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Biomedical subjects

N de Tribolet

Publications and source records attributed to N de Tribolet.

At least 163 records · Page 9Linked to original sources

[Normal-pressure hydrocephalus in adults. Analysis of results and complications following ventriculo-cardiac derivation].

The results of ventriculo-atrial shunting have been analyzed in 37 patients with normal pressure hydrocephalus. The nature and severity of the symptoms and their progression in time, together with the results of computed tomography and clinical response to CSF withdrawal by lumbar puncture, were compared with the outcome after shunting, in order to define reliable prognostic criteria. In the long term, 43% of the patients improved and 30% died. The complication rate was 22%, including primarily subdural hematoma and shunt malfunction. Amongst the symptoms, ataxia responded best to shunting. Clinical improvement after subtraction of lumbar CSF, and demonstration by computed tomography of ventricular dilation with a hypodense area around the frontal horns in the absence of cortical atrophy, were associated with a favorable outcome.

Aged↗

The effects of midazolam reversal by RO 15-1788 on cerebral perfusion pressure in patients with severe head injury.

In patients with severe head injury, midazolam is a convenient agent for sedation during mechanical ventilation, although its sedative effect can be prolonged. We investigated the effects of acute midazolam reversal by RO 15-1788 (RO), a benzodiazepine antagonist, on intracranial pressure (ICP), cerebral perfusion pressure (CPP) and on recovery in 18 studies performed on 15 patients with severe head injury (Glasgow coma score less than 8). ICP increased significantly from 16.3 mmHg +/- 2 (mean +/- SEM) to 24.1 mmHg +/- 4.2 (p less than 0.02) and to 25.2 mmHg +/- 4 (p less than 0.01), 5 and 10 min respectively after RO administration. Analysis of the results showed 2 patterns of response in ICP. In patients with good control of ICP before RO administration, there was no change in ICP and CPP, whereas in patients with abnormal ICP, RO injection induced severe increase in ICP and concomitant decrease in CPP. Arousal after midazolam reversal was obvious in 5 patients who were quickly extubated. Midazolam reversal by RO should not be attempted in patients with severe head injury and unstable ICP.

Adult↗

Hyponatremia hypo-osmolarity in neurosurgical patients. "Appropriate secretion of ADH" and "cerebral salt wasting syndrome".

This prospective study is based on 256 patients with severe brain injury. Six patients (2.3%) developed the clinical picture of inappropriate secretion of antidiuretic hormone (SIADH): 3 in the first 3 days following the injury, 3 after more than a week. Their ADH plasmatic level were measured by radio-immunoassay. In the former, many factors, largely iatrogenic, can explain the increased secretion of ADH we found and which is then definitely "appropriate". It should be prevented by fluid restriction. In the latter, we found adequately low ADH levels, when the hypo-osmolarity is taken into account. Here, the aetiology seems to be a renal salt loss, eventually in relation to a natriuric factor (e.g. atrial natriuretic factor), justifying the term: "Cerebral salt wasting syndrome". With the resistance to fluid restriction, the treatment still remains a problem.

Adult↗

Plasma pituitary hormone levels in severe trauma with or without head injury.

In order to evaluate the effect of head injury in severely traumatized patients on the response of ACTH, GH, PRL, and TSH plasma levels, 36 patients were prospectively studied over 5 consecutive days following injury. They were divided into three groups: Group I, severe isolated head injury (n = 14); Group II, multiple injury combined with severe head injury (n = 12); Group III, multiple injury without head injury (n = 10). No significant trend was observed during the 5 consecutive days. The following changes in plasma levels were observed, compared to normal reference value (median values): ACTH was normal in the three groups; PRL was elevated in Group II and normal in the other groups; GH was elevated in all groups; TSH was elevated in Group III and reduced in Groups I and II. Intergroup comparisons showed significantly lower plasma levels for PRL (p less than 0.05) and TSH (p less than 0.01) in Groups I and II, i.e., head-injured patients, compared to Group III, i.e., traumatized patients without head injury. A relationship was observed between the severity of head injury, as expressed by Glasgow Coma Score, intracranial pressure levels, outcome, and TSH and PRL levels.

Adolescent↗

Identification of proliferating cells in human gliomas using the monoclonal antibody Ki-67.

