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Biomedical subjects

M M Ruchoux

Publications and source records attributed to M M Ruchoux.

At least 19 recordsLinked to original sources
PubMed2007

Outcome of children treated with preradiation chemotherapy for a high-grade glioma: results of a French Society of Pediatric Oncology (SFOP) Pilot Study.

BACKGROUND: To evaluate the efficacy of BCNU, cisplatin, and vincristine (BCV regimen) in a prospective nonrandomized study among newly diagnosed children with high-grade glioma. PROCEDURE: Following surgery, patients received a combination of BCNU + cisplatin + VP16 (BCV), over 3 consecutive days. Patients with residual tumor continued this regimen unless no further improvement was observed on MRI, for a maximum of six courses. Patients who underwent complete surgical resection received six courses of adjuvant BCV. RESULTS: Seventy-three patients were enrolled. Out of 66 eligible patients with central pathology review, the diagnosis of high-grade glioma was confirmed in 53 cases. The response rate was 20%. With a median follow-up of 128 months, 5- and 10-year event free survival rates are 16 +/- 9 and 13.3 +/- 9.4%. In univariate analysis, two prognostic factors were statistically significant: extent of resection and tumor location, while macroscopic total resection was the only significant prognostic factor in the multivariate analysis. The response to BCV did not translate into improved event free survival. Interstitial pneumonitis occurred in seven patients, leading to six deaths. CONCLUSION: This BCV regimen could not be recommended in the treatment of high-grade gliomas in children, according to its lack of efficacy and its unacceptable pulmonary toxicity.

Adolescent↗
PubMed2006

Could the pale, soft, and exudative condition be explained by distinctive histological characteristics?

Pork quality depends on various genetic and environmental factors. Despite the improvement of slaughter conditions, the PSE type is still one of the main concerns in this field. This study was conducted on nonstressed animals to evaluate the tissue characteristics of some muscles usually involved during stress compared with a reference muscle, the M. triceps brachii, which is actually not subject to stress-caused damages. Samples of M. triceps brachii, M. longissimus dorsi, M. biceps femoris, and M. semimembranosus were taken from pigs exhibiting 1 of the 3 HAL genotypes (NN, Nn, or nn) and 2 of the 3 RN genotypes (rn+rn+ or rn+RN-). Histoenzymology and immunohistochemistry were used to compare the fiber typing and capillary network in these muscles within these different stress susceptibility genotypes. In comparison with the reference muscle, M. triceps brachii, the combination of a high value of the number of type IIb fibers and a low vascular network showed a primary effect on muscles usually involved during stress. This led to the definition of a PSE index. A dramatic increase (P < 0.001) in this PSE index was systematically found in muscles usually involved in the PSE-type condition. These results show that distinctive histological characteristics were associated with the vulnerability of some muscles independently of the genotypes. Moreover, this study highlights the distinctive histological features of each genotype and is likely to suggest some interactions between them.

Animals↗
PubMed2006

Small vessel abnormalities in alternating hemiplegia of childhood: pathophysiologic implications.

BACKGROUND: The pathophysiology of alternating hemiplegia of childhood (AHC) is unclear. The authors evaluated the skin and muscle biopsies from patients with AHC for vascular abnormalities. METHODS: Skin biopsy specimens from four patients ages 18 months, 8 years, 9 years, and 18 years and muscle biopsies from two of these patients were examined by electron microscopy and compared with healthy controls. RESULTS: Vascular abnormalities were found in both skin and muscle. Skin biopsies showed similar abnormalities in all four patients. Vacuoles were visible in the endothelium. The most striking abnormality was the presence in the tunica media of small and unevenly shaped vascular smooth muscle cells (VSMCs) containing intracytoplasmic vacuoles and, occasionally, apoptotic nuclei, with variations according to patient age. Moreover, most VSMCs had lost junctions with neighboring cells, and some were completely isolated. In vessels from muscle biopsies, the VSMCs showed vacuoles, residual osmiophilic deposits, and myofilament loss with substitution by vacuoles. CONCLUSIONS: The vascular abnormalities in our patients suggest a primary or secondary vascular pathophysiology to alternating hemiplegia of childhood. The vascular smooth muscle cells may be the initial target of the disease process.

Adolescent↗
PubMed2005

Similar brain tau pathology in DM2/PROMM and DM1/Steinert disease.

Neurofibrillary degeneration (NFD) occurs in the brains of patients with myotonic dystrophy (DM) type 1. The authors report a similar tau pathology in the CNS of a patient with DM2 and compare it to that of patients with DM1. A reduced expression of tau exon 2 and exon 3 epitopes is observed in both DM1 and DM2. This suggests a similar physiopathologic process that may contribute to common neurologic features in patients with DM.

