bluuebunny/crossref_metadata_2025 huggingface dataset:
Peripheral Exendin-4 and Peptide YY3–36 Synergistically Reduce Food Intake through Different Mechanisms in Mice
Authors: Talsania Tanvi , Anini Younes , Siu Stephanie , Drucker Daniel J. , Brubaker Patricia L.
Published: June 2005

Glucagon-like peptide-17–36NH2 (GLP-1) and peptide YY3–36NH2 (PYY3–36NH2) are cosecreted from the intestine in response to nutrient ingestion. Peripheral administration of GLP-1 or PYY3–36NH2 decreases food intake (FI) in rodents and humans; however, the exact mechanisms by which these peptides regulate FI remain unclear. Male C57BL/6 mice were injected (ip) with exendin-41–39 (Ex4, a GLP-1 receptor agonist) and/or PYY3–36NH2 (0.03–3 μg), and FI was determined for up to 24 h. Ex4 and PYY3–36NH2 alone decreased FI by up to 83 and 26%, respectively (P < 0.05–0.001), whereas a combination of the two peptides (0.06 μg Ex4 plus 3 μg PYY3–36NH2) further reduced FI for up to 8 h in a synergistic manner (P < 0.05–0.001). Ex4 and/or PYY3–36NH2 delayed gastric emptying by a maximum of 19% (P < 0.01–0.001); however, there was no significant effect on locomotor activity nor was there induction of taste aversion. Capsaicin pretreatment prevented the inhibitory effect of Ex4 on FI (P < 0.05), but had no effect on the anorexigenic actions of PYY3–36NH2. Similarly, exendin-49–39 (a GLP-1 receptor antagonist) partially abolished Ex4-induced anorexia (P < 0.05), but did not affect the satiation produced by PYY3–36NH2. Conversely, BIIE0246 (a Y2 receptor antagonist) completely blocked the anorexigenic effects of PYY3–36NH2 (P < 0.001), but had no effect on Ex4-induced satiety. Thus, Ex4 and PYY3–36NH2 suppress FI via independent mechanisms involving a GLP-1 receptor-dependent, sensory afferent pathway (Ex4) and a Y2-receptor mediated pathway (PYY3–36NH2). These findings suggest that administration of low doses of Ex4 together with PYY3–36NH2 may increase the suppression of FI without inducing significant side effects.
Carotid Angioplasty with or without Stent Placement versus Carotid Endarterectomy for Treatment of Carotid Stenosis: A Meta-analysis
Authors: Qureshi Adnan I. , Kirmani Jawad F. , Divani Afshin A. , Hobson Robert W.
Published: May 2005

OBJECTIVE:

Carotid angioplasty with or without stent placement (CAS) has been proposed as an alternative method to carotid endarterectomy (CEA) for treatment of carotid stenosis. Small randomized trials have evaluated the comparative efficacy of both methods; however, definitive evidence is lacking.

METHODS:

A search was made for randomized clinical trials comparing CAS and CEA for treatment of carotid stenosis. A literature search of MEDLINE, PubMed, and Cochrane databases was supplemented by a review of bibliographies of relevant articles and personal files. A meta-analysis was performed using a random effects model because significant heterogeneity was observed. Outcomes compared included 1-month composite rates of stroke or death, all strokes, disabling strokes, myocardial infarction, cranial nerve injury, and major bleeding and 1-year rates of both minor and major ipsilateral strokes.

RESULTS:

We analyzed five randomized trials totaling 1154 patients (577 randomized to CEA and 577 randomized to CAS). The composite end point of 1-month stroke or death rate was not different between patients treated with CAS compared with those treated with CEA (relative risk [RR], 1.3; 95% confidence interval [CI], 0.6–2.8; P = 0.5). The 1-month stroke rate (831 patients analyzed: RR, 1.3; 95% CI, 0.4–3.6; P = 0.7) and disabling stroke rate (831 patients analyzed: RR, 0.9; 95% CI, 0.2–3.5; P = 0.9) was similar for CAS and CEA. The 1-month rates of myocardial infarction (814 patients analyzed: RR, 0.3; 95% CI, 0.1–0.9) and cranial nerve injury (918 patients analyzed: RR, 0.05; 95% CI, 0.01–0.3) were significantly lower for CAS. No significant differences were observed in 1-year rates of ipsilateral stroke (814 patients analyzed: RR, 0.8; 95% CI, 0.5–1.2; P = 0.2).

CONCLUSION:

The 30-day stroke and death rates associated with CAS and CEA were not significantly different. Lower rates of myocardial infarction and cranial nerve injury were observed with CAS compared with CEA.
Brainstem Cavernomas: Long-term Results of Microsurgical Resection in 52 Patients
Authors: Ferroli Paolo , Sinisi Marco , Franzini Angelo , Giombini Sergio , Solero Carlo Lazzaro , Broggi Giovanni
Published: May 2005

OBJECTIVE:

To review the natural history and the long-term results of microsurgical resection of brainstem cavernous angiomas operated on in one institution.

METHODS:

A retrospective analysis was conducted of the preoperative and postoperative course in 52 consecutive patients who underwent microsurgical resection of a brainstem cavernoma between 1990 and 2002. The role of sex, age, cavernoma location, size, multiple bleedings, relationships to the pial-ependymal surface, surgical approach, and preoperative magnetic resonance imaging appearance were evaluated as prognostic factors possibly influencing outcome. Discrete data were compared by use of the χ2 test and Fisher's exact test as appropriate.

