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Biomedical subjects

J Honnorat

Publications and source records attributed to J Honnorat.

At least 91 records · Page 5Linked to original sources
PubMed1997

Molecular cloning of a new unc-33-like cDNA from rat brain and its relation to paraneoplastic neurological syndromes.

Anti-CV2-autoantibodies from patients with paraneoplastic neurological syndromes were used to purify protein(s) related to this disease. A novel cDNA, c-22, was obtained by PCR with primers based on amino-acid sequence of peptides obtained from this protein and rat brain cDNA as template. The deduced amino-acid sequence of c-22 shows homology to the Unc-33 gene from C. elegans in which mutations lead to defects in neuritic outgrowth and axonal guidance and cause uncoordinated movements of the nematode. Several consensus sites for putative protein kinase C phosphorylation were found, suggesting that the c-22 gene product may be a phosphoprotein. Northern hybridizations show that the apparently unique 3.8-kb mRNA of c-22 is present in rat brain tissue and its expression is developmentally regulated: the levels of C-22 mRNA, detectable in brain at embryonic day 17 (E17), increase up to post-natal day 7 (P7) and decline rapidly to an almost undetectable level in adult.

Amino Acid Sequence↗
PubMed1997

[Paraneoplastic intestinal pseudo-occlusion and sensory neuronopathy disclosing small-cell bronchial cancer].

This report describes a case of paraneoplastic neurological syndrome associating a subacute sensory neuronopathy and an intestinal pseudo-obstruction in a 64-year old man with a small cell lung cancer. Various paraneoplastic neurological syndromes have been described in association with small cell lung cancer. In our patient anti-Hu antibodies were identified by indirect immunohistochemistry and western-blot analysis. This antibody constitutes an informative tool in assessing the paraneoplastic origin of neurologic symptoms when the etiological inquiry is negative. Its positivity is important in promoting the search for an underlying malignancy and should lead to repeat investigations if the first investigations are normal.

Carcinoma, Small Cell↗
PubMed1997

Small-cell lung cancer, paraneoplastic cerebellar degeneration and the Lambert-Eaton myasthenic syndrome.

Several cancers, especially lung, ovarian and breast, can cause paraneoplastic cerebellar degeneration. The presence of different antineuronal antibodies associated with different cancers and paraneoplastic cerebellar degeneration suggests that several immunological mechanisms may result in the same neurological disorder. In patients with small-cell lung cancer, paraneoplastic cerebellar degeneration may occur with or without Hu antineuronal antibodies (HuAb), indicating that patients with the same tumour can develop paraneoplastic cerebellar degeneration by different immunological mechanisms. Furthermore, paraneoplastic cerebellar degeneration sometimes occurs in association with the Lambert-Eaton myasthenic syndrome. In order to try to understand the clinical implication of antineuronal antibodies in patients with small-cell lung cancer, we examined the serum of 57 patients with presenting symptoms of paraneoplastic cerebellar degeneration for the presence of HuAb and P/Q- and N-type voltage-gated calcium channel antibodies. Patients with paraneoplastic cerebellar degeneration who were HuAb positive were compared with HuAb negative patients with respect to neurological symptoms, course of the neurological disorder, response to treatment, tumour prognosis, pathological findings, and cause of death. The tumour outcome and serological findings of these patients were also compared with those of 109 small-cell lung cancer patients without paraneoplastic syndromes of the CNS. Titres of HuAb were classified as 'high' (immunoblot titre > 1:10,000) or 'low' (< 1:10,000), the latter similar to the antibody titres detected in some small-cell lung cancer patients without paraneoplastic symptoms. Twenty-five patients with paraneoplastic cerebellar degeneration (44%) had high titres of HuAb, four (7%) had low titres of HuAb, and 28 (49%) were HuAb negative; for clinical comparisons with the patients with high titres of HuAb, the four patients with low antibody titres were included in the HuAb negative cohort. None of the 109 small-cell lung cancer patients without paraneoplastic symptoms had high titres of HuAb. The presence of high titres of HuAb defined a subset of patients who differed from the HuAb negative paraneoplastic cerebellar degeneration cohort, HuAb positive patients were more likely to be female (P < 0.01), to have multifocal neurological disease (brainstem encephalopathy and sensory neuropathy being common extracerebellar manifestations) (P < 0.002), and be severely disabled (P < 0.005). A total of nine patients (16%) from both paraneoplastic cerebellar degeneration groups developed electrophysiologically confirmed Lambert-Eaton myasthenic syndrome. Seven of these nine patients had serum available for P/Q-type voltage-gated calcium channel antibody testing and all seven were positive. In addition, 20% of HuAb negative paraneoplastic cerebellar degeneration patients without clinically identified Lambert-Eaton myasthenic syndrome had P/Q-type voltage-gated calcium channel antibodies, while only 2% of small-cell lung cancer patients without paraneoplastic symptoms had these antibodies. Treatment of the tumour and/or immunomodulation did not alter the course of paraneoplastic cerebellar degeneration, but improved Lambert-Eaton myasthenic syndrome symptoms. At the time of death, in 60% of HuAb positive and 20% of HuAb negative paraneoplastic cerebellar degeneration patients, the tumour was either not evident or localized to the chest (P < 0.007); neurological disease was the cause of death of 65% HuAb positive paraneoplastic cerebellar degeneration and 10% HuAb negative paraneoplastic cerebellar degeneration patients (P < 0.001). (ABSTRACT TRUNCATED)

