bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transplantation of human fetal brain cells into ischemic lesions of adult gerbil hippocampus
Authors: Barami Kaveh , Hao Hsiao-nan , Lotoczky Gregory A. , Diaz Fernando G. , Lyman William D. 
Published: May 2009

Object. The goal of this study was to establish whether transplanted cells derived from fetal human brain can survive in an ischemic lesion.
Methods. Sixteen adult male Mongolian gerbils underwent transient bilateral common carotid artery occlusion. One week later, cell suspensions prepared from fetal human brain were injected using stereotactic guidance into the CA1 region of the hippocampus on one side. On the contralateral side injection of the cell suspension medium only was performed. One week after transplantation, the animals were perfusion fixed and their brains were processed for histological studies as well as expression of neuron and glia-specific antigens. Data from ischemic animals were compared with eight nonischemic gerbils that served as sham-operated controls. Last, the in vivo data were correlated with observations made from matching in vitro cultures of the fetal brain cell suspension.
The in vivo data indicated that transplanted human fetus—derived brain cells survived in ischemic lesions of gerbil hippocampus after 1 week, provided that the host animal underwent adequate immunosuppression and the transplanted cells were not incorporated into the scar caused by the transplantation procedure. Unlike their in vivo counterparts, after 1 week, most cultured fetal brain cells expressed either neuron- or astrocyte-specific antigens.
Conclusions. This work demonstrates that xenotransplanted fetal human brain cells are able to survive in an ischemic lesion in a rodent model. These data might be useful for future neural transplantation studies of treatments for cerebrovascular ischemia in humans.
Cerebral hemodynamic impairment after aneurysmal subarachnoid hemorrhage as evaluated using transcranial Doppler ultrasonography: relationship to delayed cerebral ischemia and clinical outcome
Authors: Rätsep Tõnu , Asser Toomas 
Published: May 2009

Object. In this study the authors evaluated the relative role of cerebral hemodynamic impairment (HDI) in the pathogenesis of delayed cerebral ischemia and poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH).
Methods. Cerebral hemodynamics were assessed daily with transcranial Doppler (TCD) ultrasonography in 55 consecutive patients with verified SAH. Hemodynamic impairment was defined as blood flow velocity (BFV) values consistent with vasospasm in conjunction with impaired autoregulatory vasodilation as evaluated using the transient hyperemic response tests in the middle cerebral arteries. A total of 1344 TCD examinations were performed, in which the evaluation of HDI was feasible during 80.9% and HDI was registered during 12% of the examinations. It was found that HDI occurred in 60% of patients and was frequently recorded in conjunction with severe vasospasm (p < 0.05) and a rapid increase of BFV values (p < 0.05). Detection of HDI was closely associated with the development of delayed ischemic brain damage after SAH (p < 0.05). Furthermore, because delayed ischemia was never observed in cases in which vasospasm had not led to the development of HDI, its occurrence increased significantly the likelihood of subsequent cerebral ischemia among the patients with vasospasm (p < 0.05). Detection of HDI was independently related to unfavorable clinical outcome according to Glasgow Outcome Scale at 6 months after SAH (p < 0.05).
Conclusions. The results showed that HDI is common after SAH and can be evaluated with TCD ultrasonography in routine clinical practice. Detection of HDI could be useful for identifying patients at high or low risk for delayed ischemic complications and unfavorable clinical outcome after SAH.
A method to estimate urinary electrolyte excretion in patients at risk for developing cerebral salt wasting
Authors: Carlotti Ana P. C. P. , Bohn Desmond , Rutka James T. , Singh Sheila , Berry W. A. David , Sharman Asheer , Cusimano Michael , Halperin Mitchell L. 
Published: May 2009

