bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonylphenol concentration and estrogenic activity in Kaoping River and its tributaries, Taiwan
Authors: Shue Meei-Fang , Chen Fu-An , Kuo Yu-Tsung , Chen Ting-Chien
Published: May 2009

This study investigated the occurrence of nonylphenol (NP) and 17β-estradiol equivalent quotient (EEQ) concentrations in Kaoping River and two of its tributaries in Taiwan. During this study 44 water samples were collected from four sampling campaigns. Concentrations of NP in these samples ranged from 0.19 to 183.4 μg/L; EEQ ranged from less than limit of detection (1.41) to 32.2 ng-E2/L. NP concentrations in the main watercourse ranged from 0.19 to 9.21 μg/L; EEQ ranged from less than limit of detection to 2.13 ng-E2/L. These values are comparable to most rivers worldwide. The Wulo Creek tributary was polluted by animal waste discharges and the NP concentrations ranged from 0.72 to 6.8 μg/L. The EEQ ranged from 3.86 to 32.2 ng-E2/L. The Niouchou Creek tributary was polluted with domestic wastewater. Concentrations of NP ranged from 8.79 to 183.4 μg/L and EEQ ranged from 2.94 to 27.8 ng-E2/L. These data suggest that both inadequately treated livestock and human wastewater can cause high NP and EEQ concentrations.
Ureolytic phosphate precipitation from anaerobic effluents
Authors: Desmidt E. , Verstraete W. , Dick J. , Meesschaert B. D. , Carballa M.
Published: May 2009

In this work, the elimination of phosphate from industrial anaerobic effluents was evaluated at lab-scale. For that purpose, the ureolytic method previously developed for the precipitation of Ca2 +  from wastewater as calcite was adapted for the precipitation of phosphate as struvite. In the first part of the study, computer simulations using MAPLE and PHREEQC were performed to model phosphate precipitation from wastewater as struvite. The results obtained showed that relative high concentrations of ammonium and magnesium are needed to precipitate phosphate as struvite. The total molar concentrations ratio of Mg2 + :PO43−-P:NH4+ required to decrease PO43−-P concentrations from 20 to 6 mg PO43−-P/l at pH 8.4-8.5 was estimated on 4.6:1:8. In the second part of the study, lab-scale experiments with either synthetic wastewater or the anaerobic effluent from a vegetable processing industry were carried out in batch and continuous mode. Overall, the continuous operation at a hydraulic retention time (HRT) of 2.4 h and an added molar concentration [Mg2 + ]:[PO43−-P]:[NH4+] ratio of 1.6:1:2.3 resulted in a constant pH value in the reactor (around 8.5) and an efficient phosphate removal (>90%) to residual levels of 1–2 mg PO43−-P/l. Different operational conditions, such as the initial phosphate concentration, HRT and the use of CaCl2 or MgO instead of MgCl2, were analysed and the performance of the reactor was satisfactory under a broad range of them. Yet, overall, optimal results (higher phosphate removal) were obtained with MgCl2.
Achieving integrated urban water management: planning top-down or bottom-up?
Authors: Gabe J. , Trowsdale S. , Vale R.
Published: May 2009

Integrated Urban Water Management (IUWM) acknowledges a broad range of environmental and socio-economic outcomes but the link between design intentions and operational performance is not always clear. This may be due in part to a lack of shared principles that remove bias and inconsistency in assessing the operational performance of IUWM. This paper investigates the possibility of developing shared principles through examination of shared objectives and shared indicators within two logical and integrated frameworks for urban residential developments that aspire for IUWM and sustainable development. The framework method was applied using very different approaches—one a top-down urban planning process, the other a bottom-up community consultation process. Both frameworks highlight the extent to which IUWM is part of a broad social and environmental system. Core environmental performance objectives and indicators were very similar, highlighting the potential to develop shared principles in reporting and benchmarking the environmental performance of neighbourhood developments. Socio-economic indicators were highly variable due to process and likely contextual differences, thus it is unclear if the influence of IUWM on these variables can transcend the social context unless the practice of urban water management can expand its core responsibility beyond “hard” physical infrastructure.
Recovering nutrients from wastewater treatment plants through struvite crystallization: CFD modelling of the hydrodynamics of UBC MAP fluidized-bed crystallizer
Authors: Rahaman M. S. , Mavinic D. S.
Published: May 2009

This paper is an attempt to model the hydrodynamics of the UBC (University of British Columbia) MAP (magnesium ammonium phosphate) fluidized bed crystallizer. In this study, a numerical investigation of hydrodynamics of the UBC MAP crystallizer was performed, using commercial computational fluid dynamics (CFD) software, Fluent 6.3. One of the main findings of this modelling effort is the relative distribution of the different phases, in this case solids (struvite crystals) and liquid (water), within the reactor. This information is very important, in the sense that it helps fixing the size of the crystallizer, which can be a significant factor, affecting the total cost of the process. Another finding of this simulation is the volume fraction distribution of the different sizes of solid particles, which actually provides insight into the hydrodynamics of the reactor and will fill up the knowledge gap in developing an overall mechanistic model for the crystallizer.
Effects of natural organic matter removal by integrated processes: alum coagulation and PAC-adsorption
Authors: Szlachta M. , Adamski W.
Published: May 2009

