A new test principle for the detection of specific IgM-class antibodies was developed and applied in an Enzyme-Linked Immuno Sorbent Assay (ELISA) for the detection of hepatitis A IgM antibodies. A solid phase coated with anti-IgM was incubated successively with serum sample, specific antigen, and enzyme-labeled F (ab')2 fragments from IgG antibodies against the antigen and enzyme substrate. F(ab')2 fragments were used to avoid interference with rheumatoid factor. Specificity and sensitivity are very high. This test principle appears generally applicable in the diagnosis of infectious and parasitic diseases by testing only one serum sample.

Antibodies, Viral↗

PubMed1979

An outbreak of hepatitis A investigated by immune electron microscopy and enzyme-linked immunosorbent assay.

In a small outbreak of hepatitis A among members of a hospital staff, excretion of hepatitis A virus could be detected by immune electron microscopy (IEM) and enzyme-linked immunosorbent assay (ELISA) in 3 out of 3 cases tested. Significant increases in antibody titre could be shown in 4 out of 6 cases (IEM), and development of virus specific IgM was shown in all 6 cases (ELISA). Among these patients IgM could be detected after 3 months, while sera drawn after 10 months were negative.

Antibodies, Viral↗

PubMed1979

Poliovirus-induced suppression of lymphocyte stimulation: a macrophage-mediated effect.

Poliovirus was shown to suppress the in vitro response of human mononuclear blood cells stimulated with phytohaemagglutinin (PHA), pokeweed mitogen (PWM), tuberculin purified protein derivative (PPD) or allogeneic cells. The suppression required infectious virus and the presence of macrophages. Experiments with combined cultures of human lymphocytes stimulated with PHA, PWM, PPD or allogeneic cells, and different numbers of autologous macrophages indicated that both lymphocyte stimulation and the inhibitory effect of poliovirus increased with increasing ratio of macrophages to lymphocytes. The response of human lymphocytes to PHA also was enhanced when autologous macrophages were replaced with murine macrophages. Mouse hepatitis virus inhibited this enhancing effect whereas poliovirus failed to do so. The findings confirm our previous suggestion that poliovirus inhibits stimulation of lymphocytes by suppressing the enhancing effect of macrophages.

Cells, Cultured↗

PubMed1978

Specific detection of IgM-antibodies by ELISA, applied in hepatitis-A.

Explore the source record for details and available documents.

Animals↗

PubMed1978

ELISA in hepatitis A.

Explore the source record for details and available documents.

Antibodies, Viral↗

PubMed1978

Morphology of the early hemostasis in human skin wounds: influence of acetylsalicylic acid.

The in vivo formation of hemostatic plugs was studied in humans in skin wounds made using the template bleeding procedure of Mielke (34). The wounds were excised by punch biopsy 10 seconds, 30 seconds, 2 minutes, and 3 minutes after they were made. The wounds were V-shaped and approximately 0.4 mm. deep. Within 30 seconds small hemostatic plugs were observed at the end of transected vessels. The plugs grew in size in the subsequent minutes and became impermeable. The platelets degranulated and formed pseudopods which became strongly interdigitated. The platelets at the periphery of the plugs showed discontinuities of the membranes. Cytoplasmic matrix and cell organelles had disappeared in many of these peripheral cells. Small fibrin fibers were already found at 30 seconds, mostly along the margins of the wounds and also at the periphery of the hemostatic plugs. Fibrin was absent from the center of the plugs and from the lumen of transected vessels. When part of a plug was extending into the vessel lumen, the platelets inside the vessel were less degranulated and less interdigitated than the rest of the plug. The effect of acetysalicylic acid (ASA) was studied in wounds before and 2.5 hours after ingestion of 2 gm. of ASA. Wounds were excised by punch biopsy 3 or 10 minutes after they had been made. Platelets in ASA were less degranulated, had fewer pseudopods, and showed less interdigitation than platelets in control plugs. Ballooning and fibrin deposition were similar in control and ASA plugs. Pronounced differences between control and ASA plugs were observed in a subject who exhibited a considerably prolonged bleeding time after ASA. The ASA plugs were very large; many plugs had fused and in addition numerous small platelet clumps, most likely fragments from the plugs, were found in the superficial scab of the wound. It is postulated that ASA plugs are less stable due to decreased interdigitation. This allows more disruption of the plugs and rebleeding. Consequently, more platelets are needed and longer time is required for hemostasis to occur.

Adult↗

PubMed1978