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Biomedical subjects

M Poisson

Publications and source records attributed to M Poisson.

At least 19 recordsLinked to original sources
PubMed2002

Palmar erythema: cutaneous marker of neoplasms.

BACKGROUND: Acral erythema on the palms is observed in several conditions. However, the relationship with malignant tumors has only been reported exceptionally. It should be noted that tumors produce angiogenic mediators. OBJECTIVE: These mediators might promote palmar erythema (PE), and the aim of the present study was to investigate the vasodilation of palmar skin capillaries and angiogenesis, mainly with tumors of the central nervous system. METHODS: In a prospective study of 107 patients affected by brain tumors, we assessed PE clinically and the rate of dilated vessels histologically. We also evaluated the mean surface of the lumen of capillaries on skin biopsies and brain tumors. RESULTS: 6.5% of the patients had an important erythema and 18.5% had slight and/or localized PE. In the skin biopsies, the rate of dilated vessels and the mean surface of the lumen of capillaries were higher than in normal skin. Moreover, the intensity of palmar redness was related to the increase in these vascular changes in the histopathological slices of brain tumors. The intensity also depended on the type of tumor and on its growth. CONCLUSION: The results of the present study strongly suggest that acral erythema is associated with malignant tumors and that the intensity of erythema and the vascular changes of brain tumors are related, probably due to angiogenic factors.

Adult↗
PubMed1999

Dementia following treatment of brain tumors with radiotherapy administered alone or in combination with nitrosourea-based chemotherapy: a clinical and pathological study.

A retrospective clinical and pathological study of 4 patients who developed the syndrome of radiation induced dementia was performed. All patients fulfilled the following criteria: (1) a history of supratentorial irradiation; (2) no evidence of symptomatic recurrent tumor; (3) no other cause of progressive cerebral dysfunction and dementia. The clinical picture consisted of a progressive "subcortical" dementia occurring 3-12 months after a course of cerebral radiotherapy. Examination revealed early bilateral corticospinal tract involvement in all patients and dopa-resistant Parkinsonian syndrome in two. On CT scan and MRI of the brain, the main features consisted of progressive enlargement of the ventricles associated with a diffuse hypodensity/hyperintensity of the white matter best seen on T2 weighted images on MRI. The course was progressive over 8-48 months in 3 patients while one patient had stabilization of his condition for about 28 years. Treatment with corticosteroids or shunting did not produce sustained improvement and all patients eventually died. Pathological examination revealed diffuse white matter pallor with sparing of the arcuate fibers in all patients. Despite a common pattern on gross examination, microscopic studies revealed a variety of lesions that took two basic forms: (1) a diffuse axonal and myelin loss in the white matter associated with tissue necrosis, particularly multiple small foci of necrosis disseminated in the white matter which appeared different from the usual "radionecrosis"; (2) diffuse spongiosis of the white matter characterized by the presence of vacuoles that displaced the normally-stained myelin sheets and axons. Despite a rather stereotyped clinical and radiological course, the pathological substratum of radiation-induced dementia is not uniform. Whether the different types of white matter lesions represent the spectrum of a single pathological process or indicate that the pathogenesis of this syndrome is multifactorial with different target cells, remains to be seen.

Adolescent↗
PubMed1999

Treatment of meningeal gliomatosis.

To evaluate whether vigorous treatment is beneficial for patients with meningeal gliomatosis (MG) we reviewed the case records of 20 consecutive patients treated for a symptomatic MG in our center. All received systemic or intrathecal chemotherapy and six received additional cranial or spinal radiotherapy. Six patients (30%) achieved a partial response (one low-grade astrocytoma, two anaplastic astrocytomas, one anaplastic oligodendroglioma and two glioblastomas). In these cases, clinical improvement was associated with radiological improvement on CT scan or MRI in five and with a major cerebrospinal fluid improvement in three. Three patients (15%) were stable for 3 months or more and 11 (55%) had progressive disease. Median survival was longer for the responding patients (10 months) than for the other patients (2 months). This study suggests that some patients with MG may benefit from a treatment combining radiotherapy to symptomatic areas and chemotherapy with agents that cross the blood-brain barrier or are delivered directly into the CSF.

Adult↗
PubMed1998

Analysis of the p21 gene in gliomas.