Age Distribution↗
PubMed1996

Antibodies to a subpopulation of glial cells and a 66 kDa developmental protein in patients with paraneoplastic neurological syndromes.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) are inflammatory disorders that probably depend on autoimmune processes. Several autoantibodies (anti-Hu, anti-Ri, and anti-Yo) have been characterised in PNS and proved to be helpful in the diagnosis. However, these do not account for all the cases and the possibility that other types of antibodies could be detected was investigated. METHODS AND RESULTS: Of 45 patients with PNS whose serum was probed on paraformaldehyde fixed rat brain sections, 11 patients were identified whose serum samples recognised a cytoplasmic antigen in a subpopulation of glial cells in the white matter of adult rat brainstem, cerebellum, and spinal cord that were double labelled with a monoclonal antibody specific for oligodendrocytes. All serum samples reacted with a 66 kDa protein of newborn rat brain on western blot analysis. These antibodies were designated as anti-CV2 antibodies. Only one of the 11 patients had one of the well characterised autoantibodies (anti-Hu). Five patients had cerebellar degeneration, three had limbic encephalitis, two had encephalomyelitis, and one had Lambert-Eaton myasthenic syndrome. The tumours were small cell lung cancer or undifferentiated mediastinal cancer in seven patients, uterine sarcoma in two, and malignant thymoma in two. Among 1061 control serum samples, only two patients had anti-CV2 antibodies. One had small cell lung cancer and the other malignant thymoma. CONCLUSIONS: The detection of anti-CV2 antibodies in patients with neurological disorders should be considered as an indication of the presence of an occult cancer.

Aged↗
PubMed1995

Autoantibodies to glutamate decarboxylase in a patient with cerebellar cortical atrophy, peripheral neuropathy, and slow eye movements.

OBJECTIVE: To study the existence of autoimmunity against the cerebellum in patients with sporadic cortical cerebellar atrophy. DESIGN: The presence of autoantibodies against the cerebellum in the serum and cerebrospinal fluid samples that were obtained from patients with sporadic cortical cerebellar atrophy and control patients was investigated by using immunohistochemical techniques. SETTING: University hospital and research laboratory in Lyons, France. PATIENTS: Eight patients with cortical cerebellar atrophy that was associated with or without other neurological symptoms; 350 patients with various neurological diseases; and 33 normal, healthy subjects. OUTCOME MEASURES: Serum and cerebrospinal fluid anti-cerebellar autoantibodies were investigated by using indirect immunofluorescence techniques in rat cerebellum. To characterize antigen labeled by patient's serum, we used an immunotrapping enzyme activity assay of glutamate decarboxylase. RESULTS: Serum and cerebrospinal fluid samples that were taken from one patient with sporadic cortical cerebellar atrophy associated with peripheral neuropathy and slow eye movements contained anti-glutamate decarboxylase autoantibodies. CONCLUSIONS: These results suggest a participation of autoimmunity in the pathogenesis of some cases of sporadic cerebellar cortical atrophy and the involvement of the cerebellar gamma-aminobutyric acid-ergic system in the pathogenesis of this disease.

Adult↗
PubMed1995

Limbic encephalitis and immunological perturbations in two patients with thymoma.

Two patients with clinical and radiological evidence of limbic encephalitis associated with an invasive lymphoepithelial thymoma who improved after thymectomy and radiotherapy are reported. The serum of both patients and the CSF of one of them contained different types of antibodies that immunoreacted with human and rat brain and newborn rat thymus. After treatment of the tumour, the antibody titres decreased. Similar antibodies were not found in various controls. Two out of 16 patients with thymoma, myasthenia gravis, and no CNS involvement had low titres of antibodies reacting with the brain. It is suggested that in some patients with thymoma, an autoimmune reaction involving antigens common to the brain and thymus is possibly misdirected against the CNS.

