The long history of hematoxylin

Hematoxylin is a naturally occurring chemical used as the basis of a dye in laboratories throughout the world to stain nuclei in microscope slide preparations. This chemical is extracted from the logwood tree Hematoxylon campechianum and was discovered by Spanish explorers to the Yucatan in 1502. A vigorous trade soon developed related to growing and preparing hematoxylin for use in dyeing fabrics in Europe. In the mid 1800s, amateur microscopists first used hematoxylin to stain cellular components. Later scientists developed a wide range of techniques to demonstrate different cellular components. Hematoxylin remains the most popular nuclear stain in histology. This paper briefly describes the history of hematoxylin production and use in histology.     

The long history of hematoxylin

Hematoxylin is a naturally occurring chemical used as the basis of a dye in laboratories throughout the world to stain nuclei in microscope slide preparations. This chemical is extracted from the logwood tree Hematoxylon campechianum and was discovered by Spanish explorers to the Yucatan in 1502. A vigorous trade soon developed related to growing and preparing hematoxylin for use in dyeing fabrics in Europe. In the mid 1800s, amateur microscopists first used hematoxylin to stain cellular components. Later scientists developed a wide range of techniques to demonstrate different cellular components. Hematoxylin remains the most popular nuclear stain in histology. This paper briefly describes the history of hematoxylin production and use in histology.     

Immunosuppression in experimental staphylococcal infection and its effect on antimicrobial resistance

Experiments on CBA and (CBA X C57BL)F1 mice have revealed that a prolonged period of antigen-nonspecific immunosuppression of humoral immunity develops in experimental staphylococcal infection; this period of suppression may be preceded by a short phase of antigen-nonspecific immunostimulation. Immunosuppression is linked with the accumulation of antigen-nonspecific T-suppressors in the spleen, these T-suppressors being capable of the manifestation of their activity both in vitro and in vivo in cases of their transplantation to semi-syngeneic recipients. Immunosuppression does not aggravate the course of staphylococcal infection and is accompanied by an increase in resistance to Pseudomonas aeruginosa superinfection, which is due to the stimulation of inflammatory reaction at the site of the injection of the superinfecting agent.     

The role of regioselective hydroxylation on toxicity of diclofenac and related derivatives

ABSTRACT

Diclofenac and related derivatives become more toxic after biotransformation reactions in the body by electron or hydrogen transfers. The structure–reactivity study on regioselective hydroxylation of diclofenac acid was elucidated by using quantum chemistry calculations at level of DFT/B3LYP/6-31G(d,p). HOMO, ionisation potential, bond dissociation energy, and spin density distributions were used as chemical reactivity parameters. Also, some properties are related to lumiracoxib and fenclofenac. The higher flexibility of lumiracoxib can be responsible for the increase of COX₂ selectivity. Diphenyl-amine moiety is responsible for their potent antioxidant capacity. Chloro atoms have a strong effect under electron transfer capacity when compared to acetic acid group. Hydroxylation for the 5-hydroxydiclofenac is more favoured in either electron or hydrogen transfers. Both hydroxylation increased the electron donation and antioxidant capacity. These properties were observed to the fenclofenac derivatives and can be related to their toxicity by redox mechanism.