The p21 gene encodes a cyclin dependent kinase inhibitor protein (p21) which has a tumor suppressive activity in a variety of tumor cell lines. Since, the p21 gene is up-regulated by the p53 tumor suppressor gene, which is frequently mutated in gliomas, acting therefore in the same control pathway, it constitutes a good candidate gene to be also inactivated in these tumors. To test this hypothesis, DNAs from 81 gliomas (48 glioblastomas, 11 anaplastic astrocytomas, 10 low-grade astrocytomas, 12 oligodendrogliomas and mixed gliomas), were investigated for mutations in the p21 coding sequence by denaturant gradient gel electrophoresis followed by sequencing. All these tumors have been previously screened for p53 mutations. Three different DNA variants were identified on codon 31 (17 cases), 27 (1 case) and 117 (1 case) and shown to be also present in matching constitutional DNA, suggesting they were polymorphisms. None of the tumors demonstrated a somatic mutation. No significant correlation between the presence of a p21 variant and the p53 mutation tumor status was observed. In conclusion, mutation in the p21 gene unlikely contributes to the development of gliomas.

Alleles↗
PubMed1997

Descriptive epidemiology of cerebral gliomas in France.

BACKGROUND: Descriptive epidemiology of cerebral gliomas has recently been the subject of several studies, indicating a possible increase in brain tumor rates, particularly in the elderly population. METHODS: Between 1983 and 1990, 1376 registered patients with diagnoses of malignant astrocytomas, low grade astrocytomas, oligodendrogliomas - mixed oligoastrocytomas, and tumors without histologic confirmation were reviewed in 6 French cancer registries. The incidence rates by histologic type, age, and gender were calculated. The variation of the incidence between 1983 and 1990 was also analyzed. RESULTS: The highest incidence was observed in the malignant astrocytoma group (2.38/100,000/year) followed by the low grade astrocytoma group (0.54/100,000/year) and the oligodendroglioma - mixed oligoastrocytoma group (0.25/100,000/year). A significant male predominance was observed in the malignant astrocytoma group (male/female [M/F] ratio of 1.59; P < 0.001) and in the group without histologic confirmation (M/F ratio of 2.6; P = 0.008). Between 1983 and 1990, an increasing trend of 5% per year was observed in the incidence of malignant astrocytomas in the population older than 65 years. CONCLUSIONS: These data confirm the observation made in other countries that the incidence of primary brain tumors (particularly malignant astrocytomas) is increasing in elderly patients.

Adolescent↗
PubMed1997

Methionine deprivation and methionine analogs inhibit cell proliferation and growth of human xenografted gliomas.

Growth of numerous malignant tumors depends on an exogenous methionine (MET) supply, while endogenously synthesized MET supports normal cell proliferation. Because an antitumor effect should be obtained by aggravating the altered MET metabolism in gliomas, MET dependency of human xenografted gliomas was evaluated and a therapeutic approach using MET deprivation or MET analogs to induce MET starvation was applied. In vitro proliferation inhibition of glioma cell lines by MET deprivation and two MET analogs, ethionine (ETH) and trifluoromethylhomocysteine (TFH), was measured. Proliferation of 7 human glioma cell lines tested was inhibited in MET-free medium, and was poorly or not reversed by homocysteine (HCY). ETH or TFH (concentration range: 0.005-2 mg/ml) inhibited proliferation of all cell lines tested. MET analog-induced inhibition was abolished by MET and enhanced by HCY. Cell-cycle alterations due to MET deprivation were optimally assessed after 30 h of culture and bromodeoxyuridine incorporation. In MET- medium, cells were arrested in the G1-phase. ETH induced a dramatic accumulation of cells in the G2-phase. ATP contents were reduced by MET analogs only in HCY+ medium, suggesting complementary effects of MET analogs and HCY. Human glioma bearing nude mice were fed an amino acid-substituted MET- HCY-supplemented diet (MET-HCY+) and/or treated with MET analogs, injected intraperitoneally daily. Using two human xenografted tumors derived from gliomas, antitumor effects were obtained by subjecting tumor-bearing nude mice to MET starvation. TG-1-MA was more sensitive to MET depletion (40% of growth inhibition, P < 0.10) than TG-8-OZ (no growth inhibition). Antitumor effects of a MET-HCY+ diet and 200 mg/kg of ETH were potentiated when co-administered to glioma-bearing mice (77% GI, P < 0.025 and 67%, P < 0.0057 to TG-1-MA and TG-8-OZ respectively). A dose-response effect with no toxicity was obtained when the ETH dose was increased 10 fold. Potentiation of the effects of ETH and a MET-free diet indicates that they probably act on the same pathway but not the same target. In conclusion, experimentally induced MET deprivation and MET-analog treatment retarded the growth of human gliomas. Combination of MET-analog therapy with MET substitution by HCY enhanced their respective effects.

