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Biomedical subjects

P Cornu

Publications and source records attributed to P Cornu.

At least 73 records · Page 4Linked to original sources
PubMed1996

A special form of cerebral lacunae: expanding lacunae.

The case of a 42 year old man with headache, blurred vision, and diplopia allowed the description of a particular form of cerebral lacunae-that is, expanding lacunae. Brain MRI showed hydrocephalus and multiple lesions in the thalamomesencephalic region. The radiological features of these lesions were similar to the histological brain coronal section of a case reported in 1983 in which expanding lacunae were related to a dilatation of the perivascular spaces and a focal segmental necrotising angiitis. The role of the lymphatic drainage of the brain is discussed to explain the dilatation of the perivascular spaces. The hypothesis of a hydrodynamic factor being responsible for the expanding character of the lacunae was suggested by the location of the lesions and the influence of various clinical events on the symptomatology.

Adult↗
PubMed1996

[Iridium 192 brachytherapy of supra-tentorial high grade glioma recurring in irradiated areas: technique and preliminary results of the Pitié-Salpêtrière hospital group].

UNLABELLED: Our aim was to analyse feasibility and preliminary results obtained with iridium 192 re-irradiation of recurrent high grade gliomas. MATERIAL AND METHODS: a technique for implanting rigid plastic tubes afterloaded with iridium 192 wires was developed that utilised a stereotactic Leksell frame. Nineteen glioblastomas and one anaplastic glioma (12 males and 8 females: age: 20-69 years, median: 50) were implanted between January 1993 and December 1994. Previous treatments included surgery (18/20). 55-60 Gy external beam radiotherapy (20/20), and chemotherapy (16/20); interval between initial treatment and retreatment with iridium 192 was 6 to 39 months (median: 10). Maximum diameter of the tumour at the moment of implantation was 2.1-10.1 cm (median: 6.4 cm) and tumour volume 2.122 cm3 (median: 22 cm3). All tumours were supra-tentorial (right hemisphere: 9; left hemisphere: 11). Karnofsky index was 60-100 (median: 80). Implantation was carried out under local anaesthesia; tumour contours were visualised using either a CT-scan (16/20) or a MRI (4/20). Dosimetry was carried out using two orthogonal films and CT-scan images. Total dose on the reference isodose was 40-60 Gy (60 Gy: 9; 50 Gy: 7; 40 Gy: 4); dose-rate was 0.24-0.73 Gy/h (median: 0.38). RESULTS: probability of overall survival is 90% at 6 months, 55% at one year, and 26% at two years. Median survival is 56 weeks. Eleven patients died from local failure, and three from leptomeningeal metastasis. Six patients are alive, 15-30 months after the implantation. Two were reoperated for brain necrosis. Three patients showed evidence of bacterial meningitis, and three others of skin necrosis. CONCLUSION: according to this preliminary analysis, results obtained after reirradiation of high grade gliomas with iridium 192 are encouraging. More patients and longer follow-up are needed to draw definitive conclusions.

Adult↗
PubMed1995

Analysis of the NF2 tumor-suppressor gene and of chromosome 22 deletions in gliomas.

Recurrent deletions of chromosome fragments observed in neoplasms are thought to participate in tumor development through the inactivation of tumor-suppressor genes. In gliomas, the most frequent deletions involve chromosome arms 9p, 10q, 17p, 19q and 22q. We have analysed deletions of chromosome 22 in gliomas by studying loss of heterozygosity (LOH) at 8 microsatellite loci. LOH for this chromosome fragment was observed in 17/70 (24%) cases, most of them encompassing the region which encodes the gene altered in neurofibromatosis 2 (NF2), an inherited disease which predisposes to tumors of the nervous system. To investigate the possible involvement of the NF2 tumor-suppressor gene in the tumorigenesis of gliomas, we searched for alterations in its genomic structure and in its mature transcript. Northern-blot and reverse transcriptase-PCR experiments showed that the NF2 transcript is expressed and does not demonstrate obvious structural alterations. Moreover, analysis, at the genomic level, of the 16 coding exons of the NF2 gene by denaturing gradient gel electrophoresis failed to detect any somatically acquired point mutations. Altogether, these data strongly suggest that, although gliomas demonstrate recurrent chromosome 22 deletions most frequently encompassing the NF2 region, the NF2 gene is not altered in these tumors.

