bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved distribution of small molecules and viral vectors in the murine brain using a hollow fiber catheter
Authors: OH Seunguk , Odland Rick , Wilson Scott R. , Kroeger Kurt M. , Liu Chunyan , Lowenstein Pedro R. , Castro Maria G. , Hall Walter A. , Ohlfest John R. 
Published: January 2008

Object
A hollow fiber catheter was developed to improve the distribution of drugs administered via direct infusion into the central nervous system (CNS). It is a porous catheter that significantly increases the surface area of brain tissue into which a drug is infused.

Methods
Dye was infused into the mouse brain through convection-enhanced delivery (CED) using a 28-gauge needle compared with a 3-mm-long hollow fiber catheter. To determine whether a hollow fiber catheter could increase the distribution of gene therapy vectors, a recombinant adenovirus expressing the firefly luciferase reporter was injected into the mouse striatum. Gene expression was monitored using in vivo bioluminescent imaging. To assess the distribution of gene transfer, an adenovirus expressing green fluorescent protein was injected into the striatum using a hollow fiber catheter or a needle.

Results
Hollow fiber catheter–mediated infusion increased the volume of brain tissue labeled with dye by 2.7 times relative to needle-mediated infusion. In vivo imaging revealed that catheter-mediated infusion of adenovirus resulted in gene expression that was 10 times greater than that mediated by a needle. The catheter appreciably increased the area of brain transduced with adenovirus relative to a needle, affecting a significant portion of the injected hemisphere.

Conclusions
The miniature hollow fiber catheter used in this study significantly increased the distribution of dye and adenoviral-mediated gene transfer in the mouse brain compared with the levels reached using a 28-gauge needle. Compared with standard single-port clinical catheters, the hollow fiber catheter has the advantage of millions of nanoscale pores to increase surface area and bulk flow in the CNS. Extending the scale of the hollow fiber catheter for the large mammalian brain shows promise in increasing the distribution and efficacy of gene therapy and drug therapy using CED.
Bioluminescence monitoring of intracranial glioblastoma xenograft: response to primary and salvage temozolomide therapy
Authors: Dinca Eduard B. , Sarkaria Jann N. , Schroeder Mark A. , Carlson Brett L. , Voicu Ramona , Gupta Nalin , Berger Mitchel S. , James C. David 
Published: January 2008

Object
Bioluminescence imaging (BLI) offers a rapid and accurate means for longitudinal study of tumor cell growth and response to therapy in rodent models. Because this technology has only recently come into use in the field of small animal imaging, applications in this area have been limited. In the current study we have applied BLI to the analysis of clinically relevant issues involving use of the DNA methylating agent temozolomide (TMZ) in a mouse model.

Methods
An invasive glioblastoma multiforme xenograft was modified for BLI via transduction with a luciferase-encoding lentivirus. Supratentorial tumors were established in athymic nude mice that were subsequently assigned randomly to control and TMZ treatment groups, and the extent of intracranial tumor was monitored using BLI.

Results
In an experiment designed to compare the extent of antitumor effect between a single high-dose TMZ treatment and a protracted low-dose TMZ regimen, BLI revealed the protracted regimen as having superior antitumor effect, and this interpretation was consistent with results from a survival comparison between the two TMZ treatment groups. In a second experiment designed to assess the utility of BLI for testing therapies against recurrent glioblastoma multiforme, mice with intracranial tumors were retreated with TMZ at a time when BLI monitoring revealed tumor regrowth following initial TMZ treatment, and retreatment was successful in providing additional survival benefit.