This paper presents the results of bench-scale research into the efficiency of NOM removal by integrated processes—alum coagulation and PAC-adsorption. Experiments were conducted using riverine water samples (collected from the Odra River, Poland) and commercial powdered activated carbon. It has been shown that a PAC-enhanced coagulation process reduces the coagulant dose required and increases the process efficiency at the same time. For example, a coagulant dose of 2.0 mgAl/L and a PAC dose of 5 mg/L have produced results comparable to those of a coagulation process with no adsorbent aid but with a coagulant dose increased by 54%. The coagulation-adsorption tests were carried out at a pH of 6.0, which was lower than the pHIEP of the adsorbent. This procedure yielded a high extent of DOC and UV-254 removal, at 90% and 77%, respectively. The drop observed in the SUVA value after the process implied a decrease in reactive DOC forms and consequently a diminished risk that disinfection by-products might form. HPSEC analyses made it possible to describe the changes in the molecular weight distribution for the organic substances persisting in the water both after coagulation and after PAC-aided coagulation, and to evaluate their propensity to removal by the two methods. The coagulation process was effective as far as the removal of high-molecular-weight fractions is concerned. An increase in the removal of the low molecular weight NOM was achieved when the PAC-adsorption process had been combined with coagulation.
Stable Isotopes (H, C, S) and the Origin of Baltic Amber
Authors: Gaigalas Algirdas , Halas Stanislaw
Published: May 2009

New results of isotope analysis of light elements (H, C and S) of a dozen Baltic amber samples are described and discussed. Carbon isotope composition was nearly constant (ca. -23‰), whereas sulphur and hydrogen varied in their isotope compositions from +4 to -28‰ and from -171 to -213‰, respectively. The formation and subsequent evolution of this material since its origin in Paleogene time until present is outlined.
The surgical technique of anterior cervical fusion using bone grafts obtained from cervical vertebral bodies
Authors: Isu Toyohiko , Kamada Kyosuke , Kobayashi Nobuaki , Mabuchi Shoji
Published: May 2009

✓ The authors describe the surgical technique of anterior cervical fusion using bone grafts obtained from cervical vertebral bodies. This series consisted of 90 patients with cervical intervertebral disc disease suffering from cervical spondylotic myelopathy. Thirty-five patients were operated on at one level, 33 at two levels, and 22 at three levels. Postoperative x-ray films showed solid bone fusion in all patients at a mean follow-up time of 24 months (range 1 year to 3 years 6 months). Anterior angulation was found in four (4.4%) of the 90 patients. This surgical procedure has two major advantages: 1) there are no complications related to the iliac donor site, allowing early patient mobilization; and 2) the extensive posterior spur can be removed safely and easily under a wide operative field without damaging the spinal cord and nerve roots.
Early repeat surgery for persistent Cushing's disease
Authors: Ram Zvi , Nieman Lynnette K. , Cutler Gordon B. , Chrousos George P. , Doppman John L. , Oldfield Edward H.
Published: May 2009

✓ The potential efficacy of early repeat transsphenoidal surgery for persistent Cushing's disease has not previously been examined. On 222 patients with no prior pituitary treatment and a preoperative diagnosis of Cushing's disease, 29 (13%) remained hypercortisolemic after an initial transsphenoidal pituitary exploration. Seventeen of these 29 patients underwent further surgery 7 to 46 days after the initial transsphenoidal approach in order to completely excise suspected residual tumor. Patients were followed for 4 to 84 months (mean ± standard deviation, 34 ± 25 months) to document sustained remission or recurrence of Cushing's disease (a urine free cortisol level > 90 µg/day was considered evidence of recurrence).

Of the 17 patients with repeat surgery, 12 (71%) had resolution of hypercortisolism (morning plasma cortisol level < 5 µg/dl); however, in three of these 12, hypercortisolism recurred 5, 12, and 24 months later. In 14 patients a lesion that appeared to be a tumor was identified during the initial procedure or on histological examination. Of these, 12 had immediate resolution of hypercortisolism and nine are still in remission. Three patients, in whom no adenoma could be identified during the initial surgery or an examination of the partial hypophysectomy specimen from the initial surgery, had persistent Cushing's syndrome after the second operation. Seven (41%) of the 17 patients developed hypopituitarism requiring treatment with thyroid hormone, gonadal steroid, or vasopressin replacement.

The low incidence of identification of an adenoma on computerized tomography or magnetic resonance images (three of 17 patients), the failure to find a corticotrophic adenoma during the initial surgery (10 of 17 patients), and the failure of these 17 patients to respond to the initial transsphenoidal surgery suggest that they may comprise a subset of patients who are more difficult to treat successfully with surgery than most patients with Cushing's disease. Despite that, early reoperation induced immediate remission of hypercortisolism in 71% of cases, but did so at the expense of a high risk of hypopituitarism. However, since the alternative treatments (such as radiation therapy, long-term drug therapy, or bilateral adrenalectomy) also have potential adverse effects, early reoperation deserves consideration for the management of persistent Cushing's disease, especially when an adrenocorticotrophic hormone-secreting adenoma was partially excised during the first surgery.
Role of intracranial pressure monitoring in severely head-injured patients without signs of intracranial hypertension on initial computerized tomography
Authors: O'Sullivan Michael G. , Statham Patrick F. , Jones Patricia A. , Miller J. Douglas , Dearden N. Mark , Piper Ian R. , Anderson Shirley I. , Housley Alma , Andrews Peter J. , Midgley Susan , Corrie Jane , Tocher Janice I. , Sellar Robin
Published: May 2009

✓ Previous studies have suggested that only a small proportion (< 15%) of comatose head-injured patients whose initial computerized tomography (CT) scan was normal or did not show a mass lesion, midline shift, or abnormal basal cisterns develop intracranial hypertension. The aim of the present study was to re-examine this finding against a background of more intensive monitoring and data acquisition.

