Investigation of interaction behaviours of cesium and strontium ions with engineering barrier material to prevent leakage to environmental.

This study deals with performance of removal of cesium (Cs+) and strontium (Sr2+) ions from synthetic aqueous solution using amino pyridine sulfone amid resin as a barrier material for nuclear waste storage areas to reduce environmental risk. The effects of adsorbate concentration, temperature and contact time on the efficiencies of the engineering barrier material for Cs+ and Sr2+ ions were investigated and evaluated. It was found that total adsorption capacity was higher for cesium ions than strontium ions. Dubinin-Radushkevich (D-R) isotherm model was well fitted to the adsorption data for both ions. The micropore capacity of the barrier material was found as 4.20 mg for strontium ions and 5.40 mg for cesium ions. ΔH values were indicated that the interaction process is exothermic for both ions. The positive value of entropy for both ions show that randomness at the solid-solution interface increased. Pseudo-second-order model was well fitted the kinetic data.

Fallout radionuclide-based techniques for assessing the impact of soil conservation measures on erosion control and soil quality: an overview of the main lessons learnt under an FAO/IAEA Coordinated Research Project.

This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of ¹³7Cs (half-life of 30.2 years), ²¹°Pb(ex) (half-life of 22.3 years) and 7Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably--a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation.

Early ultrastructural findings and superoxide dismutase levels in experimental ischemic optic neuropathy: effect of hypertension and hypotension on ischemic changes.

We induced ischemia, hypertension and hypotension in 15 rabbits in order to evaluate the ischemic changes in the optic nerve and the effect of hypertension and hypotension on ischemia. We cauterized the right internal and external carotid arteries of 15 rabbits and applied dopamine hydrochloride and glycerol trinitrate to 5 each of these rabbits. Two rabbits were used as controls. We enucleated both eyes of all animals at the 24th hour. All of the optic nerves underwent biochemical, histopathological and ultrastructural examination. Histopathological and transmission electron-microscopic changes were found to be more prominent in the hypotensive group. We observed decreased superoxide dismutase levels in all groups, but it was more evident in the third group. In comparison to hypertension, hypotension is found to be a more important factor in the development of early degenerative changes.

Correlation of the relationships of brain-tumor interfaces, magnetic resonance imaging, and angiographic findings to predict cleavage of meningiomas.

OBJECT: The authors examined the relationships of brain-tumor interfaces, specific magnetic resonance (MR) imaging features, and angiographic findings in meningiomas to predict tumor cleavage and difficulty of resection. METHODS: Magnetic resonance imaging studies, angiographic data, operative reports, clinical data, and histopathological findings were examined retrospectively in this series, which included 126 patients with intracranial meningiomas who underwent operations in which microsurgical techniques were used. The authors have identified three kinds of brain-tumor interfaces characterized by various difficulties in microsurgical dissection: smooth type, intermediate type, and invasive type. The signal intensity on T1-weighted MR images was very similar regardless of the type of brain-tumor interface (p > 0.1). However, on T2-weighted images the different interfaces seemed to correlate very precisely with the signal intensity and the amount of peritumoral edema (p < 0.01), allowing the prediction of microsurgical effort required during surgery. On angiographic studies, the pial-cortical arterial supply was seen to participate almost equally with the meningeal-dural arterial supply in vascularizing the tumor in 57.9% of patients. Meningiomas demonstrating hypervascularization on angiography, particularly those fed by the pial-cortical arteries, exhibited significantly more severe edema compared with those supplied only from meningeal arteries (p < 0.01). Indeed, a positive correlation was found between the vascular supply from pial-cortical arteries and the type of cleavage (p < 0.05). CONCLUSIONS: In this analysis the authors proved that there is a strong correlation between the amount of peritumoral edema, hyperintensity of the tumor on T2-weighted images, cortical penetration, vascular supply from pial-cortical arteries, and cleavage of the meningioma. Therefore, the consequent difficulty of microsurgical dissection can be predicted preoperatively by analyzing MR imaging and angiographic studies.

Huge meningiomas: a review of 93 cases.

Between 1972 and 1996, 450 consecutive patients with intracranial meningiomas were operated on at Cukurova University School of Medicine. By size, intracranial meningiomas were classified as huge (>6 cm minimum diameter when extrapolated to anatomic size) or not huge (<6 cm). The present study involves 93 patients who underwent 109 craniotomies for the removal of huge meningiomas. All patients are adult, with 31 men and 62 women or a 1:2 male to female ratio, with a mean age of 48.7 +/- 2.3 years at the time of diagnosis. The average duration of observed survival in 85 patients followed in the computed tomography (CT) era was 4.8 years and that of 8 patients in the pre-CT era was 8.8 years. Eleven patients died by the last follow-up assessment. Seventy-nine patients were still alive at the last follow-up assessment. The overall postoperative mortality rate was 3.2%. The overall recurrence rate was 19%. In descending order of frequency, the first five anatomic locations of the huge meningiomas were the parasagittal region in 18 patients (19.3%), the cerebral convexity in 15 (16.1%), the olfactory groove in 15 (16.1%), the falx in 12 (12.9%), and the tuberculum sellae in 11 (11.8%). The overall results of surgical treatment in 93 patients were total removal in 59 (63.4%), radical subtotal in 18 (18.3%), and subtotal in 16 (17.2%), with good outcome in 69 (74.1%), fair in 16 (17.2%), and poor in 5 (5.3%). In conclusion, the huge size of meningiomas affects the extent of removal, recurrence rate, postoperative outcome, operative morbidity and mortality rates, and survival time negatively.