RESULTS:

The risk of hemorrhage was 3.8% per patient per year. The rebleeding rate was 34.7%. Nineteen of 29 patients who experienced new neurological deficits after surgery improved over time to their preoperative condition or better. Permanent morbidity was observed in 10 (19%) of 52 patients (follow-up: 1.5–10.5 yr; mean, 4.7 yr; median, 4.3 yr; standard deviation, 0.2 yr). The final Karnofsky Performance Scale score for these 10 patients was 90 in 2 patients, 80 in 2, 70 in 2, 60 in 2, 50 in 1, and 30 in 1. The mortality rate was 1.9%. The incidence of permanent new neurological deficits was lower in the 20 patients whose lesion could be removed through an anterolateral pontine approach (5 versus 29%; P = 0.035).

CONCLUSION:

Surgical resection is recommended for superficial lesions and for lesions that can be reached through the anterolateral pontine surface. Surgery is also recommended for symptomatic cavernomas with a satellite subacute hematoma.
Usefulness of the Neuroform Stent for the Treatment of Cerebral Aneurysms: Results at Initial (3–6-mo) Follow-up
Authors: Fiorella David , Albuquerque Felipe C. , Deshmukh Vivek R. , McDougall Cameron G.
Published: May 2005

OBJECTIVE:

The Neuroform microstent, a flexible, self-expanding, nitinol stent specifically designed for use in the cerebral vasculature, became available in North America for aneurysm treatment in November 2002. The present report details our experience with the Neuroform stent over the past 2 years, with an emphasis on evolving treatment strategies and treatment durability at initial (3–6 mo) follow-up.

METHODS:

All patients included in this report were registered in a prospectively maintained database. We assessed the clinical history, indications for stent use, aneurysm dimensions, technical details of the procedures, degree of aneurysm occlusion, angiographic and clinical findings at follow-up, and complications.

RESULTS:

Over a 20-month period, 64 patients with 74 aneurysms were treated with 86 Neuroform stents. Of 64 patients, 16 (25%) were treated in the context of subarachnoid hemorrhage (8 acute, 7 subacute, 1 remote). Indications for stent use included broad aneurysm neck (n = 51 stents; average neck, 5.1 mm; aneurysm size, 8.2 mm), fusiform/dissecting morphology (n = 17), salvage/bailout for coils prolapsed into the parent vessel (n = 7), and giant aneurysm (n = 11). Sixty-one aneurysms were stented and coiled with complete or near complete (>95%) occlusion in 28 patients (45.9%) and partial occlusion (<95%) in 33 patients (54%). Follow-up angiographic (n = 43) or magnetic resonance angiographic (n = 5) data (average follow-up, 4.6 mo; median, 4 mo; range, 1.5–13 mo) for 48 aneurysms (46 patients) after stent-supported coil embolization demonstrated progressive thrombosis in 25 patients (52%), recanalization in 11 patients (23%) (8 of whom were retreated), and no change in 12 patients (25%). Follow-up angiography in 5 additional patients with dissecting aneurysms treated with stents alone demonstrated interval vascular remodeling with decreased aneurysm size in all patients. Delayed, severe, in-stent stenosis was observed in 3 patients, 1 of whom was symptomatic and required angioplasty and subsequently superficial temporal artery-to-middle cerebral artery bypass surgery. Using the second-generation Neuroform2 delivery system (n = 53), very few technical problems with stent delivery and deployment have been encountered (n = 2).

CONCLUSION:

The Neuroform stent facilitates adequate embolization of complex cerebral aneurysms, which would not otherwise be amenable to endovascular therapy. Initial follow-up data indicate favorable progressive thrombosis and recanalization rates for aneurysms after Neuroform stent-assisted embolization. These advantages of stenting were most evident for small aneurysms with wide necks.
Results of Transsphenoidal Surgery in a Large Series of Patients with Pituitary Adenoma
Authors: Mortini Pietro , Losa Marco , Barzaghi Raffaella , Boari Nicola , Giovanelli Massimo
Published: May 2005

OBJECTIVE:

To report the efficacy and safety of microsurgical transsphenoidal surgery in a series of previously untreated patients with pituitary adenoma.

METHODS:

One thousand one hundred forty consecutive patients undergoing transsphenoidal resection of a pituitary adenoma at our department from January 1990 through December 2002 were included in our study. Postoperative results were classified uniformly during the period of the study. Patients were considered in remission of disease when strict hormonal and radiological criteria of cure were met.

RESULTS:

The most frequent tumor type was clinically nonfunctioning adenoma (NFPA) (33.2%), followed by growth hormone-secreting adenoma (28.1%), adrenocorticotropin-secreting adenoma (23.0%), prolactin-secreting adenoma (13.2%), and last, thyrotropin-secreting adenoma (2.5%). The patient population was 59.7% female and 40.3% male. Mean age was 43.0 ± 0.4 years. There were 788 macroadenomas (69.1%), and in 233 patients (20.4%), the tumor invaded one or both cavernous sinuses. The overall rate of early surgical success was achieved in 504 (66.1%) of the 762 patients with a hormone-active adenoma. Surgical outcome was better in patients with microadenomas than in patients with macroadenomas (78.9% and 55.5%, respectively), whereas tumors invading the cavernous sinus had a poorer outcome (7.4%). In patients with NFPA, no residual adenoma was present in 234 patients (64.8%). Normalization of visual defects occurred in 117 (40.5%) of the 289 patients with visual disturbances and improved in another 148 patients (51.2%). Three patients (0.3%) died as a consequence of surgery.

CONCLUSION:

Transsphenoidal surgery is an effective and safe treatment for most patients with pituitary adenoma and could be considered the first-choice therapy in all cases except for prolactinomas responsive to dopamine agonists. Other treatment methods, such as radiotherapy, stereotactic radiosurgery, and medical therapy, play an important role in patients not cured by surgery.
Safety and Feasibility of Convection-enhanced Delivery of Cotara for the Treatment of Malignant Glioma: Initial Experience in 51 Patients
Authors: Patel Sunil J. , Shapiro William R. , Laske Douglas W. , Jensen Randy L. , Asher Anthony L. , Wessels Barry W. , Carpenter Susan P. , Shan Joseph S.
Published: May 2005

OBJECTIVE:

We report the safety and feasibility of using convection-enhanced delivery to administer Cotara (Peregrine Pharmaceuticals, Inc., Tustin, CA), a novel radioimmunotherapeutic agent, to patients with malignant glioma.

