PubMed Health⌕ Search

Biomedical subjects

H Baron

Publications and source records attributed to H Baron.

At least 37 records · Page 2Linked to original sources
PubMed1992

An insert mutation in the chromosome 20 amyloid precursor gene in a Gerstmann-Sträussler-Scheinker family.

We report the finding of an insert mutation in the chromosome 20 amyloid precursor gene in a family with neuropathologically-verified, experimentally-transmitted Gerstmann-Sträussler-Scheinker syndrome (GSS). The insert consisted of 8 extra copies of a repeating octapeptide coding sequence in the region between codons 51 and 91; it was identified in the proband and a presently unaffected at-risk niece by full sequencing of the open reading frame, and was visualized electrophoretically in the proband and 6 of 12 at-risk relatives. Although affected members in this French-Breton family have shown a variety of clinical profiles, including durations of illness that ranged from 3 months to 13 years, all autopsied cases (including the patient with the shortest illness) have had the distinctive multicentric amyloid plaques that define GSS as a nosologic entity.

Adult↗
PubMed1992

Transgenic mice expressing polyoma virus large T antigen in astrocytes develop severe dysmyelination of the central nervous system.

Transgenic mice were generated using a construct that encodes mouse polyoma virus large T antigen, one of three oncogenic products of the "early region" of the polyoma viral genome. Of 16 transgenic families developed, 1 was characterized by a neurologic disorder consisting of constant tremor and recurrent seizures. Morphologic analysis of the central nervous system (CNS) of affected transgenic mice included: classical light and electron microscopic examination; immunohistochemical assessment of the presence and localization of myelin-specific proteins, of the astrocyte marker glial fibrillary acidic protein, of the oligodendrocyte marker galactosyl cerebroside, and of large T; double immunolabeling of glial fibrillary acidic protein or galactosyl cerebroside and large T to identify the CNS cell type in which large T is expressed; and in situ hybridization to study myelin basic protein gene expression. Our results suggest that polyoma large T is expressed in astrocytes, possibly resulting in altered glial-glial interactions causing impaired oligodendroglial development and secondary dysmyelination. Transgenic oligodendrocytes exhibit features of immaturity, failing to myelinate axons properly and producing morphologic phenotypes of early stages of myelination, such as numerous mesaxonal profiles. Myelin proteins are markedly reduced in transgenic CNS, and myelin basic protein transcripts, while present, are generally decreased. We believe that expression of large T in astrocytes could influence the complex and dynamic interactions between astrocytes and oligodendrocytes, perhaps with regard to the molecular (trophic) signals in the local CNS environment, bringing about arrested oligodendroglial maturation and hypomyelination. This raises intriguing questions concerning the importance of glial-glial interactions in the CNS and the complex levels of control involved in biological expression of genetic information in glial cells.

Animals↗
PubMed1992

[Gerstmann-Sträussler-Scheinker disease. Pathologal and genetic study].

Gerstmann-Sträussler-Scheinker's disease is a familial spongiform encephalopathy whose pathological hallmark is the existence--especially in the cerebellum--of numerous amyloid plaques. We report here the third clinicopathological case in a French family. Brain tissue from one of its members--initially described as familial Creutzfeldt-Jakob's disease--has been reported as successfully inoculated to monkeys. We present the currently accumulating data favouring the hypothesis of a common etiology for familial Creutzfeldt-Jakob's disease and Gerstmann-Sträussler-Scheinker's disease. The familial characteristics, resulting in different durations of incubation and evolution, could lead to different clinical and histological expressions.

Amyloidosis↗
PubMed1991

Transmissible familial Creutzfeldt-Jakob disease associated with five, seven, and eight extra octapeptide coding repeats in the PRNP gene.

The PRNP gene, encoding the amyloid precursor protein that is centrally involved in Creutzfeldt-Jakob disease (CJD), has an unstable region of five variant tandem octapeptide coding repeats between codons 51 and 91. We screened a total of 535 individuals for the presence of extra repeats in this region, including patients with sporadic and familial forms of spongiform encephalopathy, members of their families, other neurological and non-neurological patients, and normal controls. We identified three CJD families (in each of which the proband's disease was neuropathologically confirmed and experimentally transmitted to primates) that were heterozygous for alleles with 10, 12, or 13 repeats, some of which had "wobble" nucleotide substitutions. We also found one individual with 9 repeats and no nucleotide substitutions who had no evidence of neurological disease. These observations, together with data on published British patients with 11 and 14 repeats, strongly suggest that the occurrence of 10 or more octapeptide repeats in the encoded amyloid precursor protein predisposes to CJD.

Adult↗
PubMed1990

Coexistence of Creutzfeldt-Jakob disease and Alzheimer's disease in the same patient.

