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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]

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]

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]

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]

The article provides information about the research papers that will be presented at the spring meeting of The Society for Investigative Dermatology Inc. that will be held on April 27-28, 1973 in Atlantic City, New Jersey. Cathepsin D (CD), one of the major lysosomal proteinases, has been identified in rabbit skin. Extracts of skin were capable of degrading hemoglobin, at pH 3.2, to peptides that are soluble in trichioracetic acid. This activity was blocked by the CD inhibitor pepstatin and was eluted from a Sephadex G-100 column at a position identical to that of ultimately pure rabbit liver CD. A line of complete identity between crude skin extracts and ultimately pure CD was found in immunodiffusion studies using sheep anti-rabbit CD.

The removal of stratum corneum in vivo by cellophane tape stripping is a traumatic procedure, as evidenced by considerable acute erythema. This may render the skin less suitable for subsequent experimentation. Hydration of the stratum corneum by occlusion under a water-saturated patch for 24 hours prior to stripping greatly facilitates the procedure. Removal is accomplished with less force, and with about ⅓ the number of strippings ordinarily required. Also, there is usually less erythema than after stripping of dry skin. Why hydration should loosen stratum corneum cells from each other is not known. [ABSTRACT FROM AUTHOR]

An in vitro method of culturing dermatophytic spores on stratum corneum alone is described. The stratum corneum is stripped onto a translucent adhesive tape and fixed to a microscope slide. Spores are applied and the tape is incubated under controlled conditions. The technique has been made semiquantitative and applied to the study of a topical anti- fungal agent. [ABSTRACT FROM AUTHOR]

Within solid neoplasms. the population of tumor cells and the population of capillary endothelial cells constitute a highly integrated ecosystem. Tumor cells release an endothelial mitogen. Tumor-Angiogenesis-Factor (T.A.F.) which continually stimulates new capillaries to grow into the tumor. When T.A.F. is blocked, neovascularization is prevented and tumor nodules stop expanding at a diameter less than 2.5 mm. They enter a dormant phase because they are forced to live by simple diffusion of nutrients and wastes. Thus "anti-angiogenesis can force a population of tumor cells to become dormant at a tiny diameter. In this paper an analogy is drawn between tumor angiogenesis and the angiogenesis which accompanies psoriasis. if the relationship between psoriatic epithelium and its capillary endothelium turns out to be similar to the integration of capillaries by solid tumors, then "anti-angiogenesis' may eventually become a useful therapeutic approach in psoriasis. [ABSTRACT FROM AUTHOR]

Immediately after plucking the hairs from a mouse, with its skin in the resting phase of the hair growth cycle, both the labeling index and incorporation levels of ³HTdR are lowered. This depression persists until stimulated cells enter S, usually about 10 hours after plucking. These observations are confirmed using a combination of liquid scintillation and autoradiographic procedures. The dpm per punch of fixed skin, the labeling index of the basal layer, the grains per labeled basal layer cell and the proportion of labeled DNA are all reduced following plucking. The dpm per punch of fresh skin is concomitantly enlarged by plucking through an increase in the fixative-soluble pool, which may be due to the induction of vascular changes. Anesthesia apparently reduces slightly the incorporation levels into fixed unplucked skin. The vascular changes and anesthesia depression of incorporation cannot account for the depression in incorporation into fixed tissue which must be due to a more direct effect on DNA synthesis. The data could be explained on the basis of a reduction in the rate of synthesis combined with a block to entry into S or to progression through S. Using the autoradiographic and liquid scintillation techniques presented in this paper and published previously, a number of calculations were made regarding the proliferative population size in the epidermis and hair follicle. The cycle time for basal layer cells in unplucked skin is estimated to be 141 hours with an upper limit on the growth fraction of 0.92. [ABSTRACT FROM AUTHOR]

This paper presents evidence of the production of hyaluronidase by Corynebacterium acnes. In a study of seven random isolates of C. acnes from lesions of cystic acne and from normal skin, hyaluronidase activity ranged from less than one turbidity reducting unit. (TRU) to 72 TRU per mg of extracellular protein. These findings raise the interesting possibility that C. acnes hyaluronidase may play a role in the development of acne by contributing to the inflammatory phase through an increased permeability of the follicular epithelium to free fatty acids and other irritants. [ABSTRACT FROM AUTHOR]

