Effects of different fuchsin analogs on the Feulgen reaction

Morphological abnormalities of peripheral blood cells among patients with COVID-19 disease

Purpose

The hematological changes in COVID-19 patients continue to receive great attention, especially in the field of public health. To our knowledge, coronavirus disease may be identified based on the severity of illness, and the study of peripheral blood smears may offer important information to facilitate the identification. Thus, we evaluated the morphological abnormalities (atypical and immature lymphocytes, lymphocytes with micronuclei, various nuclear abnormalities among erythrocytes) and quantitative changes in peripheral blood cells among 48 individuals with COVID-19 disease.

Methods

The present study is a retrospective analysis of 48 individuals, including 24 hospitalized patients diagnosed with COVID-19 disease. The blood smears of all patients were subjected to a hematological examination to identify various morphological abnormalities in white and red blood cells. In addition, a micronucleus test was conducted to assess the incidence of chromosomal damage in lymphocytes. Furthermore, the complete blood count (CBC) was performed to evaluate changes in peripheral blood cells, particularly the differential total leukocyte count, which could indicate the immune response against viral infection in COVID-19 patients.

Results

The findings of the hematological study conducted on patients diagnosed with COVID-19 disease revealed neutrophilia, eosinophilia, mild monocytosis, decreased hematocrit level, elevated erythrocyte sedimentation rate (ESR), and immature leukocytes. It was observed that patients who were infected with coronavirus demonstrated mild thrombocytopenia. Furthermore, the micronucleus test indicated the presence of immature cells with micronuclei among lymphocytes and numerous nuclear abnormalities in red blood cells. These results help to shed light on the hematological changes that occur in COVID-19 patients, and could potentially contribute to the development of more effective treatments for the disease.

Conclusions

The examination of complete blood counts (CBCs) in conjunction with peripheral blood smears offers a potential means of identifying the impact of SARS-CoV-2 infection on the hematopoietic and immune systems, thereby providing early indications of inflammation. Based on a study, it has been suggested that SARS-CoV-2 may affect red and white blood cells causing morphological alterations thereby establishing a corresponding relationship with disease severity.

Practical aspects of fixatives in high resolution nuclear image analysis

Three different methods of fixation (ethanol/Carbowax, formaldehyde, and Carnoy) and four different protocols (without Böhm post-fixation on an uncoated slide, and with Böhm post-fixation on Poly-L-Lysine coated slide, an uncoated slide and a previously Papanicolaou stained slide) were evaluated for their application in high resolution image analysis of Feulgen stained nuclei. The aim of the study was to find a combination with the best reproducibility and the least variance under normal laboratory conditions. Care was taken not to exclude any "normal" laboratory variability. The combinations were evaluated for densitometric, geometric, as well as texture features. Selected features were determined on a CAS-100 using the Cell Measurement Program (Cell Analysis Systems, Inc. Lombard, IL). Diploid and tetraploid rat liver nuclei were used. Ethanol/Carbowax fixation-with Böhm post-fixation proved most stable. This fixation method also gave feature values for previously Papanicolaou stained slides that were comparable to direct Feulgen stained nuclei. Acceptable results were achieved with all three fixatives and the various combinations if one adhered strictly to protocol. In routine practice this usually does not happen. Therefore Ethanol/Carbowax fixation with Böhm post-fixation was considered most suited for routine determination of feature values on the CAS-100.

Separation of fuchsin homologs using high performance liquid chromatography

Commercial samples of basic fuchsin contain variable proportions of four homologs, pararosaniline, rosaniline, magenta II, and new fuchsin. That different samples of dyes give variable staining is documented in the literature. Three commercial samples of basic fuchsin were investigated using high performance liquid chromatography. Separation of homologs was achieved using a C18 adsorbant and a solvent system of methanol:water:glacial acetic acid (66:24:10).