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Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), by Emma Duke

The book Infant Mortality: Results of a Field Study in Johnstown, PA., Based on Births in One Calendar Year (1915), written by Emma Duke, detailed one of the first infant mortality field studies conducted by the US Children's Bureau. In the study, Duke and her colleagues collected information about over one thousand infants in the city of Johnstown, Pennsylvania. They used that information, along with interviews conducted with the families of the infants, to identify factors that affected infant mortality rates in the community.

Format: Articles

Subject: Experiments, Publications

Alexis Carrel's Immortal Chick Heart Tissue Cultures (1912-1946)

In an effort to develop tissue culture techniques for long-term tissue cultivation, French surgeon and biologist Alexis Carrel, and his associates, produced and maintained a series of chick heart tissue cultures at the Rockefeller Institute in New York City. From 1912 to 1946, this series of chick heart tissue cultures remained alive and dividing. Since the duration of this culture greatly exceeded the normal chick life span, the cells were deemed immortal.

Format: Articles

Subject: Experiments

"On the Permanent Life of Tissues outside of the Organism" (1912), by Alexis Carrel

'On the Permanent Life of Tissues outside of the Organism' reports Alexis Carrel's 1912 experiments on the maintenance of tissue in culture media. At the time, Carrel was a French surgeon and biologist working at the Rockefeller Institute in New York City. In his paper, Carrel reported that he had successfully maintained tissue cultures, which derived from connective tissues of developing chicks and other tissue sources, by serially culturing them.

Format: Articles

Subject: Experiments

The First Successful Cloning of a Gaur (2000), by Advanced Cell Technology

Advanced Cell Technology (ACT), a stem cell biotechnology company in Worcester, Massachusetts, showed the potential for cloning to contribute to conservation efforts. In 2000 ACT researchers in the United States cloned a gaur (Bos gaurus), an Asian ox with a then declining wild population. The researchers used cryopreserved gaur skin cells combined with an embryo of a domestic cow (Bos taurus). A domestic cow also served as the surrogate for the developing gaur clone.

Format: Articles

Subject: Experiments

Action of MER-25 and of Clomiphene on the Human Ovary (1963)

Between 1958 and 1962, physicians Olive W. Smith, George V. Smith, and Robert W. Kistner performed experiments that demonstrated the effects of the drugs MER-25 and clomiphene citrate on the female human body. MER-25 and clomiphene citrate are drugs that affect estrogen production in women. At the time of the experiment, researchers did not know which organ or organs the drugs affected, the ovaries and/or the anterior pituitary gland.

Format: Articles

Subject: Experiments

The Discovery of p53 Protein

The p53 protein acts as a pivotal suppressor of inappropriate cell proliferation. By initiating suppressive effects through induction of apoptosis, cell senescence, or transient cell-cycle arrest, p53 plays an important role in cancer suppression, developmental regulation, and aging. Its discovery in 1979 was a product of research into viral etiology and the immunology of cancer. The p53 protein was first identified in a study of the role of viruses in cancer through its ability to form a complex with viral tumor antigens.

Format: Articles

Subject: Experiments

The Effects of Gene Regulation on Aging in Caenorhabditis elegans (2003)

In 2003, molecular biology and genetics researchers Coleen T. Murphy, Steven A. McCarroll, Cornelia I. Bargmann, Andrew Fraser, Ravi S. Kamath, Julie Ahringer, Hao Li, and Cynthia Kenyon conducted an experiment that investigated the cellular aging in, Caenorhabditis elegans (C. elegans) nematodes. The researchers investigated the interactions between the transcription factor DAF-16 and the genes that regulate the production of an insulin-like growth factor 1 (IGF-1-like) protein related to the development, reproduction, and aging in C. elegans.

Format: Articles

Subject: Experiments

"In vitro Experiments on the Effects of Mouse Sarcomas 180 and 37 on the Spinal and Sympathetic Ganglia of the Chick Embryo" (1954), by Rita Levi-Montalcini, Viktor Hamburger, and Hertha Meyer

"In vitro Experiments on the Effects of Mouse Sarcomas 180 and 37 on the Spinal and Sympathetic Ganglia of the Chick Embryo" were experiments conducted by Rita Levi-Montalcini in conjunction with Viktor Hamburger and Hertha Meyer and published in Cancer Research in 1954. In this series of experiments, conducted at the University of Brazil, Levi-Montalcini demonstrated increased nerve growth by introducing specific tumors (sarcomas) to chick ganglia. Ganglia are clusters of nerve cells, from which nerve fibers emerge.