Base Sequence↗
PubMed1995

Significant and persistent improvement of thrombocytopenia after splenectomy in an adult with the Wiskott-Aldrich Syndrome and intra-cerebral bleeding.

The Wiskott-Aldrich syndrome is an X-linked inherited immunodeficiency disorder characterized by thrombocytopenia, recurrent infections and eczema. Its best management option is HLA-identical bone marrow transplantation; when this is not feasible, splenectomy, followed by continuous prophylactic antibiotics, represents the alternative of choice. The present case report relates the excellent outcome of an adult with the Wiskott-Aldrich syndrome who suffered his first major complication of the disease at age 33 years, an intracerebral hemorrhage. Since an uneventfull splenectomy, thrombocytopenia has significantly improved, and he has remained free of infections for a follow-up period of 3 years while being treated with prophylactic antibiotics.

Adult↗
PubMed1994

The role of the right medial temporal lobe in the control of memory-guided saccades.

The role of the hippocampal formation in the control of memory-guided saccades is unclear. We tested two types of memory-guided saccades with short memorization delay in three patients with a lesion affecting the right medial temporal lobe and involving the hippocampal formation. In single memory-guided saccades, testing spatial working memory, the gain of the patient group did not differ from that of an age-matched control group. In contrast, in sequences of memory-guided saccades, testing chronological working memory, there was a marked and significant increase in the percentage of erroneous sequences in patients, compared to controls. These results suggest an important role of the hippocampal formation in the memorization of the chronological order of saccade sequences. In contrast, this structure does not appear to be crucial for spatial working memory, used in single memory-guided saccades.

Aged↗
PubMed1994

Neurosurgical anatomy of the anterior interhemispheric approach for aneurysms of the anterior communicating artery (26.6.92).

The anterior interhemispheric approach for aneurysms of the anterior communicating artery was studied in ten cadavers. This approach presents several advantages over the pterional approach widely used in neurosurgery. It allows direct access to the region of the anterior communicating artery complex with minimal retraction of the brain and preservation of the olfactory tract and the gyrus rectus.

Cerebral Arteries↗
PubMed1994

[Long-term hematological management of cyanotic congenital heart diseases].

The long-term management of cyanotic congenital heart disease requires treatment of raised haematocrit (> 65%) whilst conserving the quality of the red blood cells [mean corpuscular volume, mean corpuscular haemoglobin concentration (MCHC)]. Since 1975, the author has chosen chemotherapy (hydroxyurea, pipobroman) as first-line treatment, reserving iron supplements, phlebotomy and platelet antagonists as adjuvant therapy. Pre-treatment data of 170 patients showed: a high prevalence of hypochromic microcytosis due to iron deficiency and of thrombopaenia, in relation to the severity and duration of the polycythaemia. Hyperuricaemia was greater than 420 mumol/l in 67% of cases; effort tolerance and hyperviscosity were related to the haematocrit and iron deficiency. One hundred and forty seven patients were followed up for a total duration of 769 years of chemotherapy. Clinical tolerance was good: biological tolerance was marked by a high frequency of thrombocytopaenia requiring withdrawal (10 cases) or reduction of treatment (34 cases). The causes of the 39 deaths observed are analysed: none was related to the hydroxyurea or pipobroman. The treatment or follow-up was stopped in 29 cases: the reasons are reported. Seventy eight patients under treatment had a favourable outcome with normal social reinsertion in 74 cases. This efficiency was related to maintenance of a haematocrit < 65%, to correction of the iron deficiency and increase in the MCHC. These results were obtained with an average dosage of 19 +/- 4.5 mg/kg/day of hydroxyurea (69 patients). By slowing erythropoiesis, chemotherapy reduces the indication of phlebotomy, so reducing iron loss: it also inhibits excessive bouts of polycythaemia in cases of iron therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

MR of isolated leptomeningeal glioma.