The effect of collagen, interleukin-1 alpha and glicosaminoglycan on the neovascularization of central nervous system.

Neovascularization, the development of a new microvasculature, has an important role in physiological and pathological processes. The vascular changes in the brain can be easily detected because the proliferation of endothelial cells in its vascular structure is quite small, and so constitutes a good model for neovascularization studies. In the present investigation, to induce intracerebral neovascularization, we implanted collagen, Interleukin-1 alpha (IL-1 alpha) and glicosaminoglycan into the brain of pigs, in order to test the hypothesis that IL-1 alpha, collagen and glicosaminoglycan play a pivotal role in the process of neovascularization. Both pure collagen and collagen combined with IL-1 alpha induced neovascularization according to light-electron microscopic findings and values of enzymes' activities. In particular, collagen combined with IL-1 alpha synergically affected the increase of neovascularization. However, glicosaminoglycan did not affect it significantly. Although the results of this study provided us with some interesting data indicating the beneficial effects of collagen combined with IL-1 alpha on neovascularization, further studies should be done to study the short term effect of these biochemical substances.

The effect of trapidil on the reactive astrocytic proliferation following spinal cord trauma in rats: light and electron microscopic findings.

Platelet-derived growth factor (PDGF) released from platelets is one of the mitogens in serum, which plays a major role upon the cell biology, namely enhancing cell division and controlling of the maturation, especially upon the glial cell growth and its differentiation. Trapidil, which is an anti-PDGF agent, inhibits the effect of PDGF, especially the proliferative effects on the glial and tumoral cells in vitro. Previous studies suggested that the astrocytic proliferation stimulated by PDGF was inhibited by trapidil via the selective antagonism. Trapidil was not found to have a considerable effect on the prevention of nonpermissive astrocytes in this study. It should be theorized that trapidil, administered immediately even after the trauma, could not reach the injury site in effective measure because of secondary events such as edema and impairment of blood circulation. This suggestion should be another subject for studies concerning trapidil which is administered prior to the trauma.

A giant dissecting aneurysm mimicking serpentine aneurysm angiographically. Case report and review of the literature.

Intracranial dissecting and giant serpentine aneurysms are rare vascular anomalies. Their precise cause has not yet been completely clarified, and the radiological appearance of such lesions can be different in each case according to the effect of hemodynamic stress on a pathologic vessel wall. For berry aneurysms, available evidence overwhelmingly favors their causation by hemodynamically induced degenerative vascular disease and there is an obvious need to determine the hemodynamic parameters most likely to induce the precursor atrophic lesions. In this study, a case of a giant dissecting aneurysm angiographically mimicking serpentine aneurysm of the right ophthalmic artery is reported and the relevant literature is reviewed to investigate the pathological characteristics and pathogenesis of this lesion. In the present case, radiological investigation of the lesion suggested a serpentine aneurysm, but the diagnosis was corrected to dissecting aneurysm subsequent to the pathological examination of the resected aneurysm. A giant dissecting aneurysm angiographically mimicking serpentine aneurysm and developing as the result of a circumferential dissection located between the internal elastic lamina and media is of particular interest when the etiology of these aneurysms is considered. To our knowledge this is the first report on intracranial dissecting aneurysm mimicking serpentine aneurysm angiographically. Our case illustrates the importance of careful serial section studies for a better understanding of the vascular pathology underlying the processes involved in intracranial serpentine aneurysms. We conclude that serpentine, dissecting and berry aneurysms may all arise by way of similar pathophysiological mechanisms.

The effect of trapidil on the reactive astrocytic proliferation following spinal cord trauma in rats: Light and electron microscopic findings.

Platelet-derived growth factor (POCF) released from platelets is one ofthe mitogens in serum, which plays a major role upon the cell biology, namely enhancing cell division and controlling of the maturation, especially upon the glial cell growth and its differentiation. Trapidil, which is an anti-POCF agent, inhibits the effect of POCF, especially the proliferative effects on the glial and tumoral cells in vitro. Previous studies suggested that the astrocytic proliferation stimulated by POCF was inhibited by trapidil via the selective antagonism. Trapidil was not found to have a considerable effect on the prevention of nonpermissive astrocytes in this study. It should be theorised that trapidil, administered immediately even after the trauma, could not reach the injury site in effective measure because of secondary events such as edema and impairment of blood circulation. This suggestion should be another subject for studies concerning trapidil which is administered prior to the trauma. [Neural Res 1998; 20: 365-373].