Conclusion
The results of these experiments indicate that BLI monitoring can be used as a surrogate for predicting survival benefit from TMZ treatment, permits early determination of relative survival benefit associated with distinct TMZ therapeutic regimens, and offers a means of investigating secondary/salvage therapy efficacy following tumor regrowth from initial therapy.
Distal aneurysms of basilar perforating and circumferential arteries
Authors: Sanchez-Mejia Rene O. , Lawton Michael T. 
Published: January 2008

✓Distal aneurysms of basilar perforating and circumferential arteries are exceedingly rare. The authors encountered one patient with a distal basilar perforating artery aneurysm and two with aneurysms arising from circumferential branches of the basilar artery (BA). The diagnostic features, microsurgical treatment, and outcomes in these three patients are described. The first patient, a 27-year-old man, presented with an angiogram-negative subarachnoid hemorrhage (SAH), and subsequent readmission for a new hemorrhage revealed a centrally thrombosed aneurysm arising from a basilar apex perforating artery. The second patient, a 68-year-old man, presented for follow-up evaluation 2 months after an angio-gram-negative SAH, and an aneurysm was identified on a circumferential artery originating from the BA trunk. The third patient, a 2-year-old boy, presented with blunt head trauma and a pseudoaneurysm arising from a basilar apex circumferential artery.
All three aneurysms were managed microsurgically with aneurysm trapping, via either an orbitozygomatic or an extended retrosigmoid approach. Occlusion of the distal perforating or circumferential artery was well tolerated in all cases, with no neurological sequelae resulting from surgery. Features common to all three aneurysms were dolichoectatic morphology, intraluminal thrombus, and SAH. These aneurysms may be difficult to diagnose given their small size and delayed filling on angiographic studies. Consequently, their presence in cases of angiogram-negative SAH may be underestimated. These aneurysms are not amenable to endovascular treatment, but excellent results can be obtained with microsurgical exposure and trapping.
Transmaxillary exploration of the intracranial portion of the maxillary nerve in malignant perineural disease
Authors: DeMonte Franco , Hanna Ehab 
Published: January 2008

Object
Achieving microscopically tumor-free margins during resection of skull base malignancies has consistently been identified as a positive prognostic factor for patient survival. When malignancies extend perineurally into the major nerves traversing the skull base and entering the cavernous sinus, achieving tumor-free margins can be challenging and typically necessitates performing a craniotomy to access the lateral wall of the cavernous sinus. This report describes a novel technique used to access and resect malignancy extending perineurally into the intracranial portion of V2 via the maxillary sinus.

Methods
Seven patients with maxillary sinus tumors and perineural extensions along V2, who underwent resection of the primary tumor and transmaxillary intracranial exposure and dissection of the maxillary nerve to achieve maximal tumor resection, were analyzed. Prospectively collected data, including symptoms, clinical signs, diagnostic imaging data, pathological diagnosis, incidence and nature of complications, adjuvant therapies, and oncological outcomes, were retrospectively analyzed.

Results
All patients in this cohort had trigeminal nerve symptomatology as well as abnormal enhancement in the pterygopalatine fissure as noted on magnetic resonance imaging. The transmaxillary exploration of the maxillary nerve technique was used in all seven patients, resulting in gross-total resection of the tumors in every patient. At the last follow-up (mean 30 months, range 13–58 months, in four of seven patients for > 2 years), six patients were alive without evidence of local disease. One patient with squamous cell carcinoma died of progressive infratemporal fossa and regional neck disease 26 months after resection. No intracranial or cavernous sinus disease was present.

Conclusions
This technique extended the limits of resection without the need for a craniotomy and improved local tumor control in this patient cohort.
Correlation between copper/zinc superoxide dismutase and the proliferation of neural stem cells in aging and following focal cerebral ischemia
Authors: Takemura Sunao , Kayama Takamasa , Kuge Atsushi , Ali Hasmat , Kokubo Yasuaki , Sato Shinya , Kamii Hideyuki , Goto Kaoru , Yoshimoto Takashi 
Published: January 2008

Object
Neural stem cells (NSCs) have been demonstrated in the subventricular zone (SVZ) of the lateral ventricle and the subgranular zone of the hippocampal dentate gyrus (DG). Although aging rats manifest a decrease in NSCs, rats exposed to stress (for example, ischemia, epilepsy, radiation, and trauma) show an increase in these cells. In transgenic mice, the overexpression of human copper/zinc superoxide dismutase (SOD1), an endogenous antioxidant, has been reported to be a protective enzyme against transient focal cerebral ischemia. The authors investigated the correlation between SOD1 and the proliferation of NSCs in aging as chronic oxidative stress (Experiment 1) and acute oxidative stress induced by transient focal cerebral ischemia (Experiment 2) in mice.