Eight severely head-injured patients with a Glasgow Coma Scale score of 8 or less, whose admission CT scan did not show a mass lesion, midline shift, or effaced basal cisterns, underwent minute-to-minute recordings of arterial blood pressure, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) derived from blood pressure minus ICP. Intracranial hypertension (ICP ≥ 20 mm Hg lasting longer than 5 minutes) was recorded in seven of the eight patients; in five cases the rise was pronounced in terms of both magnitude (ICP ≥ 30 mm Hg) and duration. Reduced CPP (≤ 60 mm Hg lasting longer than 5 minutes) was recorded in five patients.

Severely head-injured (comatose) patients whose initial CT scan is normal or does not show a mass lesion, midline shift, or abnormal cisterns nevertheless remain at substantial risk of developing significant secondary cerebral insults due to elevated ICP and reduced CPP. The authors recommend continuous ICP and blood pressure monitoring with derivation of CPP in all comatose head-injured patients.
Generation of cytotoxic immune responses during the progression of a rat glioma
Authors: Holladay Frank P. , Choudhuri Rajani , Heitz Teresa , Wood Gary W.
Published: May 2009

✓ Cytotoxic T lymphocytes specific for tumor-associated antigens are produced by exposing animals to tumor cells and stimulating lymphocytes from animals immunizedin vitrowith tumor cells and small amounts of interleukin-2 (IL-2). This study was designed to determine whether a fast-growing immunogenic avian sarcoma virus-induced glioma produces primed cytotoxic T lymphocyte precursors during its progression. Lymphocytes from intracerebral glioma-bearing rats generally failed to proliferatein vitroin response to immunization with tumor cells and IL-2 and, when proliferative responses were observed, the lymphocytes were not cytotoxic for glioma cells. However, when the same tumor was growing subcutaneously, lymphocytes proliferated and exhibited glioma-specific cytotoxicity when stimulatedin vitrowith autologous tumor cells and IL-2. Subcutaneous immunization of intracerebral glioma-bearing rats with tumor cells and adjuvant induced strong cytotoxic T lymphocyte responses. The results demonstrated that, while intracerebral tumor progression itself does not induce an antiglioma immune response, immune responses to tumor-associated antigens may be induced by systemic immunization of tumor-bearing animals. The results suggest that the immunogenicity of brain tumors is masked by the immunologically privileged status of the brain, not by the induction of generalized immune suppression during tumor progression.
The effects of methylprednisolone and the ganglioside GM1 on acute spinal cord injury in rats
Authors: Constantini Shlomo , Young Wise
Published: May 2009

✓ Recent clinical trials have reported that methylprednisolone sodium succinate (MP) or the monosialic ganglioside GM1 improves neurological recovery in human spinal cord injury. Because GM1 may have additive or synergistic effects when used with MP, the authors compared MP, GM1, and MP+GM1 treatments in a graded rat spinal cord contusion model. Spinal cord injury was caused by dropping a rod weighing 10 gm from a height of 1.25, 2.5, or 5.0 cm onto the rat spinal cord at T-10, which had been exposed via laminectomy. The lesion volumes were quantified from spinal cord Na and K shifts at 24 hours after injury and the results were verified histologically in separate experiments. A single dose of MP (30 mg/kg), given 5 minutes after injury, reduced 24-hour spinal cord lesion volumes by 56% (p = 0.0052), 28% (p = 0.0065), and 13% (p > 0.05) in the three injury-severity groups, respectively, compared to similarly injured control groups treated with vehicle only. Methylprednisolone also prevented injury-induced hyponatremia and increased body weight loss in the spine-injured rats. When used alone, GM1 (10 to 30 mg/kg) had little or no effect on any measured variable compared to vehicle controls; when given concomitantly with MP, GM1 blocked the neuroprotective effects of MP. At a dose of 3 mg/kg, GM1 partially prevented MP-induced reductions in lesion volumes, while 10 to 30 mg/kg of GM1 completely blocked these effects of MP. The effects of MP on injury-induced hyponatremia and body weight loss were also blocked by GM1. Thus, GM1 antagonized both central and peripheral effects of MP in spine-injured rats.

Until this interaction is clarified, the authors recommend that MP and GM1 not be used concomitantly to treat acute human spinal cord injury. Because GM1 modulates protein kinase activity, protein kinases inhibit lipocortins, and lipocortins mediate anti-inflammatory effects of glucocorticoids, it is proposed that the neuroprotective effects of MP are partially due to anti-inflammatory effects and that GM1 antagonizes the effects of MP by inhibiting lipocortin. Possible beneficial effects of GM1 reported in central nervous system injury may be related to the effects on neural recovery rather than acute injury processes.
Delayed induction of mild hypothermia to reduce infarct volume after temporary middle cerebral artery occlusion in rats
Authors: Karibe Hiroshi , Chen Jun , Zarow Gregory J. , Graham Steven H. , Weinstein Philip R.
Published: May 2009

