It is what it eats: Chemically defined media and the history of surrounds.

The cultivation of living organs, cells, animals, and embryos in the laboratory has been central to the production of biological knowledge. Over the twentieth century, the drive to variance control in the experimental setting led to systematic efforts to generate synthetic, chemically defined substitutes for complex natural foods, housing, and other substrates of life. This article takes up the history of chemically defined media with three aims in mind. First, to characterize patterns of decontextualization, tinkering, and negotiation between life and experimenter that occur across disparate histories of cultivation. Second, to highlight the paradoxical historicity of cultivated organisms generated to be freed from context, as they incorporate and embody the purified amino acids, vitamins, plastics, and other artificial supports developed in the name of experimental control. Third, to highlight the figure-ground reversal that occurs as these cells and organisms are reconsidered as accidentally good models of life in industrialized conditions of pollution and nutrient excess, due to the man-made nature of their surrounds. Methodologically, the history of surrounds is described as an epigenetic approach that focuses on the material relations between different objects and organisms previously considered quite separately, from explanted organs to bacteria to plant cells to rats to human embryos.

IVF culture media: past, present and future.

BACKGROUND: The advances in the world of IVF during the last decades have been rapid and impressive and culture media play a major role in this success. Until the 1980s fertility centers made their media in house. Nowadays, there are numerous commercially available culture media that contain various components including nutrients, vitamins and growth factors. This review goes through the past, present and future of IVF culture media and explores their composition and quality assessment. METHODS: A computerized search was performed in PubMed regarding IVF culture media including results from 1929 until March 2014. Information was gathered from the websites of companies who market culture media, advertising material, instructions for use and certificates of analysis. The regulation regarding IVF media mainly in the European Union (EU) but also in non-European countries was explored. RESULTS: The keyword 'IVF culture media' gave 923 results in PubMed and 'embryo culture media' 12 068 results dating from 1912 until March 2014, depicting the increased scientific activity in this field. The commercialization of IVF culture media has increased the standards bringing a great variety of options into clinical practice. However, it has led to reduced transparency and comparisons of brand names that do not facilitate the scientific dialogue. Furthermore, there is some evidence suggesting that suboptimal culture conditions could cause long-term reprogramming in the embryo as the periconception period is particularly susceptible to epigenetic alterations. IVF media are now classified as class III medical devices and only CE (Conformité Européene)-marked media should be used in the EU. CONCLUSION: The CE marking of IVF culture media is a significant development in the field. However, the quality and efficiency of culture media should be monitored closely. Well-designed randomized controlled trials, large epidemiological studies and full transparency should be the next steps. Reliable, standardized models assessing multiple end-points and post-implantation development should replace the mouse embryo assay. Structured long-term follow-up of children conceived by assisted reproduction technologies and traceability are of paramount importance.

Selective proliferation of normal human melanocytes in vitro in the presence of phorbol ester and cholera toxin by Eisinger and Marko.

Melanocytes are pigment producing cells that arise from the neural crest and migrate to the skin early in fetal development. The pigment that melanocytes synthesize, melanin, plays a critical role in protecting the skin from mutagenic ultraviolet irradiation. Melanocytes are also precursor cells for melanoma, a deadly form of skin cancer. Because melanocytes make up a minority population of cells in the epidermis they have been difficult to propagate in culture. The landmark paper by Eisinger and Marko, described below, was the first successful report of large scale propagation of pure cultures of melanocytes. This paper set the stage for an explosive growth in knowledge in the biology of human melanocytes and allowed scientists to begin dissecting the different oncogenic events involved in the transition of melanocytes to melanoma.

Connections between preimplantation embryo physiology and culture.

PURPOSE: To review the history of experimental embryo culture and how culture media that permitted complete preimplantation development in vitro were first discovered, and the physiological insights gained. METHODS: This article reviews the history of in vitro mammalian embryo culture, in particular the efforts that led to the current generation of successful culture media and how these reflect embryo physiology, highlighting the contributions of Dr. John D. Biggers and his colleagues and students. RESULTS: The culture of mammalian embryos began about a century ago. However, defined media without biological fluids were only developed in the late 1950s, and the first live young born from cultured embryos, using these media, were produced by McLaren and Biggers in 1958. It wasn't until the late 1980s, however, that preimplantation mammalian embryos could generally be cultured in vitro from fertilized eggs to blastocysts. These new media led to insights into embryo physiology, including the importance of cell volume homeostasis to early embryo viability. CONCLUSIONS: The development of successful preimplantation embryo culture media has had a profound effect on assisted reproduction technologies and on research into early embryo physiology.