METHODS:

Between April 1998 and November 2002, 51 patients with histologically confirmed malignant glioma received Cotara by convection-enhanced delivery. Most patients (88%) were treated with Cotara targeting tumor volume-dependent, single or multiple administrations of activity ranging from 0.5 to 3.0 mCi/cm3 of baseline clinical target volume. Two weeks after infusion, single-photon emission computed tomographic imaging determined the spatial distribution of Cotara. Patients were followed for as long as 41 months (average follow-up, 5 mo). Safety was evaluated on the basis of incidence of procedure-related, neurological, and systemic adverse events. Feasibility was evaluated in a subset of patients on the basis of the correlation between the prescribed activity and the actual activity administered to the targeted region.

RESULTS:

Fifty-one patients, 37 with recurrent glioblastoma multiforme, 8 with newly diagnosed glioblastoma multiforme, and 6 with recurrent anaplastic astrocytomas, were treated. Average tumor volume was 36 ± 27.6 cm3 (range, 5–168 cm3). Of the 67 infusions, 13 (19%), 52 (78%), and 2 (3%) delivered less than 90%, 100 ± 10%, and more than 110%, respectively, of the prescribed administered activity to the targeted region. Treatment-emergent, drug-related central nervous system adverse events included brain edema (16%), hemiparesis (14%), and headache (14%). Systemic adverse events were mild. Several patients had objective responses to Cotara.

CONCLUSION:

The majority of Cotara infusions delivered between 90 and 110% of the prescribed administered activity to the targeted region. This method of administration has an acceptable safety profile compared with literature reports of other therapeutics delivered by convection-enhanced delivery.
Staged Stereotactic Irradiation for Acoustic Neuroma
Authors: Chang Steven D. , Gibbs Iris C. , Sakamoto Gordon T. , Lee Elizabeth , Oyelese Adetokunbo , Adler John R.
Published: May 2005

OBJECTIVE:

Stereotactic radiosurgery has proven effective in the treatment of acoustic neuromas. Prior reports using single-stage radiosurgery consistently have shown excellent tumor control, but only up to a 50 to 73% likelihood of maintaining hearing at pretreatment levels. Staged, frame-based radiosurgery using 12-hour interfraction intervals previously has been shown by our group to achieve excellent tumor control while increasing the rate of hearing preservation at 2 years to 77%. The arrival of CyberKnife (Accuray, Inc., Sunnyvale, CA) image-guided radiosurgery now makes it more practical to treat acoustic neuroma with a staged approach. We hypothesize that such factors may further minimize injury of adjacent cranial nerves. In this retrospective study, we report our experience with staged radiosurgery for managing acoustic neuromas.

METHODS:

Since 1999, the CyberKnife has been used to treat more than 270 patients with acoustic neuroma at Stanford University. Sixty-one of these patients have now been followed up for a minimum of 36 months and form the basis for the present clinical investigation. Among the treated patients, the mean transverse tumor diameter was 18.5 mm, whereas the total marginal dose was either 18 or 21 Gy using three 6- or 7-Gy fractions. Audiograms and magnetic resonance imaging were obtained at 6-months intervals after treatment for the first 2 years and then annually thereafter.

RESULTS:

Of the 61 patients with a minimum of 36 months of follow-up (mean, 48 mo), 74% of patients with serviceable hearing (Gardner-Robinson Class 1–2) maintained serviceable hearing at the last follow-up, and no patient with at least some hearing before treatment lost all hearing on the treated side. Only one treated tumor (2%) progressed after radiosurgery; 29 (48%) of 61 decreased in size and 31 (50%) of the 61 tumors were stable. In no patients did new trigeminal dysfunction develop, nor did any patient experience permanent injury to their facial nerve; two patients experienced transient facial twitching that resolved in 3 to 5 months.

CONCLUSION:

Although still preliminary, these results indicate that improved tumor dose homogeneity and a staged treatment regimen may improve hearing preservation in acoustic neuroma patients undergoing stereotactic radiosurgery.
Long-term Reliability of Endoscopic Third Ventriculostomy
Authors: Kadrian David , van Gelder James , Florida Danielle , Jones Robert , Vonau Marianne , Teo Charles , Stening Warwick , Kwok Bernard
Published: May 2005

OBJECTIVE:

To describe the short-term operative success and the long-term reliability of endoscopic third ventriculostomy (ETV) for treatment of hydrocephalus and to examine the influence of diagnosis, age, and previous shunt history on these outcomes.

METHODS:

We retrospectively analyzed 203 consecutive patients from a single institution who had ETV as long as 22.6 years earlier. Patients with hydrocephalus from aqueduct stenosis, myelomeningocele, tumors, arachnoid cysts, previous infection, or hemorrhage were included.

RESULTS:

The overall probability of successfully performing an ETV was 89% (84–93%). There was support for an association between the surgical success and the individual operating surgeon (odds ratios for success, 0.44–1.47 relative to the mean of 1.0, P = 0.08). We observed infections in 4.9%, transient major complications in 7.2%, and major and permanent complications in 1.1% of 203 procedures. Age was strongly associated with long-term reliability. The longest observed reliability for the 13 patients 0 to 1 month old was 3.5 years. The statistical model predicted the following reliability at 1 year after insertion: at 0 to 1 month of age, 31% (14–53%); at 1 to 6 months of age, 50% (32–68%); at 6 to 24 months of age, 71% (55–85%); and more than 24 months of age, 84% (79–89%). There was no support for an association between reliability and the diagnostic group (n = 181, P = 0.168) or a previous shunt. Sixteen patients had ETV repeated, but only 9 were repeated after at least 6 months. Of these, 4 procedures failed within a few weeks, and 2 patients were available for long-term follow-up.