We report the MR study of a case of high-grade glioma that mimics leptomeningeal carcinomatosis. Superficial gliomas should thus be included in the differential diagnosis of isolated meningeal enhancement.

Adult↗
PubMed1994

A technique of measuring the precision of an MR-guided stereotaxic installation using anatomic specimens.

PURPOSE: To develop a method for direct measurement, using anatomic specimens, of the precision of MR-guided stereotaxic location and to describe its application to a 1.5-T MR unit with a Leksell stereotaxic frame. METHODS: Small pieces of gelfoam (1 X 1 X 1 mm), soaked in gadopentetate dimeglumine, were stereotaxically introduced into formalin-fixed human heads using a Leksell D (three experiments) or G (nine experiments) stereotaxic frame. The head and the frame were then introduced into a 1.5-T MR unit. The target coordinates (as set on the stereotaxic frame by one investigator) were then compared with the MR-determined stereotaxic coordinates (calculated independently by another investigator). The imprecisions Ex, Ey, and Ez in each direction were defined as the differences between the calculated and the chosen coordinates. RESULTS: Regarding the three targets studied with the D frame, mean imprecision Ex was 1.08 +/- 0.50 mm (mean +/- SEM), Ey 0.83 +/- 0.58 mm, and Ez 0.75 +/- 0.25 mm. For the nine targets studied with the G frame, Ex was 0.48 +/- 0.17 mm, Ey 0.69 +/- 0.14 mm, and Ez 0.82 +/- 0.13 mm. Statistical analysis of the results showed no significant difference between Ex or Ey and half the size of a pixel, indicating that, in the axial plane, stereotaxic MR precision is limited only by pixel size. A statistically significant difference was observed in the coronal plane between Ez and half the size of a pixel, but it must be stressed that Ez remained smaller than 1 mm. CONCLUSION: MR-guided stereotaxic location can be used with confidence for most diagnostic, functional, and therapeutic procedures.

Calibration↗
PubMed1993

[Late disclosure of intra-cerebral epidermoid cyst].

Symptoms of right hemisphere dysfunction had developed over a 10-month period in a 69-year old woman. She had experienced transient episodes of facial asymmetry for 10 years. CT scan showed a hypodense hourglass tumor extending above and below the tentorium. MRI showed a low-intensity signal with T1-weighted sequences and a high-intensity signal with T2-weighted sequences. The tumour was removed. Pathological examination proved the tumor to be an epidermoid cyst. Such a tumor may have been responsible for transient deficits in the late stages of development.

Aged↗
PubMed1993

MRI evaluation of sacral cysts.

Sacral cysts or intrasacral sacral meningeal cysts constitute a well-defined entity. Their clinical presentation is protean. Few cases have been reported concerning their MR aspects. From a series of six patients, the authors present the MR images. MRI is the examination of choice to demonstrate their liquid content. MRI provides a good evaluation of the lesion, and sagittal images show the intrasacral development. MRI scan appears to be superior to CT scan.

Adult↗
PubMed1992

Treatment of malignant gliomas with surgery, intraarterial chemotherapy with ACNU and radiation therapy.