Adenosine Triphosphate↗
PubMed1997

Treatment of recurrent malignant supratentorial gliomas with the association of carboplatin and etoposide: a phase II study.

Thirty one patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of carboplatin (CBDCA) and etoposide (VP16) at tumor progression. Carboplatin and etoposide (CE) were given, each at a dose of 100 mg/m2/day from day 1 to 3. The response was evaluated at each course and a minimum of three course was required to definite stable patient. Tolerance was evaluated in 31 patients. None had renal or auditory toxicity. Side effects consisted of grade III hematologic toxicity in 6 patients (19%), and grade III hepatic toxicity in one patient. No grade IV WHO toxicity was observed. All 31 patients could be evaluated for therapeutic response. A partial response was noted in 4 patients during 13, 34 +, 35 + and 51 + weeks. Ten patients had stable disease after a minimum of 3 courses (19 to 37 weeks). The rate of partial response (PR) and stabilisation (S) was 45% (14/31). The median time to tumor progression (MTTP) for responding and stable patients was 28 weeks. The median survival time (ST) for the entire group was 45 weeks and over 51 weeks for PR and S patients.

Adult↗
PubMed1996

A prospective study of cognitive functions following conventional radiotherapy for supratentorial gliomas in young adults: 4-year results.

PURPOSE: To evaluate the effects of limited field conventional cerebral radiotherapy (RT) on cognitive functions of adults. METHODS AND MATERIALS: A prospective neuropsychological study was performed on 17 patients who underwent conventional limited field RT for a low-grade glioma or for a good-prognosis anaplastic glioma. Results were compared with 14 control patients with low-grade gliomas who did not receive radiotherapy. RESULTS: A transient significant decrease of performances for the Reaction Time test was observed at 6 months in the irradiated group with return to baseline values 12 months post-RT. Subsequently, no other significant changes were observed over a 48-month follow-up period in the irradiated and nonirradiated groups. Nonetheless, when the scores of each patient were considered over time instead of the mean values of the group, one irradiated patient (5.8%) experienced progressive deterioration while two irradiated patients (11.7%) experienced long-lasting improvement. Individual changes did not occur in the control group. CONCLUSION: This study suggests that a transient early delayed drop of neuropsychological performances at 6 months is frequent following limited field conventional RT, but the risk of long-term cognitive dysfunction after irradiation is low, at least in the first 4 years after RT and when it is administered alone in young adults.

Adolescent↗
PubMed1996

Intra arterial chemotherapy with ACNU and radiotherapy in inoperable malignant gliomas.

For the non-operable malignant glioma patients, prognosis remains poor, with a survival of 8 months for the glioblastomas (G), and 15 months for anaplastic astrocytomas (AA). 27 histologic proven malignant gliomas (17 AA and 10 G) were treated between April 1991 and June 1992. Median age was 48 years. The therapeutic protocol consisted of three courses of intra arterial chemotherapy (IAC) with ACNU, at intervals of six weeks, and a localised 60 Gy radiotherapy between the first and the second IAC course. 72 courses of IAC were delivered (2.4 per patient). Response rate was 51.8%. Median survival (MS) was 13 months, with a survival rate of 28% at 24 months. For the AA, MS was 21 months, with a survival rate of 37% at 24 months. For the G, median survival was 10 months. Responders were 65% for AA, 30% for G. Non responders all died before 24 months had relapsed with a MS of 9 months. 54% of responding patients had a 2 years survival. Toxicity were acceptable with 7% of haematological toxicity and partial loss of visual acuity in 11% of the case. No chronic neurological sequellae were noted. We compare theses results with two previous trials, concerning inoperable patients, treated by association of radiotherapy and systemic chemotherapy. Survival seems to be equivalent with HeCNU and with this treatment, but toxicity decrease with ACNU. Early radiotherapy does not increase complications. This treatment can be used for patients with inoperable malignant gliomas.

Adult↗
PubMed1996

Clinical polymorphism of cystinosis encephalopathy. Results of treatment with cysteamine.