Aged↗
PubMed2005

Management of delayed intracranial and intraspinal metastases of intradural spinal paragangliomas.

The preferential site of extra-adrenal paragangliomas is the head and neck region. However intradural spinal paragangliomas are commonly described and are considered as benign entities. We report the case of a paraganglioma of the cauda equina followed after complete surgical removal by intracranial and intraspinal cerebrospinal fluid metastases. Seven years after the first operation, a cystic cerebellar lesion was successfully treated by surgery. During a long follow-up, four locations in the posterior fossa, a lumbar recurrence and metastatic nodules at T6 and S1-S2 level were also discovered. Radiotherapy stopped the lesions' growth and allowed improvement of the neurological status. Through a review and analysis of the literature, we discuss the management of this unusual evolution.

Adolescent↗
PubMed2004

[Cerebellar cortical dysplasia: MRI aspects and significance].

Because it is now possible to obtain high-resolution multiplanar MR imaging of the cerebellum and because of the developing interest on the role of the cerebellum on higher brain functions, we have decided to study the process of cerebellar fissuration. All brain MRI examinations performed in children for varied neurological and neurosurgical indications, especially children with non-specific mental retardation and patients with cerebral malformation detected at initial imaging work-up, were reviewed. Fissuration and lobulation anomalies (abnormal orientation of fissures, pseudopolymicrogyria, cortical thickening, subcortical cysts and heterotopia) were identified that we called cerebellar cortical dysplasia (CCD). In order to better understand the origin of this malformation, current data on cerebellar embryogenesis and histogenesis will be reviewed, and the pathological and radiological features will be illustrated. Milder forms of CCD represent a distinct group of anomalies that should be distinguished from other types of cerebellar dysplasia (agenesis, hypoplasia or complex dysplasia with involvement of the cerebellar vermis (rhombencephalosynapsis)) or combined cerebellar and cerebral dysplasia (muscular dystrophies and lissencephaly). Recognition of cerebellar cortical dysplasia could be a first step towards a broader understanding of its pathogenesis and significance.

Adolescent↗
PubMed2004

[Endocrine and pulmonary histiocytosis: a case diagnosed through stereotoxic biopsy].

INTRODUCTION: Despite intensive investigation, the pulmonary lesions of Langerhans cell histiocytosis can sometimes prove difficult to yield a diagnosis of this potentially multi-focal disease. CASE REPORT: We report the case of a sixteen year old woman, who presented with a hypothalamo-hypophyseal mass associated with endocrine clinical signs, dyspnoea, and micro-nodular pulmonary lesions on computerised tomography. A Langerhans cell histiocytosis was initially suspected, but then thought unlikely in the light of negative pulmonary investigations and spontaneous regression of the pulmonary lesions. However, an increase in the size of the cerebral mass prompted a brain biopsy finally confirming the diagnosis of Langerhans cell histiocytosis. CONCLUSIONS: This case report identifies a possible dissociation between the clinical courses of cerebral and pulmonary Langerhans cell histiocytosis, and confirms the usefulness of extra-thoracic biopsies in making a diagnosis on the disseminated form of the disease.

Adolescent↗
PubMed2001

Short stature, abnormal face, joint laxity, dislocation, hernias, delayed bone age, and severe psychomotor retardation in two brothers: previously undescribed MCA/MR syndrome.

We describe two brothers with severe psychomotor retardation, short stature, microbrachycephaly, flat occiput, ptosis, low set and prominent ears, "beaked" nose, joint hyperlaxity and dislocation, hernias, delayed bone age, and abnormalities on skin biopsy. Their parents are first cousins. To the best of our knowledge, this syndrome has not been reported before.

Abnormalities, Multiple↗
PubMed2001

Lactoferrin is synthesized by activated microglia in the human substantia nigra and its synthesis by the human microglial CHME cell line is upregulated by tumor necrosis factor alpha or 1-methyl-4-phenylpyridinium treatment.

