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Biomedical subjects

O De Witte

Publications and source records attributed to O De Witte.

28 records · Page 2Linked to original sources
PubMed1996

Prognostic value positron emission tomography with [18F]fluoro-2-deoxy-D-glucose in the low-grade glioma.

OBJECTIVE: The natural history of the supratentorial low-grade glioma (LGG) of the adult is variable, and its malignant transformation is hardly predictable. Because positron emission tomography with [18F]fluoro-2-deoxy-D-glucose (FDG) has prognostic value in high-grade gliomas, this study was designed to search for a possible relationship between glucose metabolism and risk of malignant evolution in LGGs. METHODS: Positron emission tomography with FDG was performed in 28 patients with LGGs (22 at the time of diagnosis and 6 after the diagnosis). A metabolic grading system based on the visual inspection of the positron emission tomographic images was used. RESULTS: In 19 patients, no area of FDG uptake higher than in the white matter was detected (metabolic Grade 1). All of those patients were alive at the end of the follow-up period. Only one of the patients presented a histological modification 7 months after the diagnosis. Nine patients presented areas of increased FDG uptake (metabolic Grade 2 or 3). Those areas were found in the tumor area in eight patients and in an area of radionecrosis in one. Of the nine patients with FDG "hot spots," six died, two had recurrence but were alive at the end of the follow-up period, and the patient with radionecrosis had no signs of recurrence. CONCLUSIONS: The presence of areas of increased FDG uptake in a histologically proven LGG predicts, in most cases, a deleterious evolution. This metabolic feature, detectable with a noninvasive procedure, may provide a clue to cellular changes, announcing malignant transformation in a tumor that retains the histological features of an LGG. Protocols with aggressive therapeutic strategies in this situation should be considered for evaluation.

Adolescent↗
PubMed1996

[Cerebral metastases of gynecological origin].

BACKGROUND: A few cases of brain metastasis from gynecological cancer have been reported. This tumor usually dissaminates via the blood stream, normally through surface implantation or lymphatic spread. PURPOSE: We report four cases of brain metastases from gynecological cancer (2 from ovarian cancer and 2 from endometrial cancer). RESULTS: Several months later, three patients developed brain metastases without any other location elsewhere. For the other patient, brain metastasis was the first sign of her malignant disease. CONCLUSIONS: In brain metastases from gynecological cancer, treatment should consist in surgical resection, radiation therapy and chemotherapy.

Adult↗
PubMed1995

[Association of traumatic cortical aneurysm of the middle cerebral artery and spontaneous aneurysm of the trifurcation of the same cerebral artery].

Traumatic aneurysms constitute a very small percentage of all intracranial aneurysms. A high mortality results of a catastrophic rupture and they run an unpredictable course. Traumatic aneurysms usually involve the large basal arteries or the middle meningeal arteries. We report a case of an association of a traumatic aneurysm with a congenital aneurysm located on the same middle cerebral artery. At our knowledge, it is the first described case of the literature.

Adult↗
PubMed1994

Acute effect of carmustine on glucose metabolism in brain and glioblastoma.

BACKGROUND: Adjuvant chemotherapy benefits a minority of patients with recurrent glioblastoma; a critical question therefore is how to select such responders. Metabolic reaction of the tumor, studied by positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG), may be a suitable test of tumor responsiveness. In an effort to evaluate their prognostic value, the early effects of carmustine on brain and recurrent glioblastoma glucose metabolism were studied. METHODS: Positron emission tomography with [18F]fluoro-2-deoxy-D-glucose was used to study 10 patients with recurrent glioblastoma before and 24 hours after a first dose of carmustine (120 mg/m2). Absolute quantification of glucose metabolism was obtained, and metabolic changes were analyzed and confronted with survival duration. RESULTS: The mean ratios of pre- to postchemotherapy values were 0.98 +/- 0.06 (range, 0.90-1.06) for the cortex and 0.97 +/- 0.06 (range, 0.89-1.09) for the white matter. There was no statistical difference between pre- and post-chemotherapy metabolism. In the glioblastoma, individual ratios of pre- to postchemotherapy values were considerably more scattered than in the nonneoplastic tissues, ranging from 0.76 to 1.51. A significant positive correlation (P < 0.002) was found between post- to pre-chemotherapy ratios of glucose metabolism and survival length. CONCLUSIONS: In patients with recurrent glioblastoma, the first administration of carmustine produces no acute change of glucose metabolism in the noninvolved cerebral tissues. Acute changes of glucose metabolism in tumor tissue in response to this treatment varied, and a hypermetabolic reaction possibly predicts longer survival.