✓ Deep to moderate hypothermia (24° to 30°C) during focal cerebral ischemia reduces infarct volume but must be initiated before the onset of ischemia to be effective and has deleterious pulmonary, myocardial and neurological effects. It is not known whether mild hypothermia (32° to 33°C) protects against ischemic neuronal damage, whether hypothermia induced after the onset of ischemia has protective effects, or whether these effects are associated with alterations in cortical blood flow. In this study, mild whole-body hypothermia was induced in rats just before or 10, 30, or 60 minutes after the onset of 2 hours of temporary middle cerebral artery occlusion; rewarming began immediately after reversal of occlusion and normothermia was maintained throughout 22 hours of reperfusion. Infarct volume, measured 24 hours after the end of reperfusion, was significantly smaller in rats made hypothermic within 30 minutes after the onset of ischemia than in normothermic controls; hypothermia induced at 60 minutes of ischemia did not reduce infarct volume. Cortical blood flow, measured by laser Doppler ultrasound flowmetry, was not significantly different between groups during ischemia; however, postischemic cortical blood flow correlated positively with total infarct volume. These results indicate that mild hypothermia initiated during temporary focal ischemia in rats can reduce infarct volume without attenuating the reduction in cortical blood flow.
Experimental model of posttraumatic syringomyelia: the role of adhesive arachnoiditis in syrinx formation
Authors: Cho Ki Hong , Iwasaki Yoshinobu , Imamura Hiroyuki , Hida Kazutoshi , Abe Hiroshi
Published: May 2009

✓ An experimental model was devised to elucidate the role of spinal blockade in posttraumatic syringomyelia. Thirty-eight Japanese White rabbits, each weighing about 3 kg, were used in this study. The animals were divided into four groups: in Group 1, eight animals received traumatic injury only; in Group 2, 12 animals received traumatic injury following injection of 100 mg kaolin suspended in 1 cc normal saline solution into the subarachnoid space at the site of trauma; in Group 3, nine animals received traumatic injury following injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space at the site of trauma; and in Group 4, nine animals without traumatic injury received an injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space.

The subjective criteria for syrinx formation were the presence of a definite round cyst having a smooth margin and an upper or lower extension of more than 2 cm from the injured site. Syrinx formation was seen in 12.5% (one of eight rabbits) in Group 1, 41.7% (five of 12 animals) in Group 2, 55.5% (five of nine rabbits) in Group 3 and 0% (none of nine animals) in Group 4 (p < 0.05). There was a tendency for the combined trauma/kaolin injection groups to be more prone to develop a syrinx. In the kaolin injection only group (Group 4), no animal showed a definite cyst or an extending cavity during the experimental period. The results suggest that kaolin enhances the extension of multiple small cavities that have already formed at the time of initial injury. The difference between the frequency of syrinx formation and the time of survival was statistically significant well beyond the 0.05% level. The overall difference, relating to the frequency of syrinx development, group, and duration of survival, was also statistically significant. In summary, subarachnoid block secondary to adhesive arachnoiditis is important in initiating the extension of the syringomyelia cavity.
The effect of surgery on the severity of vasospasm
Authors: Macdonald R. Loch , Wallace M. Christopher , Coyne Terry J.
Published: May 2009

✓ Intracranial aneurysm surgery performed between 4 and 12 days after subarachnoid hemorrhage (SAH) has been associated with an increased risk of delayed cerebral ischemia and poor outcome compared to surgery performed before or after this time. To investigate whether this increased risk is due to aggravation of vasospasm, the angiograms obtained before and after surgery in 56 patients operated on at various times after aneurysmal SAH were studied. Vasospasm was quantitated by measuring the diameters of intracranial arteries and expressed as the ratio of the diameters of the intracranial arteries to the diameter of the extracranial internal carotid artery. Aggressive surgical clot removal was not performed at surgery. To correct for differences in prognostic factors for vasospasm between patients operated on at different times after SAH, multiple regression analysis was performed using the arterial diameter ratio during vasospasm as the dependent variable and the prognostic factors for vasospasm, including the time of surgery, as independent variables. Equations predicting the severity of vasospasm could be generated using the clinical grade on admission, patient age, and preoperative arterial diameter ratio.

The time of surgery had no effect on vasospasm. Cerebral infarction due to vasospasm developed in five (15%) of 34 patients operated on within 3 days after SAH and in four (20%) of 20 operated on between 4 and 12 days after SAH (p = 0.66). A good outcome for these two groups was achieved in 88% and 85%, respectively (p = 1.00). These results suggest that the timing of surgery does not affect the development of vasospasm. Any increased risk of cerebral ischemia associated with surgery performed between 4 and 12 days after SAH is due to factors other than aggravation of vasospasm.
Combined effect of L-arginine and superoxide dismutase on the spastic basilar artery after subarachnoid hemorrhage in dogs
Authors: Kajita Yasukazu , Suzuki Yoshio , Oyama Hirofumi , Tanazawa Toshihiko , Takayasu Masakazu , Shibuya Masato , Sugita Kenichiro
Published: May 2009

✓ To investigate the function of nitric oxide (a major endothelium-derived relaxing factor) in cerebral arteries after subarachnoid hemorrhage (SAH)in vivo, several nitric oxide-related substances were administered to dogs that had undergone double SAH. These included L-arginine (a substrate for the formation of nitric oxide), NG-monomethyl-L-arginine (L-NMMA, an analog of L-arginine that inhibits the formation of nitric oxide from L-arginine), and superoxide dismutase (SOD, which protects nitric oxide from oxidation by superoxide anion), which were given via intracisternal injection. The diameter of the basilar artery was assessed angiographically.