Object. Two major criteria are necessary to diagnose cerebral salt wasting (CSW): a cerebral lesion and a large urinary excretion of Na+ and Cl− at a time when the extracellular fluid (ECF) volume is contracted. Nevertheless, it is difficult for the physician to confirm from bedside observation that a patient has a contracted ECF volume. Hyponatremia, although frequently present, should not be a criterion for a diagnosis of salt wasting. A contracted ECF volume is unlikely if there are positive balances of Na+ and Cl−.
The goal of this study was to assess the accuracy of calculating balances for Na+ plus K+ and of Cl− over 1 to 10 days in an intensive care unit (ICU) setting.
Methods. A prospective comparison of measured and estimated quantities of Na+ plus K+ and of Cl− excreted over 1 to 10 days in 10 children and 12 adults who had recently received a traumatic brain injury or undergone recent neurosurgery. Plasma concentrations of electrolytes were recorded at the beginning and end of the study period. The total volumes infused and excreted and the concentrations of Na+, K+, and Cl− in the infusate were obtained from each patient's ICU chart. The electrolytes in the patients' urine were measured and calculated. Correlations between measured and calculated values for excretions of Cl− and of Na+ plus K+ were excellent.
Conclusions. Mass balances for Na+ plus K+ and for Cl− can be accurately estimated. These data provide information to support or refute a clinical diagnosis of CSW. The danger of relying on balances for these electrolytes measured within a single day to diagnose CSW is illustrated.
Analysis of hearing loss after shunt placement in patients with normal-pressure hydrocephalus
Authors: van Veelen-Vincent Marie-Lise C. , Delwel Ernst J. , Teeuw Rozemarijn , Kurt Erkan , de Jong Dirk A. , Brocaar Michel P. , Pauw Bernard K. H. , Avezaat Cees J. J. , van Zanten Bert G. A. 
Published: May 2009

Object. Following shunt placement for treatment of normal-pressure hydrocephalus (NPH), several patients suffered hearing loss. The authors undertook a study to analyze this outcome.
Methods. Sixteen patients in whom NPH was diagnosed were treated by placement of a ventriculoperitoneal shunt. Their hearing was assessed pre- and postoperatively by using pure tone audiometry. Two thirds of the ears tested showed a postoperative hearing loss of more than 10 dB. Recovery of the hearing loss occurred 6 to 12 weeks after shunt placement in 75% of the ears examined.
Conclusions. Although shunt insertion for treatment of NPH results in a decrease in hearing, most of the loss can be recovered.
Nestin expression in cortical dysplasia
Authors: Duggal Neil , Iskander Sam , Hammond Robert R. 
Published: May 2009

Object. It is recognized that cortical dysplasia (CD) is associated with an increased incidence of glioneuronal neoplasms. Among hypothetical considerations, there is the possibility that CD and other neuronal migration abnormalities harbor dysmature cells with the potential to give rise to glioneuronal neoplasms. Such cells, if present, would be reasonably expected to display immature features. The goal of the present study was to characterize the expression of nestin, a neuroepithelial precursor/stem cell antigen, in CD, along with other pathological and clinical features of this entity.
Methods. Clinical and surgical features of 10 recent cases meeting the histological criteria for CD were reviewed. Expressions of nestin, MAP2, neurofilament, and glial fibrillary acidic protein (GFAP) were assessed using immunohistochemical analysis and confocal scanning laser microscopy.
Immunoreactivity for both glial and neuronal antigens as well as nestin was found in a select group of cells within regions of CD. Immunohistochemical and confocal microscopic findings demonstrated that these cells with neuronal or ambiguous features are a mixed population, some of which are dysmature neurons (positive for nestin and MAP2), whereas others are astrocytic (positive for nestin and GFAP).
Conclusions. Further insight into the nature of nestin-positive neurons may shed light on the cause and pathogenesis of the associated glioneuronal tumors and the accompanying chronic seizures.
Improvement of endothelial function in insulin-resistant carotid arteries treated with pravastatin
Authors: Dumont Aaron S. , Hyndman M. Eric , Dumont Randall J. , Fedak Paul M. , Kassell Neal F. , Sutherland Garnette R. , Verma Subodh 
Published: May 2009

