, the pathogenesis and gene expression associated with vasospasm remain poorly understood. The present study used fluorescent differential display to identify differentially expressed genes in a rat model of SAH. By using quantitative RT-PCR, we found that heme oxygenase-1 (HO-1) mRNA was prominently induced in the basilar artery and modestly in brain tissue in a rat vasospasm model. A significant correlation was observed between the degree of vasospasm and HO-1 mRNA levels in the basilar arteries exhibiting vasospasm. Intracisternal injection of antisense HO-1 oligodeoxynucleotide (ODN) significantly delayed the clearance of oxyhemoglobin and deoxyhemoglobin from the subarachnoid space and aggravated angiographic vasospasm. Antisense HO-1 ODN inhibited HO-1 induction in the basilar arteries but not in the whole brain tissue. This phenomenon was not observed in the nontreated, sense HO-1 ODN-treated, or scrambled ODN-treated arteries. We report the protective effects of HO-1 gene induction in cerebral vasospasm after SAH, a finding that should provide a novel therapeutic approach for cerebral vasospasm.

Transcranial Doppler pattern after intracarotid papaverine and prostaglandin E1 incorporated in lipid microsphere in patients with vasospasm

We studied the effects of intracarotid papaverine and prostaglandin E1 incorporated in lipid microsphere (Lipo-PGE1) in relation with transcranial Doppler parameters such as mean flow velocity (MFV) and pulsatile index (PI) of the proximal segment of the middle cerebral artery. Eighty patients with subarachnoid hemorrhage (SAH) were included in this study. In the case of angiographic vasospasm, papaverine at 7 mg/min with total dose below 300 mg per artery and 10-20 micrograms of Lipo-PGE1 were injected in the supraclinoid portion of the internal carotid artery. Vasospasm was improved in 24 patients (63%), however, it was unchanged in 14 patients (37%). The former patients had more favorable outcomes than the latter patients (p < 0.005). After intracarotid injection therapy, the correlation between MFV and PI was classified into three types: type 1, both MFV and PI decreased; type 2, MFV decreased but PI increased; and type 3, both MFV and PI fluctuated. The Glasgow Outcome Scale 3 months after SAH was as follows: type 1 (n = 15), good in 14 (93%) and moderate disability in one (7%); type 2 (n = 9), good in eight (89%) and vegetative state in one (11%); and type 3 (n = 14), moderate disability in five (36%), severe disability in seven (50%), and death in two (14%). Chi-square analysis showed significant differences between type 1 and type 3 (p < 0.005), and type 2 and type 3 (p < 0.005). In conclusion, intracarotid papaverine combined with Lipo-PGE1 was effective for vasospasm but type 3 patients require a different treatment protocol.

Assessment of long-distance running performance in elite male runners using onset of blood lactate accumulation

The purpose of this study was to evaluate the relationship between onset of blood lactate accumulation (OBLA) and long-distance running performance in order to examine whether OBLA can be a good predictor of long-distance running performance even in elite male runners with similar performance levels. Eleven highly-trained male long-distance runners participated in this study. The average running velocities of the individuals' running performance were 5.918 +/- 0.084 m.s-1 and 5.672 +/- 0.095 m.s-1 for 5000 m (V5000) and 10,000 m (V10000), respectively. The blood lactate concentrations and heart rate responses were measured immediately after field running, and the average value of running velocity corresponding to OBLA (VOBLA) was 5.447 +/- 0.132 m.s-1. Variations of these three velocities expressed as a coefficient of variance (CV) ranged from 1.4 to 2.4%. A strong inverse relationship between heart rate corresponding to OBLA (HROBLA) and performance was observed (r = -0.709, p < 0.02 for V5000 and r = -0.830, p < 0.01 for V10000), while there was a lack of significant relationship between VOBLA and performance (r = 0.293, NS for V5000 and r = 0.130, NS for V10000). Furthermore, the average value of HROBLA obtained in this study (174.5 +/- 8.2 b.min-1) was quite similar to that of the heart rate threshold reported by some previous researchers. In conclusion, VOBLA alone could not explain the small variation of long-distance running performance, and HROBLA should be used in place of VOBLA for evaluating long-distance running performance in elite runners with quite similar performance levels.