Estudio del oligodendroglioma y sus variantes por medio del cultivo de tejidos / Oligodendroglioma and its variants study by tissue culture

Junto a las formas clasicas, el oligodendroglioma incluye formas inusuales con aumento de la actividad proliferativa, alteraciones vasculares, tumores mixtos (oligodendroastrocitoma) y tumores con celulas eosinófilas. El estudio con cultivo de tejidos nos ha permitido: a) confirmar el patron de crecimiento in vitro, b) la expresión de GFAP en todos los casos cultivados, c) el carácter primario de la transformación eosinófila citoplásmica. A la luz de este estudio, puede concluirse que: a) el patrón in vitro del oligodendroglioma es característico y permite identificar este tipo tumoral sea cual sea el subtipo, b) la expresión de GFAP es constante en todas las formas de oligodendroglioma, c) la tendencia a la maduración astrocítica parace ser una capacidad propia del oligodendrocito tumoral (AU)

Chemically defined media and the culture of mammalian preimplantation embryos: historical perspective and current issues.

Considerable advances in media development for the culture of preimplantation mammalian embryos have been made since mouse embryos were first cultured and successfully transferred to foster mothers. The purpose of this review is to detail the history of the development of chemically defined media for the culture of preimplantation embryos. Two approaches have been used to determine the composition of chemically defined media: the 'back-to-nature' approach and 'let the embryo choose' or empirical optimization approach. Recent developments, including the supplementation of media with amino acids and the use of sequential media for the extended culture of preimplantation embryos, are critically assessed. Importantly, it is recognized that even the best media currently used are not optimal and inevitably cause imbalances and stress to the embryos. Consequently, preimplantation embryos must adapt to the culture environment in order to survive. The adaptations to stress that occur when embryos are placed in a chemically defined environment are reviewed. The implications of these various stresses on the patterns of gene expression in the early embryo and their potential long-term effects are also emphasized. The scientific and ethical issues raised by the commercialization of human embryo culture media are briefly addressed.

Cultural and physiological observations on Trypanosoma rhodesiense and Trypanosoma gambiense. 1949.

1. A diphasic medium of simple preparation is described for the indefinite cultivation of T. rhodesiense and T. gambiense. 2. The chief advantage of the medium is that it contains rabbit blood and thus obviates the necessity of using human blood. 3. The flagellates develop only to the proventricular stage; hence the cultures are noninfective. 4. The proventricular forms of both T. rhodesiense and T. gambiense consume sugar with the concomitant formation of acid. They are aerobic fermenters. 5. Very little, if any, ammonia is produced by the living parasites.

Technological problems in cultivation of plant cells at high density. Reprinted from Biotechnology and Bioengineering, Vol. XXII, No. 6, Pages 1203-1218 (1981).

Using Cudrania tricuspidata cells as model plant cells which have high sensitivity to hydrodynamic stress, technological problems in the cultivation of the plant cells at high density were investigated. Using "shake" flasks on a reciprocal shaker and Erlenmeyer flasks on a rotary shaker and with a high supply of oxygen in order to obtain high cell densities in shaken cultures, particle breakdown and damage to the largest cell aggregate group (above 1981 microm in diameter) occurred and normal cell growth became impeded. The mass-transfer coefficient (K) for a model solid-liquid system (beta-naphthol particles and water) in place of a system of plant cells and a liquid medium was proposed as an intensity index of hydrodynamic stress effects on plant cells in suspension cultures under various conditions in the bioreactor systems. Normal cell growth was obtained under culture conditions for K values less than about 4.4 x 10(-3) cm/sec. The characteristics of various bioreactors used until now were investigated by considering the three main technological factors (capacity of oxygen supply, intensity of hydrodynamic stress effects on plant cells, and intensity of culture broth mixing and air-bubble dispersion). The most suitable bioreactor for culturing plant cells at high density was a jar fermentor with a modified paddle-type impeller (J-M). The yield of cell mass in the 10-liter J-M (working volume 5 liter) was about 30 g dry weight per liter of medium.

A clinical look at Stuart's transport medium.

The development of Stuart's Transport Medium is described, followed by an inquiry into the rationale of its composition. Suggestions are made for the optimal use of the medium.