Object. Insulin resistance and hypertension are independent risk factors for stroke. Endothelial dysfunction in response to risk factors and carotid artery (CA) disease are important in the pathogenesis of stroke. Pravastatin may have cholesterol-independent pleiotropic effects. In the present study the authors examined the effects of short-course pravastatin treatment on endothelial function in CAs obtained in control and insulin-resistant rats with fructose-induced hypertension.
Methods. Thirty rats were divided into two experimental groups, in which 14 were fed a regular diet and 16 were fed a fructose-enriched diet for 3 weeks. The rats were then divided into four groups: control, pravastatin-treated control, fructose-fed, and pravastatin-treated fructose-fed. Pravastatin was administered (20 mg/kg/day) for 2 weeks. Excretion of the urinary nitric oxide (NO) metabolite nitrite (NO2−) was also assayed. The CAs from all rats were subsequently removed and assessed for endothelium-dependent and -independent vascular reactivity in vitro. The rats in the fructose-fed group were insulin resistant, hyperinsulinemic, and hypertensive relative to the rats in the control and pravastatin-treated control groups and exhibited diminished endothelium-dependent vasomotion and urinary NO2− excretion (p < 0.05), with preserved endothelium-independent vasomotion. Strikingly, pravastatin treatment restored endothelium-dependent vasomotion and urinary NO2− excretion in rats in the fructose-fed pravastatin-treated relative to the fructose-fed group (p < 0.05).
Conclusions. The authors report, for the first time, that pravastatin restores endothelial function in CAs from insulin-resistant rats with fructose-induced hypertension. These beneficial effects were ascribed to direct, cholesterol-independent vascular effects of pravastatin and are likely the result of augmentation of NO production. These data provide impetus for further investigation of nonlipid-lowering indications for pravastatin therapy in the prevention and treatment of CA disease.
Possible control of intermittent cerebral ischemia by monitoring of direct-current potentials
Authors: Sakaki Takayuki , Graf Rudolf , Nozaki Hiroyuki , Rosner Gerhard , Heiss Wolf-Dieter 
Published: May 2009

Object. Neurosurgically induced temporary occlusion of intracranial arteries carries the risk of cerebral ischemic damage. Because negative shifts in the cortical direct-current (DC) potential indicate tissue depolarization and, thus, critical ischemic stress, the authors hypothesized that recordings of these potentials could help to determine the optimal duration and frequency of induced intermittent focal ischemia to prevent brain injury. The investigators related the results of DC recordings both to simultaneously recorded decreases in extracellular Ca++ concentration ([Ca++]o), which reflect Ca++ entry into cells, and to histological outcome.
Methods. In cats anesthetized with halothane the effects of intermittent brief (10 minutes long, six times [6 × 10-min group]) and prolonged (20 minutes long, three times [3 × 20-min group]) episodes of middle cerebral artery occlusions were compared with those of a single continuous episode (1 × 60-min group). Laser Doppler flow probes and ion-selective microelectrodes were used to measure cerebral blood flow, DC potentials, and [Ca++]o in cortical tissues of ectosylvian gyri.
Negative shifts in DC potential were evaluated in the three groups during the entire 60-minute-long period of ischemia and were smallest in the 6 × 10-min group, larger in the 3 × 20-min group, and largest in the 1 × 60-min group. Accordingly, infarct volumes were smallest in the 6 × 10-min group, intermediate in the 3 × 20-min group, and largest in the 1 × 60-min group. Decreases in ischemic [Ca++]o were significantly greater in the 1 × 60-min group than in the two groups in which there were repetitive occlusions, and recovery of [Ca++]o after reperfusion normalized only in the 1 × 60-min group.
Conclusions. The DC potential may provide a reliable measure to optimize intermittent ischemia and to achieve minimal ischemic brain injury during temporary neurosurgical occlusion of cerebral arteries.
Methods of experimental and clinical assessment of the relative measurement accuracy of an intracranial pressure transducer
Authors: Morgalla Matthias Hubert , Krasznai Làszlo , Dietz Klaus , Mettenleiter Holger , Deininger Martin , Grote Ernst Heinrich 
Published: May 2009