Of the 26 cystinotic patients over 19 years of age followed in our institution, 7 developed CNS complications at a mean age of 23 years. Two forms were observed. The first, associating cerebellar and pyramidal signs, mental deterioration and finally pseudo-bulbar palsy, may be called cystinosis encephalopathy. The other form resembled a stroke-like episode with coma and hemiplegia or milder symptoms. Hydrocephalus was rare and not associated with clinical symptoms in this series. Cysteamine was administered for longer than 6 months to 4 of the patients with encephalopathy. Two had an almost complete disappearance of their symptoms including the gross abnormalities of MR imaging in one; one improved partially and remained stable, and one continued to deteriorate but was suspected of non-compliance. These results suggest that cysteamine may be an effective treatment of cystinosis encephalopathy and encourage prescription of this drug in cystinosis in order to prevent this complication.

Adolescent↗
PubMed1996

Multiple infusions of anti-epidermal growth factor receptor (EGFR) monoclonal antibody (EMD 55,900) in patients with recurrent malignant gliomas.

In a prospective phase I/II trial, EMD 55,900, a murine monoclonal antibody (MAb) directed against EGF receptor, was administered at tumour recurrence to 16 patients previously treated with surgery, radiotherapy and chemotherapy for high grade supratentorial gliomas (11 glioblastomas, five anaplastic astrocytomas). Duration of treatment was planned for at least 4 weeks. The first 10 patients received 40 mg of MAb three times per week (median cumulative dose, 760 mg) and the last 6 patients received 200 mg three times per week (median cumulative dose, 2400 mg). Serum levels of EMD 55,900 were proportional to the injected dose. Repeated infusions of EMD 55,900 were well tolerated. In 13/16 patients, there were no adverse events. Among the 3 others, one had a grade IV neutropenia, one had a clinically asymptomatic hepatitis, and one had a skin rash. This last patient was the only one who had increased human antimouse antibodies (HAMA). After 4 weeks of therapy, 13 patients were evaluable for response. No measurable tumour regression was obtained with either schedule. 6 of the 13 patients (46%) showed evidence of progressive disease, while 7/13 (54%) had stable disease. All patients had progressive disease by 3 months. In this study, repeated infusions of EMD 55,900 were well tolerated but no therapeutic benefit was demonstrated.

Adult↗
PubMed1996

Loss of heterozygosity on chromosome 22 in human gliomas does not inactivate the neurofibromatosis type 2 gene.

The molecular genetic alterations that underlie development of gliomas, the most common neoplasm of the human central nervous system, include activation of cellular proto-oncogenes as well as inactivation of tumor suppressor genes. Although research has identified some affected loci, others clearly remain to be identified. We have investigated loss of heterozygosity on chromosome 22 in a panel of sporadic gliomas, and have assessed the possibility that inactivation of the neurofibromatosis type 2 (NF2) tumor suppressor gene on 22q plays a role in development of sporadic gliomas in humans. Loss of heterozygosity for loci on chromosome 22 loci was observed in 15 of 47 informative blood-tumor pairs, although no common area of loss of heterozygosity shared by all of these tumors could be identified. The most frequently affected segment, distal to the NF2 locus and bounded proximally by D22S15 and distally by a gene for myoglobin, was shared by as many as 11 tumors. Loss of heterozygosity at the NF2 locus was observed in 10 tumors. No rearrangements of the NF2 gene could be detected by Southern analysis of restriction endonuclease-digested genomic DNA, and no abnormally migrating bands were detected on single strand conformation analysis of individual exons of the NF2 gene. Thus, although frequent loss of heterozygosity on chromosome 22 suggests that inactivation of a tumor suppressor gene on this chromosome plays a role in development of gliomas, there is no evidence that inactivation of the NF2 gene is implicated in this process, confirming the results of other studies of the NF2 gene in human gliomas. The identity of the putative tumor suppressor gene on 22q involved in development of gliomas remains unknown.

Brain Neoplasms↗
PubMed1996

Treatment of recurrent malignant supratentorial gliomas with ifosfamide, carboplatin and etoposide: a phase II study.