We report the case of a 73-year-old patient in whom a diagnosis of Creutzfeldt-Jakob disease, suggested by the clinical course, was verified by the neuropathologic finding of widespread spongiform change and astrogliosis, the presence of proteinase-resistant protein in brain extracts, and the experimental transmission of spongiform encephalopathy to primates inoculated with brain tissue. However, neuropathologic examination also revealed a profusion of senile and neuritic plaques and neurofibrillary tangles that reacted with antibody to the amyloid beta-protein characteristic of Alzheimer's disease, but not with antibody to the scrapie amyloid protein characteristic of Creutzfeldt-Jakob disease.

Aged↗
PubMed1989

Neurological disorder in transgenic mice that express the large T antigen of polyoma virus in the nervous system.

Among a series of 44 transgenic families established after microinjection into fertilized eggs of a plasmid DNA where the structural gene for the large T antigen of polyoma virus is located downstream from the viral early promoter-enhancer region, one family with a hereditary neurological disorder was observed. At about three weeks of age, these animals developed a syndrome of constant tremor with recurrent seizures. Histological and ultra-structural examination revealed extensive dysmyelination in the white matter of the brain stem, cerebellum and spinal cord, as well as of peripheral nerves. This phenotype is reminiscent of that of the mouse "twitcher" (twi) mutant and of the human hereditary leukodystrophies. Expression of the viral sequences, assayed by Northern analysis and immunolabeling of T antigen, occurred predominantly in cells of the central nervous system. Integration of the transgene was mapped by in situ hybridization on metaphasic plaques in region B-C1 of chromosome 12 (where the twi locus was previously localized). Long-term cultures of cells with neural characteristics could be established readily from the brain of the transgenic mice.

Animals↗
PubMed1988

Antiserum to scrapie-associated fibril protein reacts with amyloid plaques in familial transmissible dementia.

Scrapie-associated fibrils (SAF) are disease-specific markers for the unconventional agent-induced, transmissible spongiform encephalopathies. Polyclonal rabbit antiserum to SAF protein was reacted with brain sections from scrapie-infected mice, two familial cases of transmissible dementia, and three cases of Alzheimer's disease (AD). Specific immunostaining of cerebral amyloid plaques occurred in the scrapie-infected mice and in the two familial cases of transmissible dementia. No immunoreactivity was detected in senile plaques or neurofibrillary tangles in the three cases of AD. Our results suggest that SAF, the causative pathogenic agent, and extracellular deposits of amyloid in the brain are closely related. Immunohistochemical detection of SAF protein could serve as a useful diagnostic adjunct in the postmortem evaluation of difficult cases of dementia. The identification of SAF protein in the brains of two affected members of a family combining the clinical and pathological features of Creutzfeldt-Jakob disease (CJD) and the Gerstmann-Straüssler syndrome (GSS) substantiates earlier conclusions of a nosological relationship between the two. Our study provides further evidence of the similarity of SAF protein to prion protein (PrP 27-30).

Adult↗
PubMed1987

Sleep abnormalities with REM disorder in experimental Creutzfeldt-Jakob disease in cats: a new pathological feature.

Alterations in sleep organization were studied during the clinical phase of experimental Creutzfeldt-Jakob disease (CJD) in cats. Twenty months after intracerebral inoculation of a CJD agent, cats developed clinical signs including behavioral changes, diminished grooming activity, dysmetria, startle reflex, myoclonus, and unusual sleep abnormalities. Rapid eye movement (REM) sleep displayed a new and irreversible organization, with a continuous and constant pseudoperiodic pattern of rapid eye movements, synchronous with diffuse bursts of cortical abnormalities and with ponto-geniculo-occipital (PGO) wave activity. Computer analysis revealed a constant morphology of cortical bursts and their temporal relationship with ocular episodes. Induction of PGO wave activity with benzoquinolizine derivative Ro 4-1284 demonstrated the PGO-dependent nature of the cortical alterations. Abnormal unresponsive states were observed during REM sleep phases and arousal thresholds were increased in CJD cats during REM sleep. The percentages of wakefulness and slow-wave sleep were reversed in these animals. Preliminary neuropathological observations included discrete to minimal spongiosis of cerebral gray matter and a remarkably focalized intracytoplasmic vacuolation in neurons of the raphé system. Our findings suggest that particular neuronal systems involved in sleep regulation are impaired in CJD cats.

2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-↗
PubMed1987

Chronic localised encephalitis (Rasmussen's) in an adult with epilepsia partialis continua.

A 29 year old male presented with epileptic fits, progressive left sided focal seizures and epilepsia partialis continua, increasing left hemiparesis and mental slowing. Death occurred 2 years after the onset of the illness. Lesions were limited to the right cerebral hemisphere. Hypertrophic astrocytosis was diffuse throughout the gray and white matter but was more severe in the deep cortical layers and U fibres, where it was associated with vacuolar changes and capillary proliferation. Sparse perivascular lymphocytic cuffs, rod shaped microglia and microglial nodules were present. No inclusion bodies were found. These clinico-pathologic features were similar to the cases described by Rasmussen. Only five necropsy cases of this rare disease have been reported previously, all in children. The aetiology is unknown.

Adult↗
PubMed1986

Spread of scrapie agent to the central nervous system: study of a rat model.