✓ The assessment of the actual measurement accuracy of an intracranial pressure (ICP) transducer is imperative but still very difficult in practice. The authors tested the Codman MicroSensor ICP transducer experimentally. Additionally, a bedside test for assessment of measurement accuracy was used before and after clinical monitoring. For laboratory testing, seven new transducers were examined for measurement accuracy at increasing pressures ranging from 0 to 75 mm Hg. Drift was evaluated for 10 days at six different pressure levels ranging from 0 to 50 mm Hg. Temperature drift was assessed over a temperature range from 20 to 45°C. The percentage absolute difference was used in the assessment of measurement accuracy. For clinical testing, measurement accuracy was assessed intraoperatively just before the insertion of the transducer and in an open water bath after its explantation, at 10 cm H2O both times.
The maximum percentage absolute difference was 9% at a pressure of 10 mm Hg, and declined toward 2.3% at a pressure of 75 mm Hg. The maximum drift over 10 days was −4 mm Hg. Within the range of 30 to 40°C, temperature drift was negligible. Over a period of 2 years, between June 1997 and June 1999, 40 ICP transducers were implanted in 35 patients by one surgeon. Of these devices, a malfunction was detected in two of them by testing them in a water bath before insertion. Experimental and clinical results indicate that this miniature strain-gauge transducer measures accurately; however, control readings for the probe by means of measurement in an open water bath just before insertion are strongly recommended.
Influence of premorbid factors on survival following subarachnoid hemorrhage
Authors: Pobereskin Louis H. 
Published: May 2009

Object. The goal of this study was to explore the relationships between premorbid patient characteristics, especially cigarette smoking, and the risk of death following subarachnoid hemorrhage (SAH).
Methods. A population-based study design was used with multiple overlapping methods of case identification. A strict definition of SAH was used. Relationships between patients' age and sex as well as their cigarette smoking and hypertension statuses were explored by calculating relative risks (RRs). Confounding effects were examined using logistic regression analysis.
The author identified 800 cases in which the patient had experienced his or her first SAH. Seventy-seven percent of cases were verified by review of computerized tomography scans, 22% by autopsy, and 1% by lumbar puncture. A prior history of hypertension had no effect on the risk of mortality. There was a higher case mortality rate in female patients than in male patients, but this did not reach statistical significance. The RR of death at 30 days post-SAH for patients older than 60 years compared with those who were younger was 2.95 (95% confidence interval [CI] 2.18–3.97). The RR of death at all time intervals was lower for smokers than for nonsmokers (smokers/nonsmokers RR 0.47 [95% CI 0.32–0.69] at 7 days). The protective effect of smoking diminished on Day 3 post-SAH and increased again on Day 7.
Conclusions. Advanced age is an important determinant of survival following SAH. Smoking appears to have a protective effect. The author presents evidence indicating that increased vasospasm in smokers may reduce the severity of the initial hemorrhage.
Surgical management and outcome in patients with radial nerve lesions
Authors: Kim Daniel H. , Kam Andrew C. , Chandika Padmavathi , Tiel Robert L. , Kline David G. 
Published: May 2009

Object. The goal of this paper was to review surgical management and outcomes in patients treated for radial nerve (RN) lesions at Louisiana State University Health Sciences over a period of 30 years.
Methods. Two hundred sixty patients with RN injuries were evaluated. The most common mechanisms of injuries involving the RN included fracture of the humerus, laceration, blunt contusions, and gunshot wounds. One hundred and eighty patients (69%) underwent surgery. Lesions not in continuity required primary or secondary end-to-end suture repairs or graft repairs. With the use of direct intraoperative nerve action potential recording, RN injuries in which the lesion was in continuity required external or internal neurolysis or resection of the lesion followed by end-to-end suture or graft repair. A minimum of 1.5 years follow-up review was available in 90% of the patients who underwent surgery. Motor function recovery to Grade 3 or better was observed in 10 (91%) of 11 patients who underwent primary suture repair, 25 (83%) of 30 who underwent secondary suture repair, 43 (80%) of 54 who received graft repair, and 63 (98%) of 64 in whom neurolysis was performed. Sixteen (71%) of 21 patients with superficial sensory RN injury achieved satisfactory pain relief after complete resection of a neuroma or neurolysis.
Conclusions. This study clearly demonstrates that excellent functional recovery can be achieved with proper surgical management of RN injuries.
Predictive value of progression-associated chromosomal aberrations for the prognosis of meningiomas: a retrospective study of 198 cases
Authors: Ketter Ralf , Henn Wolfram , Niedermayer Isolde , Steilen-Gimbel Heike , König Jochem , Zang Klaus D. , Steudel Wolf-Ingo 
Published: May 2009

