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Biomedical subjects

J Sabatier

Publications and source records attributed to J Sabatier.

At least 19 recordsLinked to original sources

Detection of human cytomegalovirus genome and gene products in central nervous system tumours.

Human cytomegalovirus (HCMV) genome and related proteins have been reported in a great proportion of malignant gliomas. However, these results are unexpected since HCMV is not known as an oncogenic virus. By immunohistochemistry (with an anti-IE1 monoclonal antibody) and in situ hybridisation (with biotinylated DNA probes) on tissue microarrays and frozen sections, we investigated a French series of central nervous system (CNS) tumours, including 97 glioblastomas. In 10 cases of glioblastoma, rare astrocyte-like cells, admixed with tumour cells, stained positively for HCMV and in one case a doubtful staining of rare cells was noticed. This may indicate a reactivation of the virus under local immunosuppression but none of the cases of CNS tumours (n=132) contained HCMV genomes and/or proteins in a significant proportion of tumour cells. Our results strongly suggest that HCMV is unlikely to be implicated in the development of human malignant gliomas, at least in French cases.

Adult↗

Immunodetection of SV40 large T antigen in human central nervous system tumours.

BACKGROUND/AIMS: DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus. METHODS: A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls. RESULTS: None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells. CONCLUSIONS: The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.

Adolescent↗

[French neurosurgical practice in Neuro-Oncology (national survey--part I)].

OBJECTIVE: The aim of this work is to summarize the elements of the "Cancer Plan" applicable to neurosurgical practice, and to give the results of a national inquiry concerning the daily practice of Neuro-Oncology from the neurosurgical point of view. METHOD: The Neuro-Oncology Group of the French Society of Neurosurgery has submitted a questionnaire to every department of Neurosurgery in France. RESULTS: The response rate of the public centers was 96.5%. Moreover, responses were available from 7 private centers. The results are detailed in the text. CONCLUSION: This national survey highlights the interest and implication of French neurosurgeons in the field of Neuro-Oncology. But also, to be in accordance with the guidelines for good clinical practice, the importance of developing official neuro-oncological networks in order to offer the best access to clinical and fundamental data and hence optimise patient's care. The publication of the "Cancer Plan", the creation of a National Neuro-Oncology Group, and the results of this survey (actual multidisciplinary approach, better information and transparency, individualized care of the patients), are in the line with updating our daily practice, even though discrepancies remain among centers. French neurosurgeons must continue along the same path, but at the same time there is a need for additional help to definitely reach a truly, and homogeneous, optimized care of neuro-oncological patients.

France↗

Deep brain stimulation for parkinson's disease: correlation between intraoperative subthalamic nucleus neurophysiology and most effective contacts.

Though intraoperative neurophysiology is essential to precisely define the definitive target, little is known regarding its predictive value in defining the most effective contact for chronic deep brain stimulation. In this retrospective study, we reviewed the correlation between intraoperative neurophysiology and contacts selected for chronic stimulation. Twenty consecutive patients implanted for subthalamic nucleus (STN) stimulation were reviewed. There was no significant correlation between the electrophysiologically defined STN and the most effective contact for chronic stimulation at 3 months or at 6 months. Furthermore, there was a discrepancy between the most effective contact for rigidity versus akinesia or tremor at 3 months. Interestingly, at 3 months, the same electrode contact was maximally efficient for rigidity, akinesia and tremor in only 13 of the 39 cases. This lack of correlation did not affect the global improvement.

Adult↗

PSA kinetics after external beam radiotherapy alone or combined with an iridium brachytherapy boost to deliver 85 grays to prostatic adenocarcinoma.