Aged↗
PubMed1995

[Effect of buspirone, a serotonergic 5-HT-1A agonist in cerebellar ataxia: a pilot study. Preliminary communication].

We propose a serotonergic hypothesis for cerebellar ataxia. The levorotatory form of 5 hydroxytryptophan has been shown to be partially active in subtypes of cerebellar ataxia, including cerebellar cortical atrophy (CCA). Buspirone, a 5-HT1A agonist usable in human medicine, has been studied in a group of 14 patients with cerebellar cortical atrophy. Patients were given Buspirone for 2 months. The evaluation of cerebellar ataxia was made by a semi-quantitative scale, 10 fully quantitative measures and measurements of the sway path and sway area of the center of gravity at posturography. The primary endpoints were the modifications of the ataxia scores. At 2 months, the decrease of the ataxia scores was significant, both in the intention-to-treat (14 cases) and target (11 cases) populations. In the target population, secondary endpoints like the time measurements for pronouncing a standard sentence, the time for drawing a ladder and posturographic parameters were significantly improved; the mean global ataxia score was improved by 37.4%. These preliminary data might confirm a link between cerebellar ataxia and the metabolism of serotonin.

Adult↗
PubMed1994

[Value of the detection of anti-nervous system autoantibodies in neurologic paraneoplastic syndromes].

In the last decade, anti-neurons autoantibodies have been found in serum and cerebro spinal fluid of patients suffering from neurological paraneoplastic syndrome. This discovery has made possible to improve the knowledge of these syndromes as well as to characterize some proteins specific to the nervous system, unknown until now. Paraneoplastic encephalomyelitis can manifest together with an ataxic sensitive neuropathy, a limbic encephalitis, a brainstem or cerebellum syndrome. This encephalomyelitis is almost always associated with a small cells lung cancer and auto-antibodies, called anti-Hu, which recognize all the neurons of the nervous system. Patients with paraneoplastic cerebellar degeneration present an antibody, called anti-Yo, directed against Purkinje cells. In this case, the tumor is a gynecologic cancer. Patients presenting with an opso-myoclonus and a breast cancer have an antineurons anti-body, called anti-Ri, which is absent when the opso-myoclonus is associated with a lung cancer or a neuroblastoma. These three antibodies are the most frequently found and the best studied, but others, rarer, have been described. The genes coding for the proteins recognized by these three antibodies have been cloned. These proteins seem to play a major role in the neuronal maturation and homeostasis. These antibodies prove to be irreplaceable tools to study the phenomenons subtending the neuronal degeneration and the cellular proliferation.

Autoantibodies↗
PubMed1994

High resolution two-dimensional polyacrylamide gel electrophoresis using Immobilines. Application to the study of brain proteins.

Cytoplasmic soluble proteins of unknown origin but which could be associated with the development and maturation of the central nervous system are recognized by antibodies found in serum of patients with a paraneoplastic neurological syndrome. The associated antigens are of great interest in understanding these neurological pathologies. To study these antigens we describe and criticize a two dimensional polyacrylamide gel electrophoresis (2D-PAGE), using immobilized pH gradient (IPG) in first dimension. Proteins from brain complex mixtures were separated by this technique in order to identify and characterize (molecular weight, p-isoelectric point, sequencing) a protein of interest. Results prove the high reproducibility and the good resolution of the technique. Without applying enrichment method prior to 2D-PAGE, any proteins are not sequenceable after transblotting to PVDF (polyvinylidene difluoride) membrane and Coomassie blue staining. In these cases the meaning to reach the wanted aim, i.e. sequencing, was discussed.

Animals↗
PubMed1993

Posterior uveitis, paraneoplastic encephalomyelitis and auto-antibodies reacting with developmental protein of brain and retina.

We report a 68-year-old woman who presented with posterior uveitis, cerebellar ataxia, dysautonomia, peripheral neuropathy and undifferentiated carcinoma. Autopsy showed slight brain inflammatory changes and severe Purkinje cell degeneration. By immunocytochemistry, the serum and CSF contained antibodies that reacted with the cytoplasm of cells in the brain and retina of rat. Some neurons and glial cells were stained. However, the most labelled cells were immature cells of the subventricular layers of the dentate gyrus, olfactory bulb and lateral ventricles. In rat retina, the plexiform layers and cells of the inner granular layer were stained. E15 rat embryo showed diffuse staining of post-mitotic cells and process in the central and peripheral nervous system. With the patient's IgG, various bands of 45, 60, 70 and 135 kDa apparent molecular weight were demonstrated on immunoblots of adult human, adult and E15 embryonic rat brain and rat and bovine retina. Eluates of tissue bound IgG labelled the same bands.