In intact dogs, intracisternal bolus injections of L-arginine (1, 10, or 100 µmol) produced a dose-dependent increase in the internal diameter of the basilar artery; conversely, L-NMMA reduced the diameter of the basilar artery from baseline in a dose-dependent manner. On Days 4 and 7, after two intracisternal injections of autologous blood, L-arginine produced transient vasodilation of the spastic basilar artery, whereas L-NMMA produced no significant vasoconstriction. The vasodilator effect of L-arginine after SAH was stronger on Day 4 than on Day 7, but less than in intact dogs. Intracisternal injection of SOD, which caused no effectper se, enhanced the duration of the vasodilator effect of L-arginine on the basilar artery on Day 4 and both the magnitude and duration of that effect on Day 7.

Thus, the basal release of nitric oxide was impaired after SAH, but the ability to synthesize nitric oxide in the vascular wall was not abolished. The finding that the simultaneous injection of SOD enhanced and prolonged the vasodilation induced by sufficient exogenous L-arginine suggests that the inactivation of nitric oxide by superoxide anion contributes to the development of vasospasm.
Effect of suramin on 125I-insulin-like growth factor-I binding to human meningiomas and on proliferation of meningioma cells
Authors: Tsutsumi Keisuke , Kitagawa Naoki , Niwa Masami , Himeno Akihiko , Taniyama Kohtaro , Shibata Shobu
Published: May 2009

✓ Suramin, a polyanionic compound, has been shown to inhibit the binding of various growth factors to cell surface receptors. The effects of suramin on125I-insulin-like growth factor (IGF)-I binding to human meningioma tissues and IGF-I-induced deoxyribonucleic acid (DNA) synthesis in cultured meningioma cells were examined using the quantitative receptor autoradiographic method and3H-thymidine incorporation, respectively. Suramin inhibited specific125I-IGF-I binding to meningioma tissue sections in a concentration-dependent manner, with a 50% inhibiting concentration (IC50) of 8.7 ± 0.5 × 10−5M. The addition of 10−3M suramin to the incubation buffer potently dissociated125I-IGF-I previously bound to meningioma tissue as a function of time (dissociation half-life (T½) 6.8 minutes). After preincubation of tissue sections with 10−3M suramin for 120 minutes, there was no inhibition of the subsequent125I-IGF-I binding to meningiomas. Suramin inhibited the IGF-I-induced incorporation of3H-thymidine into meningioma cells in a dose-dependent manner, with an IC50of 4.6 ± 1.4 × 10−5M. The growth rate of meningioma cells (determined 4 days after seeding) was reduced by 10%, 20%, and 50% of the control culture in the presence of 10−6, 10−5, and 10−4M suramin, respectively. These results suggest that suramin interferes with IGF-I binding to meningioma tissue and inhibits proliferation of cells, at least partially by preventing IGF-I-induced DNA synthesis and probably by interacting with IGF-I directly rather than with its binding sites.
Venous ischemia caused by dural arteriovenous malformation
Authors: Kurata Akira , Miyasaka Yoshio , Yoshida Takatomo , Kunh Masatake , Yada Kenzoh , Kan Shinichi
Published: May 2009

✓ A case is presented of tentorial dural arteriovenous malformation (AVM) associated with visual hallucinations and quadrant hemianopsia. Computerized tomography (CT) and magnetic resonance imaging showed an ischemic region, mainly affecting the white matter of the right occipital lobe, that was defined as an area of increased blood volume on dynamic CT scans and as a decrease in cerebral blood flow on N-isopropylp-123I-iodoamphetamine single-photon emission CT scans. Angiography demonstrated venous congestion, probably because the retrograde arterial inflow from the dural AVM into the corticomedullary vein was direct and not via the sinuses. The symptoms and radiological findings improved immediately after endovascular treatment. The origin of these symptoms was fully evaluated and confirmed to be a reversible ischemic change caused by disturbance of the volume of venous return over an extensive area.
Von Recklinghausen's disease with diencephalic syndrome in an adult
Authors: Tanabe Michiharu , Watanabe Takashi , Hori Tomokatsu
Published: May 2009

✓ The case of a 39-year-old man with von Recklinghausen's disease, presenting with emaciation and a marked increase in serum growth hormone concentration, is presented. Neuroradiological and histological examination confirmed anaplastic astrocytoma in the optic chiasm-hypothalamic region. This is a rare case of diencephalic syndrome and von Recklinghausen's occurring together in an adult.
Intraoperative use of Doppler ultrasound and endoscopic monitoring in the stereotactic biopsy of malignant brain tumors
Authors: Yamasaki Toshiki , Moritake Kouzo , Takaya Mikio , Kagawa Takato , Nagai Hidemasa , Akiyama Yasuhiko , Kawahara Masako
Published: May 2009