CONCLUSION:

Age was the only factor statistically associated with the long-term reliability of ETV. Patients less than 6 months old had poor reliability.
Functional Outcome after Central Corpectomy in Poor-grade Patients with Cervical Spondylotic Myelopathy or Ossified Posterior Longitudinal Ligament
Authors: Rajshekhar Vedantam , Kumar G Samson Sujith
Published: May 2005

OBJECTIVE:

We studied the long-term functional outcome in poor-grade patients (Nurick Grades 4 and 5) with cervical spondylotic myelopathy (CSM) or ossified posterior longitudinal ligament after central corpectomy (CC). We sought to determine whether there were any prognostic factors that could predict functional outcome in these patients.

METHODS:

Functional outcome data were collected for 72 patients (68 men and 4 women; mean age, 49.7 yr; range, 30–67 yr) with CSM (60 patients) or OPLL (12 patients) of Nurick Grades 4 (55 patients) and 5 (17 patients). Uninstrumented CC was performed at 1 level in 12 patients, at 1 level combined with a discoidectomy at another level in 4 patients, at 2 levels in 50 patients, and at 2 levels plus a discoidectomy in 5 patients. The age at presentation (≤50 yr or >50 yr), grade before surgery (4 or 5), the number of levels operated (1 or >1), diagnosis (CSM or ossified posterior longitudinal ligament), and duration of myelopathic symptoms (≤12 mo or >12 mo) were studied for their effect on the functional outcome noted at the last follow-up. Functional outcome was graded as poor (no change in Nurick grade), fair (improvement of one Nurick grade), good (improvement of two Nurick grades), and cure (follow-up Nurick grade of 0 or 1).

RESULTS:

The follow-up ranged from 9 to 104 months (mean, 36.3 mo). One patient died 3 weeks after CC after surgery for a perforated duodenal ulcer. There was transient operative morbidity in 12 patients (16.9%). The mean Nurick score improved from 4.24 to 2.47 (P < 0.001). Of the 54 patients (76%) who improved in their Nurick grade, the functional outcome was graded as fair in 13 patients (18.3%), good in 24 patients (33.8%), and cure in 17 patients (23.9%). The functional outcome was poor in 17 patients (23.9%). Functional improvement after CC was uniformly correlated with myelopathic symptoms of 12 months' duration or shorter. The other favorable prognostic indicators for improvement after CC were a diagnosis of CSM and preoperative Nurick Grade 5; however, patients with a preoperative Nurick grade of 4 were more likely to experience a cure.

CONCLUSION:

More than three-fourths of patients with poor-grade CSM improve in their functional status after CC, with nearly 24% of patients obtaining a cure. Because patients with a duration of myelopathic symptoms of 12 months or less had the best functional outcome, early decompressive surgery should be offered to patients with poor-grade CSM.
Bilateral Subthalamic Nucleus Stimulation for Parkinson's Disease: A Systematic Review of the Clinical Literature
Authors: Hamani Clement , Richter Erich , Schwalb Jason M. , Lozano Andres M.
Published: May 2005

OBJECTIVE:

To evaluate the benefits and adverse effects of bilateral subthalamic nucleus stimulation in the treatment of Parkinson's disease (PD) by systematically reviewing the published literature.

METHODS:

A search of the PubMed database using the key words subthalamic, nucleus, and stimulation yielded 624 articles published between 1966 and December 2003. Only articles that included original, nonduplicated descriptions of patients with PD treated with bilateral subthalamic nucleus stimulation were selected for further analysis.

RESULTS:

A total of 38 studies from 34 neurosurgical centers in 13 countries were identified for critical review. The outcomes for 471 patients with PD treated with bilateral subthalamic nucleus stimulation were assessed according to the Unified Parkinson's Disease Rating Scale in both on-medication and off-medication conditions. With stimulation, Unified Parkinson's Disease Rating Scale motor scores in the off-medication condition improved by 50% after 6 months, 56% after 12 months, 51% after 2 years, and 49% after 5 years compared with preoperative off-medication scores. At 12 months of subthalamic nucleus stimulation, the mean improvement in tremor was 81%, in rigidity was 63%, in bradykinesia was 52%, in gait was 64%, and in postural instability was 69% when compared with preoperative off-medication subscores. On-medication dyskinesias were reduced by 94%, as assessed 12 months after stimulation using the Unified Parkinson's Disease Rating Scale IV complications of therapy score. There was an overall 52% reduction in the l-dopa-equivalent dose intake after 12 months of stimulation. Most adverse effects were mild to moderate. There was a 1 to 2% incidence of severe adverse effects (death or permanent neurological deficits related to intracerebral hemorrhages). Nineteen percent of the patients had adverse effects related to stimulation that could be reversed by changing stimulation parameters. There was a 9% incidence of adverse effects related to the hardware (infections, lead and pulse generator problems).

CONCLUSION:

Bilateral subthalamic nucleus stimulation is effective in the treatment of PD. Further refinements in patient selection and surgical technique may lessen the incidence of complications associated with this procedure.
Meningeal Melanocytoma Associated with Ipsilateral Nevus of Ota Presenting as Intracerebral Hemorrhage: Case Report
Authors: Hino Ken , Nagane Motoo , Fujioka Yasunori , Shiokawa Yoshiaki
Published: May 2005

OBJECTIVE AND IMPORTANCE:

The authors report a rare case of meningeal melanocytoma presenting with unconsciousness, which was caused by an intracerebral hematoma and associated with a history of ipsilateral nevus of Ota.

