Cytokeratin 19 (CK19) expression by thyroid neoplasms in a Nigerian tertiary health centre

Introduction

despite the observed appreciable sensitivity and specificity of the use of CK19 in predicting thyroid malignancies, there is still a paucity of information about its uses in Nigeria. Current information across the world is also scarce. This study was to review the histopathological diagnosis of thyroid neoplasms seen in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile Ife, using cytokeratin 19 immunohistochemical marker.

Methods

a retrospective study of fifty-six cases of thyroid neoplasm seen over a period of twenty years was conducted. The tissue samples were subjected to immunohistochemical staining for CK19 using monoclonal antibodies. The expression of the markers on the various thyroid neoplasms was assessed histologically.

Results

the expression of CK19 was significantly higher in malignant thyroid neoplasms compared to benign neoplasms (p<0.05). The sensitivity and specificity for cytokeratin 19 were 90.0% and 75.0% respectively.

Conclusion

diffuse immunohistochemical expression of CK19 is a strong indicator of thyroid malignancy. This biomarker can help in the diagnosis of thyroid neoplasms especially those with incomplete or equivocal histomorphology features.

Experimental determination of the physicochemical properties of lumefantrine

BACKGROUND

The physicochemical properties of lumefantrine, a first line combination medicine for the treatment of uncomplicated falciparum malaria have been determined experimentally rather than theoretically as a guide to understanding its disposition in human.

METHOD

The solubility of lumefantrine in various organic solvents was evaluated by estimating the volume of solvent that completely dissolved 15 mg of the drug. Melting point determination was carried out using a melting point apparatus. Dissociation constant of the drug was determined potentiometrically in 0.1M perchloric acid and partition coefficient was by the method of Leo Hansch, using ratio of the concentration of organic to aqueous phase.

RESULT

Lumefantrine has a melting point of 128-131 degrees C. Its solubility in selected solvents range from 0.013% in acetonitrile (very slightly soluble) to 7.5% in chloroform and dichloromethane (soluble), and it is practically insoluble (0.002%) in water. The ionization constant (pKa), determined in 0.1 M perchloric acid was found to be 9.35. The Log P lies in the range 2.29-3.52, confirming the lipophilicity of lumefantrine.

CONCLUSION

The physicochemical properties of lumefantrine reveal that it is highly lipophilic, weakly basic and readily dissolves in non-polar and/or aprotic organic solvents. While these properties will favour its distribution across cellular membranes, the rate-limiting step will be at the dissolution-absorption stage which will require biopharmaceutical modifications.