✓ An intraoperative monitoring tool is described that prevents mechanical injury to intracerebral vessels during stereotactic surgery. The method, which combines pulse Doppler ultrasonography and fiberendoscopy, allowed stereotactic biopsy to be performed without serious intracerebral bleeding in 25 patients with hypervascular malignant brain tumors, 13 with glioblastoma multiforme, five with anaplastic astrocytoma, five with metastatic tumor, and two with malignant lymphoma. The ultrasound apparatus has a built-in fast-Fourier transformation system analyzer and an improved filtering system that provide real-time measurement of blood flow velocity. The source of flow (arterial or venous) could be identified by both real-time sonography and acoustic signal frequencies. It was possible to measure the size and distance of a vessel by adjusting the Doppler signal gain dial from initially waxing to waning sounds, because the acoustic signal was adjusted to the axial flow of each vessel in 0.1-mm steps. Each of three Doppler probes (1 mm, 2 mm, and 3 mm in diameter) fit through the outer cannula of the biopsy needle. Vessels located within 7 mm from the tip of these probes could be detected easily and rapidly, so the biopsy needle could be advanced safely to the desired target in 7-mm steps. If sonograms revealed blood flow, indicating the presence of larger vessels in the intended stereotactic trajectory, the angle of the needle was changed slightly to avoid vascular injury. Because the fiberendoscope was connected to a video processor, the vessel could be visualized at a higher magnification on the video display, unless there was active bleeding. This technically simple and reliable system enhances operative safety while maintaining accuracy.
Treatment of cranial dural arteriovenous fistulae by interruption of leptomeningeal venous drainage
Authors: Thompson B. Gregory , Doppman John L. , Oldfield Edward H.
Published: May 2009

✓ Cranial dural arteriovenous fistulae (AVF's) of the tentorial incisura or the dura of the middle fossa have a much higher incidence of draining via leptomeningeal veins than do AVF's of the transverse-sigmoid sinuses or the cavernous sinus. Such a drainage pattern is associated with an increased incidence of intracranial hemorrhage and progressive focal neurological deficits. Patients with cranial dural AVF's often undergo surgical excision and/or endovascular embolization for elimination of the AVF. Since these lesions are frequently large and involve the skull base or adjacent dural sinuses, extensive surgery is often required. In contrast, spinal dural AVF's with only intradural venous drainage to the medullary venous system are treated successfully by simply interrupting the vein that drains the dural AVF as it enters the subarachnoid space. The authors identified a subgroup of patients with cranial dural AVF's in whom the AVF was drained only by leptomeningeal veins, and sought to establish whether simple interruption of the vein draining the blood from the AVF into the subarachnoid space is effective and lasting treatment in this subgroup of patients, as it is in patients with spinal dural AVF's.

Four adult patients with symptomatic cranial dural AVF's (two petrotentorial, one middle fossa floor, and one posterior fossa base) were identified on arteriography as having fistulae that were supplied by the internal and/or external carotid arteries and drained only via leptomeningeal veins (two entered the petrosal vein, one a cerebellar hemispheric vein, and one a mesencephalic vein). All patients underwent interruption of the vein draining the dural AVF as it penetrated the dura to enter the subarachnoid space, and experienced neurological improvement after surgery. Repeat arteriography at 1 to 2 weeks (three patients), 3 months (3 patients), 12 to 15 months (three patients), and 4 years (two patients) revealed no residual AVF and no evidence of abnormal blood flow.

Many cranial dural AVF's with leptomeningeal venous drainage (the type with the most aggressive behavior) are drained only by leptomeningeal veins. This subgroup of patients can be identified by selective arteriography and requires only interruption of the draining vein as it enters the subarachnoid space for successful, lasting elimination.
CO2 reactivity in arteriovenous malformations of the brain: a transcranial Doppler ultrasound study
Authors: De Salles Antônio A F. , Manchola Iñaki
Published: May 2009

✓ Arteriovenous malformations (AVM's) are congenital tangles of vessels that have a high blood flow through a low-resistance nidus. The vessels in the nidus may lack normal vasoreactivity in response to changes in PaCO2 or perfusion pressure (autoregulation). Arteriovenous malformation hemodynamics have been assessed based on the response of AVM feeding arteries to hypocapnia.

Twenty-five AVM patients, aged 34 ± 11 years (mean ± standard deviation), were admitted to the Massachusetts General Hospital for proton-beam radiation therapy. Fourteen healthy volunteers aged 30 ± 7 years served as control subjects. Angiograms with calibrated markers permitting magnification correction were available for all patients. The limits of the middle cerebral artery, as determined by transcranial Doppler ultrasonography, were compared to measurements made on the angiograms. Hyperventilation was induced at a rate set by a metronome. Fixed bilateral Doppler probes allowed almost simultaneous sampling of two vessels. Volunteer control subjects were hyperventilated in two steps. The two PaCO2 step decreases were significant (mean resting PaCO2 40.6 ± 3.5 mm Hg, Step 1 level 29.4 ± 3.5 mm Hg and Step 2 level 23.8 ± 3.5 mm Hg; p < 0.01). These decreases induced a significant decrease in mean flow velocity (Vm) and an increase in the pulsatility index (p < 0.001). Mean carbon dioxide reactivity (%ΔVm/ΔPaCO2) was 2.74 ± 1.0 for Step 1 and 1.44 ± 1.8 for Step 2 (p < 0.003). The mean PaCO2 decrease in patients was from 39.5 ± 4.0 mm Hg to 27.0 ± 3.5 mm Hg. Carbon dioxide reactivity was 0.92 ± 1.12 for feeding vessels and 2.59 ± 1.78 for nonfeeding vessels (p < 0.001).

