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R Rubenstein

Publications and source records attributed to R Rubenstein.

At least 55 records · Page 3Linked to original sources
PubMed1991

Clinical and molecular genetic study of a large German kindred with Gerstmann-Sträussler-Scheinker syndrome.

We have verified, by full open reading frame sequencing, the presence of an amino-acid-altering mutation in codon 102 of the scrapie amyloid protein gene in three affected members of a large and well-documented German family with experimentally transmitted Gerstmann-Sträussler-Scheinker syndrome. In addition, we identified the mutation by partial sequencing or DNA restriction enzyme analysis in three of 12 presently healthy family members with an affected parent, and none of 12 members without an affected parent. Thus, a total of six of 15 family members at risk for the disease (including the three established cases) had the same codon 102 mutation, a proportion consistent with the autosomal dominant inheritance pattern of disease expression. It is undetermined whether the mutation influences susceptibility to infection by an exogenous agent or is itself a proximate cause of disease.

Adult↗
PubMed1990

Creutzfeldt-Jakob disease and kuru patients lack a mutation consistently found in the Gerstmann-Sträussler-Scheinker syndrome.

We and others have recently reported that patients with the Gerstmann-Sträussler-Scheinker syndrome have a mutation at codon 102 of the gene coding for amyloid protein that accumulates in this disease. We report here that this mutation was not found in 5 familial and 27 sporadic cases of Creutzfeldt-Jakob disease or in 3 patients with kuru, so that although this mutation may be responsible for amyloidogenesis and transmissibility in Gerstmann-Sträussler-Scheinker syndrome, it cannot be the only cause of human spongiform encephalopathy.

Base Sequence↗
PubMed1990

Further characterization of scrapie replication in PC12 cells.

The rat pheochromocytoma cell line, PC12, undergoes neuron-like morphological, biochemical and electrophysiological differentiation, in the presence of low concentrations of nerve growth factor (NGF). NGF-treated PC12 cells have been shown previously to support 139A scrapie agent replication. In the present report we extended these findings and analysed the cellular conditions necessary for agent replication. Following the infection of differentiated PC12 cells, scrapie replicated to relatively high titres as determined by an incubation period assay. The removal of NGF, which causes the gradual dedifferentiation of PC12 cells, resulted in the inability of scrapie to replicate. The scrapie infectivity detected in PC12 cultures is cell-associated and not released into the medium. Cells in infected cultures did not show any change in morphology when compared to cells in mock-infected cultures. Titration studies of scrapie infectivity in PC12 cells have indicated that up to 4 LD50 units per cell can be obtained although a yield of 1 LD50 per cell was more common. Using an approximate m.o.i. of 1, only differentiated PC12 cells supported 139A scrapie agent replication when compared to two other differentiated, neuronal cell types, indicating that PC12 cells are more susceptible to agent replication. These studies support further the suitability of using differentiated PC12 cells as an in vitro model to study scrapie agent replication.

Adrenal Gland Neoplasms↗
PubMed1989

Mutations in familial Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker's syndrome.

A host protein encoded by the gene specifying the scrapie amyloid precursor affects pathogenesis of the transmissible spongiform encephalopathies: Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker's syndrome (GSS), and kuru in man, and scrapie in animals. We found a mutation in this gene of two patients with CJD from one family and a second mutation in the same gene in three patients with GSS from another family. The mutation in two related familial CJD patients changed glutamine in position 200 tolysine. This mutation was absent in other individuals including unrelated patients with familial CJD, sporadic CJD, and GSS. The other mutation in three GSS patients changed proline in position 102 to leucine, the same mutation described recently in some GSS families. We did not find it in six unaffected relatives of the GSS patients or in other individuals including sporadic and familial CJD patients. A rare insertion described earlier in one CJD family was also absent in all tested individuals.

Base Sequence↗
PubMed1989

Classic genetics of scrapie.

Many years ago, observations of natural scrapie revealed differences in clinical manifestations and in the areas of the brain that showed the most intense histopathological changes. In experimental work with scrapie in mice two fundamental points were established in early studies: (1) A mouse gene, termed Sinc for scrapie incubation, affects the length of the incubation period. (2) In a single strain of mice, incubation periods of different "strains" of scrapie can differ by as much as 3-4 fold, e.g., the incubation period of the ME7 scrapie strain in C57BL mice is approximately 122 days, whereas the incubation period for the 22A strain is 360 days. From this "classic" beginning our knowledge about the parameters influenced by genetic characteristics of both host and agent have expanded. In a number of instances, initial examination of an aspect of host-agent interaction has subsequently revealed surprising influences of informational molecules from both host and agent. A partial list of the parameters under genetic control follows: (1) The extent of vacuolation in various regions of the brain; (2) The quantity of amyloid plaques in the brain; (3) The occurrence of increased weight in the preclinical phase of disease; (4) The development of aberrant glucose tolerance; (5) The area of the brain which yields the shortest incubation period after stereotaxic injection; and (6) The physical-chemical and immunological characteristics of scrapie associated fibrils. In several well documented instances differences between scrapie strains were evident after repeated passages of the strains in the same host strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Detection of scrapie-associated fibrils (SAF) and SAF proteins from scrapie-affected sheep.