Ser-534 in the hinge 1 region of Arabidopsis nitrate reductase is conditionally required for binding of 14-3-3 proteins and in vitro inhibition

14-3-3 proteins bind to the hinge 1 region of nitrate reductase (NR) and inhibit its activity. To determine which residues of NR are required for 14-3-3-inhibitory interactions, wild-type and mutant forms of Arabidopsis NR were examined in the yeast two-hybrid system and in vitro inhibition assays. NR fragments with or without hinge 1 were introduced into yeast with one of seven Arabidopsis 14-3-3 isoforms (called GF14s). NR fragments (residues 1-562 or 487-562) containing hinge 1 interacted with all GF-14s tested; an NR fragment (residues 1-487) lacking hinge 1 did not. GF14 binding to NR fragments was dependent on Ser-534, since Asp or Ala substitutions at this site blocked the interaction. Revertants with second site substitutions restoring interaction between GF14omega and the Ala- or Asp-substituted NR fragments were identified. One isolate had a Lys to Glu substitution at position 531, which is in hinge 1, and six isolates had Ile to Leu or Phe substitutions at 561 in the heme binding region. Double mutant forms of holo-NR (S534D plus K531E, I561F, or I561L) were constructed and found to be partially inhibited by protein extracts from Arabidopsis containing 14-3-3 proteins. Wild-type NR is phosphorylated and inhibited by these extracts, but S534D single mutant forms are not. These results show that inhibitory NR/14-3-3 interactions are dependent on Ser-534 but only in the context of the wild-type sequence, since substitutions at second sites render 14-3-3 binding and in vitro NR inhibition independent of Ser-534.

Effects of tirilazad mesylate on vasospasm and phospholipid hydroperoxides in a primate model of subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Tirilazad mesylate has been used in the attempt to prevent cerebral vasospasm after subarachnoid hemorrhage (SAH), although the actual targets of this agent in vivo have thus far been controversial. Chemiluminescence/high-performance liquid chromatography provided a new method for direct measurements of phosphatidylcholine hydroperoxide (PCOOH) and phosphatidylethanolamine hydroperoxide (PEOOH) in vivo and showed that phosphatidylcholine is the lipid class most susceptible to lipid peroxidation. In the present study we measured those levels in a primate model of SAH for determination of the effects of tirilazad on vasospasm.

METHODS

Fourteen Macaca monkeys of both sexes were randomly assigned into 2 groups: a tirilazad group receiving a dosage of 0.3 mg/kg and a placebo group receiving only the vehicle in which tirilazad was delivered. After the induction of experimental SAH around the right middle cerebral artery on day 0, tirilazad or vehicle was administered intravenously every 8 hours for 6 days. On day 7, the animals were killed after angiography and regional cerebral blood flow measurements were performed. The levels of PCOOH and PEOOH were measured in the clots, bilateral parietal cortices, right frontal cortex contact with clots, cerebellar hemispheres, bilateral middle cerebral arteries, and basilar arteries.

RESULTS

In the placebo group, a significant vasospasm occurred in the cerebral arteries on both sides, but most prominently on the right side. The degree of vasospasm in the cerebral arteries was significantly attenuated in the tirilazad group (P<0.005). There were no significant differences in regional cerebral blood flow, PCOOH, and PEOOH levels in the clots, cerebral cortices, and cerebellar hemispheres between the 2 groups. In contrast, the levels of PCOOH in the cerebral arteries were significantly higher in the placebo group than in the tirilazad group (P<0.025). It was remarkable that the tirilazad treatments eliminated PCOOH in any vascular territory after SAH.

CONCLUSIONS

PCOOH in the artery wall may be an important indicator for vasospasm, and the inhibition of PCOOH may explain the efficacy of tirilazad on vasospasm.