CLINICAL PRESENTATION:

A 75-year-old woman developed nevus of Ota in the first and second divisions of the right trigeminal nerve territory, which had been treated with a skin graft 40 years earlier. She noticed right exophthalmos but left it untreated for 2 years and then became comatose owing to orbital and intracranial tumors, the latter manifesting with hemorrhage.

INTERVENTION:

She underwent craniotomy, during which the tumor was partially removed with intracerebral hematoma. Histopathologically, the tumor was diagnosed as meningeal melanocytoma. Western blot analysis demonstrated a retained protein expression of cell cycle inhibitor p16INK4A and a high level of antiapoptotic Bcl-2 in the resected tumor.

CONCLUSION:

The combination of nevus of Ota and meningeal melanocytoma has been reported in only four cases in the literature, including the current case. This is the first case coinciding with intracerebral hemorrhage, suggesting the necessity for careful follow-up with radiological images.
A Highly Vascular Intracranial Solitary Fibrous Tumor Treated with Radiotherapy and Toremifene: Case Report
Authors: Macfarlane Rebecca Gillian , Galloway Malcolm , Plowman Piers Nicholas , Thomas David Glyndor Treharne
Published: May 2005

OBJECTIVE AND IMPORTANCE:

A case of an unusual intracranial solitary fibrous tumor with features of high vascularity and resultant difficulty at resection is presented. The use of surgery, radiotherapy, and toremifene has been successful with no recurrence after 18 months.

CLINICAL PRESENTATION:

A 33-year-old male patient presented with a 1-year history of loss of vision on the left side and a 3-month history of headache and lethargy. Magnetic resonance imaging showed a lobulated mass (7.6 × 4.5 cm) in the left temporal fossa and left parasellar, sellar, and suprasellar regions, with a “dural tail” more typical of meningioma. Vascular supply was from both the internal carotid arteries and the left middle meningeal artery, precluding embolization.

INTERVENTION:

At the time of the craniotomy, a highly vascular tumor was found. Intraoperative hemorrhage limited resection to 20% of the tumor. The histological diagnosis was of a solitary fibrous tumor with an unusually angiomatoid architecture. After the operation, radiotherapy and toremifene were administered. A dramatic reduction in the size of the tumor was seen with no recurrence to date.

CONCLUSION:

The use of surgery, radiotherapy, and toremifene in treatment of a vascular intracranial solitary fibrous tumor has been successful and warrants further research.
Solitary Thoracic Osteochondroma: Case Report and Review of the Literature
Authors: Brastianos Priscilla , Pradilla Gustavo , McCarthy Edward , Gokaslan Ziya L.
Published: May 2005

OBJECTIVE AND IMPORTANCE:

Osteochondromas are common benign bone tumors that rarely arise in the vertebral column. Intraspinal presentation of these tumors is usually circumscribed to the cervical regions with few tumors presenting in the thoracic vertebrae. We report a case of a thoracic solitary osteochondroma arising from within the vertebral body, review the cases reported in the literature, and propose recommendations for the surgical management of these challenging lesions.

CLINICAL PRESENTATION:

A 26-year-old woman presented with clinical signs of spinal cord compression consisting of right lower extremity weakness and left lower extremity numbness. Magnetic resonance imaging showed a small enhancing epidural mass behind the vertebral body of T12.

INTERVENTION:

A T12 corpectomy was performed with thoracolumbar fixation and fusion.

CONCLUSION:

Our case is atypical in that the tumor arose from the posterior portion of the T12 body, causing spinal cord dysfunction that necessitated an anterior approach to T12 for corpectomy with thoracolumbar fixation and fusion. Surgical intervention was effective in completely resolving the patient's right lower extremity weakness.
Neural Damage Caused by Cerebral Hyperperfusion after Arterial Bypass Surgery in a Patient with Moyamoya Disease: Case Report
Authors: Ogasawara Kuniaki , Komoribayashi Nobukazu , Kobayashi Masakazu , Fukuda Takeshi , Inoue Takashi , Yamadate Keiko , Ogawa Akira
Published: May 2005

OBJECTIVE AND IMPORTANCE:

The prognosis of cerebral hyperperfusion syndrome after vascular reconstructive surgery, including extracranial-intracranial arterial bypass, is not poor unless intracerebral hemorrhage develops secondary to hyperperfusion.

CLINICAL PRESENTATION:

A 48-year-old man with symptomatic moyamoya disease with misery perfusion in the right cerebral hemisphere underwent double right superficial temporal artery-to-middle cerebral artery bypasses. The postoperative course was uneventful until the patient developed headache and agitated delirium on the 4th postoperative day.

INTERVENTION:

Perfusion computed tomographic imaging demonstrated hyperperfusion in the right temporal lobe. The symptoms resolved by institution of intensive blood pressure control. Positron emission tomography performed 2 months after surgery demonstrated a postoperative reduction of the cerebral metabolic rate of oxygen in the right temporal lobe, where brain atrophy was observed on magnetic resonance images 3 months postoperatively. Neuropsychological testing performed 3 months postoperatively showed worsening digit span, which adversely affected the patient's quality of life.

CONCLUSION:

The current case suggests that cerebral hyperperfusion after vascular reconstructive surgery can cause irreversible neural damage, which results in cognitive impairment.
Ruptured Arteriovenous Malformation in the Auditory Nerve: Technical Case Report
Authors: Oya Soichi , Matsui Toru , Asai Akio
Published: May 2005

OBJECTIVE AND IMPORTANCE:

Arteriovenous malformations in the cranial nerves are very rare, and only one case has been reported in the literature. To our knowledge, this is the first case report of an arteriovenous malformation in the auditory nerve.

CLINICAL PRESENTATION:

A 30-year-old woman presented with a subarachnoid hemorrhage resulting from rupture of an arteriovenous malformation in the auditory nerve.