Scrapie-associated fibrils (SAF) were detected by negative-stain electron microscopy in the brains (by two different isolation procedures) and spleens of sheep naturally and experimentally infected with scrapie. Although the numbers of SAF varied from case to case, the yield of SAF from brains of naturally affected sheep was lower than that from experimentally affected sheep. SAF-specific, protease-resistant proteins (PrPs) were detected by silver staining and western blot analysis in most samples of brain from experimentally affected sheep. PrPs, however, could be detected in only a limited number of natural cases of sheep scrapie because of the lower yields of SAF. PrPs from sheep SAF appear biochemically and antigenically similar to PrPs from other species infected with unconventional agents. This study further establishes the unique association of SAF and PrPs with natural or experimentally induced scrapie in its natural host.

Animals↗
PubMed1987

Antisera to scrapie-associated fibril protein and prion protein decorate scrapie-associated fibrils.

Scrapie-associated fibrils (SAF) are an infection-specific structure observed in the unconventional-agent diseases. Polyclonal antisera raised to scrapie proteins were used to test the antigenic relationship between purified fibrils and SAF isolated from non-protease-treated synaptosomal-mitochondrial preparations. The experimental design utilized fibrils from scrapie strain 263K-infected hamsters, scrapie strain 139A-infected mice, and scrapie strain ME7-infected mice. Preparations were examined by negative-stain immune electron microscopy and Western blot analysis of the polypeptides. Fibrils and polypeptides from each preparation reacted with a rabbit antiserum raised to each of the following: hamster 263K prion protein (PrP 27-30), hamster 263K SAF protein, and mouse ME7 SAF protein. Immune electron microscopy and Western blot analysis revealed similar antigenic relationships among the three scrapie antisera. Thus, fibrils and polypeptides can be considered to be the same in each preparation. No reactivity of the fibrils was observed with antisera raised to Alzheimer neurofibrillary tangles or a synthetic peptide of cerebrovascular amyloid. Thus, the fibrils observed in purified preparations share structural and antigenic similarities plus biochemically related peptides with SAF present in non-protease-treated preparations.

Animals↗
PubMed1987

Mouse polyclonal and monoclonal antibody to scrapie-associated fibril proteins.

Antibody response in mice to scrapie-associated fibril proteins (protease-resistant proteins [PrPs]) was generated to different epitopes depending on the source of antigen. Mice responded differently to PrPs isolated from scrapie-infected animals of homologous (mouse) versus heterologous (hamster) species. An enzyme-linked immunosorbent assay established to monitor this antibody response in mice immunized with PrPs was unable to detect such a response in scrapie-infected mice. A monoclonal antibody (MAb), 263K 3F4, derived from a mouse immunized with hamster 263K PrPs reacted with hamster but not mouse PrPs. MAb 263K 3F4 also recognized normal host protein of 33 to 35 kilodaltons in brain tissue from hamsters and humans but not from bovine, mouse, rat, sheep, or rabbit brains. This is the first demonstration of epitope differences on this host protein in different species. The defining of various epitopes on PrP through the use of MAbs will lead to a better understanding of the relationship of PrPs to their host precursor protein and to the infectious scrapie agent.

Animals↗
PubMed1987

Childhood epidermolysis bullosa acquisita. Detection in a 5-year-old girl.

A 5 1/2-year-old girl with a blistering disease involving the skin and the oral, ocular, and anogenital mucosa is described. The initial clinical, histologic, and immunofluorescence findings suggested a diagnosis of cicatricial pemphigoid. However, immunoelectron microscopy demonstrated linear deposits of several immunoreactants within the sub-lamina densa region of the dermoepidermal junction, consistent with the diagnosis of epidermolysis bullosa acquisita. Although epidermolysis bullosa acquisita is considered a disease of adult onset, it should be included in the differential diagnosis of blistering diseases in children.

Basement Membrane↗
PubMed1987

Pruritus: a new look at an old problem.

Pruritus, a frequent complaint heard by family physicians, is a complex physiological phenomenon mediated by histamine and other peptides. It is associated with a number of common dermatologic diseases but has significant psychological factors as well. In some patients pruritus may be an important marker of systemic disease. Diagnostic approach includes a careful physical examination of primary skin lesions and goal-directed laboratory tests. Careful skin care and oral antihistamines are basic measures to alleviate pruritus.