PURPOSE: Increasing the dose to prostatic adenocarcinoma in conformal external beam therapy (EBT) has resulted in increased levels of PSA normalization and increased percentage of biochemical disease-free survival rates. However technical problems due to prostate motion inside the pelvis or patients' set-up make difficult the realization of the EBT boost fields above 72 Gy. Brachytherapy which overcomes these problems was investigated to deliver the boost dose to achieve 85 Gy. PSA nadir which has been identified as the strongest independent predictor of any failure in many studies has been used as the end point for early evaluation of this work. PATIENTS AND METHODS: In a retrospective way we report on 163 patients' PSA kinetics after EBT alone to 68 Gy or EBT first and a brachytherapy boost up to 75 or 85 Gy. RESULTS: At 12 months follow-up, PSA nadirs percentage < or = 0.5 or < or = 1 ng/ml increased from 7.5 and 20.7% after 68 Gy EBT to 49.8 and 71.2% after a brachytherapy boost to deliver 85 Gy (p < 0.0001). In the Cox PH model analysis, the total dose remained the most important factor for predicting PSA normalization. CONCLUSIONS: These results are in accordance with the most recent results published after conformal EBT at the same 80 Gy level of dose. If confirmed on a higher number of patients they could place brachytherapy among the most accurate methods of boosting in the radiation treatment of prostatic carcinoma.

Adenocarcinoma↗

Prosthetic graft infection after descending thoracic/ thoracoabdominal aortic aneurysmectomy: management with in situ arterial allografts.

PURPOSE: Prosthetic graft infection is an uncommon but life-threatening complication of descending thoracic/thoracoabdominal aortic aneurysmectomy. The purpose of this study was to assess the value of in situ arterial allografts in the management of this complication. METHODS: From 1992 to 2000 we treated 11 consecutive patients with prosthetic graft infection after descending thoracic/thoracoabdominal aortic aneurysmectomy by replacing the prosthetic graft with an in situ arterial allograft. There were 10 men and one woman with a mean age of 50.8 years (range, 32-73 years). The primary aortic disease was degenerative aneurysm in 6 patients, chronic type B dissection in 2 patients, inflammatory aneurysm in 1 patient, Marfan's disease in 1 patient, and Behçet's disease in 1 patient. Replacement involved only the descending thoracic aorta in three patients and more or less extensive segments of the thoracoabdominal aorta in eight patients. Signs of severe infection were present in all patients, and false anastomotic aneurysms were noted in six patients. Aortoenteric fistula occurred in three patients and aortobronchial fistula in two patients. The causative organisms were identified in nine patients. The mean interval between the primary surgery and reoperation was 33.4 +/- 27.5 months. Reoperation was performed under emergency conditions because of hemorrhage in three patients. Cardiopulmonary bypass with deep hypothermic circulatory arrest was used in seven patients. Allograft replacement of the aorta was associated with reimplantation of intercostal and/or visceral arteries in all patients. RESULTS: One patient died intraoperatively of heart failure during emergency surgery. Two patients died of persistent infection during the postoperative period at 19 and 58 days. Mean follow-up was 34 +/- 19 months. One patient died during the late follow-up period after surgery of the infrarenal aorta. Another patient underwent surgery for stenoses of one branch of a bifurcated allograft and a renal bypass graft to a solitary kidney. CONCLUSIONS: The use of in situ arterial allografts is a significant advance in the management of prosthetic graft infection after descending thoracic/thoracoabdominal aortic aneurysmectomy provided that reoperation is performed early.

Adult↗

[Anaplastic temporal ganglioglioma with spinal metastasis].

We report the case of a 26-year-old male who was operated on after an acute episode complicating a long history of seizures. The resected temporal lesion was an anaplastic ganglioglioma. Ganglioglioma is a tumor of children and young adults, characterized by two cell components, neuronal and glial. It is usually a benign lesion. The present case is remarkable in several aspects. Hemorrhage led to the discovery of a supra-tentorial tumour. Microscopic examination revealed anaplastic foci in an otherwise typical lesion. There was a long past medical history but outcome was rapidly unfavorable after surgical resection and associated with dissemination along the spinal cord.

Adult↗

[Brain tumors: interest of magnetic resonance spectroscopy for the diagnosis and the prognosis].