Methods
Bromodeoxyuridine (BrdU) was used in the evaluation of NSCs. In Experiment 1, NSCs in the SVZ significantly increased in 16-month-old transgenic mice compared with wild-type mice (p = 0.0001). In Experiment 2, mice were subjected to 30-minute occlusions of the middle cerebral artery. The increase in NSCs in the DG in transgenic mice was significantly greater than that in wild-type mice (p < 0.05).

Conclusions
Results in this study suggest that chronic and acute oxidative stress may inhibit the proliferation of NSCs and that SOD1 may play a key role in NSC proliferation.
Category-specific cortical mapping: color-naming areas
Authors: Roux Franck-Emmanuel , Lubrano Vincent , Lauwers-Cances Valérie , Mascott Christopher R. , Démonet Jean-François 
Published: January 2008

Object
It has been hypothesized that a certain degree of specialization exists within language areas, depending on some specific lexical repertories or categories. To spare hypothetical category-specific cortical areas and to gain a better understanding of their organization, the authors studied patients who had undergone electrical stimulation mapping for brain tumors and they compared an object-naming task with a category-specific task (color naming).

Methods
Thirty-six patients with no significant preoperative language deficit were prospectively studied during a 2-year period. Along with a reading task, both object- and color-naming tasks were used in brain mapping. During color naming, patients were asked to identify 11 visually presented basic colors. The modality specificity of the colornaming sites found was subsequently tested by asking patients to retrieve the color attributes of objects.
High individual variability was observed in language organization among patients and in the tasks performed. Significant interferences in color naming were found in traditional language regions—that is, Broca (p < 0.003) and Wernicke centers (p = 0.05)—although some color-naming areas were occasionally situated outside of these regions. Color-naming interferences were exclusively localized in small cortical areas (< 1 cm2). Anatomical segregation of the different naming categories was apparent in 10 patients; in all, 13 color-specific naming areas (that is, sites evoking no object-naming interference) were detected in the dominant-hemisphere F3 and the supramarginal, angular, and posterior parts of the temporal gyri. Nevertheless, no specific brain region was found to be consistently involved in color naming (p > 0.05). At five sites, although visually presented color-naming tasks were impaired by stimulation, auditory color naming (for example, “What color is grass?”) was performed with no difficulty, showing that modality-specific areas can be found during naming.

Conclusions
Within language areas, a relative specialization of cortical language areas for color naming can be found during electrical stimulation mapping.
Cerebral hemodynamic changes gauged by transcranial Doppler ultrasonography in patients with posttraumatic brain swelling treated by surgical decompression
Authors: Bor-Seng-Shu Edson , Hirsch Roberto , Teixeira Manoel Jacobsen , de Andrade Almir Ferreira , Marino Raul 
Published: January 2008

Object
The use of decompressive craniectomy has experienced a revival in the previous decade, although its actual benefit on patients’ neurological outcome remains the subject of debate. A better understanding of the intracranial pressure dynamics, as well as of the metabolic and hemodynamic brain processes, may be useful in assessing the effect of this surgery on the pathophysiology of the swollen brain. The aim of this study was to use transcranial Doppler (TCD) ultrasonography to examine the hemodynamic changes in the brain after decompressive craniectomy in patients with head injury, in addition to examining the relationship between such hemodynamic changes and the patient’s neurological outcome.

