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Biomedical subjects

N de Tribolet

Publications and source records attributed to N de Tribolet.

At least 91 records · Page 5Linked to original sources
PubMed1994

Release of an inhibitor of angiogenesis upon induction of wild type p53 expression in glioblastoma cells.

The earliest genetic alteration in human astrocytoma progression is mutation of the p53 tumour suppressor gene, while one of the earliest phenotypic changes is the stimulation of neovascularization. Here, we tested the role of p53 in the angiogenic process by introducing a tetracycline-regulated wild type p53 gene into null glioblastoma cells. The parental cells expressed strong angiogenic activity while upon induction of wild type, but not mutant, p53 expression, the cells secreted a factor able to neutralize the angiogenicity of the factors produced by the parental cells as well as of basic fibroblast growth factor.

Angiogenesis Inhibitors↗
PubMed1994

Total intravenous anesthesia is best for neurological surgery.

We believe that today balanced TIVA represents the best anesthetic technique for neurological surgery. Freely acknowledging that this point of view is unproven (36) with regard to the hard criterion of patient outcome on leaving the hospital, we submit that the intermediate or surrogate criteria discussed make a convincing case for preferring TIVA to volatile-based anesthetic techniques. Until a study demonstrating hard outcome differences between the two techniques is achieved, we will continue to encourage the use of TIVA in neuroanesthesia, based on its practical (anesthetic depth, neuromonitoring, surgical field) and theoretical (homeostasis, metabolism, antinociception, neuroprotection) advantages.

Analgesics↗
PubMed1994

The superior orbital fissure: a microanatomical study.

The superior orbital fissure (SOF) is a small (3 x 22 mm), but functionally very important, region. The microsurgical anatomy of the SOF was studied on five adult, formalin-fixed cadavers. The vascular structures of three of them were injected with latex. The SOF contains the third, fourth, and sixth nerves, the ophthalmic branch of the fifth nerve, and the superior orbital vein. It is divided by the two tendons of the lateral rectus muscle: the superior part contains the fourth nerve, the frontal and the lacrimal branches of the ophthalmic division of the fifth nerve, and the superior orbital vein; the inferior part contains the superior and inferior branches of the third, the nasociliary, and the sixth nerves. In regard to surgical access to lesions involving the SOF, the question is often raised as to whether the dissection should be started from the cranial or the orbital side. The following procedure is recommended: 1) frontotemporo-orbital craniotomy; 2) resection of the lesser wing of the sphenoid bone, of the anterior clinoid, and of the superolateral part of the orbital roof and opening of the dura along the Sylvian fissure, with an extension to the frontal lobe and another extension to the temporal lobe; 3) incision of the periorbita in its superolateral part and identification of the frontal nerve; and 4) dissection of the frontal nerve in an anteroposterior direction. The fourth nerve will be found medially and inferiorly to the frontal nerve. The third nerve will be found inferomedially to the frontal nerve in the SOF, and the sixth nerve will be found inferiorly to the inferior branch of the third nerve.

Adult↗
PubMed1994

Meningiomas involving the anterior clinoid process.

We report a series of 34 clinoidal meningiomas treated surgically and analyse the results according to cavernous sinus involvement. Fifteen tumours extended into the cavernous sinus. Only four of these could be resected completely, and global outcome was improved or stable in 10 cases. Overall, 20 tumours had a total resection and 14 had a partial resection. Complete removal of the sphenoid wing, including the anterior clinoid and part of the planum sphenoidale, allows early devascularization of the tumour and minimizes brain retraction when associated with resection of the zygomatic arch. The most frequent postoperative complication was transient CSF leak, occurring in three patients. Two patients died postoperatively, and three suffered permanent complications. There was no recurrence after total removal, but five patients showed signs of progressive tumour growth after partial removal, treated by radiotherapy in three and by surgery in two cases. Twenty patients showed preoperative visual impairment. Outcome of vision was improved or stable in 13 (68%) and worse in six cases (32%). We suggest that progressive visual impairment should lead to aggressive surgical treatment, especially when complete resection of cavernous sinus involvement can be performed.

