Biomedical subjects

D Jaarsma

Publications and source records attributed to D Jaarsma.

23 records · Page 2Linked to original sources

PubMed1991

Localization of NMDA and AMPA receptors in rat barrel field.

The aim of this study was to assess the distribution of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-S-methyl-4-isoxazole propionic acid (AMPA) receptors in the barrel field of rat primary somatosensory (SI) cortex using light-microscopic in vitro autoradiography. NMDA receptors were labeled with the competitive antagonist [3H]CGP39653 or with [3H]glycine in the presence of strychnine, and AMPA receptors with [3H]AMPA. In the SI cortex high densities of the NMDA receptor occurred in the supragranular layers and in layer Va. In layer IV high NMDA receptor densities were specifically confined to the barrel hollows. The AMPA binding sites showed less intralaminar variation and no apparent density differences between the barrel hollows and sides in layer IV. It can be concluded that the distribution of NMDA (but not AMPA) receptors in the rat barrel field shows a strong coincidence with the zone of termination of the specific sensory afferents from the ventral posterior nucleus of the dorsal thalamus.

2-Amino-5-phosphonovalerate↗

PubMed1991

Reduction of adenosine A1-receptors in the perforant pathway terminal zone in Alzheimer hippocampus.

The cells of origin of the perforant pathway are destroyed in Alzheimer's disease (AD). In rat the adenosine A1-receptors are specifically localized on the perforant path terminals in the molecular layer of the dentate gyrus. In the present study the density of A1-receptors in the hippocampus of Alzheimer's disease (AD) patients (n = 9) and non-dement controls (n = 3) has been investigated autoradiographically with [3H]8-cyclopentyl-1,3-dipropylxanthine ([3H]CPDPX) as the ligand probe. In AD hippocampi binding of [3H]CPDPX was greatly reduced in the outer two thirds of the dentate gyrus molecular layer, likely due to the degeneration of the perforant path. Binding of [3H]CPDPX was not significantly altered in other parts of the AD hippocampus, e.g. the CA1 and the CA3, in spite of a pronounced cellular pathology and reduced N-methyl-D-aspartate (NMDA) receptor densities, assessed as strychnine insensitive [3H]glycine autoradiography. This contrasts with the presumed localization on dendrites of pyramidal neurons of A1 receptors within the CA1 and the CA3.

Adenosine↗

PubMed1990

A novel non-perfusion Timm method for human brain tissue.

A simple modification of the Timm sulphide-silver method for unfixed brain tissue is described. Instead of perfusing animals with a sodium sulphide solution, sulphide treatment was performed by exposure to mounted frozen sections to H2S gas. The staining pattern in the rat brain obtained with this modification is similar to that With the Neo-Timm method, primarily yielding staining of the neuropil of telencephalic structures. Because perfusion is not required, the modified Timm method can also be applied to postmortem human tissue. Application of the modified Timm stain to the human tissue is exemplified on the hippocampus with special attention to the non-mossy fiber staining.

Animals↗

PubMed1988

Sequential development of antibodies to specific Sm polypeptides in a patient with systemic lupus erythematosus: evidence for independent regulation of anti-double-stranded DNA and anti-Sm antibody production.

We describe a patient with systemic lupus erythematosus who, after a disease flare, sequentially produced antibodies to specific Sm polypeptides (demonstrated by counterimmunoelectrophoresis, immunoblotting, and RNA immunoprecipitation) concomitantly with the disappearance of anti-double-stranded DNA antibodies. Immunoblotting studies revealed that antibodies to the D polypeptide appeared first, followed by antibodies to BB' and E polypeptides, respectively. Our findings suggest that antibodies to the Sm-specific polypeptides do not occur simultaneously and that the regulation of their production is independent of that of antibodies to double-stranded DNA.

Adult↗

PubMedDate not supplied

Detection of autoantibodies to ribonucleoproteins by counter-immunoelectropheresis, immunoblotting and RNA-immunoprecipitation: comparison of results.

Counterimmunoelectropheresis (CIE), immunoblotting (IB) and RNA-immunoprecipitation (RNA-IP) were compared for their potential to detect antibodies to U1RNP, Sm and SS-B in sera from 50 patients with SLE and 18 with MCTD. Anti-SS-B were detected in 6 SLE-sera (12%) and one MCTD-serum (6%) by all three techniques. Anti-Sm were present in 7 SLE-sera (14%) by RNA-IP and IB; 3 of these sera showed identity with a-Sm and 4 with a-U1RNP by CIE. Antibodies precipitating U1RNA were present in 8 SLE sera (16%); 4 of these sera were positive for anti-U1RNP by CIE (8%) and 4 sera recognized one or more of the U1RNA-associated proteins by IB (8%). All MCTD-sera were positive for anti-U1RNP by RNA-IP including one serum negative by IB and CIE. RNA-IP allowed the detection of antibodies precipitating U1-U2RNA in 4 sera; in IB, the U2RNA specific protein B" was recognized by 3 sera. RNA-IP appears to be a sensitive method for detecting anti-URNP's.

Autoantibodies↗