Methods
Nineteen patients presenting with traumatic brain swelling and cerebral herniation syndrome who had undergone decompressive craniectomy with dural expansion were studied prospectively. The TCD ultrasonography measurements were performed bilaterally in both the middle cerebral artery (MCA) and in the distal portion of the cervical internal carotid artery (ICA) immediately prior to and after surgical decompression.
After surgery, the mean blood flow velocity (BFV) rose to 175 ± 209% of preoperative values in the MCA of the operated side, while rising to 132 ± 183% in the contralateral side; the difference between the mean BFV increase in in the MCA of both the decompressed and the opposite side reached statistical significance (p < 0.05). The mean BFV of the extracranial ICA increased to 91 ± 119% in the surgical side and 45 ± 60% in the opposite side. Conversely, the MCA pulsatility index (PI) values decreased, on average, to 33 ± 36% of the preoperative value in the operated side and to 30 ± 34% on the opposite side; the MCA PI value reductions were significantly greater in the decompressed side when compared with the contralateral side (p < 0.05). The PI of the extracranial ICA reduced, on average, to 37 ± 23% of the initial values in the operated side and to 24 ± 34%, contralaterally. No correlation was verified between the neurological outcome and cerebral hemodynamic changes seen on TCD ultrasonography.

Conclusions
Decompressive craniectomy results in a significant elevation of cerebral BFV in most patients with traumatic brain swelling and transtentorial herniation syndrome. The increase in cerebral BFV may also occur in the side opposite the decompressed hemisphere; the cerebral BFV increase is significantly greater in the operated hemisphere than contralaterally. Concomitantly, PI values decrease significantly postoperatively, mainly in the decompressed cerebral hemisphere, indicating reduction in cerebrovascular resistance.
Use of a self-expanding stent with balloon angioplasty in the treatment of dural arteriovenous fistulas involving the transverse and/or sigmoid sinus: functional and neuroimaging-based outcome in 10 patients
Authors: Levrier Olivier , Métellus Philippe , Fuentes Stephane , Manera Luis , Dufour Henry , Donnet Anne , Grisoli François , Bartoli Jean-Michel , Girard Nadine 
Published: January 2008

Object
The goal of this study was to evaluate the clinical and angiography results in 10 patients with transverse–sigmoid dural arteriovenous fistulas (DAVFs) treated using sinus angioplasty and dural sinus stent insertion.

Methods
Between 2001 and 2003, 10 consecutive patients (six men and four women, age range 54–79 years) who had presented with transverse and/or sigmoid sinus DAVFs with or without sinus thrombosis underwent self-expanding stent placement and balloon angioplasty. Eight fistulas involved the transverse sinus, three the sigmoid sinus, and one the torcular and occipital sinuses. According to the Djindjian-Merland grading system, there were two Type I, five Type IIa, one Type IIb, and two Type IV DAVFs. The mean clinical follow-up period was 21.1 months. At the last follow-up examination, seven patients were asymptomatic and three were dramatically improved. The mean angiography follow-up period was 7.5 months for the available population: four patients had complete DAVF occlusion, four had significant flow reduction, and two who experienced clinical improvement refused conventional angiography control studies. Delayed computerized tomography angiography scans were obtained to evaluate stent permeability in nine of the 10 patients. Stent permeability was demonstrated in eight of the nine patients with available control studies at a mean follow up of 20.8 months. There were two transient neurological deficits but no severe and permanent complications.

Conclusions
In this series, sinus stent insertion resulted in a cure or significant clinical improvement in all patients harboring a DAVF, with no severe or permanent complication. Stent placement for transverse and/or sigmoid sinus DAVFs is a promising technique whose viability should be confirmed in larger series with longer follow-up periods.
Intrinsically radiopaque iodine-containing polyvinyl alcohol as a liquid embolic agent: evaluation in experimental wide-necked aneurysms
Authors: Dudeck Oliver , Jordan Olivier , Hoffmann Karl-Titus , Tesmer Kai , Kreuzer-Nagy Tibor , Podrabsky Petr , Heise Michael , Meyer Rudolf , Okuducu Ali Fuat , Bruhn Harald , Hilborn Jöns , Rüfenacht Daniel A. , Doelker Eric , Felix Roland 
Published: January 2008

Object
To evaluate iodine-containing polyvinyl alcohol (I-PVA) as a precipitating liquid embolic agent, implant characteristics—including radiopacity, setting behavior, and biocompatibility—were studied in an aneurysm model in swine.