Forty patients with malignant supratentorial gliomas received iterative intraarterial (IA) infusions of ACNU, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea at a dose of 150 mg repeated every 6 weeks. Group A consisted of eighteen patients previously treated with surgery, radiation therapy (RT) and sometimes chemotherapy, who received IA ACNU at tumor recurrence. Group B consisted of twenty two patients who received IA ACNU in the postoperative pre-RT period. In group A, 8/18 patients (44%) had an objective response, including 6/12 anaplastic astrocytomas (AA) and 2/6 glioblastoma multiforme (GBM), while 10/18 patients (56%) did not respond. Median survival time was 6 months for GBM and 12 months for AA. In group B, 6/22 patients (27%) had an objective response (4/18 GBM and 2/4 AA) and 16/22 patients (73%) did not respond. Nine patients had such an extensive tumor after one or two courses of IA ACNU that RT was cancelled. Median survival time was 8 months for GBM and 8 months for AA. Three patients (8%) had ophthalmologic toxicity on the infused side. There was no case of leukoencephalopathy.

Adult↗
PubMed1992

Increase in omega 3 (peripheral-type benzodiazepine) binding site densities in different types of human brain tumours. A quantitative autoradiography study.

The density of omega 3 (peripheral type benzodiazepine) binding sites, a marker of reactive and tumoural cells, has been measured in different types of human brain tumours; omega 3 sites were quantified autoradiographically in sections from biopsy or autopsy specimens labelled with the specific radioligand 3H-PK 11195. Compared to normal brain parenchyma, up to 12-fold increase in omega 3 site densities were found in apparently viable areas of high grade astrocytoma and glioblastoma specimens, whereas more limited increases (2 to 3-fold) in this marker were observed in areas of necrosis. Low grade gliomas (astrocytomas) and meningiomas exhibited only moderate increases (2 to 3-fold) in this autoradiographic marker. Metastases of lung or kidney origin were characterized by greatly elevated (up to 20-fold) omega 3 site densities as compared to normal brain parenchyma. In every case, there was a good spatial correspondence between the histopathological limits of the tumour and the anatomical location of the increase in omega 3 site densities. These results suggest that omega 3 site densities in human brain tumours reflect their proliferative activity and point to a possible future usefulness of positron or gamma-ray emitting omega 3 site ligands for the clinical investigation and detection of human brain proliferative diseases.

Astrocytoma↗
PubMed1992

Morphology of demyelination in the human central nervous system.

The principles of the neuropathological classification of disorders of central nervous system myelin are recalled. They are illustrated by a few selected examples. Dysmyelination is characterized by the production of an abnormal and unstable myelin sheath; it is often associated with hypomyelination (paucity of myelin formation) and is due to metabolic disorders. It is the main process in leukodystrophies. Storage of different lipids (e.g. sulfatides, long-chain fatty acids) or associated pathology of various cell types (in Alexander's disease, for example) are used for classifying these disorders. Biochemical and genetic characterizations are presently ongoing. Demyelination is the destruction of apparently normal myelin. It is often followed by remyelination. Our present knowledge on the neuropathology of multiple sclerosis, the most common demyelinating disease, is summarized. Cell-mediated demyelination affects the myelin sheaths for an obscure reason. The causes of the multifocal and sharply demarcated plaques, and of the fading of the remyelination process at the edge of some plaques, are not clear. A few examples of demyelinating diseases of known etiology and of various mechanisms are given. The similarities between acute disseminated leukoencephalitis and experimental autoimmune encephalitis are stressed. In progressive multifocal leukoencephalopathy, chronic infection of oligodendrocytes by JC virus induces poorly defined areas of demyelination. In AIDS, the pathogenesis of the myelin change is unclear. Macrophages may be responsible. Toxic and vascular disorders provide also good models for the understanding of mechanisms of demyelination.

Central Nervous System Diseases↗
PubMed1992

[Mechanical preparation of the colon with sodium picosulfate].

We tested the laxative sodium picosulfate for mechanical bowel preparation in elective colorectal surgery. The quality of this preparation was assessed on a visual analog scale on 277 patients who were then followed prospectively for wound and intraabdominal infectious complications for 42 days. Picosulfate preparation resulted in a complication rate similar to whole gut irrigation but was more acceptable for the patients and the nurses.

Adult↗