Ki-67 is a monoclonal antibody directed against a nuclear antigen present only in proliferating cells in the G1, S, G2, and M phases of the cell cycle. Fifty-one frozen glioma specimens were stained with Ki-67 using the avidin-biotin immunoperoxidase system. For each tumor, six different randomly selected fields were examined. The percentage of Ki-67-positive cells in the total number of cells in the five fields counted with counterstaining has been calculated. The areas of necrosis and the vascular endothelial cells when they were distinguishable were not included in the calculation. The indices determined on this material ranged from 0% to 4.5% (mean, 1.0; SD, 1.5) for 16 low grade astrocytomas; from 0.7% to 7.4% (mean, 3.5; SD, 2.2) for 8 anaplastic astrocytomas; and from 1.7% to 32.2% (mean, 11.1; SD, 8.2) for 27 glioblastomas. The differences among the means of each group are statistically significant. Five patients with malignant gliomas with an index of less than 2.5 had survival times of more than 40 weeks. These results show that the Ki-67 index of proliferating cells in human gliomas correlates with the usual histological classification of these tumors. There is a potential interest in using this technique in routine histopathology because it is simple and more rapid than the classic methods of evaluation of proliferating cells.

Adolescent↗

Computed tomography of the postoperative intervertebral disc and lumbar spinal canal: investigation of twenty-five patients after successful operation for lumbar disc herniation.

Twenty-five patients with good outcome after operation for lumbar disc herniation underwent unenhanced computed tomography (CT) and plain radiography of the lumbar spine before, 5 to 7 days after, and 6 to 7 weeks after the operation to define the radiological features of the postoperative disc and spinal canal. After operation, the center of the disc appears hypodense. The anterior and lateral borders remain sharply delimited, but in 44% of the cases the posterior border shows an image suggesting the persistence of disc herniation. In 84% of the cases, there are major changes in the spinal canal with complete occlusion of the extradural space on the operated side by a heterogeneous material the attenuation value of which ranged between those of cerebrospinal fluid and disc. The outline of the dural sac and of the nerve root is lost. This aspect did not significantly change between the 1st and the 6th postoperative week, except for the disappearance of any air within the canal and a slight movement on the dural sac toward the operated side. From these major radiological modifications found in asymptomatic postoperative patients, it is concluded that positive CT in patients with the failed back surgery syndrome has limited value. Myelography is preferred as the primary neuroradiological investigation.

Adult↗

Thyroid function in severely traumatized patients with or without head injury.

The pattern of thyroid function changes following severe trauma was assessed prospectively in 35 patients during the first 5 days after injury. Patients were divided into 2 groups to evaluate the effect of head injury: group I, patients with severe head injury; group II, patients with multiple injuries without head injury. The results demonstrate a low T3 and low T4 syndrome throughout the study, with decreases in both total and free levels of T3 and T4, normal or increased rT3 levels, and normal TSH levels. The presence of severe head injury was associated with lower levels of TSH and free T3. Mortality was 37%. Survival was associated with higher TSH and T3 levels, but not with higher T4 levels. TSH levels exceeding 1 mU/l on the first day were only observed in survivors. These findings show that a typical low T3 and low T4 syndrome is present after severe trauma in patients with multiple injury as well as with head injury. Primary hypothyroidism can be excluded, pituitary or hypothalamic hypothyroidism is likely in these patients.

Adult↗

In situ characterization, clonogenic potential, and antitumor cytolytic activity of T lymphocytes infiltrating human brain cancers.

Mononuclear cells infiltrating human brain tumors were isolated from seven of nine surgical biopsy specimens. These cells were small T11+, T3+ lymphocytes that did not express DR antigens or the receptor for interleukin-2. In addition, large granular lymphocytes were recovered from two of these tumors. The clonogenic potential of tumor-infiltrating lymphocytes (TIL's) was assessed by limiting-dilution analysis (LDA) using a microculture system that permits proliferation of virtually 100% of normal peripheral blood T lymphocytes (PBL-T's). In comparison to normal and autologous PBL-T's, TIL's had a strikingly reduced proliferative potential revealed by a decrease in the frequency of proliferating T lymphocyte precursors calculated by LDA. On average, only one of every 100 T cells from TIL's was able to proliferate, as compared to one of every two or all of the T cells from the patient's peripheral blood or from normal donors. Furthermore, the TIL populations showed depressed proliferative responses to the lectins phytohemagglutinin and concanavalin A and to the phorbol ester 12-0-tetradecanoyl-phorbol-13-acetate. Clonal analysis performed on the proliferating microcultures from three tumors demonstrated that the majority of these clones possessed cytolytic activity against various tumor cell targets. Among clones tested for cytolytic activities with glioma cells, four lysed cultured autologous tumor cells, and the specific lysis was greater than 50% in all cases. Numerous clones with natural killer (NK)-like activity were obtained from two TIL preparations, and the frequency of cytolytic T lymphocyte precursors with NK-like activity was determined for one of these preparations and was found to be higher than that in the patient's peripheral blood. Glioma cells grown in culture and then mixed with normal peripheral blood lymphocytes (PBL's) were capable of inhibiting the PBL's response to lectins. This inhibitory property may account in part for the observed poor clonogenicity of TIL's from brain tumors. Nevertheless, nearly all proliferating clones displayed cytotoxicity against either autologous or allogeneic tumor cell targets and may imply selective accumulation of cytolytic effector cells at the tumor site.

