Assessing learner engagement with virtual educational events: Development of the Virtual In-Class Engagement Measure (VIEM)

BACKGROUND

The COVID-19 pandemic has necessitated virtual education, but effects on learner engagement are unknown. We developed a virtual in-class engagement measure (VIEM) to assess learner engagement in online surgical education events.

METHODS

Using the STROBE, an observer collected tool to document student engagement, as a template an ASE committee workgroup developed the VIEM. The VIEM had two parts: observer assessment and learner self-assessment of engagement. Trained observers collected engagement data from two institutions using the VIEM. Surgical attendings, fellows and residents were observed during virtual learning events. Educator attitudes towards online teaching were also assessed via survey.

RESULTS

22 events with 839 learners were observed. VIEM distinguished between sessions with low and high engagement. 20% of learners pretended to participate. Half of instructors were comfortable with virtual teaching, but only 1/3 believed was as effective as in-person. 2/3 of teachers believed video learners were more engaged than audio learners.

CONCLUSIONS

Virtual platforms do not automatically translate into increased engagement. Standard tools such as VIEM may help with assessment of engagement during virtual education.

Serodiagnosis of infectious mononucleosis with a bovine erythrocyte glycoprotein

A glycoprotein from bovine erythrocyte membrane was evaluated in two immunoassays as a reagent for the serodiagnosis of infectious mononucleosis (IM). We previously reported that a partially purified preparation of this glycoprotein, when attached to latex beads, agglutinated in the presence of IM heterophile antibody. In the present study, we used a highly purified form of the glycoprotein both as an agglutinating reagent, covalently bound to latex, and in a solid-phase sandwich-type radioimmunoassay (RIA) for IM antibody detection in a larger population of patients. We tested serum samples from college students with symptoms suggestive of IM with the latex reagent (143 samples) and with the RIA (245 samples). Correlation of these two tests, both with each other and with the classical differentially absorbed, agglutination tests for Paul-Bunnell antibody in IM sera, using fresh sheep or horse cells, was excellent (greater than 97% agreement). The new tests also corresponded in most cases with a rapid, unabsorbed preserved horse erythrocyte slide test. However, in this study of 245 samples, both apparent false-positives (5 samples) and apparent false-negatives (3 samples) were observed with this slide test. In conclusion, we found that the bovine glycoprotein as a reagent can facilitate the diagnosis of IM, giving results comparable to those with erythrocyte agglutination tests on differentially absorbed sera. The advantages are ease and speed of performance (latex test), potential for automation (RIA test), stability and uniformity of the glycoprotein reagent (latex and RIA tests), and most importantly, the ability to use unabsorbed sera (latex and RIA tests).

Horse erythrocyte glycoprotein-latex reagent that reacts with infectious mononucleosis heterophile antibody

A sialoglycoprotein from horse erythrocytes was isolated in essentially homogeneous form and found to contain the neuraminidase-sensitive determinant of the horse erythrocyte for Paul-Bunnell heterophile antibodies of infectious mononucleosis. This reactivity was retained after covalent coupling of the antigen to latex particles. The latex reagent has greater stability (greater than 3 years) than either fresh or preserved horse erythrocytes. It can be used in a direct slide test; no absorption of the serum is necessary. The new test compared favorably with some standard tests for infectious mononucleosis antibody which use horse erythrocytes. Agreement of the latex test with the absorbed fresh horse cell test was 100%, and agreement with a stabilized horse erythrocyte spot test was 94%. The latex test also agreed 100% with a radioimmunoassay for the detection of heterophile antibody with 125I-labeled horse erythrocyte glycoprotein. The new latex test was compared with a bovine erythrocyte glycoprotein-latex test, and a correlation of 94% was observed. In addition, it was compared with the Wöllner test (enzyme-treated sheep cell-absorbed sheep cell agglutination test) with which it agreed in 92% of samples tested.

Immunochemical studies of infectious mononucleosis--X. Characterization of a glycoprotein from horse erythrocytes which reacts with Paul-Bunnell antibody

A highly purified preparation of horse erythrocyte glycoprotein was prepared from an aqueous ethanolic extract of hemoglobin-free membranes. The subunit apparent mol. wt was 30,000. In aqueous solution the glycoprotein formed globular aggregates of 93 +/- 16 A diameter. The glycoprotein had a receptor for the Paul-Bunnell antibody of infectious mononucleosis which was associated with an O-glycosidically linked oligosaccharide and dependent on the presence of N-glycolylneuraminic acid. In addition the glycoprotein had a neuraminidase-sensitive receptor for human peripheral blood lymphocytes. Fifty per cent inhibition of the rosetting of sheep red cells by 4 x 10(5) lymphocytes was caused by 30 microgram of glycoprotein.

Immunochemical studies of infectious mononucleosis. VIII. A glycoprotein from sheep erythrocytes with sialic acid-dependent receptor properties

A glycoprotein was solubilized from sheep erythrocyte membranes with hot aqueous ethanol. The glycoprotein was purified by phosphocellulose chromatography, ethanol precipitation, lipid solvent extraction, and DEAE chromatography. In water solution the glycoprotein existed as globular aggregates with a diameter of 7.1 +/- 2.2 nm. In the presence of sodium dodecyl sulfate, 80% of the material exhibited a subunit m.w.app of 27,000. Approximately 10% of the material had a m.w.app of only 9000 and another 10% had a m.w.app of 35,000. All three fractions were reactive with Paul-Bunnell heterophile antibody from the sera of patients with infectious mononucleosis and with Limulus polyphemus lectin. These activities were destroyed by neuraminidase treatment. Complete inhibition of the rosetting of sheep red blood cells by 4 X 10(5) human peripheral blood lymphocytes was seen at 100 to 200 micrograms glycoprotein/ml. Neuraminidase-treated glycoprotein was not inhibitory. Pronase-derived sialoglycopeptide was inhibitory. Most likely, the receptor for lymphocytes resides in the carbohydrate portion of the glycoprotein. By using 125I-glycoprotein, binding studies were carried out that yielded an estimate of approximately 2 X 10(5) binding sites for sheep erythrocyte glycoprotein per lymphocyte. Purified glycoprotein contained 44.4% amino acid. Carbohydrate components and their molar ratios were sialic acid (1.0): galactose (1.0):N-acetylglucosamine (1.3): N-acetylgalactosamine (1.2).