INTERVENTION:

During the operation, the auditory nerve bundle was found to be severely damaged and a nidus was identified inside the bundle.

CONCLUSION:

Although arteriovenous malformations are thought to arise in the 4th to 8th weeks of gestation, this case might indicate a more specific time of emergence based on embryogenesis of the cranial nerves.
Prophylaxis for Deep Venous Thrombosis in Craniotomy Patients: A Decision Analysis
Authors: Danish Shabbar F. , Burnett Mark G. , Ong Joseph G. , Sonnad Seema S. , Maloney-Wilensky Eileen , Stein Sherman C.
Published: May 2005

OBJECTIVE:

We sought to determine the most efficient perioperative prophylactic strategy for deep venous thrombosis (DVT) in craniotomy patients by use of a decision analysis model.

METHODS:

We conducted a structured review of the relevant literature and compiled the reported incidences of DVT, pulmonary embolism, and postoperative intracranial hemorrhage (ICH) in craniotomy patients. We also obtained from the literature estimates of the likelihood and the impact of various outcomes of these complications. Data from 810 craniotomies performed at our own institution were also examined. The decision analytic model was then used to compare the effectiveness of pneumatic compression boots with pneumatic compression boots combined with either unfractionated or low-molecular-weight heparin. The model dealt with variability by using both sensitivity analysis and Monte Carlo simulation.

RESULTS:

As expected, the addition of heparin lowered the incidence of both DVT and pulmonary embolism, but at the cost of increasing ICH. Because the deleterious effects of ICH were so much greater than the benefits from heparinization, overall outcomes were best with mechanical prophylaxis alone. This was especially true for low-molecular-weight heparin, which is associated with a relatively high risk of ICH. Our own institutional data support the findings in the literature. Although the differences are modest, they reach statistical significance in the case of low-molecular-weight heparin.

CONCLUSION:

Using decision analytic modeling, we have shown that mechanical prophylaxis yields outcomes in craniotomy patients superior to those of either unfractionated or low-molecular-weight heparin.
Patient Reports of Satisfaction after Microvascular Decompression and Partial Sensory Rhizotomy for Trigeminal Neuralgia
Authors: Zakrzewska Joanna M. , Lopez Benjamin C. , Kim Sung Eun , Coakham Hugh B.
Published: May 2005

OBJECTIVE:

There are no reports of patient satisfaction surveys after either a microvascular decompression (MVD) or a partial sensory rhizotomy (PSR) for trigeminal neuralgia. This study compares patient satisfaction after these two types of posterior fossa surgery for trigeminal neuralgia, because it is postulated that recurrences, complications, and previous surgical experience reduce satisfaction.

METHODS:

All patients who had undergone their first posterior fossa surgery at one center were sent a self-complete questionnaire by an independent physician. Among the 44 questions on four standardized questionnaires were 5 questions that related to patient satisfaction and experience of obtaining care. Patients were divided into those having their first surgical procedure (primary) and those who had had previous ablative surgery (nonprimary).

RESULTS:

Response rates were 90% (220 of 245) of MVD and 88% (53 of 60) of PSR patients. Groups were comparable with respect to age, sex, duration of symptoms, mean duration of follow-up, and recurrence rates. Overall satisfaction with their current situation was 89% in MVD and 72% in PSR patients. Unsatisfied with the outcome were 4% of MVD and 20% of PSR patients, and this is a significant difference (P < 0.01). Satisfaction with outcome was higher in those undergoing this as a primary procedure. In the primary group, satisfaction was dependent on recurrence and complication/side effects status (each P < 0.01), but this was not the case in the nonprimary group. Patients expressed a desire for earlier posterior fossa surgery in 73% of MVD and 58% of PSR patients, and this was highest in the primary group. The final outcome was considered to be better than expected in 80% of MVD and 54% of PSR patients, but 22% of the PSR group (P < 0.01) thought they were worse off.

CONCLUSION:

Patients undergoing posterior fossa surgery as a primary procedure are most satisfied and PSR patients are least satisfied, partly because of a higher rate of side effects.
Hyperacute Neuropathological Findings after Proton Beam Radiosurgery of the Rat Hippocampus
Authors: Brisman Jonathan L. , Cosgrove G Rees , Thornton Allan F. , Beer Thomas , Bradley-Moore Maria , Shay Christina T. , Hedley-Whyte E Tessa , Cole Andrew J.
Published: May 2005

OBJECTIVE:

To study the hyperacute histological and immunohistochemical effects of stereotactic proton beam irradiation of the rat hippocampus.

METHODS:

Nine rats underwent proton beam radiosurgery of one hippocampus with nominal doses of cobalt-2, -12, and -60 Gray equivalents (n = 3 each). Control animals (n = 3) were not irradiated. Animals were killed 5 hours after irradiation and brain sections were stained for Nissl, silver degeneration, deoxyribonucleic acid (DNA) fragmentation (DNAF), and the activated form of two mitogen-activated protein kinases (MAPKs), phospho-Erk1/2 (P-Erk1/2) and p38. Stained cells in the hippocampus expressing DNAF and/or P-Erk1/2 were counted. Confocal microscopy with double immunofluorescent staining was used to examine cellular colocalization of DNAF and P-Erk1/2.

RESULTS:

Both DNAF and P-Erk1/2 showed quantitative dose-dependent increases in staining in the targeted hippocampus compared with the contralateral side and controls. This finding was restricted to the subgranular proliferative zone of the hippocampus. Both markers also were up-regulated on the contralateral side when compared with controls in a dose-dependent fashion. Simultaneous staining for DNAF and P-Erk1/2 was found in fewer than half of all cells. p38 was unchanged compared with controls. Although Nissl staining appeared normal, silver stain confirmed dose-dependent cellular degeneration.

