Search PubMed⌕ Search

Biomedical subjects

M L Beck

Publications and source records attributed to M L Beck.

At least 91 records · Page 5Linked to original sources

Auto anti-Kpb associated with weakened antigenicity in the Kell blood group system: a second example.

An 84-year-old woman with intestinal bleeding had marked reduction of red blood cell antigenicity in the Kell system, and a positive direct antiglobulin test caused by auto-anti-Kpb. KX antigen activity of her cell was increased, an observation which supports the belief that KX marks a precursor structure utilized in the normal Kell biosynthetic pathway. It is postulated that reduced Kell antigenicity was an acquired change that resulted from enzymatic degradation, possibly of bacterial origin.

Adolescent↗

The immunoglobulin structure of human anti-M agglutinins.

Fifty examples of human anti-M agglutinins were subjected to reductive cleavage using both 2-mercaptoethanol (2-ME) and dithiothreitol (DTT). Thirty-nine (78%) were resistant to inactivation by sulphydryl compounds indicating IgG composition. This was confirmed by column chromatography. The remaining eleven sera were sensitive to reduction cleavage. There was no obvious association of immunoglobulin composition of the antibody with previous immune exposure to the M antigen. These results confirm observations in the literature that anti-M agglutinins are an exception to the generally expected correlation of saline agglutinating activity with IgM structure.

Agglutinins↗

Hemolytic disease of the newborn associated with anti-Jk3.

This report documents a mild case of hemolytic disease of the newborn (HDN) associated with anti-Jk3. The Filipino mother had previously had six children none of whom had been affected by HDN. She had been transfused at the time of her second pregnancy. Anti-Jkb and anti-Jk3 were detected in the maternal serum at the time of her seventh delivery. No prenatal serologic tests for blood group antibodies had been performed. The cord blood was found to have a positive direct antiglobulin test and anti-Jkb plus anti-Jk3 were eluted. The infant was treated with phototherapy.

Adult↗

Anti-s reagents.

Explore the source record for details and available documents.

Female↗

A modified capillary test using 4% ficin.

A capillary technique is described for economical Rh-phenotyping of large numbers of blood samples using diluted antisera and 4% ficin solution. This system is no more time consuming that conventional tube techniques, since enzyme premodification of the cells is not required.

Blood Grouping and Crossmatching↗

Hemagglutination in capillaries: correlation with blood group specificity and IgG subclass.

Two hundred four examples of blood group antibodies, reactive only by the indirect antiglobulin test, were examined by the two-layer albumin capillary (TLAC) technique. Fifty-nine per cent of the examples tested were reactive by this technique. TLAC reactivity appeared to be related to antibody specificity, but a positive association between TLAC reactivity and IgG subclass composition was not confirmed.

Antibody Specificity↗

Monocyte-mediated erythrocyte destruction. A comparative study of current methods.

Three assay systems-EAIgG rosette formation, 51Cr release, and erythrophagocytosis-were used to quantitate interaction between antibody-coated human erythrocytes and normal blood monocytes. The three methods were compared in terms of time requirements and sensitivity. Erythrophagocytosis required more time to perform (2 hours) than did rosette tests (30 minutes) but less than minimum 51Cr release assays (5.5 hours). Erythrophagocytosis was 20-fold more sensitive than either of the other two procedures. Results obtained with purified IgG anti-D and with antibodies induced by transfusion or pregnancy were similar.

Antibodies, Anti-Idiotypic↗

Factors influencing monocyte recognition of human erythrocyte autoantibodies in vitro.

Erythrocytes, serum, and blood monocytes from patients with erythrocyte autoantibodies were examined by in vitro serologic and cell culture procedures in order to evaluate factors modulating patient mononuclear phagocyte activity. Monocyte recognition of autoantibody-coated erythrocytes was influenced both by antibody titer score and by the monocyte source. The results suggest that patients with low serum autoantibody titer scores and normal monocyte behavior are less likely to destroy autologous or normal donor erythrocytes than are patients with high-serum antibody titer scores or enhanced monocyte activity. We conclude that patient, rather than normal donor monocytes, must be used in cellular assays designed to predict the fate of erythrocytes transfused into patients with erythrocyte autoantibodies.

ABO Blood-Group System↗

Anti-Wj: an autoantibody that defines a high-incidence antigen modified by the In(Lu) gene.

An IgG autoantibody, named anti-Wj, reacts with all random and most selected red cell samples. It does not agglutinate cells of Lu(a-b-) type caused by the In(Lu) dominant inhibitor gene, but cells of recessive Lu(a-b-) type are reactive. These data establish that synthesis of the Wj antigen is suppressed by the In(Lu) gene, but it is not a part of the Lutheran blood group system. The Wj antigen is not well developed on fetal red cells. This example of auto anti-Wj is a non-complement-binding IgGl protein that did not appear to cause accelerated in vivo destruction of the patient's red cells.

Adult↗

Incompatibility associated with the bite of a brown recluse spider (Loxosceles reclusa).

