The humoral immune response more than one year after SARS-CoV-2 infection: low detection rate of anti-nucleocapsid antibodies via Euroimmun ELISA.

Purpose: Antibody assays against SARS-CoV-2 are used in sero-epidemiological studies to estimate the proportion of a population with past infection. IgG antibodies against the spike protein (S-IgG) allow no distinction between infection and vaccination. We evaluated the role of anti-nucleocapsid-IgG (N-IgG) to identify individuals with infection more than one year past infection.

Potential pitfalls of comparative measurements of reticulocytes with flow cytometry and microscopy in prematures and infants.

Reticulocyte counting by flow cytometry (Bayer H*3, ADVIA 120) in blood of prematures, infants and children > 1 year of age was compared with microscopic counting under research conditions (9000 counted red blood cells per slide). While in children >1 year a good concordance of both methods was observed, 2.3-2.

Serial transplants of DMBA-induced mammary tumors in Fischer rats as a model system for human breast cancer. VI. The role of different forms of tumor-associated stress for the regulation of pineal melatonin secretion.

Previous studies on human breast cancer patients showed a decline in circulating melatonin levels corresponding to primary tumor growth and an increase when relapse occurred. The aim of the current investigation was to study in an experimental model possible mechanisms involved. Inbred female F344 Fischer rats were used for serial passages derived from a chemically induced mammary adenocarcinoma.