Adolescent↗
PubMed1994

Analysis of cytokine receptor messenger RNA expression in human glioblastoma cells and normal astrocytes by reverse-transcription polymerase chain reaction.

To elucidate which cytokine receptors may be expressed by human glioblastoma and normal astrocytic cells, the presence of messenger ribonucleic acid (RNA) for a number of cytokine receptors was examined in 16 glioblastoma cell lines and adult and fetal astrocytes. A complementary deoxyribonucleic acid copy of total RNA was synthesized and amplified with specific primers using the polymerase chain reaction method. The receptors studied were interleukin (IL)-1 receptor type I (IL-1RI) and type II (IL-1RII), p75 and p55 tumor necrosis factor (TNF) receptors (p75TNFR and p55TNFR), interferon (IFN)-alpha/beta and -gamma receptors (IFN-alpha/beta R and IFN-gamma R), granulocyte-macrophage (GM) colony-stimulating factors receptor alpha subunit (GM-CSFR), G-CSF receptor (G-CSFR), M-CSF receptor (c-fms, M-CSFR), stem cell factor receptor (c-kit, SCFR), IL-6 receptor (IL-6R), and IL-8 receptor (IL-8R). Transcripts for IL-1RI, p55TNFR, IFN-alpha/beta R, and IFN-gamma R were present in all cell lines. The presence of IL-1RII, p75TNFR, GM-CSFR, M-CSFR, SCFR, IL-6R, and IL-8R was identified in 13, eight, seven, eight, 14, three, and one cell lines, respectively. Normal astrocytes were positive for IL-1RI, p75TNFR, p55TNFR, IFN-alpha/beta R, IFN-gamma R, M-CSFR, and SCFR, showing a similarity to glioblastoma cells. Expression of IL-1RII was observed in adult astrocytes but not in fetal astrocytes. Furthermore, gene expression was assessed in normal brain tissue and 11 glioblastoma tissue specimens. The normal brain tissue expressed IL-1RI, IL-1RII, IFN-alpha/beta R, M-CSFR, and SCFR. Of the 11 glioblastoma tissue specimens, IL-1RI was positive in 11, IL-1RII in 10, p75TNFR in nine, p55TNFR in nine, IFN-alpha/beta R in 10, IFN-gamma R in 10, GM-CSFR in two, G-CSFR in three, IL-8R in eight, and M-CSFR and SCFR in 11. These expressions were consistent with those in the cell lines, except for IL-8R. It is concluded that glioblastoma cells and normal astrocytes express a similar set of cytokine receptor genes in vitro and in vivo. Possible autocrine loops are suggested for IL-1 alpha/IL-1RI, TNF-alpha/p55TNFR, IFN-beta/IFN-alpha/beta R, M-CSF/M-CSFR, and SCF/SCFR in glioblastomas.

Adult↗
PubMed1994

[Overexpression of p53 protein in gliomas].

We analyzed the levels of p53 protein in 10 frozen astrocytoma specimens by using an ELISA kit. p53 protein was detected in seven of ten specimens, and ranged from 0.4 to 18.0ng/ml. To confirm that the p53 protein detected in this study actually represented mutations occurring within the p53 gene, we determined the nucleotide sequence in five of six positive cases, and in three of four negative cases. We amplified exons 5 to 9 by the PCR and sequence analysis was carried out by the dideoxy chain termination method. Point mutations resulting in amino acid substitutions were found in four of five positive cases but not in negative cases. Then we analyzed the presence of p53 protein in sera of 42 patients with malignant astrocytoma and 34 healthy donors, by the same method. p53 protein was detected in sera of 7 of 42 patients and 6 of 34 healthy donors, suggesting that this result may be due to non-specific responses. In conclusion, using the ELISA kit, overexpression of p53 protein, resulting from p53 mutations, in frozen astrocytoma specimens can be detected. This may be a good screening method for the detection of overexpression of p53 protein.

Astrocytoma↗
PubMed1993

Variant CD44 adhesion molecules are expressed in human brain metastases but not in glioblastomas.

