Scientific Finds

Journal 3

Distribution and orientation of microtubules in milk secreting epithelial cells of rat mammary gland

“Quantitative ultrastructural analysis of mid-lactation rat mammary gland demonstrated that cytoplasmic microtubules were present in nearly all secretory epithelial cells examined. Most microtubules were oriented perpendicular to the apical membrane and were found in the apical and medial portions of the cell cytoplasm. There was no statistical difference between the number of microtubules associated with vesicles and the number that were not. Most vesicles which were in contact with microtubules were small (50 to 150 nm), appeared electron lucent and were located in a supra-Golgi complex position. Many of these vesicles were seen to be aligned along the axis of longitudinally sectioned microtubules oriented perpendicular to the apical plasma membrane. As measured by a colchicine binding assay, the total tubulin content of mammary tissue from mid-lactation rats was about 107 [pic]g/100 mg wet weight. Approximately 19% of the total tubulin was in polymerized form. This study provides evidence that microtubules may be involved in guiding transport of small secretory vesicles to the apical regions of cells for exocytosis.”

SC Nickerson, TW Keenan - Cell and Tissue Research, 1979 – Springer

Journal 4

Effects of human growth hormone therapy on melanocytic naevi. Lancet 1993

“On the basis of an observation that melanocytic nevi were stimulated in a patient with Turner's syndrome receiving human growth hormone (HGH) therapy, these authors investigated the effect of HGH on the growth of melanocytic nevi. For six months they photographically followed all melanocytic nevi from 19 patients receiving HGH therapy for hypopituitarism or Turner's syndrome and from 29 control patients, 6 of whom also had Turner's syndrome or hypopituitarism. The authors found a two-fold increase in the rate of growth of the melanocytic nevi in patients receiving...