CONCLUSION:

DNAF, a marker of cell death, was present in rat hippocampi within 5 hours of delivery of cobalt-2 Gray equivalents stereotactically focused irradiation, suggesting that even low-dose radiosurgery has hyperacute neurotoxic effects. Activated mitogen-activated protein kinase was incompletely colocalized with DNAF, suggesting that activation of this cascade is neither necessary nor sufficient to initiate acute cell death after irradiation.
Gamma Knife Radiosurgery for Trigeminal Neuralgia
Authors: McNatt Sean A. , Yu Cheng , Giannotta Steven L. , Zee Chi-Shing , Zelman Vladimir , Apuzzo Michael L.J. , Petrovich Zbigniew
Published: May 2005

OBJECTIVE:

The purpose of this study was to assess outcomes in patients treated with gamma knife radiosurgery for trigeminal neuralgia.

METHODS:

From 1997 to 2003, a total of 49 patients with trigeminal neuralgia underwent gamma knife radiosurgery. The trigeminal root entry zone immediately adjacent to the pons was targeted by use of a 4-mm collimator to deliver 40 Gy to the 50% isodose line (maximum dose, 80 Gy). Special care was taken to limit radiation dose to the adjacent pons to 12 Gy. Of the 49 study patients, all had undergone previous medical therapy, 8 (16%) had undergone microvascular decompression, 8 (16%) had undergone percutaneous rhizotomy, 2 (4%) had undergone linear accelerator-based radiosurgery, and 5 (10%) presented with multiple sclerosis. The median duration of symptoms was 6 years. There were 29 female patients (59%) and 20 male patients (41%). Facial pain outcomes were assessed by use of the Barrow Neurological Institute pain score. Other outcomes assessed included recurrence of symptoms and treatment toxicity. The median follow-up period was 49 months.

RESULTS:

At last evaluation, a total of 27 patients (61%) with idiopathic trigeminal neuralgia reported pain relief (scores of IIIb or less). This included 14 patients (32%) who reported complete pain relief when not receiving medications. Significant recurrence of pain after an initial interval of relief was reported by 10 patients (23%). Mean time to pain recurrence was 9.6 months (range, 2–36 mo). Mild to moderate facial numbness was experienced by 13 patients (29%), whereas 8 (18%) reported mild dysesthesias.

CONCLUSION:

Gamma knife radiosurgery established durable pain relief in 61% of patients with medically refractory idiopathic trigeminal neuralgia. A longer follow-up period is necessary to fully assess the incidence of late complications and recurrences.
Ewing's Sarcoma of the Cavernous Sinus: Case Report
Authors: Kushen Medina , Gulbahce H Evin , Lam Cornelius H.
Published: May 2005

OBJECTIVE AND IMPORTANCE:

The Ewing's sarcoma (ES) family of tumors is a relatively rare entity, presenting most commonly in children. While the most common sites for this group of tumors are the trunk and the extremities, this case is unique in that we describe a long-term follow-up with an ES presenting in the cavernous sinus.

CLINICAL PRESENTATION:

We report the case of a 13-year-old girl presenting with the symptoms of classic orbital apex syndrome. Magnetic resonance imaging disclosed a cavernous sinus mass engulfing the optic nerve and extending into the superior orbital fissure.

INTERVENTION:

Evaluation of this patient included intracranial magnetic resonance imaging angiography and biopsy of the cavernous sinus mass lesion. Histopathological findings yielded a diagnosis of ES. Further work-up demonstrated that the patient's thyroid was also involved. The tumor was treated with radiation therapy to both sites and, subsequently, after confirmed metastases to other sites, 11 cycles of doxorubicin-based chemotherapy, as well as bone marrow transplantation. However, the patient succumbed to the illness 18 months after her initial diagnosis.

CONCLUSION:

The cavernous sinus is an unusual site for ES, but given the vascularity and the frequency of this tumor in childhood, the diagnosis should be entertained. This patient with an ES of cavernous sinus may be the first reported case with a long-term follow-up in the literature.
Optimization of anvil design for ensuring dimensional precision of forged round billet without forging defects by three-dimensional rigid-plastic finite element analysis
Authors: Tamura K , Akiyama M , Tajima J
Published: June 2005

Focusing upon finding an optimum anvil design of the spiral forging stage for manufacturing a round billet to good dimensional precision directly from an octagonal work-piece without forging defects, three-dimensional rigid-plastic finite element analyses have been carried out. By analysis and laboratory experiment, the mechanism through which overlapping defects are caused in spiral forging has been quantitatively clarified and a new parameter to predict overlapping defect generation proposed. By making use of the parameter, an anvil design of the entrance side has been proposed to prevent overlapping defects. Moreover, the whole geometry of the anvil has been optimized in order to ensure dimensional precision of the final round billet. As a result, a fundamental scheme to optimize anvil design for manufacturing a round billet directly from an octagonal workpiece has been established and the total number of passes was successfully reduced in the production line.
Tensile properties and microstructural aspects of 304L stainless steel weldments as a function of strain rate and temperature
Authors: Lee W-S , Lin C-F , Chen B-T
Published: June 2005

This paper presents an investigation into the effects of loading rate and temperature on the tensile properties and microstructural evolution of 304L stainless steel weldments. The stress-strain behaviour during tension was determined by loading specimens in a material testing system at strain rates ranging from 10−3 to 10−1 s−1 and temperatures between −100 and 500°. Extensive quantitative microstructural examinations were performed to identify the correlation between the tensile response and the substructure of dislocations and α’ martensite. It was found that the tensile flow stress increased with increasing strain rate, but decreased with increasing temperature. For a test conducted below room temperature, a negative strain rate sensitivity was apparent at strains exceeding 0.3. Fracture feature examination revealed that an enhanced fracture resistance was evident in the base metal at low temperatures, whereas it is evident in the weld metal at high temperatures owing to their different hardening rates and microstructural states. Microstructural analysis revealed that both the dislocation density and the α’ martensite volume fraction increased with increasing strain rate, but decreased as the temperature was increased. In the range of -100-25°, both dislocations and α' martensite enhanced the strength of the tested weldment. However, between 300 and 500°, the strengthening effect was dominated only by dislocation mechanisms. For a given strain rate and temperature, a higher dislocation density existed in the weld metal, whereas a larger volume fraction of α' martensite was present in the base metal. Both increased dislocations and volume fractions of α' martensite yielded a greater work-hardening stress.
A study of the interaction between operator style and machine capability for a hydraulic mining excavator
Authors: Hall A S , McAree P R
Published: June 2005