Adult↗

Chondromyxoid fibroma of the petrous-sphenoid junction.

A case of primary chondromyxoid fibroma of the petrous and sphenoid bones extending into the posterior clinoid process, sella, and cavernous sinus in a 26-year-old man is reported. The presence of this tumor was heralded solely by the progressive paresis of the abducens nerve. The occurrence of this tumor is exceedingly rare, and to our knowledge, this is the first report of a primary chondromyxoid fibroma in the parasellar region. The natural history of this tumor, its pathologic diagnosis, and its treatment will be discussed with reference to this unusual case.

Adult↗

Comparative localization of glioma-reactive monoclonal antibodies in vivo in an athymic mouse human glioma xenograft model.

Radioiodinated murine monoclonal antibodies (Mabs) 81C6, Me 1-14, C12, D12, and E9, made against or reactive with human gliomas but not normal brain, and Mab UJ13A, a pan-neuroectodermal Mab reactive with normal human glial and neural cells, were evaluated in paired label studies in the D-54 MG subcutaneous human glioma xenograft model system in nude mice. Following intravenous injection in the tail vein of mice bearing 200-400 mm3 tumors, specific localization of Mabs to tumor over time (6 h-9 days) was evaluated by tissue counting; each Mab demonstrated a unique localization profile. The comparison of localization indices (LI), determined as a ratio of tissue level of Mab to control immunoglobulin with simultaneous correction for blood levels of each, showed Mabs 81C6 and Me 1-14 to steadily accumulate in glioma xenografts, maintaining LI from 5-20 at 7-9 days after Mab injection. Mab UJ13A peaked at day 1, maintaining this level through day 2, and declining thereafter. Mabs D12 and C12 peaked at days 3 and 4, respectively, and E9 maintained an LI of greater than 3 from days 3-9. Percent injected dose localized/g of tumor varied from a peak high of 16% (81C6) to a low of 5% (Me 1-14 and UJ13A). Immunoperoxidase histochemistry, performed with each Mab on a battery of primary human brain neoplasms, revealed that Mabs 81C6 and E9, which demonstrated the highest levels of percent injected dose localized/g of tumor over time, reacted with antigens expressed in the extracellular matrix. This finding suggests that extracellular matrix localization of antigen represents a biologically significant factor affecting localization and/or binding in the xenograft model used. The demonstration of significant localization, varied kinetics and patterns of localization of this localizing Mab panel warrants their continued investigation as potential imaging and therapeutic agents for human trials.

Animals↗

Cultured human fetal astrocytes can be induced by interferon-gamma to express HLA-DR.

Interferon-gamma (IFN-gamma) modulates the expression of Class II major histocompatibility antigens (MHC), thus providing a potential regulatory mechanism for local immune reactivity in the context of MHC-restricted antigen presentation. Within the central nervous system (CNS), the expression of MHC Class II antigens has been demonstrated on human reactive astrocytes and glioma cells. In order to investigate the modulation of HLA-DR on normal astrocytes, two cell lines were grown from a 20-week-old fetal brain. In situ none of the fetal brain cells expressed HLA-DR as determined by immunohistology on frozen tissue sections. The two cell lines, FB I and FB II, expressed GFAP indicating their astrocytic origin. FB I was HLA-DR negative at the first tissue culture passages, but could be induced to express HLA-DR when treated with 500 U/ml IFN-gamma. FB II was spontaneously HLA-DR positive in the early passages, lost the expression of this antigen after 11 passages and could also be induced to express HLA-DR by IFN-gamma. The induction of HLA-DR expression was demonstrated both by a binding RIA and by immunoprecipitation using a monoclonal antibody (MAB) directed against a monomorphic determinant of HLA-DR. The HLA-DR alloantigens were determined on FB II cells after IFN-gamma treatment, by immunofluorescence and by cytotoxicity assays, and were shown to be DR4, DR6, Drw52, DRw53 and DQwl. These results show that human fetal astrocytes can be induced to express HLA-DR by IFN-gamma in vitro and support the concept that astrocytes may function as antigen-presenting cells.