Magnetic resonance spectroscopy (MRS) is a tool for a non-invasive monitoring of brain tumor metabolism. In vivo proton MRS became possible with the development of whole-body high-field magnets. First, it allows to distinguish brain tumors from abscesses. Second, along with other imaging techniques, it permits the differentiation of primary brain tumors, mainly gliomas, from tumors of various origins such as meningiomas or metastasis. However, its ability to give a grading of gliomas stays controversial. Choline, a marker of cell membrane proliferation, could give information on the degree of malignancy but reports on its role are somewhat contradictory. Brain tumor biopsy and histology stay mandatory in the management of brain tumors. In vitro MRS spectra obtained from tumor extracts show that the signal at 3.2ppm, the so-called "cholin peak", corresponds to several compounds among them, glycerophosphocholine, phosphocholine, and choline. Their repartition differs with the grade of the tumor. In vivo proton MRS is the only metabolic technique of non-invasive monitoring of treated brain tumors. It can separate recurrence from radionecrosis. Improved methodology and availability of MR imagers will strengthen its importance in the future.

Aspartic Acid↗

Usefulness of motor functional MRI correlated to cortical mapping in Rolandic low-grade astrocytomas.

The indications for surgery of slow growing tumours like low grade astrocytomas in eloquent areas are difficult. The timing and the benefit/risk ratio of the surgery must be evaluated, taking into account the potential post operative deficit. The purpose of this study was: a) to validate the data obtained with functional MRI (FMRI) by direct cortical stimulation in patients who are candidate for surgery; b) to demonstrate the usefulness of FMRI coupled with cortical brain mapping and 3D reconstructions of the surfaces of the brain in low grade astrocytoma. FMRI of the hand-motor cortex was performed in 8 patients with low grade astrocytomas. They subsequently underwent direct cortical mapping to correlate the results of FMRI and resective surgery sparing the functional area. In the 8 cases, the results of direct cortical mapping in the precentral region matched accurately those obtained from FMRI. When surgical resection of low grade astrocytoma in the motor areas is considered, FMRI used with intra-operative cortical mapping can help the surgeon to spare functional areas during tumour removal.

Adult↗

Evaluation of frequency and type of errors detected by a computerized record and verify system during radiation treatment.

BACKGROUND: Computerized record and verify systems (RVS) have been introduced to improve the precision of radiation treatment delivery. These systems prevent the delivery of ionizing radiations when the settings of the treatment machine do not match the intended parameters within some maximal authorized deviation. PURPOSE: To assess the potential alteration of the frequency of errors associated with the use of RVS during radiation treatment delivery. MATERIALS AND METHODS: The software of the RVS was altered in order to record the settings actually used for radiation treatment delivery whereas the verification function was suppressed. At the end of the study period, the settings used during daily administration of radiation treatment were compared to the parameters recorded in the RVS using the computer. They were also compared with the planned ones written in the patient treatment chart. RESULTS: Out of the 147,476 parameters examined during the study period, 678 (0.46%) were set erroneously. At least one error occurred in 628 (3.22%) of the 19,512 treated fields. An erroneous parameter was introduced in the RVS memory in 22 (1.17%) of the 1885 fields. CONCLUSIONS: RVS has the potential to improve precision of radiation treatment delivery by detecting a significant number of setting errors. However, excessive confidence in RVS could lead to repeated errors as there is a potential for the entry of erroneous parameters into the RVS memory.

Humans↗

Cortical intraoperative stimulation in brain tumors as a tool to evaluate spatial data from motor functional MRI.

RATIONALE AND OBJECTIVE: The purpose of this prospective, double-blind study was to correlate motor functional MRI (fMRI) with cortical brain mapping by intraoperative stimulation using 3D reconstructed images of the surface of the brain, and to validate the spatial data of fMRI in patients with brain tumors. METHODS: Fourteen patients with tumors of the rolandic region underwent functional MR mapping of the hand region and subsequently cortical mapping before tumor resection. Data obtained with fMRI and brain mapping were not known previously by the neurosurgeon and by the neuroradiologist, respectively (double-blind study). RESULTS: In each case, the results of direct cortical mapping matched those obtained with fMRI, both positively and negatively, although the extent of the functional activations was larger than the area required to elicit the corresponding movement during intraoperative brain mapping. CONCLUSION: fMRI can be used before surgery to assess motor functional area in patients with rolandic tumors. More studies are needed to validate during surgery the real extent of fMRI activations.