Although human glioblastomas are highly invasive tumors intracerebrally, only rarely do they metastasize outside the central nervous system. In contrast, the brain is a major target for metastatic spread of many systemic tumors. Recently, it was demonstrated that expression of splice variants of CD44 (CD44v), but not standard CD44 (CD44s), was sufficient to confer metastatic potential to low- or nonmetastatic rat tumor cells. Because CD44 is expressed in brain tumors, we examined whether differential expression of CD44 isoforms was correlated with the metastatic behavior of these tumors. We compared CD44s and CD44v expression in 17 human glioblastomas, 18 glioma cell lines, and metastases of 15 other tumors to the brain by reverse transcription/polymerase chain reaction, Northern blotting, and immunocytochemistry. These experiments showed that 0 of 17 glioblastomas and 0 of 18 glioma cell lines expressed CD44v as compared to 12 of 15 brain metastases. These data show a correlation between CD44v expression and the metastatic ability of the tumors analyzed (P < 0.01). This suggests (a) that the biological significance of the lack of CD44v expression in human glioblastomas warrants further examination with regard to their inability to metastasize extraneurally and (b) that CD44v expression may play a role in the intracerebral spread of about 80% [corrected] of the brain metastases. Therefore, CD44v expression should be further considered as a potential marker for differential diagnosis and prognosis of patients with brain metastases.

Base Sequence↗
PubMed1993

Turcot's syndrome of glioma and polyposis occurs in the absence of germ line mutations of exons 5 to 9 of the p53 gene.

The term "Turcot's syndrome" has been used to describe approximatively 55 patients with an association of colonic polyposis and primary neuroepithelial tumors of the central nervous system. The p53 tumor suppressor gene is a possible candidate underlying the syndrome because (a) mutations in the p53 gene are ubiquitous in human cancer, including colon carcinoma and gliomas, and (b) somatic or germ line mutations of the p53 tumor suppressor gene cause the Li-Fraumeni syndrome, which is characterized by the association of breast and soft tissue tumors. We determined the DNA sequence of the conserved regions of the p53 gene (exons 5 to 9) in the tumor tissues and lymphocytes of two patients with glioma-polyposis and found that mutations did occur as independent tumor-specific alterations but did not involve the germ line of these patients, suggesting that p53 may play a role in progression but not initiation of the disease.

Base Sequence↗
PubMed1993

Long-term results after ventriculoatrial shunting in children.

A consecutive series of 120 patients with infantile hydrocephalus who were subjected to ventriculoatrial shunting was studied. The average length of follow-up was 11 years. Operative mortality was zero. Seven patients died during the follow-up period; in all cases but one of these the cause of death was not a consequence of a shunt-related procedure. The incidences of infection and slit ventricle syndrome were 4.2% and 1.8% respectively. Two hundred and fifty-three shunt revisions were performed, yielding a revision rate of 2.2 per patient. Of these 253 revisions 167 (66%) were elective lengthening of the atrial catheter. The number of reoperations for adjusting the length of the atrial catheter of for revision of the distal end of the shunting system is a major disadvantage of ventriculoatrial shunting which actually speaks in favor of ventriculoperitoneal shunting as the primary procedure for the treatment of pediatric hydrocephalus.

Adolescent↗
PubMed1993

Human glioblastoma cells produce 77 amino acid interleukin-8 (IL-8(77)).

The production of interleukin 8 (IL-8), a neutrophil chemotactic factor, and its amino acid sequence were examined in glioblastoma cell lines in vitro. Neutrophil chemotactic activity was demonstrated in 9 conditioned media of 15 human glioblastoma cell lines. Tumor necrosis factor (TNF)-alpha stimulated secretion of the activity in 7 lines and induced secretion in 4 other lines. ELISA quantification disclosed that the conditioned media contained interleukin 8 (IL-8) in an amount equivalent to the chemotactic activity. The IL-8 secretion increased with the stimulation by TNF-alpha. Northern blot analysis and the RT-PCR method confirmed expression of mRNA in the glioblastoma cells and its augmentation by TNF-alpha and/or IL-beta. Reversed-phase HPLC following ion-exchange chromatography revealed that the chemotactic activity was a single peptide, which was determined to be IL-8 by the retention time and ELISA. Furthermore, amino acid analysis disclosed that a major part of the glioblastoma-cell derived IL-8 peptide was 77 amino acid IL-8 (IL-8(77); with the N-terminal sequence AVLPRSAKELRCQCI-).