Transcranial Doppler ultrasound and angiographic depth measurements correlated well. Hyperventilation induced significantly more hemodynamic changes in control and nonfeeding middle cerebral arteries than in feeding vessels. Impaired CO2 reactivity may help to identify AVM feeding vessels as well as the relative magnitude of the flow provided to the malformation.
Feeding artery pedicle aneurysms: association with parenchymal hemorrhage and arteriovenous malformation in the brain
Authors: Perata Humberto J. , Tomsick Thomas A. , Tew John M.
Published: May 2009

✓ The association between arteriovenous malformations (AVM's) and aneurysms is well documented in the literature. However, a specific type of aneurysm, termed a “pedicle” aneurysm, has received little attention despite its role as a primary source of hemorrhage. The authors report four recent cases of patients with cerebral AVM's who bled from aneurysms arising from the midportion of AVM-feeding artery pedicles. Angiography, computerized tomography, and magnetic resonance imaging confirmed the origin of the hemorrhage from the pedicle aneurysm in each case. Because pedicle aneurysms are at risk for recurrent rupture, they represent an important subclassification of aneurysms associated with AVM's. The authors have expanded the previous classification systems for aneurysms associated with AVM's to include pedicle aneurysms; this classification is based on the location of the aneurysm and its relationship to the malformation. Complete documentation of such aneurysms as the potential source of hemorrhage is recommended, and prompt intervention by embolization and/or surgical resection is indicated for this dangerous aneurysm associated with cerebral AVM's.
Early surgery for ruptured vertebrobasilar aneurysms
Authors: Peerless Sydney J. , Hernesniemi Juha A. , Gutman Frederick B. , Drake Charles G.
Published: May 2009

✓ The authors present a series of 1767 patients with aneurysms of the vertebrobasilar circulation, most of whom were operated on 14 days or more following their last subarachnoid hemorrhage (SAH). Since 1970, 206 patients with vertebrobasilar aneurysms have been surgically treated within 7 days after their last SAH (day of SAH = Day 0). Of patients with a good preoperative grade (Botterell Grade 1 or 2), a good or excellent outcome was obtained in 80% during the first postsurgical month, irrespective of the timing of surgery. All except one of the Grade 5 patients died, and 70% of the Grade 4 patients were significantly disabled or dead. The overall operative mortality rate was the same whether surgery took place in the 1st week after SAH or was delayed. The frequency of rupture of the aneurysm during early surgery was not higher than during late surgery. Thirteen percent of patients developed a delayed ischemic neurological deficit as a consequence of reactive arterial narrowing (vasospasm). The authors recommend early surgery for patients with a good preoperative grade, whose aneurysm does not present a particular technical difficulty because of size, configuration, or location, and occasionally in patients whose lives appear to be in jeopardy because of recurrent hemorrhage.
The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect
Authors: Halbach Van V. , Higashida Randall T. , Dowd Christopher F. , Barnwell Stanley L. , Fraser Kenneth W. , Smith Tony P. , Teitelbaum George P. , Hieshima Grant B.
Published: May 2009

✓ Endovascular obliteration of intracranial aneurysms with preservation of the parent artery (endosaccular occlusion) has been advocated for patients who fail or are excluded from surgical clipping and cannot undergo Hunterian ligation therapy. To clarify the effect that endosaccular occlusion has on the presenting neurological signs, 26 patients with aneurysms and symptoms related to mass effect who underwent this therapy were followed for a mean of 60 months. Only patients with objective neurological deficits who had not suffered a hemorrhage were included in this series. Response to therapy was classified into one of three groups: “resolved,” if the patient had complete resolution of presenting signs; “improved,” if significant and sustained improvement was recorded in the neurological examinations, and “unchanged,” if no change was observed.

Thirteen patients (50%) were classified as resolved, 11 (42.3%) as improved, and two (7.7%) as unchanged. A comparison of patients classified as resolved with those who were improved revealed that the former group had less wall calcification (30% vs. 60%) and a shorter duration of symptoms. Patients with neurological sign resolution (62%) were more likely to have totally occluded aneurysms on late follow-up arteriograms than those who had improvement (28%) or were unchanged (0%). This study suggests that endosaccular embolization therapy can improve or alleviate presenting neurological signs unrelated to hemorrhage or distal embolization in the majority of cases.
Dialysis-associated spondylarthropathy
Authors: Cuffe Mark J. , Hadley Mark N. , Herrera Guillermo A. , Morawetz Richard B.
Published: May 2009

✓ Ten patients undergoing long-term renal dialysis for end-stage renal failure developed a destructive, noninfectious spondylarthropathy. All 10 patients had biopsy-proven dialysis-associated spondylarthropathy and subsequent spinal instability secondary to beta 2-microglobulin deposition in the vertebrae, intervertebral disc spaces, and support structures of the spine. Nine patients had cervical spinal instability and one had thoracolumbar spinal instability, with resultant neural compression. In at least one patient, the spinal instability was rapidly progressive. All had received renal dialysis for 34 months or longer (mean 109 months, range 34 to 154 months). Each patient required spinal stabilization (external in seven patients, internal in three). Nine of the 10 patients underwent neural decompression and spinal stabilization and fusion procedures.