Thirty-six patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of ifosfamide, carboplatin and etoposide (ICE) at tumour progression. Carboplatin and etoposide were both given at a dose of 75-100 mg/m2/day for 3 days, whereas ifosfamide doses ranged from 750 mg/m2/day to 1500 mg/m2/ day for 3 days, according to haematological tolerance. Treatment was repeated every 4 weeks. A minimum of three courses was required to evaluate the response unless the patient had rapid tumour progression. Grade III and IV haematological toxicity occurred in 15 patients (42%) and was lethal in one patient. Grade II hepatic toxicity was observed in one patient. Five complete (CR) and five partial responses (PR) were noted. 9 patients had stable disease (SD) after a minimum of three courses. CR + PR + SD was 53% (19/36). The median time to tumour progression (MTTP) was 13 weeks. Median survival (MST) was 29 weeks (44 weeks for R + S patients and 17 weeks for patients with progressing disease). This study suggests that the ICE combination is active in recurrent supratentorial malignant gliomas after failure of surgery, radiation therapy and chemotherapy, but at the cost of substantial haematological toxicity.

Adult↗
PubMed1996

High glycolysis in gliomas despite low hexokinase transcription and activity correlated to chromosome 10 loss.

Loss of chromosome 10 was observed in 10 out of 12 xenografted glioblastomas studied. Chromosome 10 carries the gene coding the hexokinase type 1 isoenzyme (HK-I), which catalyses the first step of glycolysis, which is essential in brain tissue and glioblastomas. We investigated the relationships between the relative chromosome 10 number, the amount of HK-I mRNA, HK-I activity and its intracellular distribution, and glycolysis-related parameters such as the lactate-pyruvate ratio, lactate dehydrogenase (LDH) and ATP contents. Individual tumour HK-I mRNA amounts were 23-65% lower than that of normal human brain and reflected the relative decrease of chromosome 10 number (alpha < 0.01). Total HK activities of individual glioblastomas varied considerably but were constantly (a mean of seven times) lower than that of normal brain tissue. The mitochondria-bound HK-I fraction of individual tumours was generally over 50%, compared with that of normal brain tissue. As shown by lactate - pyruvate ratios, in all the gliomas, glycolysis was elevated to an average of 3-fold that measured in normal brain. An elevated ATP content was also constantly noted. Adaptation of glioblastoma metabolism to the chromosome 10 loss and to the HK-I transcription unit emphasises the critical role of glycolysis in their survival. We hypothesise that HK-I, the enzyme responsible for initiating glycolysis necessary for brain function, may approach its lowest limit in gliomas, thereby opening therapeutic access to pharmacological anti-metabolites affecting energy metabolism and tumour growth.

Adenosine Triphosphate↗
PubMed1996

A phase I study of an anti-epidermal growth factor receptor monoclonal antibody for the treatment of malignant gliomas.

OBJECTIVE: Epidermal growth factor receptor (EGFR) is an operationally specific antigen in malignant gliomas; it is overexpressed in > 60% of these tumors, whereas its expression is very low in normal brain. This study aimed to evaluate whether an adequate amount of an anti-EGFR monoclonal antibody (MAb) could reach a tumor after a single intravenous administration. METHODS: This study was open, nonrandomized, and uncontrolled. Single doses (20, 40, 100, 200, or 400 mg) of the murine MAb EMD55900 (MAb 425) were administered intravenously before surgery to 30 patients with malignant brain tumors. Serum samples were taken at defined time intervals during infusion, to determine EMD55900 concentrations, and 10, 21, and/or 42 days after infusion, to evaluate the development of human anti-mouse antibodies. Tumor samples were investigated for EGFR and EMD55900 contents. RESULTS: Tolerance to EMD55900 was good. Increased liver transaminase levels were noted for three patients with Grade 1 toxicity. Twenty patients developed significant human anti-mouse antibody titers, without correlation with the administered dose. The median half-life of EMD55900 in serum ranged from 6 hours for 20 mg to 24 hours for 400 mg. In the membrane fractions of the tumors, EGFR saturation by EMD55900 varied with the injected dose of MAb. No binding was detected after a 20-mg dose. After doses of 40, 100, 200, and 400 mg, the mean saturation levels were 33, 73, 89, and 71%, respectively. CONCLUSION: This study indicates that a single intravenous administration of EMD55900 is well tolerated and produces substantial in vivo tumor binding with doses > 100 mg.

Adult↗
PubMed1996

[Spontaneous regression of primary cerebral lymphoma].

We report on a 55 year-old women with spontaneous remission of a primary cerebral lymphoma. Initial CT scan showed a left hemispheric lesion. With steroid therapy, this lesion disappeared. Nine months later, a new lesion appeared in the right frontal lobe. Follow-up CT scan 3 weeks later, without any treatment, showed complete resolution of this lesion. We conclude that primary cerebral lymphoma may have spontaneous remission.

Brain Neoplasms↗