The effect of thyrotropin releasing hormone on carbon dioxide laser induced lesion of the cerebral artery.

Carbon dioxide laser which is used widely in neurosurgery has less traumatic effect on the tissue beside the lesion than other types of laser. There has been little study on the changes to the vascular tissue, following laser application. We performed a study on 4 groups of dogs; comprising craniectomy only, craniectomy and thyrotropin releasing hormone (TRH), craniectomy and laser, and craniectomy, laser and TRH. We applied CO2 laser on the angular artery of two groups of dogs. To one group we infused TRH for 15 days following the laser application and to the other group we did not. We investigated the ultrastructural and biochemical changes and the effect of TRH on the tissue 15 days following laser application. In our study, we observed an increase in superoxide dismutase activity and a decrease in ATP-ase activities in the degenerated tissue on which CO2 laser was applied. TRH partially prevented the vascular degeneration of CO2 laser but did not significantly change superoxide dismutase and Adenosine-5'-triphosphatase activities.

Percutaneous radiofrequency rhizotomy of lumbar spinal facets: the results of 46 cases.

The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients, with operations other than fusion. No patient had previously undergone fusion. Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.

The effect of immediate decompression on the optic nerve in retrobulbar hematoma.

We produced retrobulbar hematoma in both orbits of 10 pigs in order to assess the effects of blood elements and pressure created by the hematoma on the optic nerves. Ten other pigs were used as a control group. Following decompression in the right orbits, ocular movements, fundi, and intraocular pressure were evaluated for 6 weeks. At the end of the 6th week the optic nerves of 20 pigs were dissected bilaterally for measurements of ATP-ase activity and ultrastructural examination. The results of the ultrastructural examination of the optic nerves of the control group were normal. Optic nerves with decompressed retrobulbar hematoma showed minimal degeneration, whereas the nerves subjected to retrobulbar hematoma with no decompression showed significant degenerative changes. For all groups ATP-ase activities were measured and evaluated. Na+, K+ ATP-ase activities decreased, while Ca+2, Mg+2 ATP-ase activities increased with the extent of degeneration. Optic nerve damage can develop after trauma. Decompression procedures are not among the causes of optic nerve degeneration but retrobulbar hematoma can result in optic neuropathy caused by the compression from the hematoma and the direct effect of blood waste products on the optic nerve.

Effect of dexamethasone, barbiturate and hypothermy on edema induced by CO2 laser brain lesion in the dog: light and electron microscopic study.

Experiments were carried out to compare the effectiveness of dexamethasone, a barbiturate, and hypothermy on experimental cerebral edema caused by CO2 laser in dogs. Experimental brain lesions were created over the right frontal cortex of the dogs through the intact dura mater with CO2 laser energy (40 W impact, 0.5 second duration, for a total time of 4 seconds on a 12.5 mm surface). Animals were divided into four groups and treated with dexamethasone, a barbiturate, hypothermy, and a crystalloid (control group). The brains were examined 48 hours after injury. Histologically all brain lesions showed three distinct layers with a vaporized center bordered by a zone of coagulation necrosis surrounded by edema. The main finding in the surrounding coagulation and edematous layers was dilatation of the vessels. Hemorrhage was sometimes observed mainly in the edematous layer. The effect of these therapies on the laser lesion and the effectiveness of these therapies on surrounding cerebral edema were evaluated by both light and electron microscopy. The control group showed significantly greater edema than the dexamethasone group. There was only a minimal difference between the control group and the barbiturate group, and there was no significant difference in amount of edema between control group and the hypothermy group. There was less edema in the dexamethasone group than in the other ones. These data suggest that dexamethasone inhibits edema in CO2 laser lesions with the same efficacy as shown in the treatment of vasogenic edema.

Combined occurrence of primary cerebral lymphoma and meningioma.

A unique combination of primary cerebral lymphoma and meningioma was encountered in a 38-year-old woman who recently presented clinically with headache and papilledema. The both tumors were identified by CT scan and diagnosed histopathologically after the surgery. The association of a highly malignant primary cerebral lymphoma and a slowly growing meningioma is extremely rare. The possibility of an unknown underlying pathologic mechanism predisposing to multiple tumors should be considered.

Down gaze palsy due to periaqueductal lesion diagnosed by magnetic resonance imaging.