Aged↗
PubMed1993

[Alexander's disease in adults and diffuse cerebral gliomatosis in 2 members of the same family].

A 31-year old woman died after 10 years of progressive dysautonomia and cerebellar and pyramidal symptoms. CT scan showed pontine, bulbar and cerebellar atrophy. Post-mortem examination revealed Rosenthal's fibers widespread throughout the CNS, but especially in the subependymal and perivascular regions. White matter cavitations involving peri-ventricular regions, hilum of dentate nuclei and pons were observed, leading to a diagnosis of adult form of Alexander's disease. At the age of 5, the patient had been operated upon for a chiasmatic tumor. Microscopic examination revealed a pilocytic astrocytoma without Rosenthal's fibers. No complementary radiotherapy had been done. Her mother has been operated upon in 1972, for a high-grade glioma and is still alive 20 years later. This suggests diffuse cerebral gliomatosis. This family history may suggest a relation between these different diseases. They might be the result of a transmissible astrocytic abnormality with varying expression.

Adult↗
PubMed1992

[Autoantibodies in paraneoplastic polioencephalomyelitis: 8 cases].

Antibodies directed against the central nervous system were looked for by indirect immunohistochemistry in the sera of 8 patients with paraneoplastic neurological syndrome (group 1), 21 cancer patients without neurological signs, 23 patients with miscellaneous neurological diseases and 63 normal subjects (groups 2 to 4). Four patients in group 1 had very high titres of antibodies. In 2 patients with small-cell lung carcinoma associated with sensory neuropathy the antibody recognized the cytoplasm and nucleus of all neurons. A 37 Kd protein was recognized by Western blot. A woman with cancer of the ovary and cerebellar syndrome exhibited an antibody against Purkinje's cell cytoplasm with a band of about 50-55 Kd at Western blot. In a woman with chronic uveitis and cerebellar atrophy with disappearance of Purkinje's cells the antibody (in blood and CSF) recognized certain layers of the retina as well as glial cells and cells present in the subependymal areas of the brain. Two bands of 46 and 59 Kd were revealed by Western blot. Immunoglobulins were detected in the cytoplasm of white matter cells in the cerebellum and brain stem. Among the other groups, one patient with lung cancer had a moderate titre of neuronal antinuclear antibody. The Western blot test was negative. The relevance of these antibodies for the diagnosis and treatment is discussed.

Aged↗
PubMedDate not supplied

Effects of diabetes type and treatment on zinc status in diabetes mellitus.

Zinc status was assessed in 53 diabetic patients: 18 insulin-dependent diabetic patients (IDDM), 22 noninsulin-dependent diabetic patients (NIDDM) treated with oral antidiabetic agents, and 13 insulin-treated, noninsulin-dependent diabetic patients (IRDM). Plasma zinc concentrations were in the usual range for healthy subjects in these three groups (15.3 +/- 0.9 mumol/L). Urinary zinc excretions were elevated in the IDDM group (18.3 +/- 4.1 mumol/24 h; p less than 0.01 vs normal) and in the NIDDM group (17.5 +/- 3.5 mumol/24 h; p less than 0.01 vs normal), but normal in the IRDM group (11.3 +/- 2.4 mumol/24 h). In 14 NIDDM patients treated with transient continuous sc insulin injections, urinary zinc decreased from 16.5 +/- 2.2 mumol/24 h before insulin treatment to 11.5 +/- 0.3 mumol/24 h after insulin treatment without any modification in plasma zinc concentrations.

Blood Glucose↗
PubMedDate not supplied

Hyperacute diffusion-weighted MRI in basilar occlusion treated with intra-arterial t-PA.

Basilar artery thrombosis should be diagnosed immediately, as intra-arterial thrombolysis might improve the outcome. Diffusion-weighted (DWI)-MRI and three-dimensional time-of-flight MR angiography (3D TOF Turbo MRA) may provide additional insight into the extent of ischemia and the level of the occlusion. These methods could be helpful in the early classification of vertebrobasilar stroke, thus reserving the use of conventional angiography and possible intra-arterial thrombolysis for patients who had a severe clinical picture explained by preliminary assessments. We report the case of a 74-year-old woman who experienced a basilar artery occlusion; DWI-MRI and 3D TOF Turbo MRA provided noninvasive information concerning the level of arterial occlusion and its parenchymal ischemic impact, this leading to an intra-arterial thrombolytic therapy. These data suggest the feasibility of a noninvasive urgent diagnostic and prognostic approach with DWI-MRI and 3D TOF Turbo MRA in basilar occlusion.

Aged↗