Humans↗
PubMed1986

Paired helical filaments associated with Alzheimer disease are readily soluble structures.

Considerable controversy exists concerning the origin and composition of Alzheimer neurofibrillary tangles (ANT) and of paired helical filaments (PHF), the abnormal cytoplasmic fibers which ultrastructurally are the major components of ANT. Thus far, the unusual solubility properties of PHF have hindered the analysis of ANT. A new procedure is presented for isolating purified PHF which are soluble in the presence of sodium dodecyl sulfate. The purification protocol involves differential and rate zonal centrifugation, treatment with the detergents sarcosyl and sulfobetain 3-14, and sonication. The isolated PHF from Alzheimer disease/senile dementia of the Alzheimer type (7 cases) and Down's syndrome (one case) have been characterized structurally by negative-stain electron microscopy, biochemically by PAGE, and immunologically by both the ELISA technique and Western blot analysis using a monoclonal antibody prepared against ANT. Distinct polypeptides were shown to be associated with this structure and not seen in preparations from young and age-matched normal brains.

Adult↗
PubMed1986

Atypical keloids after dermabrasion of patients taking isotretinoin.

Six patients underwent dermabrasion while on or having recently completed isotretinoin (Accutane) therapy. All patients developed keloids in atypical locations; the keloids eventually responded to topical or intralesional steroid therapy. Retinoids have a modulatory effect on connective tissue metabolism, including suppression of collagenase, which may enhance keloid formation. Dermabrasion should be delayed in those patients taking or recently on isotretinoin therapy.

Acne Vulgaris↗
PubMed1986

Isolation of a cDNA clone encoding the leader peptide of prion protein and expression of the homologous gene in various tissues.

We have isolated a hamster cDNA clone representing the coding sequences for the entire precursor of prion protein (PrP) 27-30. This clone encodes a protein of 254 residues and contains an in-frame ATG codon 42 bases upstream from the one previously reported. Analysis of the predicted amino acid sequence suggests that the PrP precursor protein contains an amino-terminal signal sequence, and a membrane-spanning domain in the carboxyl terminus. Cleavage of the signal peptide would produce a mature protein of 232 amino acids. Sequences homologous to the hamster PrP cDNA were detected in hamster, mouse, sheep, human, and rabbit genomes. A related 2.5-kilobase transcript was present in the brain of normal and scrapie-infected rodents. Two homologous transcripts, 2.5 and 1.1 kilobases, were detected in the lung and heart of normal animals. No PrP mRNA was detected in spleen stroma, a tissue known to contain high titers of scrapie. Antisera raised to the 27- to 30-kDa polypeptide detected the PrP in both normal and infected brains but failed to detect this protein in either normal or infected spleens. Homologous mRNA species were detected in human, sheep, and rabbit brain, even though the latter is resistant to scrapie infection. Our data suggest that PrP is not a necessary component of the infectious agent.

Amino Acid Sequence↗
PubMed1986

Detection of scrapie-associated fibril (SAF) proteins using anti-SAF antibody in non-purified tissue preparations.

Antisera raised to scrapie-associated fibril (SAF) proteins were used to detect scrapie-specific polypeptides in three different non-purified brain preparations: a synaptosomal-mitochondrial fraction, 20% brain homogenate and 20% brain homogenate extracted with Sarkosyl. The concentration of SAF proteins in the preparations was greater than the quantity of SAF as detected by negative stain electron microscopy. This suggests that not all of the protein exists in the form of SAF. An immunologically reactive 33K to 35K protein was detected in both normal and scrapie brain preparations. This protein was susceptible to complete proteinase K (PK) digestion in normal brain preparations and it is suggested that scrapie infection is responsible for post-translational modifications which confer PK resistance in scrapie preparations. These modifications may also play a role in the antigenic differences seen in a variety of scrapie agents. SAF-specific proteins were also detected in the spinal cords and spleens from scrapie-affected animals. Detergent extraction of material followed by PK treatment and Western blot analysis is a highly specific and sensitive method for the detection of SAF proteins. This procedure could be applied to human neurological diseases of unknown aetiology.

Animals↗
PubMed1986

Meningococcal meningitis with a benign skin rash.

A skin eruption may be one of the early clues to meningococcal meningitis. We treated a boy with meningococcal disease accompanied by an exanthemlike eruption. Although the skin lesions in meningococcal meningitis are traditionally described as petechial, purpuric, or ecchymotic, the absence of these findings should not deter the physician from a clinical suspicion of this potentially fatal infection.

Child, Preschool↗