Hormones classifications

The area of nonsteroidal antiestrogens along with other classes of nonsteroidal antagonists of sex-steroid hormone action has been reviewed to 1986, and these compounds have been grouped by chemical stmcture as a basis of classification rather than any biochemical or biological test system utilized to assess antagonist activity (46). 

Chemiluminescence has been studied extensively (2) for several reasons (/) chemiexcitation relates to fundamental molecular interactions and transformations and its study provides access to basic elements of reaction mechanisms and molecular properties (2) efficient chemiluminescence can provide an emergency or portable light source (J) chemiluminescence provides means to detect and measure trace elements and pollutants for environmental control, or clinically important substances (eg, metaboHtes, specific proteins, cancer markers, hormones, DNA) and (4) classification of the hioluminescent relationship between different organisms defines their biological relationship and pattern of evolution. 

Hormones can be classified according to chemical composition, solubility properties, location of receptors, and the namre of the signal used to mediate hormonal action within the cell. A classification based on the last two properties is illustrated in Table 42-3, and general feamres of each group are illustrated in Table 42-. ... 

Ultraviolet light causes a chemical change in dihydrocholesterol to produce cholecalciferol, a precursor of vitamin D. The latter conforms better to the definition of a steroid hormone than a vitamin. Indeed, the classification of vitamin D as a vitamin is an historical accident. The precursor is released from the skin and is further modified in the liver and kidney to form dihydroxycholecalciferol, which is the active form of the hormone (see Chapter 15 for the reactions). It increases calcium absorption from the... 

The classification of vitamin D as a vitamin is largely an historical accident. It conforms much more to the definition of a hormone it is produced in one part of the body and released into the blood to affect other parts of the body in this case, a novel endocrine hormone (Chapter 12). 

Drags used to treat cancer are subdivided into six groups antimetabolites, alkylating agents, antibiotics, drags isolated from plants, hormones, and a group of substances not included in the classifications listed above, which are examined in another section. 

The third part. Developmental Psychopathology, delves into detailed disease-specific overviews. Each of the chapters covers issues pertaining to nosology and classification, to genetic determinants, brain systems implicated, environmental influences, and nature-nurture interactions. Neurotransmission and neuromodulation, and hormonal and other developmental influences are addressed and, whenever available, relevant animal models are incorporated into the discussion. The interplay of normative and derailed development is a core concept for these chapters. Of the part s 12 chapters, 9 are devoted to traditionally defined disease categories, and 3 cover the overarching areas of early-life stress, aggression, and affiliative behaviors. 

Another approach to the study of the effects of hormone replacement therapy on the breast is to examine breast density, using mammography and the Wolfe classification. In a randomized study of 166 menopausal women, using this technique, there was increased breast density after 6 months of treatment eight times more commonly in those who took estradiol and norethisterone acetate than in those who took tibolone (186). The significance of this increased density is not clear, but it should for the present be regarded as undesirable,... 

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