Object. The goal of this study was to determine whether in meningiomas cytogenetic findings are suitable as a predictive parameter relevant to prognosis.
Methods. Between 1992 and 1998 at the Department of Neurosurgery, Saarland University, 198 patients underwent surgery to resect meningiomas. The meningiomas were investigated cytogenetically and the patients were followed up for a mean period of 33 months.
On the basis of the cytogenetic findings, the meningiomas were subdivided into four groups: Group 0 meningiomas displayed a normal diploid chromosome set; Group 1 tumors were found to have monosomy 22 as the sole cytogenetic aberration; Group 2 tumors were markedly hypodiploid meningiomas with loss of additional autosomes in addition to monosomy 22; and Group 3 meningiomas had deletions of the short arm of a chromosome 1, as well as additional chromosomal aberrations including loss of one chromosome 22.
One hundred ninety-eight patients in whom tumor resections were determined to be Simpson Grade I or II could be followed up after complete tumor extirpation. In 20 patients, one or several recurrences were documented during the period of observation. The tumors were classified according to their different, but mostly uniform chromosomal aberrations. Recurrences were found in six (4.3%) of 139 tumors in Groups 0 and 1 and in two (10.5%) of 19 tumors in Group 2; the highest rate of recurrence was found in 12 (30%) of 40 tumors in Group 3. This supports the notion that the deletion of the short arm of one chromosome 1 is an important prognostic factor in meningiomas. The results of this study document a significant correlation between histological grade (p < 0.0001), location (p < 0.0001), and recurrences of meningiomas (p < 0.0001) (significance determined using chi-square tests).
Conclusions. The cytogenetic classification of meningiomas provides a significant contribution to the predictability of tumor recurrence and is, therefore, a valuable criterion for the neurosurgeon's postoperative management protocol.
Population-based analysis of arteriovenous malformation treatment
Authors: Hillman Jan 
Published: May 2009

Object. The author sought to describe overall management data on cerebral arteriovenous malformations (AVMs) and to focus the actuarial need for different treatment modalities on a population-based scale. Such data would seem important in the planning of regional or national multimodality strategies for the treatment of AVMs. This analysis of a nonselected, consecutive series of patients representing every diagnosed case of cerebral AVM in a population of 1,000,000 over one decade may serve to shed some light on these treatment aspects.
Methods. During the 11-year period from 1989 to 1999, data from every patient harboring a cerebral AVM that was presented clinically or discovered incidentally in a strictly defined population of 986,000 people were collected prospectively. No patient was lost to follow up. There were 12.4 de novo diagnosed AVMs per 1,000,000 population per year (135 AVMs). Large high-grade AVMs (Spetzler—Martin classification) were rare, and Grade 1 to 3 lesions represented 85% of the caseload. Hemorrhage was the initial manifestation of AVM in 69.6% of the cases. Intracerebral hematoma was the most common hemorrhagic manifestation occurring in 78 patients. There were 4.4 cases per 1,000,000 population per year of hematomas needing expedient surgical evacuation. In the remaining patients who did not require hematoma surgery, small, critically located Grade 3 and Grade 4 lesions amounted to 1.6 cases per 1,000,000 population per year. There were 5.8 cases per 1,000,000 population per year of Grade 1 to 2 and larger noncritically located Grade 3 malformations. There were 0.5 cases per 1,000,000 population per year of Grade 5 AVMs. The overall outcome in 135 patients was classified as good according to the Glasgow Outcome Scale (Score 5) in 61% of the cases, and the overall mortality rate was 9%.
Conclusions. In centers with population-based referral, AVM of the brain is predominantly a disease related to intracranial bleeding, and parenchymal clots have a profound impact on overall management outcome. The rupture of an AVM is as devastating as that of an aneurysm. Aneurysm ruptures are more lethal, whereas AVM rupture tends to result in more neurological disability due to the high occurrence of lobar intracerebral hematoma. In an attempt to quantify the need for different modalities of AVM treatment based on a population of 1,000,000 people, figures for surgeries performed range from six to 10 operations per year and embolization as well as gamma knife surgery procedures range from two to seven per year, depending on the strategy at hand. When using nonsurgical approaches to Grade 1 to 3 lesions, the number of patients requiring treatment with more than one method for obliteration increases drastically as does the potential risk for procedure-related complications.