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1.
Neurochirurgie ; 68(3): 262-266, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34534565

ABSTRACT

BACKGROUND: The prognosis for patients with recurrent glioblastoma (GBM) is dismal, and the question of repeat surgery at time of recurrence is common. Re-operation in the management of these patients remains controversial, as there is no randomized evidence of benefit. An all-inclusive pragmatic care trial is needed to evaluate the role of repeat resection. METHODS: 3rGBM is a multicenter, pragmatic, prospective, parallel-group randomized care trial, with 1:1 allocation to repeat resection or standard care with no repeat resection. To test the hypothesis that repeat resection can improve overall survival by at least 3 months (from 6 to 9 months), 250 adult patients with prior resection of pathology-proven glioblastoma for whom the attending surgeon believes repeat resection may improve quality survival will be enrolled. A surrogate measure of quality of life, the number of days outside of hospital/nursing/palliative care facility, will also be compared. Centers are invited to participate without financial compensation and without contracts. Clinicians may apply to local authorities to approve an investigator-led in-house trial, using a common protocol, web-based randomization platform, and simple standardized case report forms. DISCUSSION: The 3rGBM trial is a modern transparent care research framework with no additional risks, tests, or visits other than what patients would encounter in normal care. The burden of proof remains on repeat surgical management of recurrent GBM, because this management has yet to be shown beneficial. The trial is designed to help patients and surgeons manage the uncertainty regarding optimal care. CLINICAL TRIAL REGISTRATION: http://www. CLINICALTRIALS: gov. Unique identifier: NCT04838782.


Subject(s)
Brain Neoplasms , Glioblastoma , Adult , Brain Neoplasms/surgery , Glioblastoma/surgery , Humans , Neoplasm Recurrence, Local/surgery , Prospective Studies , Quality of Life
2.
AJNR Am J Neuroradiol ; 18(7): 1207-15, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9282843

ABSTRACT

PURPOSE: To evaluate the safety and efficacy of endovascular treatment of ophthalmic segment aneurysms with Guglielmi detachable coils (GDCs), as well as the primary indications for such treatment. METHODS: We conducted a prospective study of 26 patients with 28 aneurysms of the ophthalmic segment in whom treatment with GDCs was attempted. Anatomic results were measured by statistical analysis of variance for such factors as age, sex, presence of subarachnoid hemorrhage, anatomic type (ophthalmic or superior hypophyseal), size of aneurysmal sac, and width of aneurysmal neck. Clinical evaluation and control angiography were performed at 6 and 18 months. RESULTS: Overall, complete occlusion was obtained in 14 aneurysms (50%) and small residual necks were left in 11 aneurysms (39%). Three treatment attempts failed (11%). Complete occlusion was obtained in 76% of small-necked aneurysms as opposed to 9% of aneurysms with a large neck. The best predictor of anatomic result was the size of the aneurysmal neck. Complete occlusion was obtained in 85% of superior hypophyseal aneurysms of the paraclinoid variant. One permanent complication was related to treatment. CONCLUSION: Endovascular treatment with GDCs appears to be a safe and efficient alternative approach for ophthalmic segment aneurysms, especially for paraclinoid variants of superior hypophyseal aneurysms, which tend to have a small neck.


Subject(s)
Aneurysm/therapy , Embolization, Therapeutic/instrumentation , Ophthalmic Artery , Adult , Aneurysm/diagnostic imaging , Angiography , Equipment Safety , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Subarachnoid Hemorrhage/diagnostic imaging , Subarachnoid Hemorrhage/therapy , Tomography, X-Ray Computed , Treatment Outcome
3.
J Neurosurg ; 86(2): 211-9, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9010422