Red cell samples from a patient who was suffering from massive hemolysis due to a brown recluse spider (Loxosceles reclusa) bite were found to be reactive by indirect antiglobulin test with most ABO-compatible serum samples. Spider venom, enzymes related to those in spider venom, and antisera to plasma proteins and Rh antigens were used to investigate the unusual reactivity of the patient's cells. IgG was detected on the patient's cells by indirect antiglobulin tests. Cells treated with brown recluse spider venom or phosphatidylcholine phosphatidohydrolase reacted similarly. These findings suggest that sphingomyelinase D, which has been identified in brown recluse spider venom, may be related to the unusual reactivity of the patient's cells. Unexpected reactions were observed when venom-treated cells were tested with Rh antibodies: O negative cells absorbed and eluted anti-D from Rh immune globulin; E negative cells were reactive with a commercial anti-E reagent.

ABO Blood-Group System↗

Range forb lectins.

In this study we tested the seeds of uncultivated plants for lectin activity. Extracts prepared from the seeds of 167 forb species were tested against human red cell samples. Extracts of 54 species agglutinated unmodified or enzyme-modified red cells. In nine species, the hemagglutinating lectin activity could be neutralized by N-acetyl-D-galactosamine, mannose, or glucose.

Hemagglutination Tests↗

Solid-phase ABO grouping and Rh typing.

A solid-phase adherence method (SPAM) for ABO grouping and Rh typing of red cells (RBCs) has been developed. Adherence reactions were read spectrophotometrically and interpreted by a computer. The SPAM had a 99.6 percent correlation with conventional microplate agglutination methods for ABO grouping and Rh typing. The increased sensitivity of the SPAM was demonstrated because it directly detected Du-positive RBCs and weak subgroups of A and B.

ABO Blood-Group System↗

A solid-phase antiglobulin test.

A solid-phase antiglobulin test was developed as an alternative to hemagglutination for compatibility testing. The solid-phase endpoint of red cell adherence allowed results to be read visually or spectrophotometrically. This method was easier to perform than a hemagglutination antiglobulin test and had increased sensitivity without loss of specificity.

Antibody Specificity↗

Genetic variation in the terrestrial isopod, Armadillidium vulgare.

Allozymic variation for the terrestrial isopod, A. vulgare, is low when compared to that reported for most invertebrates, with the average individual being heterozygous at 3.4 percent of its loci. However, this level of heterozygosity is comparable to that reported in various decapods. A significant heterozygote deficiency occurred in local populations of A. vulgare, which is most likely due to selection and/or nonrandom mating.

Animals↗

Evaluation of video tape and a simulator for instruction of basic surgical skills.

Twenty first-year veterinary students with no prior participatory experience in surgery were randomly paired and assigned into two study groups. Ten students (group V) viewed a hemostatic technique video tape until they thought they could competently perform and assist in performing a hand-tied ligature on a blood vessel in a live animal. Ten students (group VS) wer also given a simulator for technique practice. Paired students were video recorded and blindly evaluated on their ability to perform and assist proper ligation of a bleeding vessel. Inexpensive hemostasis models were very helpful for teaching students essential surgeon and assistant skills involved in hand-tied ligature placement. Students who practiced with simulators performed significantly better as surgeon and assistant, and in total psychomotor skill evaluation, then students watching the video only. Students using simulators performed ligation with significantly more accuracy and tended to be more expeditious at this task. Further training is needed for students to acquire skills necessary for efficient bleeding vessel exposure and isolation.

Animals↗

Evaluation of an autotutorial-simulator program for instruction of hollow organ closure.

Forty students were randomly assigned into two study groups (traditional, T; and simulator, S) of 20 students each for a core operative practice laboratory. Students were randomly paired and their group assignment and identity remained anonymous to the evaluators throughout the study. Questionnaires were distributed to students to evaluate prior surgical experience and obtain learning resource use information. Before the evaluation sessions, both groups were given identical learning resource opportunities except students in Group S received hollow organ simulators and practice materials for gastrotomy closure. All students were forewarned that surgical instruction would not be available during the evaluation sessions. In the first live animal evaluation session, all student pairs were videotaped after which stomachs were harvested for gross evaluation of the surgical site. Group T performed an additional gastrotomy for video and gross evaluation 2 weeks later. Questionnaire, and gross and video evaluation results were compared statistically between groups and sessions. The hollow organ model did not suitably simulate live stomach tissue; the material was more fragile and stiff and suture cut-out was a problem even with appropriate suture tension and technique. The model was effective for teaching needle placement, instrument usage, creating proper tissue inversion, and methods to minimize instrument handling of tissue during gastrotomy closure. Prior practice with models did not boost student confidence during their live gastrotomy session. The autotutorials (ATs) were well received by students but did not sufficiently address how to manage mucosal eversion, suture tension, and bleeding encountered during live gastrotomy. AT viewing time positively correlated with mean total video score for Group T during both sessions. None of the students had prior experience performing hollow organ closure and no significant difference in experience level was evident between groups. Mean closure time was not significantly different between groups for session one (Group T, mean, 31.5 minutes, range, 18.4 to 53.4; Group S, mean, 28.2 minutes, range, 16.8 to 36), but was significantly reduced for session two (Group T, mean, 21.3 minutes, range, 13.9 to 31). This AT/simulator program does not significantly influence students' overall gastrotomy closure technique; gross and video evaluation scores were not significantly different between groups. Without instructor supervision, an additional gastrotomy experience did not improve surgical technique appreciably for Group T; however, these students performed the second procedure with more confidence and speed.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