Methods
Twelve broad-based carotid artery (CA) sidewall aneurysms were surgically constructed in six pigs. Iodine-containing polyvinyl alcohol dissolved in dimethyl sulfoxide (DMSO) was injected during temporary balloon occlusion bridging the aneurysm neck. Control angiography as well as multidetector row computerized tomography (CT) angiography was performed after 4 weeks. Harvested aneurysms were investigated histopathologically and by 3-tesla high-field magnetic resonance (MR) imaging. The mean degree of aneurysm occlusion achieved was 96%. In two aneurysms a minimal protrusion of I-PVA into the CA lumen was observed. During one embolization, leakage of the liquid embolic agent due to DMSO-induced damage of the microcatheter resulted in CA occlusion. Aneurysms embolized with I-PVA could be discriminated clearly from the parent artery on CT angiograms because there was no beam-hardening artifact. High-field MR imaging allowed a detailed depiction of the liquid embolic distribution within the aneurysm. Histologically, a mild to moderate inflammatory response was found in successfully embolized aneurysms, and the polymer mass was frequently covered by a membrane of fibroblasts and endothelial cells.

Conclusions
Iodine-containing polyvinyl alcohol is a ready-to-use liquid embolic agent clearly visible under fluoroscopy; additives are not required. The setting behavior allows for controlled delivery in aneurysm cavities. Histological studies performed 4 weeks after embolization revealed no sign of toxic tissue response to the liquid embolic agent. Overall, I-PVA exhibits interesting implant characteristics in that radiopaque admixtures are not necessary, thus allowing for artifact-free evaluation of treated aneurysms by using CT and MR angiography.
The effect of 17β-estradiol in attenuating experimental subarachnoid hemorrhage–induced cerebral vasospasm
Authors: Lin Chih-Lung , Shih Huei-Chuan , Dumont Aaron S. , Kassell Neal F. , Lieu Ann-Shung , Su Yu-Feng , Hwong Shen-Long , Hsu Chin 
Published: January 2008

Object
Sex differences in the outcome of aneurysmal subarachnoid hemorrhage (SAH) are controversial, and the potential influence of estradiol on vasodilation is unclear. In the present study the authors evaluate the effect and possible mechanism of 17β-estradiol (E2) on SAH-induced vasospasm in a two-hemorrhage rodent model of SAH.

Methods
A 30-mm Silastic tube filled with E2 in corn oil (0.3 mg/ml) was subcutaneously implanted in male rats. Serum levels of E2 were measured on Days 0, 1, 2, 3, 4, and 7 postimplantation. The degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery (BA) 7 days after the first SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) in the BA were also evaluated.
Serum levels of E2 in the E2-treated rats were at physiological levels (56–92 pg/ml) and were significantly higher than those in the control and vehicle-treated groups. Treatment with E2 significantly (p < 0.01) attenuated SAH-induced vasospasm. Induction of iNOS messenger (m)RNA and protein in the BA by SAH was significantly diminished by the E2 treatment but not by vehicle treatment. The SAH-induced suppression of eNOS mRNA and protein was relieved by E2 treatment.

Conclusions
These results suggest that continuous treatment with E2 at physiological levels prevents cerebral vasospasm following SAH. The beneficial effect of E2 may be in part related to the prevention of augmentation of iNOS expression and the preservation of normal eNOS expression after SAH. Treatment with E2 holds therapeutic promise in the treatment of cerebral vasospasm following SAH and merits further investigation.