Adult↗

Characterization of choline compounds with in vitro 1H magnetic resonance spectroscopy for the discrimination of primary brain tumors.

RATIONALE AND OBJECTIVES: The authors sought to compare 1H magnetic resonance spectroscopy (MRS) spectra from extracts of low-grade and high-grade gliomas, especially with respect to the signals of choline-containing compounds. METHODS: Perchloric acid extracts of six high-grade and six low-grade gliomas were analyzed by 1H MRS at 9.4 Tesla. RESULTS: The signals of glycerophosphocholine (GPC) at 3.23 ppm, phosphocholine (PC) at 3.22 ppm, and choline (Cho) at 3.21 ppm were identified in both types of tumors. The absolute concentrations of all Cho-containing compounds (GPC + PC + Cho) in high-grade and low-grade gliomas were significantly different. The relative contributions of each of the Cho-containing compounds to the total choline signal were also statistically different. For high-grade gliomas, the choline signal is composed of GPC, PC, and Cho in a well-balanced contribution, whereas in low-grade gliomas, the signal is largely due to GPC with a small involvement of PC and Cho. CONCLUSIONS: The differences in the concentration and the repartition of Cho-containing compounds seem to be a marker of high-grade gliomas. They could also help to discriminate between high- and low-grade gliomas in some difficult cases, especially if there is histologic uncertainty between anaplastic astrocytomas and low-grade oligodendrogliomas.

Adult↗

[Presurgical evaluation of cerebral tumors with functional MRI].

PURPOSE: To evaluate the capabilities and the limitations of motor functional magnetic resonance imaging (FMRI) in the presurgical planning of the cerebral tumors located in or near the motor homunculus and to correlate each type of activation with the histologic characteristics of each tumor. MATERIALS AND METHODS: FMRI was performed in 17 patients (14 adults and 3 children), without motor deficit, presenting with various intra cerebral tumors. Three FMRI activation paradigms were used, controlateral to the lesion: ballistic opposition of the fingers, flexion-extension of the foot and click of the tongue. Four patients, without motor deficit, with cerebral tumors far from the motor homunculus were used as control group to look for non specific activations. In all cases, the histopathology of the tumor was known accurately. RESULTS: In 11 patients with infiltrating tumors, the activated areas were clearly displaced. They were often intratumoral and scattered in correlation with the degree of infiltration. Two patients with non infiltrating tumors (meningioma) showed extratumoral shift of the activated areas. Four patients presenting cerebral tumors far from the homunculus motor did not show intratumoral activation. The supplementary motor area and the ipsilateral primary motor cortex were also sometimes activated during the motor tasks. The task of the tongue was often artifacted, probably because of the head motion. CONCLUSIONS: These preliminary results suggest that the histopathologic characteristics of a tumor and especially its microscopic structure plays a role, with others factors, on the motor functional area organization. In a small number of cases, the data obtained from the FMRI could be used intraoperatively, with a neuronavigation system.

Adolescent↗

Motor functional MRI for presurgical evaluation of cerebral tumors.

OBJECTIVE: To evaluate the capabilities and the limitations of motor functional magnetic resonance imaging (fMRI) in the presurgical evaluation of the cerebral tumors located in or near the motor homunculus. To correlate each type of activation with the histologic characteristics of each tumor. MATERIALS AND METHODS: fMRI was performed in 17 patients (14 adults and 3 children), without any motor deficit, presenting with various intracerebral tumors. Three fMRI activation paradigms were used: contralateral to the lesion: ballistic opposition of the fingers, flexion-extension of the foot and click of the tongue. Four patients, without motor deficit, with cerebral tumors far from the motor homunculus were used as control group to look for nonspecific activations. In all cases, the histopathology of the tumor was known accurately. RESULTS: In 11 patients with infiltrating tumors, the activated areas were clearly displaced. They were often intratumoral and scattered in correlation with the degree of infiltration. Two patients with noninfiltrating tumors (meningioma) showed extratumoral shift of the activated areas. Four patients presenting cerebral tumors far from the homunculus motor did not show intratumoral activation. The supplementary motor area and the ipsilateral primary motor cortex were also reproducibly activated during the motor tasks. The task of the tongue was often artifacted, probably because of the head motion. CONCLUSIONS: These preliminary results suggest that the histopathologic characteristics of a tumor, and especially its microscopic structure, play a role in the organization of the motor functional area. In a small number of cases, fMRI could be used intraoperatively with a neuronavigation system.