Invasion of scrapie agent into the central nervous system (CNS) was studied in rats following intracerebral and peripheral inoculation, the latter by injection into intact or transected sciatic nerve. Comparison of sleep-wakefulness alterations, neuropathological features, and time lag of electroencephalographic and clinical signs in the 3 groups suggests that hematogenous spread of infection to the CNS may predominate over neural transport, and that peripheral inoculation may closely approximate natural infection.

Animals↗
PubMed1986

Study of endemic scrapie in a flock of "Ile de France" sheep.

An "Ile de France" flock was studied over a period of 5 years. The authors found similar results concerning incidence and age of onset of scrapie to those found in the English literature. A close relationship was established between the age of the dam at parturition and the age of the progeny at onset of scrapie. In the later years of our study, scrapie was detected in younger animals than in the earlier years, suggesting a phenomenon of genetic "anticipation". Increased fecundity in this endemically affected flock might represent a form of selection which favorises the occurrence and maintenance of the disease within the flock.

Animals↗
PubMed1986

Familial Creutzfeldt-Jakob disease in France: epidemiological implications.

Of 329 patients dying of Creutzfeldt-Jakob disease (CJD) in continental France between 1968 and 1982, 19 (6%) were familial cases. Genealogical investigation permitted the identification of 19 additional cases, bringing the total number of familial CJD cases reported here to 38. There are 6 definitely affected families, yielding an average of 6.3 cases per family. Mediterranean Jews account for one-third of all the cases, with Tunisian Jews constituting two-thirds of this ethnic group. Males and females are equally affected. The overall rate of occurrence (47.3%) is consistent with autosomal dominant transmission, but wide variations in individual pedigrees (26.7%-80%) leave this hypothesis open to scrutiny. Age at death is 10 to 15 years lower in familial than in sporadic CJD, suggesting the possible inheritance of "short incubation" genes in certain CJD families. Disease duration is longer in familial than in sporadic CJD, but this could be the effect of ascertainment bias. There is no evidence for maternal lineage. While members of a given family tend to die within the same age bracket, our data fail to discriminate between vertical transmission and common source exposure as hypothetical transmission mechanisms within affected families. CJD occurrence in a woman related by marriage to an unaffected branch of a CJD family, but who was raised in early childhood by the affected branch, argues in favor of horizontal transmission early in life. Analysis of death intervals and geographic/temporal separations suggests minimal incubation periods of up to 43 years. A family combining clinico-pathological features of CJD and the Gerstmann-Straüssler syndrome (GSS) indicates a nosological relationship between the two. The "genetic susceptibility" of members of CJD-affected families may be due to accelerated derepression of normally repressed host genes, coding for abnormal amyloid-type proteins. Accumulation of these proteins may play an important role in the pathogenesis of CJD and scrapie, and constitute a common pathogenetic mechanism in several neurological diseases, including Alzheimer's disease (AD) and senile dementia of the Alzheimer type (SDAT).

Age Factors↗
PubMed1985

Epidemiologic implications of Creutzfeldt-Jakob disease in a 19 year-old girl.

A histopathologically-verified, clinically typical case of Creutzfeldt-Jakob disease (CJD) is described in a 19 year-old girl. Only 3 previous cases of CJD have been reported in adolescents, and one of these was iatrogenically transmitted, while another was familial. Epidemiologic investigation of the present case excluded a familial component, and provided no evidence for iatrogenic or natural case-to-case transmission, or of other environmental sources of viral contamination. Young patients such as this one serve to emphasize the obscurity that still surrounds the epidemiology of CJD, and invite serious reconsideration of the possibilities of transmission by undetected virus carriers, or of the agent as a natural resident of human cells, replication of which might be triggered by non-infective (e.g., traumatic or mutational) environmental events.

Adult↗
PubMed1984

Creutzfeldt-Jakob disease: a case of 16 years' duration.

A 46-year-old man with Creutzfeldt-Jakob disease confirmed postmortem had a 16-year course of very slowly progressing incoordination and mental deterioration, suggesting Alzheimer's disease. The disease course transformed abruptly into a 7-week terminal phase of florid Creutzfeldt-Jakob disease. Dementing illnesses of unknown cause were present in the patient's paternal lineage.

Brain↗
PubMed1975

[Surgical textiles-material, methods, effects (author's transl)].

Wound textiles suitable for placing immediately over a wound and materials for securing them in position are discussed. Wound texiles have a curative function (blotting-paper effect, antigravitation effect). Conditions for their use are three-dimensional capillary drainage, plane compression, and nonstick and cooling properties. Cellulose fibers absorb moisture in all three dimensions, while synthetic fibers transport moisture around their strands in a two-dimensional course. The nonstick properties are achieved by means of overtwisted threads in the warp (tunnel effect) in woven fabrics, and in nonwoven fabrics (when moisture is produced) by combination with overstretched cellulose, producing corrugations, or (for drying) by the uneven incorporation of overtwisted fibers into the fabric, which produces a ventilating effect. The nonstick properties always become obvious when the dressings are moistened.

Bandages↗