Tyrosinase was dissolved from the melanosome fraction of Harding-Passey mouse melanoma and purified further by Sephadex G-100 gel filtration and DEAE-cellulose column chromatography. The specific activity of the purified preparation was 763 times as high as that of the original melanosome. Tyrosinase thus isolated showed only a single activity in both the electrophoresis of a polyacrylamide gel and a cellulose acetate. The Km value is the same as those of the original melanosome and the smooth-surfaced-membrane. The relationship between particle bound tyrosinase and solubilized tyrosinase is discussed in this paper. [ABSTRACT FROM AUTHOR]

1. The characteristics of the Na-K-ATPase of the rhesus monkey palm eccrine sweat gland were studied. The maximal activation concentrations for Na+ and K+ were 200 mM and 40 mM respectively. 2. An attempt was made to estimate the stoichiometric relationship between Na+ flux and ATP hydrolysis by the Na-K-ATPase activity obtained in this study and ATP production estimated from CO2 and lactate production reported in our previous paper (1). Na+/ATP ratios of 3.3 and 3.0 respectively were obtained, which agree well with the usual ratio of 3 found in other transporting epithelia. 3. The distal (straight) duct was isolated and its Na-K-ATPase activity determined. The Na-K-ATPase activity in the distal duct was less than one tenth of that in the sweat gland coil (secretory coil + proximal duct) and thus the role of the distal duct as a site of active sodium transport would be relatively minor. [ABSTRACT FROM AUTHOR]

The article presents announcements related to dermatology. There will be two meetings of the Society for Investigative Dermatology Inc., in 1974. The first meeting will be on May 4, 1974 at the Chalfonte-Haddon Hall Hotel, Atlantic City, New Jersey. There will be a series of workshops on the preceding evening, and the dermatology sections of the American Federation for Clinical Research and the American Society for Clinical Investigation will be held on the day following our meeting. The American Academy of Dermatology Residents' Forum session is open and awards will be given to the resident who shall be adjudged to give the most outstanding paper in this Forum.

The Subsection of Dermatology of the Western Section of the American Federation for Clinical Research will meet as a part of the annual joint meeting of the Western Section of the American Federation for Clinical Research, the Western Society for Pediatric Research and the Western Association of Physicians, in Carmel, California, from January 31 through February 3, 1973. This Subsection of Dermatology is recognized and supported by the Society for Investigative Dermatology as a regional meeting of the Society. Papers for presentation at this meeting are hereby solicited. Dermatologists who wish to present a paper at this meeting but who are not members of one of the three parent organizations can without difficulty usually find a member to sponsor their presentation.

The subsection of Dermatology of the western section of the American Federation of Clinical Research will meet as a part of annual joint meeting of the Western Section of the American Federation for Clinical Research, the Western Society for Pediatric Research and Wester Association of Physicians in California, from January 31 to February 3, 1973. Papers for presentation at this meeting are hereby solicited. Dermatologists, who wish to present a paper at this meeting but who are not members of one of three parent organizations can usually find a member to sponsor their presentation.

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.

The Society for Investigative Dermatology and the European Society for Dermatological Research are holding a joint meeting from May 17-19, 1972 in Amsterdam, Netherlands. The purpose of this meeting will be to serve as a forum for the presentation of original dermatological research papers. All the presentations in the meeting are required to be in English. Also, the Aspen Conference for Dermatologists, being sponsored by the Rocky Mountain Dermatological Society will be held on July 22, 1971.

Applications are being invited for scientific papers to be read before the Section on Dermatology of the American Medical Association meeting on June 20-24, 1971 at Atlantic City, New Jersey. Moreover, there will be two meetings of the Society for Investigative Dermatology Inc. in the year 1971. The spring meeting will be on May 1, 1971 and the thirty-second annual meeting will be held on June 18-20, 1971. The formation of the European Society for Dermatological Research has also been announced. The objective of the society is the promotion of research related to skin and its disease through the application of methods of natural sciences.