The presence of the iron-binding protein lactoferrin (Lf) in some specific areas of the central nervous system and particularly in the normal human substantia nigra, where it is found in dopaminergic (DA) neurons and some glial cells, led us to investigate Lf synthesis in this area. Lf mRNA were identified using in situ hybridization and found in small ameboid cells. These cells were identified using immunocytochemistry as activated microglia since they exhibited macrophage markers such as the CD68 and the CR1 antigens. Double immunofluorescent labeling confirmed that the two Lf immunostained cell populations were activated microglia and DA neurons. Since activated microglia contained both Lf and its messenger, these cells are the Lf producing cells. The presence of Lf in DA neurons in which no Lf messengers were visible, might be due to an endocytosis mechanism, DA neurons probably internalizing Lf produced in microglial cells located in their neighborhood. In neuropathological disorders, such as Alzheimer's and Parkinson's diseases, inflammatory process and oxidative stress are events that contribute to neuronal death. Since Lf concentration increases during these pathologies, we studied the level of Lf expression under these different stresses and showed, using RT-PCR, that the immortalized human embryonic microglial CHME cell line produced Lf transcripts under tumor necrosis factor alpha or 1-methyl-4-phenylpyridinium treatment whereas untreated cells did not. These data confirm that Lf is produced only when microglia are activated.

1-Methyl-4-phenylpyridinium↗
PubMed2001

Paradoxical phosphorylation of the serine 199 on tau proteins from young individuals.

The microtubule-associated tau proteins are abnormally aggregated in many tauopathies. Phosphorylation modulates the functions of tau. The serine 199 residue of tau is abnormally phosphorylated at early and late stages of Alzheimer's disease. The presence of the phosphorylated Ser199 was investigated in autopsy-derived and biopsy-derived brain tissue samples from non-demented individuals. A paradoxical expression was found in the hippocampus of the youngest ones, in granule cells of the dentate gyrus and in pyramidal cells of the Ammon's horn, which are particularly prone to neurodegeneration in several tauopathies. The rate of positive cells decreased with age. These data emphasize the importance of the phosphorylation of the Ser199 residue of tau in ageing and susceptibility to neurodegeneration.

Adolescent↗
PubMed2001

New autosomal recessive cerebellar ataxia disorder in a large inbred Lebanese family.

A large inbred Lebanese pedigree with congenital spastic ataxia, microcephaly, optic atrophy, short stature, speech defect, abnormal osmiophilic pattern of skin vessels, cerebellar atrophy, and severe mental retardation transmitted as an autosomal recessive trait has been studied. None of the children had any evidence of a metabolic disease, and the analysis of respiratory chain complex abnormalities was unremarkable. Only one child had a history of perinatal difficulties. Differential diagnosis and the possibility that this disorder is a hitherto unreported one are discussed.

Adolescent↗
PubMed2001

Galectin-1 is highly expressed in human gliomas with relevance for modulation of invasion of tumor astrocytes into the brain parenchyma.

Protein (lectin)-carbohydrate interaction is supposed to be relevant for tumor cell behavior. The aims of the present work are to investigate whether galectin-1 modulates migration/invasion features in human gliomas in vitro, whether it can be detected in human gliomas immunohistochemically, and whether its expression is attributable to certain glioma subgroups with respect to invasion and prognosis. For this purpose, we quantitatively determined (by computer-assisted microscopy) the immunohistochemical expression of galectin-1 in 220 gliomas, including 151 astrocytic, 38 oligodendroglial, and 31 ependymal tumors obtained from surgical resection. We also xenografted three human glioblastoma cell lines (the H4, U87, and U373 models) into the brains of nude mice in order to characterize the in vivo galectin-1 expression pattern in relation to tumor invasion of the normal brain parenchyma. In addition, we characterized the role in vitro of galectin-1 in U373 tumor astrocyte migration and kinetics. Our data reveal expression of galectin-1 in all human glioma types with no striking differences between astrocytic, oligodendroglial, and ependymal tumors. The level of galectin-1 expression correlated with the grade in the group of astrocytic tumors only. Furthermore, immunopositivity of high-grade astrocytic tumors from patients with short-term survival periods was stronger than that of tumors from patients with long-term survivals. In human glioblastoma xenografts, galectin-1 was preferentially expressed in the more invasive parts of these xenografts. In vitro experiments revealed that galectin-1 stimulates migration of U373 astrocytes.

Adult↗
PubMed2001

Melanotic neuroectodermal tumour of the pineal region.

We describe CT and MR findings in a 23-month-old infant with a melanotic neuroectodermal tumour of the pineal gland. The tumour has been stereotactically biopsied and surgically resected. The pathological diagnosis was made on the resected piece. Embryology of the pineal gland and the histology of melanotic neuroectodermal tumour of infancy are discussed.

Brain Neoplasms↗
PubMed2001

Cerebellar gliomas in infants: specificity, pathology, and outcome.