One patient's neurological condition was worse following surgery due to a postoperative cervical epidural hematoma; in the other nine patients, the presenting symptoms and signs improved. Three of these chronically ill patients did not survive their hospitalization, for a perioperative mortality rate of 30%. Death was due to cardiopulmonary arrest in two patients on Day 5 and 9 postoperatively and to sepsis in the third on Day 14. Of the seven early survivors, two additional patients died: one on Day 59 due to congestive heart failure and the other on Day 273 due to a cerebrovascular accident. Four of five patients who were followed for 8 months or longer (mean 14 months, range 8 to 20 months) had successful neural decompression and spinal stabilization procedures with evidence of stable bone fusion, indicating that these chronically ill, difficult-to-manage patients can be successfully treated. Clinicians who treat patients with renal disease and neurosurgeons who treat spinal disorders should be aware of dialysis-associated spondylarthropathy as a potential cause of degenerative vertebral column instability.
Hemodynamics of subarachnoid hemorrhage arrest
Authors: McCormick Patrick W. , McCormick John , Zabramski Joseph M. , Spetzler Robert F.
Published: May 2009

✓ Subarachnoid hemorrhage (SAH) causes a spectrum of clinical syndromes from mild discomfort to rapid brain death. The reason for these heterogeneous consequences is poorly understood. A canine autologous shunt model of SAH was used to study this problem. The duration and volume of hemorrhage into the suprasellar cistern at each animal's mean arterial blood pressure were measured at variable hemorrhage flow rates. At high rates of bleeding in seven dogs (18.7 ± 2.2 ml/min, mean ± standard deviation), hemorrhage duration was significantly less (191 ± 116 seconds, p < 0.03) and hemorrhage volume was significantly greater (15.1 ± 7.0 ml, p < 0.05) than at low flow rates. At low flow rates of bleeding in nine dogs (4.4 ± 2.2 ml/min), hemorrhage duration was 394 ± 202 seconds and volume was 10.9 ± 6.5 ml. Cerebral perfusion pressure (CPP) decreased at all hemorrhage rates but never to 0 mm Hg (perfusion arrest). No correlation between a decrease in CPP and SAH volume or duration was identified. The initial flow rate of SAH had a positive linear correlation with the volume of hemorrhage (23 dogs, r = 0.64, p < 0.01). The data suggest that initial SAH flow rate, and not CPP, has a primary influence on hemorrhage arrest. This finding may influence the clinical rationale for acute management of SAH-induced brain injury.
Surgical treatment of spontaneous intracranial hypotension associated with a spinal arachnoid diverticulum
Authors: Schievink Wouter I. , Reimer Ronald , Folger W. Neath
Published: May 2009

✓ The authors present the case of a 22-year-old woman who developed spontaneous intracranial hypotension as a result of a cerebrospinal fluid leak from a thoracic extradural arachnoid diverticulum. The patient was successfully treated by ligation of the diverticulum. The entity of spontaneous intracranial hypotension and its relevance to neurosurgery are discussed.
Malformation of a cervical facet joint with inclusion of an arthrolith
Authors: Prestar Franz Jürgen , Potthoff Peter C.
Published: May 2009

✓ The authors present the case of a 49-year-old man with an isolated malformation of the left cervical facet joint at C5–6, with secondary spondylarthrotic hypertrophy of the joint leading to involvement of the C-6 nerve root. The etiology of this cervical joint malformation is discussed.
Evolution of the Journal of Neurosurgery
Authors: Alexander Eben
Published: May 2009

✓ The Journal of Neurosurgery, begun in 1944, has successfully fulfilled the purposes of its founders. During the 50 years of its existence it has remained pre-eminent in its field, while evolving in presentation, size, and content in response to the needs of succeeding generations of neurosurgeons and allied specialists. This article draws from the memories of many people, from the minutes of meetings of the Editorial Board, and from reports of successive editors, and touches on some of the knotty problems faced by those dedicated individuals.
A randomized trial of two doses of nicardipine in aneurysmal subarachnoid hemorrhage
Authors: Haley E. Clarke , Kassell Neal F. , Torner James C. , Truskowski Laura L. , Germanson Teresa P. , _ _
Published: May 2009

✓ High-dose intravenous nicardipine has been shown to reduce the incidence of angiographic and symptomatic vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH), but treatment may be complicated by side effects, including hypotension or pulmonary edema/azotemia. From August, 1989, to January, 1991, 365 patients at 21 neurosurgical centers were entered into a randomized double-blind trial comparing high-dose (0.15 mg/kg/hr) nicardipine with a 50% lower dose (0.075 mg/kg/hr) administered by continuous intravenous infusion for up to 14 days following SAH. Patients in all neurological grades were eligible for the study.

During the study period, 184 patients were randomly assigned to receive high-dose nicardipine and 181 to receive the low dose. There were no significant differences in patient age, admission neurological condition, or amount and distribution of blood clot on initial computerized tomography scan. Patients in the high-dose group received a significantly smaller proportion of the planned dose than those in the low-dose group (80% ± 0.2% vs. 86% ± 0.2%, p < 0.05), largely because of premature treatment termination after adverse medical events. The incidence of symptomatic vasospasm was 31% in both groups, and the overall 3-month outcomes were nearly identical. These data suggest that, from a clinical standpoint, the results of high-dose and low-dose nicardipine treatment are virtually equivalent, but administration of low-dose nicardipine is attended by fewer side effects.
Animal models for brain tumors: historical perspectives and future directions
Authors: Peterson Daniel L. , Sheridan Peter J. , Brown Willis E.
Published: May 2009

✓ The scientific understanding of the biology of human brain tumors has advanced in large part through the use of animal models. For most of this century, investigators have been evaluating the inciting factors in brain tumor development, and applying this knowledge to direct tumor growth in laboratory animals. Virus-induced, carcinogen-induced, and transplant-based models have been vigorously investigated. As knowledge of the molecular biology of neoplasia has advanced, transgenic technology has been introduced. The authors review the development of animal models for brain tumor, and focus on the role of transgenic models in elucidating the complex process of central nervous system neoplasia.