Since kainate evokes large non-desensitizing currents at alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, kainate is of limited use in discriminating between AMPA and kainate receptors. Following recent reports that (2S,4R)-4-methylglutamate is a kainate receptor-selective agonist, we have radiolabelled and subsequently characterized the binding of [3H]-(2S,4R)-4-methylglutamate to rabbit whole-brain membranes. [3H]-(2S,4R)-4-methylglutamate binding was rapid, reversible and labelled two sites (KD1 = 3.67+/-0.50 nM/Bmax1 = 0.54+/-0.03 pmol/mg protein and KD2 = 281.66+/-12.33 nM/ Bmax2 = 1.77+/-0.09 pmol/mg protein). [3H]-(2S,4R)-4-methylglutamate binding was displaced by several non-NMDA receptor ligands: domoate > kainate >> L-quisqualate > or = L-glutamate > 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) >> (S)-AMPA = (S)-5-fluorowillardiine > NMDA. Neither the metabotropic glutamate receptor agonists (1S,3R)-ACPD or L-AP4, together with the L-glutamate uptake inhibitor L-trans-2,4-PDC, influenced binding when tested at 100 microM. We conclude that [3H]-(2S,4R)-4-methylglutamate is a useful radioligand for labelling kainate receptors. It possesses high selectivity, and possesses a pharmacology similar to that for rat cloned low-affinity (Glu5 and 6) kainate receptor subunits.

Animals↗

PubMedDate not supplied

Another potential source of error in Rh-hr typing.

Three cases are presented in which the presence of sodium caprylate dependent albumin auto-agglutinins in the patients' sera resulted in erroneous Rh-hr phenotyping of their erythrocytes. In the initial testing, the albumin control was negative in each case. Since one of the cases was an Rh0(D) negative individual whose red blood cells might have been classified as Rh0(D) positive, a study was made using routine Rh-hr typing reagents from different manufacturers. Attention is drawn to the fact that Rh-hr typings should be performed using washed red blood cell samples when serum is known to contain albumin autoagglutinins.

Humans↗

PubMedDate not supplied

Autoagglutination dispersal utilizing sulphydryl compounds.

Autoagglutination caused by powerful IgM cold autoagglutinins can be dispersed by sulphydryl compounds to provide an unagglutinated red blood cell suspension suitable for immunohematologic testing. For this 0.1 M 2-mercaptoethanol is added to twice washed red blood cells. Following agitation for 10 minutes at 37 C an unagglutinated red blood cell suspension is obtained without adverse effect to red blood cell antigens and without removal of in vivo bound IgG or complement. Dithiothreital may be substituted for 2-mercaptoethanol if the incubation time is increased to 15 minutes.

Autoantibodies↗

PubMedDate not supplied

Anti-Jra in a Mexican American.

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

Auto-anti-A1: another cause of ABO discrepancy.

Anti-A1 was found in the serum of a patient of blood group A1 who had never received a blood transfusion. The patient's serum caused agglutination of his own red blood cells. The anti-A1 could be totally absorbed by red blood cells from the patient and from other A1 individuals. The anti-A1 was inhibitable by soluble group A-specific substance and was denatured by 2-mercaptoethanol. The A and H serum transferases were normal. The presence of auto-anti-A1 in the serum of an A1 individual is yet another cause of ABO discrepancy.

ABO Blood-Group System↗

PubMedDate not supplied

Transient anti-Gya in an untransfused man. Serologic characteristics and cell survival study.

Anti-Gya was identified in the serum of a 71-year-old untransfused man of German descent. The anti-Gya was reactive in the antiglobulin test phase and was of the IgG1 subclass. The patient's red cells typed as Gy(a-). A survival study using 10 ml of ABO compatible Gy(a+) 51Cr labelled red blood cells indicated normal survival up to six days. The anti-Gya diminished in reaction strength, and three months after the patient's initial hospitalization the antibody was no longer demonstrable by standard manual techniques. We conclude that intravascular hemolysis would have been unlikely if this patient were transfused with Gy(a+) cells. However, due to the possibility of a delayed hemolytic transfusion reaction, Gy(a+) cells would have been given only if Gy(a-) cells were not available and the patient's red blood cell deficit were life-threatening.

Aged↗

PubMedDate not supplied

Absorption of anti-Chido from serum using autologous red blood cells coated with homologous C4.

A method is described which absorbs anti-Chido from serum without reducing the strength of other alloantibodies. Autologous red blood cells are coated with homologous C4 by a low-ionic-strength method and then used for the absorption. This is a practical method for removing anti-Chido from serum so that underlying alloantibodies may be identified and compatibility testing performed.

Absorption↗