The dynamics of red cell chimaerism in histoincompatible parabiosed mice.

A new technique for the quantitation of isoenzymes was applied to assess the proportions of red cells in the circulation of parabiosed mice. Two parent-F1 hybrid combinations showing phosphoglucose isomerase polymorphism were examined at successive stages of parabiosis and after separation. Once red cell populations became mixed, 3 days after union, the ratio of red cell phenotypes was never significantly different from one partner to the other, although parental red cells became predominant after about 20 days. However, F1 hybrid red cells could always be detected. After separation of parabiosed mice there was a return to the original composition although this took longer than would be expected on the basis of reported red cell life span. Packed cell volume measurements indicated that a parental polycythaemia and F1 hybrid anaemia developed in one strain combination but not in the other. Evidence was adduced to support the hypothesis of a difference in red cell flux being responsible for the generation of this polycythaemia-anaemia.

Isolated motor control dysfunction related to progressive multifocal leukoencephalopathy during AIDS with normal MRI.

We describe the case of a human immunodeficiency virus-infected 34-year-old man with progressive multifocal leukoencephalopathy (PML). His case displayed unusual features, including a bizarre movement disorder, predominant involvement of the subcortical U fibers on neuropathologic examination, and the absence of MRI abnormalities suggestive of PML. Anatomic-clinical correlations are discussed.

[Gougerot-Sjögren syndrome. Central neurological involvement with recurrent development]. / Syndrome de Gougerot-Sjögren primitif. Atteinte neurologique centrale évoluant par poussées.

A 64-year-old woman was repeatedly hospitalized for various recurrent clinical signs of central nervous system involvement. The diagnosis of primary Sjögren's syndrome was established 3 years 6 months after the onset of the disease. Sicca symptoms, as well as inflammatory biological abnormalities were absent. Moreover, both lacrymal and salivary gland secretions were affected. A high level of antinuclear antibodies to SSA and SSB was associated with inflammatory lesions in minor salivary glands biopsy samples consistent with the diagnosis of Sjögren's syndrome.

[Symptomatic heterozygotic adrenoleukodystrophy in adults. 10 cases]. / Les adrénoleucodystrophies hétérozygotes symptomatiques de l'adulte: 10 cas.

Adult adrenoleukodystrophy is a X-linked peroxisomal disease associated with the accumulation of very long chain fatty acids (VLCFA) in tissues and body fluids. The diagnosis is established on the demonstration of elevated VLCFA in blood and cultured skin fibroblasts. Women are affected in nearly 15% of cases and neurological symptoms and/or signs develop in 53% of them. Identifying these women is important because of genetic counseling and a possible therapeutic approach. Ten cases of symptomatic heterozygous adult adrenoleukodystrophy are reported. Mean age at the time of diagnosis was 44.6 +/- 9.3 years. All patients presented with spastic paraparesis with inconstant and mild sensory or bladder disturbances. Cognitive impairment was present in 1 case. Cerebrospinal fluid was normal. Adrenal function in response to tetracosactide injection was abnormal in 1/7 cases. Electromyography detected a peripheral neuropathy in 1 case. Somatosensory evoked responses were abnormal in all cases, visual and auditory evoked responses in respectively 3/6 cases and 3/4 cases. Brain MRI detected non specific abnormalities in 3/7 cases; spinal cord MRI was normal in 3/3 cases. The familial history was helpful for the diagnosis in 3/10 cases. Examination of pedigrees detected 5 hemizygous and 1 asymptomatic heterozygous cases. All the patients were enrolled in a dietary study which adret with low VLCFA is currently under evaluation.

[Diagnosis of multiple sclerosis]. / Diagnostic de la sclérose en plaques.

Multiple sclerosis definition is anatomical. Its symptomatology is not specific and 4 main criteria are necessary in order to obtain a diagnosis of certitude or of presumption: 1) dissemination of signs and symptoms in space and time; 2) respect of age; 3) the symptomatology must be the expression of lesions affecting mainly the white matter; 4) elimination of other possible diagnosis. CSF examination, evoked potential and NMR study may help to the diagnosis, but no abnormality is specific of multiple sclerosis.

Immunolocalisation of type VI collagen in the intervertebral disc.

Type VI collagen has been isolated from many connective tissues, including the intervertebral disc. Distribution of this collagen, however, varies considerably within different tissues. In adult mammalian nasal and articular cartilage it is localised preferentially in the matrix immediately surrounding the cell. Intervertebral discs from various species and of various ages were studied and a similar pericellular localisation was found. When antisera to type VI collagen were used staining was seen around the cells of all sections of intervertebral disc, being particularly prominent in the nucleus pulposus. Staining on or around the cells was also seen in the adjacent cartilaginous end plate and bone.

Cognitive function in adult adrenoleukodystrophy: comparison with leukoaraiosis and multiple sclerosis.

Cognitive evaluation of 6 cases of adult adrenoleukodystrophy (ALD) included in a brain magnetic resonance (MR) study are reported: 2 males with adrenomyeloneuropathy and 4 women heterozygous for ALD. Cognition was normal in 4 and MR scan in 2 of them. In the 2 others, there were mild modifications of the white matter. One patient suffered of visual retention disturbances with abnormalities of the white matter in MR scan. In the last, cognitive decline was observed; MR scan showed atrophy of cortex and corpus callosum and periventricular high signal areas. Comparison with leukoaraiosis in healthy adults and with multiple sclerosis suggests that there is probably a relationship between cognition and extension of brain MR abnormalities. Time of appearance and frequency of cognitive dysfunction might be explained by the natural history of each of these diseases.