Hormones differentiation

Zhu, X.-G., McPhie, R, Lin, K.-H., and Cheng, S.-Y. (1997). The differential hormone-dependent transcriptional activation of thyroid hormone receptor isoforms is mediated by interplay of their domains. /. Biol. Chem. 272,9048-9054. 

Eedysone was the first insect hormone to be obtained in pure crystalline form. It has the action of the molting and metamorphosis hormone and has also been called, by Scharrer, the growth and differentiation hormone . 

Goto N, Esashi Y (1974 a) Differential hormone responses in different growing zones of the bean hypocotyl. Planta 116 225-241... 

The classical definition differentiates hormones from a variety of other substances which also act in mammals in minute concentration to produce profound biological effects, such as (1) vitamins, chemical regulators contained in the diet, (2) certain drugs, (3) humoral agents which exert a... 

In conclusion, much evidence now supports the hypothesis that ecdysone causes sclerotization in larvae epidermis cells, at least partly by inducing the synthesis in the nuclei of messenger-RNA coding for DOPA decarboxylase. It is probable that ecdysone stimulates the synthesis of other kinds of RNAs, which also play a rdle in the action of the hormone. Even in the case of a differentiating hormone, Karlson s model seems too simple. 

It is not surprising that differentiating hormones, i.e. hormones which induce a few specific proteins, such as ecdysone or in mammalian cells aldosterone, stimulate the formation of messenger RNA, but also of other RNAs and mainly ribosomal RNAs. 

Yavrapoulou MP, JG Yovos The role of the Wnt signaling pathway in osteoblast commitment and differentiation Hormones 2007, 6 4, 279-294. 

Modem cancer therapy has been primarily dependent upon surgery, radiotherapy, chemotherapy, and hormonal therapy (72) (see Chemotherapeutics,anticancer Hormones Radiopharmaceuticals). Chemotherapeutic agents maybe able to retard the rate of growth, but are unable to eradicate the entire population of neoplastic cells without significant destmction of normal host tissue. This serious side effect limits general use. More recentiy, the immunotherapeutic approach to cancer has involved modification and exploitation of the cellular and molecular mechanisms in host defense, regulation of tissue proliferation, tissue differentiation, and tissue survival. The results have been more than encouraging. 

Reconstitution of T-ceU deficiencies with thymic hormones has not been successhil even though the various hormone preparations induce prothymocyte differentiation and functions of mature T-ceUs. They do not regulate the maturation of thymocytes in the thymus. In contrast, IL-2, endotoxin, thymic epithehal cell products, but not interleukin 1, were found to promote functional maturation of immature thymocytes. Two classes of dmgs show thymomimetic actions (Table 2). Levamisole [14769-73-4], sodium salt of diethyl dithiocarbamate (imuthiol) and certain... 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

---