Immunochemical studies of infectious mononucleosis. VIII. A glycoprotein from sheep erythrocytes with sialic acid-dependent receptor properties

A glycoprotein was solubilized from sheep erythrocyte membranes with hot aqueous ethanol. The glycoprotein was purified by phosphocellulose chromatography, ethanol precipitation, lipid solvent extraction, and DEAE chromatography. In water solution the glycoprotein existed as globular aggregates with a diameter of 7.1 +/- 2.2 nm. In the presence of sodium dodecyl sulfate, 80% of the material exhibited a subunit m.w.app of 27,000. Approximately 10% of the material had a m.w.app of only 9000 and another 10% had a m.w.app of 35,000. All three fractions were reactive with Paul-Bunnell heterophile antibody from the sera of patients with infectious mononucleosis and with Limulus polyphemus lectin. These activities were destroyed by neuraminidase treatment. Complete inhibition of the rosetting of sheep red blood cells by 4 X 10(5) human peripheral blood lymphocytes was seen at 100 to 200 micrograms glycoprotein/ml. Neuraminidase-treated glycoprotein was not inhibitory. Pronase-derived sialoglycopeptide was inhibitory. Most likely, the receptor for lymphocytes resides in the carbohydrate portion of the glycoprotein. By using 125I-glycoprotein, binding studies were carried out that yielded an estimate of approximately 2 X 10(5) binding sites for sheep erythrocyte glycoprotein per lymphocyte. Purified glycoprotein contained 44.4% amino acid. Carbohydrate components and their molar ratios were sialic acid (1.0): galactose (1.0):N-acetylglucosamine (1.3): N-acetylgalactosamine (1.2).

Comparison of receptor properties of erythrocyte membrane glycoproteins

Membrane glycoproteins from horse, sheep, goat and bovine erythrocytes were solubilized and purified. These glycoproteins could be placed in three groups based on their degrees of glycosylation: The major bovine erythrocyte glycoprotein (BGII) had 77% sugar, the minor bovine glycoprotein (BGI) had 27% sugar and the others had approximately 50% sugar. Four of the glycoproteins aggregated in a uniform way in aqueous solution--one, BGII, did not. Four had similar subunit sizes of 25-34,000 daltons, but BGII was larger--55,000 daltons. Receptor functions (for plant and invertebrate lectins, antibodies and cell surfaces) of these glycoproteins were primarily those dependent upon the presence of terminal sialic acid residues.

Biochemical and morphological properties of bovine erythrocyte membrane glycoproteins

The major and minor sialoglycoproteins of the bovine erythrocyte have been solubilized and extensively purified. A comparison of composition revealed that the major glycoprotein had 77% carbohydrate and 23% peptide, and the minor one had 27% carbohydrate and 73% peptide. Molar ratios of sugars were related, however, the major glycoprotein had twice as much galactose and sialic acid as did the minor glycoprotein. Molecular weights, estimated from retardation coefficients of mobility in sodium dodecyl sulfate gel electrophoresis, were 55,000 for the major glycoprotein and 34,000 for the minor glycoprotein. The glycoproteins were studied by electron microscopy before and after delipidation and after ultracentrifugation. The major glycoprotein, prior to delipidation, formed large micelles. After delipidation, the major glycoprotein could not be visualized suggesting that it did not form aggregates in aqueous solution. The minor glycoprotein was visualized as rather uniform spherical aggregates (62 A average diameter) which tended to form short chains and small clumps. These characteristic aggregates were seen both before and after delipidation. After ultracentrifugation, fixation and sectioning both glycoproteins appeared to have formed microcrystalline arrays with average periodicity of 49 A.

Latex test for serodiagnosis of infectious mononucleosis

A glycoprotein was isolated from bovine erythrocytes which has 20% carbohydrate and migrates on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a single band. This glycoprotein carries the reactivity of bovine erythrocytes with Paul-Bunnell heterophile antibody of infectious mononucleosis. This bovine glycoprotein was coupled to carboxyl-modified latex particles with water-soluble carbodiimide. The resulting reagent was then used to develop a new test for the detection of infectious mononucleosis antibody. The bovine erythrocyte glycoprotein-latex reagent is more stable than sheep or horse erythrocytes, the traditional reagents for detection of infectious mononucleosis antibody. This new reagent is used in a direct slide test; no preabsorption of the sera is necessary. In the present study the glycoprotein-latex reagent compared favorably in terms of sensitivity and specificity with two standard tests for infectious mononucleosis antibody. Ninety-nine serum samples were tested. Agreement of the latex test with a stabilized horse erythrocyte spot test was 90%. Ten samples were weakly positive with the latex test and negative with the horse cell test. Only one of these was also positive with an enzyme-treated sheep cell test. This latter test was somewhate more sensitive than the latex test.