Astrocytes↗

Anterior inferior cerebellar artery aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation of the tentorium in the same patient.

An exceptional combination of intracranial vascular malformations is reported: distal anterior inferior cerebellar artery (AICA) aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation (DAVM) of the tentorium. The AICA aneurysm was the source of recurrent subarachnoid and cerebellar hemorrhage, revealed only after repeated vertebral angiography. After external drainage of associated hydrocephalus, both aneurysms were successfully clipped and the dural malformation was subtotally embolized. The literature concerning AICA aneurysms, DAVMs, and combined intracranial vascular malformations is reviewed and discussed.

Adult↗

Extreme lateral lumbar disc herniation.

Extreme lateral lumbar disc herniation (ELLDH) occurring into and/or outside the intervertebral foramen was encountered in 95 cases amongst 1600 operations for herniated lumbar disc (6%): 43% occurred at L5-S1, 38% at L4-5, 18% at L3-4, and 1% at L2-3. The incidence amongst all herniations at one particular level was 6% at L5-S1, 4% at L4-5, and 18% at L3-4. The clinical presentation varied according to the level of extreme lateral disc herniation, but was not different from the presentation of a classical paramedian herniation occurring one level above. Forty-three patients were investigated with computed tomography (CT) only, 2 with myelography only, and 50 with both. CT always clearly demonstrated the pathology, but some cases are presented to illustrate the differential diagnosis. Myelography was normal in 13 cases; in 27 cases it showed a typical shortening and enlargement of the nerve root sheath which enters the affected intervertebral foramen. At operation, a total facetectomy was performed in 52 patients, a partial facetectomy in 34, and a lateral approach to the intervertebral foramen in 9. The lateral approaches, either paramuscular with retraction of the paraspinal muscles from the midline, or transmuscular by splitting of the paraspinal muscles, are described and illustrated in detail.

Adult↗

[Immunobiology of the normal and tumor astrocyte].

Immunobiology of the normal and tumoral astrocytes studies interactions between these cells and the immune system. Their antigenic characterization defines 3 classes of antigens: glial antigens, tumor associated antigens (neuroectodermal and gliomatous) and lymphoid differentiation antigens which can be modulated by gamma interferon and other cytokines. Glioma associated antibodies could be used for radiolocalization of tumours and for immunotherapy. The enhancement or induction of the Major Histocompatibility Complex antigen expression by interferon gamma could enhance tumour-antigen presentation by glioma cells to helper and cytotoxic T cells and thus activate the host's immune response. The presence of oncogenes and their products in glioma cells, mainly growth factor receptors, brings new potential therapies using oncogenes products as tumoral markers or as targets for monoclonal antibodies blocking their mitogenic activity. Normal and tumoral astrocytes produce lymphokines: interleukin 1, interleukin 3, prostaglandin E as well as a suppressor factor inhibiting interleukin 2 mediated effects and probably responsible for the suppression of glioma infiltrating T cells. The interaction of astrocytes with several humoral factors related to the immune system and their capacity to function as antigen presenting cells underline their importance for immune reactions within the central nervous system.

Animals↗

[Spinal subarachnoid hemorrhage. Apropos of 2 cases of cauda equina tumors].

2 cases of spinal subarachnoid hemorrhage due to tumors of the cauda equina are reported. In both cases the existence of cephalic meningeal signs first suggested an intracranial pathology and diagnostic procedures were performed in this direction. Only when these examinations were negative was a lesion of the cauda equina suspected. The lesion was located by myelogram and was diagnosed, after surgical removal, as a schwannoma and an ependymoma. The syndrome of spinal subarachnoid hemorrhage involves spinal symptoms and signs resembling violent lumbar and radicular pain with a hemorrhagic cerebrospinal fluid, in association with symptoms of intracranial origin such as headache and meningism. Lumbar and radicular pain preceding the headaches, and an unaltered level of consciousness, point to the rare syndrome of spinal subarachnoid hemorrhage.

Adult↗