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The anatomy and development of mammary tissue and the physiology of lactation show many similarities and significant differences among various mammalian species. Although the mammary glands are skin organs whose significance has been recognized for a long time, there is much new information that is reviewed in this paper. [ABSTRACT FROM AUTHOR]

Various techniques were used to obtain cell cultures from benign and malignant tumors removed from human breasts. Cell suspensions were prepared by trypsinizing finely minced tissue or by the "spilling" technique or Lasfargues and Ozzello, and T-flasks or T-flasks coated with collagen were inoculated. Trypsinized tissue yielded predominantly fibroblastic cultures, whereas those obtained by the "spilling" technique were rich in epithelial cells. The mixed cell populations were separated into pure suspensions by density gradient centrifugation. Most epithelial cell cultures grew best when they were collected by the "spilling" technique and inoculated into collagen-coated T-flasks with Eagle's medium enriched with 30% fetal calf serum. However, tears developed in the collagen coat with subsequent peeling which led to the loss of many epithelial cell colonies. Primary epithelial cells did not remain viable for prolonged periods, and attempts to obtain subcultures were unsuccessful. In this Paper the work of several investigators is reviewed and their methods of growing breast tumor cell are discussed. [ABSTRACT FROM AUTHOR]

Among the many factors that control mammary gland growth, hormones play a leading role. To assess the importance of each factor on the growth of the gland, different methods have been devised. These methods are complementary hence no method is capable by itself of a total estimate of mammary growth. Fetal growth of the mammary rudiment is influenced by hormonal factors and at the same time (more than at any other stage of mammary growth) by the mesenchyme. A marked characteristic of the fetal period is the establishment of sexual dimorphism. This peculiar phenomenon has been studied in vitro. After birth, the gland falls under the direct control of stimuli from the hypothalamus pituitary axis. By means of its cyclic variations or changes conditioned by conception, growth is induced by pituitary hormones proper (prolactin growth hormone) or via the ovary or the adrenals. Other factors such as diet, age, mesenchyme, and genetic background modulate the action of hormones on the gland. The action of all these factors is examined in this paper throughout the life of different mammals, from the prepuberal stage, through adult nulliparous life, gestation, the maximal growth induced by the hormonal levels of lactation, and in regression (produced alter hormone removal). In vivo and in vitro studies have been correlated in demonstrate which of the stimuli induce mammary cell replication and growth in the preneoplastic and neoplastic mammary gland. [ABSTRACT FROM AUTHOR]

Some of the constituents of milk are unbiquitous biochemical compounds and others are unique products of the mammary gland. Lactose, the distinctive milk disaccharide, caseins, a group of phosphoproteins, and fat are present in nearly all milks that have been examined and the pathways involved in their biosynthesis are discussed in this paper. Milks of various species differ quantitatively in the proportions of their principal constituents. These differences suggest phylogenetic grouping and undoubtedly reflect evolutionary divergence. The extent to which this divergence has been affected by the nutritive requirements of the young, by the dietary sources of the lactating female, and by various other environmental factors has not been completely clarified. Evolutionary divergence is also evident in the composition and amino acid sequences of several families of milk proteins. The relationship between such differences and the function of these proteins has not yet been elucidated. [ABSTRACT FROM AUTHOR]

The article presents news and information related to dermatology. It states that the twelve dermatological residents will compete in December 1974 for the Fifth Henry W. Stelwagon Prize presented by the College of Physicians of Philadelphia to "the resident who shall be adjudged to give the most outstanding paper" at the annual meeting of the American Academy of Dermatology. The Stelwagon Prize stems from an endowment bequeathed to the College of Physicians of Philadelphia by Henry Weightman Stelwagon, who was the first teacher of Dermatology at Jefferson Medical College, Philadelphia, Pennsylvania.