ABSTRACT

The surgical treatment of basilar bifurcation aneurysms is difficult and the need for an alternative approach is frequently stated. To assess the efficacy and safety of endovascular treatment of aneurysms located at the basilar bifurcation, the authors prospectively studied angiographic results, clinical results, and complications in 31 patients treated with Guglielmi detachable coils (GDCs). Patients treated acutely after subarachnoid hemorrhage (SAH) were graded according to the Hunt and Hess classification and clinical outcome was determined at 1- and 6-month intervals according to the Glasgow Outcome Scale (GOS). There were 18 women and 13 men, ranging in age from 34 to 67 years (mean age 48 years). Twenty-three were treated acutely after SAH. Clinical Hunt and Hess grades at presentation were as follows: Grade I, six patients; Grade II, three; Grade III, 11; Grade IV, two; and Grade V, one. The GOS score for the group of patients treated acutely was: GOS I, 18 patients; GOS II, III, and IV, one patient each; and GOS V, two patients. There were seven technical complications in this group, most often asymptomatic, but one patient died after aneurysm rupture during treatment and one had residual diplopia at 4 months. Eight patients were treated for incidental basilar bifurcation aneurysms. One technical complication with no neurological deficit occurred in this group of patients with incidental aneurysms. Immediate angiographic results were considered to be satisfactory in 94% of patients, with complete obliteration in 42% and residual neck and dog ears in 52%. There was no bleeding episode after treatment during clinical follow-up periods ranging from 3 to 42 months (mean 15.5 months in 29 surviving patients). Angiographic results were available for 27 patients at 6 months and were as follows: 30% of the lesions were completely obliterated, 59% presented some residual neck, and 11% showed some opacification of the aneurysm sac. During the follow-up period of up to 42 months, a total of seven recurrences were noted, necessitating retreatment with GDCs in five patients. Endovascular treatment of basilar bifurcation aneurysms prevented rebleeding and could be performed without clinically significant complications in 94% of patients. Clinical results after SAH compared favorably with surgical series. Morphological results appear less satisfactory, and long-term angiographic follow-up review is mandatory to detect recurrences.


Subject(s)
Aneurysm, Ruptured/surgery , Basilar Artery/surgery , Intracranial Aneurysm/surgery , Adult , Aged , Aneurysm, Ruptured/diagnostic imaging , Basilar Artery/diagnostic imaging , Cerebral Angiography , Female , Follow-Up Studies , Glasgow Coma Scale , Humans , Intracranial Aneurysm/diagnostic imaging , Intraoperative Complications , Male , Middle Aged , Prospective Studies , Recurrence , Subarachnoid Hemorrhage/surgery , Tomography, X-Ray Computed , Treatment Outcome
4.
Am Ind Hyg Assoc J ; 57(4): 376-80, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8901240

ABSTRACT

This research measured the exposure of two groups of workers to respirable and total manganese (Mn) and characterized the Mn particles emitted from an automobile tailpipe. The exposure of 20 office workers and 9 taxi drivers in Toronto to total airborne Mn and respirable Mn was measured over a 7-day period, 24 hours per day. Subjects were asked to wear two pumps (one included a size-selective cyclone that collected the respirable particles), and two battery chargers were supplied to each person so that the pump batteries could be recharged overnight while sampling continued. All filters were analyzed by neutron activation. In addition, Mn particles emitted from a car were collected directly at the exhaust. Particles were observed using secondary electron images in a scanning electron microscope (SEM), and their elemental composition was determined by energy dispersive x-ray spectrometry. The Mn concentrations obtained for the group of office workers ranged from 0.001 to 0.034 microgram/m3 for respirable Mn and from 0.002 to 0.044 microgram/m3 for total Mn. For the taxi drivers the Mn concentrations ranged from 0.007 to 0.032 microgram/m3 for respirable Mn and from 0.008 to 0.073 microgram/m3 for total Mn. There was a significant difference (p < 0.05) between the two groups for both respirable and total Mn. SEM analysis showed that the particles were mostly heterogeneous agglomerates varying from 1 to 100 microns. Even if the specific exposure to Mn from automobiles has not been directly established, these results suggest that the related increase of exposure may be limited.


Subject(s)
Air Pollutants, Occupational/analysis , Environmental Monitoring , Manganese/analysis , Urban Health , Vehicle Emissions/analysis , Environmental Monitoring/instrumentation , Humans , Ontario , Respiratory Protective Devices , Transportation
6.
Microsc Res Tech ; 31(4): 293-9, 1995 Jul 01.
Article in English | MEDLINE | ID: mdl-7549002

ABSTRACT

The formability of galvanneal steel sheets used in the automotive industry is influenced by the presence and distribution of brittle and difficult to distinguish Zn-Fe intermetallics in the coating. Characterization of these intermetallics requires a high spatial resolution technique such as analytical transmission electron microscopy (ATEM). Sample preparation by ion milling is impossible due to iron redeposition, and traditional ultramicrotomy using water affects the coating chemistry. A technique based on dry ultramicrotomy has therefore been developed. To optimize the technique, different parameters (knife angle, cutting medium, thickness setting on the ultramicrotome, cutting speed) have been investigated for the preparation of galvanneal coatings and pure A1 sections. Results show that dry cutting does not affect the coating chemistry but shortens the life of the knife. Knife quality (cleanliness, sharpness and absence of defects) is a major factor to obtain good dry sections. The best results for the more ductile pure A1 are obtained with a 35 degrees knife whilst for the harder galvanneal coating it is recommended to use a 55 degrees knife. These results suggest that the sectioning mechanism for the harder material involves more a cleavage-fracture mechanism whilst a greater amount of shear is involved when sectioning relatively ductile A1. The optimum parameters for sectioning galvanneal coatings are established and results obtained by parallel electron energy loss spectrum imaging and energy dispersive X-ray spectrometry in the TEM are given. This study shows that with a good control of all the sectioning parameters it is possible to obtain good sections repeatedly and rapidly.