Amino Acid Sequence↗
PubMed1993

Expression and release of interleukin-1 by human glioblastoma cells in vitro and in vivo.

The present study demonstrates interleukin-1 (IL-1) production by human glioblastoma cells both in vitro and in vivo. The presence of IL-1 alpha and IL-1 beta transcripts was analyzed in 4 cell lines. IL-1 alpha mRNA was expressed constitutively in one cell line whereas constitutive IL-1 beta mRNA could not be detected in any of the cell lines. IL-1 alpha transcripts could be induced with phorbol myristate acetate (PMA) or PMA plus lipopolysaccharide (LPS) in 2 of 4 cell lines and IL-1 beta mRNA in 2 of 4 cell lines. Culture fluid from these cell lines was tested for the presence of IL-1 using a specific radio-immuno-assay for either IL-1 alpha or IL-1 beta. In agreement with the results on RNA, one of 4 cell lines was found to constitutively produce IL-1 alpha but not IL-1 beta. After treatment with PMA and LPS, IL-1 alpha was detected in the culture fluid from two other lines and IL-1 beta in the medium from three lines. That the IL-1 produced by these cell lines was biologically active was confirmed in a two step thymocyte proliferation assay. IL-1 like activity was detected in all samples that were positive in the radio-immuno-assay. Finally, immunohistological analysis on fresh frozen tumour sections provided evidence for IL-1 production by glioblastoma cells in vivo. Fourteen out of 28 glioblastomas were stained with an anti-IL-1 alpha monoclonal antibody while none of them was stained with an anti-IL-1 beta antibody.

Brain Neoplasms↗
PubMed1993

Left hemisphere strategies in visual recognition, topographical orientation and time planning.

Right hemisphere lesions are known to impair, in many cases, visual recognition and visuospatial orientation. We report here on the compensatory strategies used by a patient whose posterior part of the right hemisphere was either destroyed or visually deafferented. She presented a slight appreceptive agnosia, memory disorders, and severe topographical disorientation. Her strategy relied on detail-by-detail analysis of buildings for recognition and on identification of landmarks and memorization of their sequences for finding routes. Time planning was impaired; the patient was unable to use a bi-dimensional timetable, but relied on a (linear) list of assignments. The linear, speech-related strategy she used was sustained uniquely by left hemisphere networks, since no processing of visual information occurred in the right hemisphere.

Adolescent↗
PubMed1993

Pilocytic cerebellar astrocytoma in adults: case report.

A case of cerebellar pilocytic astrocytoma is reported. This tumor occurs typically in the first two decades of life and is seldom reported in adults. The 42-year-old patient presented with occipital headaches, nausea, and unsteady gait. Nystagmus and right dysmetria were noted. A CT scan showed a hypodense, nonenhancing, voluminous, right hemispheric cerebellar cyst. Magnetic resonance imaging showed a nodule in the wall of the cyst which became hyperintense with gadolinium. The mass was resected through a small occipital craniotomy. Neuropathological examination revealed a juvenile pilocytic astrocytoma.

Adult↗
PubMed1993

Pre- and postoperative urodynamic and anorectal manometric findings in children operated upon for a primary tethered cord.

The aim of the study was to assess the sensitivity of both urodynamics and anorectal manometry in detecting neurological signs in children with a primary tethered cord. Between 1989 and 1991, 9 children were operated upon for untethering of primary tethered cord in Lausanne. Both manometric studies were performed by the same team preoperatively and 6 months after surgery. Gaeltec catheters with micro-tip transducers were used with a standardized method. Preoperative manometric findings were pathological in 4 children without clinical signs of bladder dysfunction and in 3 without clinical fecal disorders. Postoperatively, bladder dysfunction regressed in one child and fecal disorders in another. Manometric findings remained nevertheless pathological. The authors held both urodynamics and anorectal manometry as mandatory for preoperative evaluation as well as for the postoperative monitoring of children with primary tethered cord.

Adolescent↗