This paper presents a case study that explores how operator digging style juxtaposes with mechanical capability for a class of hydraulic mining excavators. The relationships between actuator and digging forces are developed and these are used to identify the excavator's capability to apply forces in various directions. Two distinct modes of operation are examined to see how they relate to the mechanical capabilities of the linkage and to establish if one has merit over the other. It is found that one of these styles results in lower loading of the machine.
A New Route to an Endohedral Fullerene by Way of σ-Framework Transformations
Authors: Komatsu Koichi , Murata Yasujiro
Published: May 2005

The molecular surgical approach has been shown to be applicable to preparation of an endohedral fullerene. Thus, an orifice large enough to insert an atom or molecule has been constructed on the surface of fullerene C60. The orifice has been enlarged to a 13-membered ring by insertion of a sulfur atom on the rim, and 100% encapsulation of molecular hydrogen has been attained. Then, the size reduction of the orifice, without the loss of incorporated hydrogen, and complete closure of the orifice have been achieved to afford a new endohedral fullerene, H2@C60.
Two New Nortriterpenes from Ligularia tongolensis
Authors: Han Yi Feng , Gao Kun , Jia Zhong Jian
Published: May 2005

Two new nortriterpenes having a ursane type structure were isolated from the roots of Chinese Ligularia tongolensis, and their structures were elucidated by interpretation of spectral data. Their relative stereochemistries were also clarified by detailed analysis of proton–proton coupling constants and by NOE experiments.
Diastereoselective Trifluoromethylation of Chiral N-(Tolylsulfinyl)imines in the Presence of Lewis Bases
Authors: Kawano Yoshikazu , Mukaiyama Teruaki
Published: May 2005

A diastereoselctive trifluoromethylation of chiral N-(tolylsulfinyl)imines with (trifluoromethyl)trimethylsilane in the presence of Lewis bases such as tetrabutylammonium acetate or phenoxide proceeded smoothly to afford the corresponding trifluoromethylated adducts in good yields.
Porous CdS Nanowire Arrays Self-assembled in Anodic Aluminum Oxide Template
Authors: Zhang Xueru , Yuan Xiaoyou , Zhang Yong , Wei Qing , Meng Guowen , Zhang Lide
Published: May 2005

Porous CdS nanowire (NW) arrays have been synthesized by self-assemble of CdS nanoparticles (NPs) inside Sn2+/Pd2+-activated nanochannels of anodic aluminum oxide (AAO) template. XRD analysis indicates that the as-synthesized CdS NWs are hexagonal crystalline. TEM and SEM observations reveal that the CdS NWs are porous and consists of self-assembled CdS NPs.
Functional InP Nanocrystals as Novel Near-infrared Fluorescent Sensors for Mercury Ions
Authors: Zhu Changqing , Li Ling , Fang Fang , Chen Jinlong , Wu Yuqin
Published: May 2005

Water-soluble indium phosphide nanocrystals capped with mercaptoacetic acid were synthesized. The nanocrystals fluoresce in the near-infrared region with maximum excitation and emission wavelengths at 750 and 826 nm, respectively. The fluorescence intensity is significantly enhanced in the presence of Hg2+ ions. Under the optimum conditions, the fluorescence enhancement is in proportional to the concentration of Hg2+.
Blue Light Emitting Poly(N-arylcarbazol-2,7-ylene)s
Authors: Kijima Masashi , Koguchi Ryohei , Abe Shota
Published: May 2005

N-(4-alkoxyphenyl) substituted poly(carbazol-2,7-ylene)s were synthesized by Ni-catalyzed polycondensations of 2,7-dihalogenocarbazoles. The polymers intensely fluoresced blue in solution and in the solid-film state by irradiation of UV light. The introduction of the aryl group at the N-position of poly(carbazol-2,7-ylene) enhanced fluorescent quantum efficiency of the polymer, which showed higher performance than N-alkyl substituted polymers.
A Facile Chemical Solution Route to Convert Bulk Cuprous Iodide into Nanoparticles
Authors: Yang Yang , Liu Shuman , Kimura Keisaku
Published: May 2005

CuI nanoparticles were fabricated from conventional CuI powders in micrometer size. Acetonitrile was used as a dispersing agent to dissolve CuI powders. With acetonitrile evaporated, poly-2-vinylpyrolidine (PVP) in the solution could effectively restrict CuI particle growth, prevent them from aggregation, and result in the formation of CuI nanoparticles embedded in the polymer matrix.
Quantitative Evaluation of Spatial Uniformity in Spectral Characteristics for Large-area Colloidal Crystals
Authors: Kanai Toshimitsu , Sawada Tsutomu , Kitamura Kenji
Published: May 2005

We report a quantitative method for evaluating the optical quality of large-area colloidal crystals based on imaging spectroscopy. We measured the transmission spectra with the spatial resolution of large colloidal crystals having different optical quality and examined the characteristic features in terms of the standard deviation calculated on the basis of pixel-by-pixel transmittance of all pixels. As a result, it was possible to quantitatively characterize the difference between weakly and highly oriented samples prepared by a shear-induced method as a difference in the standard deviation in a pass-band wavelength region.