Adolescent↗

[Technical advances in the surgical management of thoracoabdominal aortic aneurysms].

Thoracoabdominal aortic aneurysmectomy ranks among the major cardiovascular surgical procedures. During the last two decades perioperative results have improved to the point that surgery should be discussed in the vast majority of patients seen with a thoracoabdominal aortic aneurysm. This progress is largely attributable to a variety of technical improvements including: aortic reconstruction using the graft inclusion technique, usually with direct reattachment of aortic branches to the prosthetic graft; distal aortic perfusion; selective use of deep hypothermic circulatory arrest in anatomically complex situations; preoperative visualization of arterial blood supply to the spinal cord using selective arteriography of intercostal and lumbar arteries. Current perioperative mortality is around 10% whereas the spinal cord complication rate is between 5% and 20% according to clinical and anatomical conditions. Future efforts should concentrate on the prevention of spinal cord complications.

Aortic Aneurysm, Abdominal↗

Atherosclerotic innominate artery occlusive disease: early and long-term results of surgical reconstruction.

PURPOSE: Few articles have dealt specifically with surgical management of innominate artery (IA) atherosclerotic occlusive disease. We herein present our early and long-term results in a large series of patients. METHODS: During a 20-year period (1974 to 1993) we operated on 148 patients with IA atherosclerotic occlusive disease. The mean age was 55.8 +/- 9.4 years. Approach was through a median sternotomy in 135 (91%) patients. Endarterectomy was performed in 32 (22%) patients, whereas 116 (78%) patients underwent bypass. RESULTS: Eight (5.4%) patients died in the perioperative period (four of heart-related causes, two of hemorrhage, one each of pulmonary infection and multiorgan failure). There were five (3.4%) perioperative strokes (three ipsilateral, two contralateral) and three (2.0%) ipsilateral perioperative transient ischemic attacks. Ten (7%) patients were lost to follow-up. Mean follow-up was 77 (2 to 193) months. Thirty-three (24%) patients were monitored 10 or more years. There were 45 (35%) late deaths (19 from cardiovascular-related causes, 15 from cancer, 7 from other known causes, and 4 from unknown causes). Although 11 (8.5%) patients had late neurologic events, only one late stroke occurred in the contralateral hemisphere and no ipsilateral late strokes occurred. Sixteen (11%) patients had late myocardial infarctions, nine of which were lethal. Life-table analysis and perioperative events were used to calculate the probability of survival, which was 77.5% +/- 9.5% and 51.9% +/- 20.8% at 5 and 10 years, respectively, with a 4.4% annual mortality rate. The overall probability of freedom from any neurologic/ocular event was 88.8% +/- 6.2% and 80.4% +/- 11.9% at 5 and 10 years, respectively, with a 1.6% annual occurrence rate. The probability of freedom from ipsilateral neurologic/ocular event was 92.7% +/- 4.8% and 84.0% +/- 11.2% at 5 and 10 years, respectively, with a 1.4% annual occurrence rate. The probability of freedom from ipsilateral stroke was 98.6% +/- 1.9% at 5 and 10 years. The primary patency rate was 98.4% +/- 2.1% and 96.3% +/- 4.7% at 5 and 10 years, respectively. The probability of freedom from reoperation was 95.6% +/- 3.9% and 93.5% +/- 5.9% at 5 and 10 years, respectively. CONCLUSIONS: Surgical reconstruction of IA atherosclerotic occlusive disease yields acceptable rates of perioperative complications and late mortality and excellent long-term patency and freedom from neurologic events and reoperation.

Adult↗