Cerebellar gliomas (CGs) in children are generally associated with a favorable outcome; however, data regarding these tumors in very young children are scarce. We report on our experience with CGs in children less than 3 years old at surgery, compared with a second group older than 3 years. From 1991 to 1996, we operated on 7 children with CGs in the first group and 43 in the second. Psychomotor delay and regression were the first symptoms in 3 cases, and 3 had macrocrania. The tumor was totally removed in all cases. One child died intraoperatively of air embolism and subdural bleeding. Three had malignant tumors (grade 3 or 4). There was no operative mortality or malignancy in the second group of patients. With a mean follow-up of 33 months, all survivors in the first group are disease-free, with no or minimal symptoms, and attend normal schools. The clinical, surgical, and pathological features suggest that children under 3 years of age represent a specific subgroup of CGs.

Adolescent↗
PubMed2001

Galectins are differentially expressed in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas, and significantly modulate tumor astrocyte migration.

Galectins, a family of mammalian lectins with specificity to beta-galactosides, are involved in growth-regulatory mechanisms and cell adhesion. A relationship is assumed to exist between the levels of expression of galectins and the level of malignancy in human gliomas. A comparative study of this aspect in the same series of clinical samples is required to prove this hypothesis. Using computer-assisted microscopy, we quantitatively characterized by immunohistochemistry the levels of expression of galectins-1, -3 and -8 in 116 human astrocytic tumors of grades I to IV. Extent of transcription of galectins-1, -3, and -8 genes was investigated in 8 human glioblastoma cell lines by means of RT-PCR techniques. Three of these cell lines were grafted into the brains of nude mice in order to characterize in vivo the galectins-1, -3 and -8 expression in relation to the patterns of the tumor invasion of the brain. The role of galectin-1, -3 and -8 in tumor astrocyte migration was quantitatively determined in vitro by means of computer-assisted phase-contrast videomicroscopy. The data indicate that the levels of galectin-1 and galectin-3 expression significantly change during the progression of malignancy in human astrocytic tumors, while that of galectin-8 remains unchanged. These three galectins are involved in tumor astrocyte invasion of the brain parenchyma since their levels of expression are higher in the invasive parts of xenografted glioblastomas than in their less invasive parts. Galectin-3, galectin-1, and to a lesser extent galectin-8, markedly stimulate glioblastoma cell migration in vitro. Since bands for the transcripts of human galectins-2, -4 and -9 were apparently less frequent and intense in the 8 human glioblastoma cell lines, this system provides an excellent model to assign defined roles to individual galectins and delineate overlapping and distinct functional aspects.

Adolescent↗
PubMed2001

Supratentorial ependymoma in children.

The clinical and pathological characteristics of supratentorial ependymomas (STE) in children are not well identified in the literature, because most series deal with ependymomas regardless of their location or the age of the patient. As a result, the pathological description of the disorder is still debated. We therefore reviewed our cases of children operated for STE and compared them with cases of infratentorial ependymomas (ITE) to provide a better characterization of STE and suggest guidelines for treatment. From 1985 to 1999, we operated 18 children for STE, almost half of which developed with no connection to the ventricular system. Intraoperative bleeding and infiltration of the basal ganglia prevented total removal in 4 cases and were the main causes of operative mortality and morbidity. The 5-year overall survival and recurrence-free survival rates were 54 and 37%, respectively, and were highly affected by the extent of resection, but not by histological grade. Because of the high recurrence rate, we recommend systematic postoperative irradiation limited to the tumor site for all high-grade tumors in older children, and reoperation after subtotal removal and for recurrences.

Adolescent↗
PubMed2001

[Cerebellar pilocytic astrocytomas in children. Report of 72 cases].

BACKGROUND AND PURPOSE: Cerebellar pilocytic astrocytoma (CPA) bears a well-deserved reputation of benignity. However, these tumors infiltrate the brainstem in a number of cases, and total removal may cause morbidity, whereas subtotal removal can lead to recurrence. MATERIAL AND METHODS: To define guidelines for tumor removal, management of tumor remnants and recurrence, we reviewed 72 cases of CPA of childhood operated on in our department since the introduction of CT. RESULTS: Surgical removal was total in 57 cases, had to be withheld because of brainstem infiltration in nine cases, and was revealed subtotal by postoperative imaging in six cases. Two of the latter were reoperated on; six had only radiological controls and did not progress. Early in the series, eight children had external irradiation because of subtotal removal or recurrence. Three children were reoperated on for tumor recurrence, between six and eight years after complete removal. We had no tumor-related mortality; long-term disability could be related to previous mental retardation, the severity of clinical state at presentation, and complications of surgery and irradiation. CONCLUSION: The goal of surgery is to cure the patient with minimal morbidity, however, total removal is not always possible. In our experience: i) tumor remnants can be surveyed radiologically, and reoperated only in case of progression; ii) the indications for radiotherapy should be the exception; iii) clinical and radiological follow-up should be protracted beyond entry into adulthood.

Adolescent↗