Subject(s)
Iron/analysis , Microtomy/methods , Zinc/analysis , Electron Probe Microanalysis , Microscopy, Electron , Specimen Handling
9.
J Electron Microsc Tech ; 13(2): 123-49, 1989 Oct.
Article in English | MEDLINE | ID: mdl-2809769

ABSTRACT

This article has been written for experimenters who are beginning to work with convergent beam electron diffraction patterns (CBED). The indexing of the higher-order Laue zone (HOLZ) lines inside the central spot of a CBED pattern is the first step towards studying variations in lattice parameter and three-dimensional (3D) symmetry. To index the HOLZ lines one must construct and index the HOLZ, find its interplanar spacing and the location of its projection on the zero order Laüe zone (ZOLZ) for a given zone axis, and finally find the radius of the HOLZ ring. A computer program has been developed to perform all these tasks for cubic crystals and is very useful, especially when one varies parameters such as operating voltage, zone axis, lattice parameter, and crystalline structure.


Subject(s)
Crystallography/methods , Mathematical Computing , Microscopy, Electron/methods
10.
Int Urol Nephrol ; 18(3): 227-33, 1986.
Article in English | MEDLINE | ID: mdl-3771124

ABSTRACT

The effect of 3 hydroxamic acid derivatives on urease-induced crystalluria was studied in vitro. Acetohydroxamic acid is more effective than salicylhydroxamic and gentisohydroxamic acids in inhibiting the kinetic of urease enzymatic reaction and in retarding the formation of struvite and apatite. Crystal deposits studied by scanning electron microscope (S.E.M.) and X-ray microanalysis indicated that acetohydroxamic acid favours the formation of large crystals of struvite, and less aggregation is observed. Salicyl and gentiso derivatives favour the formation of brushite together with struvite and apatite.


Subject(s)
Hydroxamic Acids/pharmacology , Magnesium Compounds , Urease/antagonists & inhibitors , Urinary Calculi/drug therapy , Apatites/urine , Calcium/urine , Crystallization , Humans , Hydroxamic Acids/therapeutic use , Hydroxamic Acids/urine , Kinetics , Magnesium/urine , Microscopy, Electron, Scanning , Phosphates/urine , Phosphorus/urine , Salicylamides/pharmacology , Struvite , Urease/pharmacology , Urinary Calculi/etiology
12.
Neuroradiology ; 16: 395-8, 1978.
Article in French | MEDLINE | ID: mdl-218137

ABSTRACT

The authors report 169 therapeutic embolizations in cases of tumoral lesions in the craniocerebral, ENT, and vertebrospinal territories. Most endovascular occlusions performed for tumoral processes are presurgical indications, with the aim of reducing hemorrhage at operation. Embolization becomes practically mandatory for nasopharyngeal angiofibromas, considerably reducing the peroperative bleeding. Indications of embolization for meningiomas must be discussed according to the size and location of the tumors: embolization is especially useful in large tumors or those inserted on the base of the skull, mainly in the middle fossa. In chemodectomas, embolization can be used presurgically or on its own when surgery becomes impossible; angiographic follow-up shows that secondary repermeabilization is frequent in spite of clinical improvement. In malignant tumors of the craniofacial region, indications of embolization must be considered with care because failure of vascularization tends to make radiotherapy less efficient; in these cases, embolization can be useful in reducing pain or to contend with cataclysmal hemorrhages.


Subject(s)
Embolization, Therapeutic , Head and Neck Neoplasms/therapy , Spinal Neoplasms/therapy , Adolescent , Adult , Aged , Child , Facial Neoplasms/therapy , Female , Glomus Jugulare Tumor/therapy , Histiocytoma, Benign Fibrous/therapy , Humans , Male , Meningeal Neoplasms/therapy , Meningioma/therapy , Middle Aged , Nasopharyngeal Neoplasms/therapy , Preoperative Care
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