Selective paralysis of downward gaze is known to be rare. There are 6 cases reported in the literature based on neuropathologic and anatomical studies. We report a 60-year-old diabetic and hypertensive patient with isolated down gaze palsy. Computed tomography failed to show the lesion in the periaqueductal region, and the diagnosis was made by Magnetic resonance imaging. The case presented is the only one still surviving.

Cerebellar medulloblastomas in adults.

Between 1981 and 1991, 11 adults over 16 years of age were treated for medulloblastoma at the authors' institutions. These patients were studied retrospectively. The patients were managed uniformly, and the treatment included extensive surgical resections and radiation therapy. Chemotherapy was used on only three patients with recurrence. Probable prognostic factors, including tumor location, extent of surgical resection, dose and extent of radiation therapy, and histological characteristics of the tumor such as neuronal or glial differentiation and desmoplasia were investigated. The classical form of medulloblastoma was present in seven cases while the desmoblastic subtype was found in four cases. All patients with the desmoplastic form had the tumor in cerebellar hemisphere. Gross total removal of the tumor was achieved in seven patients and subtotal excision in four patients. There was no surgical mortality in our series. The extent of surgical resection and location of the tumor had an important effect on longterm survival. The extent and dose of radiation therapy had a major effect on recurrence-free survival. Survival rates were best for patients receiving high-dose irradiation to the entire neuroaxis. Other factors such as age and sex had no major effect on prognosis.

Effect of GSH on cerebral vasospasm in dogs.

Reduced glutathinone (tau-glutamylcysteinglycine, GSH) is a scavenger for oxygen radicals and plays in important role in protection of cells from ischemia and from the harmful effects of free oxygen radicals. Free oxygen radicals due to cerebral vasospasm increase in both vasospasm and proliferative vasculopathy. This experiment was performed to determine whether GSH plays a role in cerebral vasospasm after subarachnoid hemorrhage by preventing the harmful effects of free oxygen radicals. In this study, GSH was administered intraarterially and intracisternally following vasospasm of the canine basilar artery. Less vasospasm was observed in the group treated with GSH intraarterially following subarachnoid hemorrhage than in the one treated with GSH intracisternally and in the control group. The arterial wall was investigated ultrastructurally. We evaluated the effect of the anti-oxidating substance through the activity of superoxide dismutase in the arterial wall. We compared the effect of glutathione reductase in the two groups treated with GSH intraarterially and intracisternally. Arterial degeneration was more prominent in the group in which GSH was used intracisternally, while the superoxide dismutase levels were low. In contrast, arterial degeneration was less in the other group in which GSH was used intraarterially, while the superoxide dismutase levels were high.

The clinical presentation of intracranial abscesses. A study of seventy-eight cases.

From 1980 through 1991, 78 patients with brain abscess were treated at the Cukurova University School of Medicine Department of Neurosurgery by surgical excision and antimicrobial therapy. Males predominated in all age groups. Although only 17 percent had a predisposing conditions such as local sinus infection, cyanotic heart disease, the majority of the cases had some evidence of a systemic infection such as peripheral leucocytosis and elevated erythrocyte sedimentation rate. The correct diagnosis was commonly not considered despite to these clues of an infective process on admission. The operative mortality was 20% which was similar to the other series reported in the literature. However in spite of significant progress with the advent of computerized tomography, microbiology and antibiotic treatment, difficulties in early diagnosis are held to be responsible for the residual high mortality. Although the appropriate antibiotic therapy, adjuvant medical therapies to control perioperative brain swelling, and the application of reliable surgical techniques have decreased the mortality and morbidity rates, the best result can only be obtained to a wider number of patients if the physician remains alert to the possibility of an intracranial abscess.

Effect of prostacyclin and adenosine triphosphate on vasospasm of canine basilar artery.

Cerebral vasospasm is one of the most important factors influencing morbidity and mortality of intracranial operations or diseases. Platelet aggregation and adhesion is increased in spastic vessels. Degradation of platelets liberates mediators, which in turn increase vasospasm, thus creating a vicious cycle. Healthy vessels cope with this by increasing the synthesis of prostacyclin. The purpose of this study was to increase experimentally the levels of arterial prostacyclin and adenosine triphosphate (ATP) in animals through intraarterial injection of these substances because they are lower in spastic vessels. Prostacyclin promotes antiaggregation and dilatation, increases blood flow, inhibits thromboxane A2, and prevents synthesis of angiotensin II. Most of these effects were done by increasing cyclic adenosine monophosphate (cAMP). After injecting autogenous blood into the cisterna magna of male dogs, both the acute and chronic phases of vasospasm and the degenerative changes in the arterial wall were observed. Injecting ATP increased the severity of vasospasm. During vasospasm it was found that when prostacyclin is used intraarterially, vasodilatation began, but degeneration of the arterial wall could not be prevented. In the group of animals in which both ATP and prostacyclin were used, there was no degeneration of the arterial wall and the basilar artery was seen to be normal when viewed under the electron microscope.