Adult↗
PubMed1994

Presence of calcitonin gene-related peptide receptors coupled to adenylate cyclase in human gliomas.

Eleven surgical samples of gliomas (1 of grade II, 3 of grade III and 7 of grade IV) were analyzed. Calcitonin gene-related peptide (CGRP) receptors were identified by 125I-alpha h-CGRP binding in 9 cases and the presence of a CGRP-stimulated adenylate cyclase in all the 11 cases. Tracer binding was inhibited by unlabelled alpha h-CGRP (Kd of 0.3 nM), by (8-37) alpha h-CGRP (Kd of 30 nM), by (12-37) alpha h-CGRP (Kd of 3.000 nM) but not by human calcitonin. The mean density of CGRP receptors (120 fmol/mg membrane protein) was comparable to that of beta-adrenergic receptors. CGRP stimulated 1.4 to 4.7-fold (mean 2.7) the adenylate cyclase activity with a K(act) of 2.0 nM. The CGRP fragments had no intrinsic activity but inhibited the CGRP effect. The (8-37)CGRP fragment had a Ki of 30 nM. Thus, at variance with previous reports on rat and human brain membranes, that showed the presence of CGRP receptors not coupled to adenylate cyclase, we observed in human gliomas the presence of CGRP receptors that, when occupied, stimulated efficiently the adenylate cyclase activity.

Adenylyl Cyclases↗
PubMed1990

Zolpidem intoxication mimicking narcotic overdose: response to flumazenil.

Zolpidem is a recently introduced sleep-inducer which is thought to act on the central-type benzodiazepine receptors. This observation is the first report of drug poisoning with this compound. The toxic response was characterized by the development of a profound but short-lasting coma, associated with pin-point pupils and respiratory depression, as observed in a narcotic overdose. These clinical signs were not influenced by the administration of naloxone, but responded dramatically to flumazenil. Some analytical data on zolpidem toxicokinetics are presented.

Adult↗
PubMedDate not supplied

Oesophageal perforation by an anterior cervical fixation device: management in debilitated patients.

Oesophageal perforation following anterior cervical fixation has been reported in the neurosurgical and orthopaedic literature as a rare complication of such procedure. The complications associated with oesophageal perforation may range from minor symptoms to mediastinitis and death. We report two oesophageal perforations following cervical fixation device migration in patients with poor prognosis, managed successfully with conservative surgical and endoscopic techniques.

Bone Plates↗
PubMedDate not supplied

Ectopic prolactinoma in the clivus.

BACKGROUND: Ectopic pituitary adenomas are rare. Only 29 cases are reported in the literature. The clivus was involved in some cases but sella turcica was occasionally involved. CLINICAL PRESENTATION: Headache was the first symptom of a 47-year-old woman. Radiological examination diagnosed a clivus tumour. No connection with the pituitary gland was observed. Pre-operative diagnosis was metastasis of an unknown cancer. INTERVENTION: By a transphenoidal approach, we removed a haemorrhagic tumour. No connection between the normal pituitary gland and the tumour was observed. Neuropathological analysis showed a prolactinoma. CONCLUSION: We report a rare case of an ectopic prolactinoma in the clivus unrelated to the pituitary gland. Only one other case has been reported in the literature.

Choristoma↗