Format: Articles

Subject: Experiments

Roger Sperry’s Split Brain Experiments (1959–1968)

In the 1950s and 1960s, Roger Sperry performed experiments on cats, monkeys, and humans to study functional differences between the two hemispheres of the brain in the United States. To do so he studied the corpus callosum, which is a large bundle of neurons that connects the two hemispheres of the brain. Sperry severed the corpus callosum in cats and monkeys to study the function of each side of the brain. He found that if hemispheres were not connected, they functioned independently of one another, which he called a split-brain.

Format: Articles

Subject: Experiments

"A Diffusible Agent of Mouse Sarcoma, Producing Hyperplasia of Sympathetic Ganglia and Hyperneurotization of Viscera in the Chick Embryo" (1953), by Rita Levi-Montalcini and Viktor Hamburger

"A Diffusible Agent of Mouse Sarcoma, Producing Hyperplasia of Sympathetic Ganglia and Hyperneurotization of Viscera in the Chick Embryo," by Rita Levi-Montalcini and Viktor Hamburger, appeared in 1953 in the Journal of Experimental Zoology. The paper provided the first evidence that nerve growth factor is a diffusible substance. Nerve growth promoting tumors were implanted into developing embryos to determine whether the tumors stimulated growth by direct contact or by a diffusible substance.

Format: Articles

Subject: Experiments

"Proliferation, Differentiation and Degeneration in the Spinal Ganglia of the Chick Embryo under Normal and Experimental Conditions" (1949), by Viktor Hamburger and Rita Levi-Montalcini

In this paper Viktor Hamburger and Rita Levi-Montalcini collaborated to examine the effects of limb transplantation and explantation on neural development. In 1947 Hamburger invited Levi-Montalcini to his lab at Washington University in St. Louis to examine this question. Independently, each had previously arrived at opposing conclusions based on the same data.

Format: Articles

Subject: Experiments

"Experiments in Transplanting Limbs and Their Bearing Upon the Problems of the Development of Nerves" (1907), by Ross Granville Harrison

In his 1907 paper, "Experiments in Transplanting Limbs and Their Bearing Upon the Problems of the Development of Nerves," in the Journal of Experimental Zoology that he edited, Ross Granville Harrison tested the development of nerves in transplanted tissue. He studied neural development by examining two competing theories. Victor Hensen proposed a syncytial theory as a way to explain neural development, suggesting that all the nerves of an embryo were connected directly by cytoplasm laid down early in development, and leaving no room for later modification.

Format: Articles

Subject: Experiments

"How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs" (2005), by Karen Warkentin

In 'How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs' (2005), Karen Warkentin reported on experiments she conducted to see how red-eyed treefrog embryos, Agalychnis callidryas, can distinguish between vibrations due to predator attacks and other environmental occurrences, such as storms. Though the ability of red-eyed treefrogs to alter their hatch timing had been documented, the specific cues that induce early hatching were not well understood.

Format: Articles

Subject: Experiments, Organisms

Digit Regeneration Is Regulated by Msx1 and BMP4 in Fetal Mice (2003), by Manjong Han et al.

In the early 2000s, Manjong Han, Xiaodang Yang, Jennifer Farrington, and Ken Muneoka investigated how genes and proteins in fetal mice (Mus musculus) influenced those fetal mice to regenerate severed toes at Tulane University in New Orleans, Louisiana. The group used hind limbs from mice to show how the gene Msx1 (Homeobox 7) functions in regenerating amputated digits.

Format: Articles

Subject: Experiments

Leonard Colebrook’s Use of Sulfonamides as a Treatment for Puerperal Fever (1935–1937)

Between 1935 and 1937, Leonard Colebrook showed that sulfonamides, a class of antibacterial drugs, worked as an effective treatment for puerperal fever. Puerperal fever is a bacterial infection that can occur in the uterus of women after giving birth. At the time of Colebrook’s study, puerperal fever remained a common disease due to both the lack of hygienic practices in hospitals and a treatment for the disease. After successfully using Prontosil, a sulfanilamide, to cure a patient who was going to die from puerperal fever, Colebrook began experiments with the drug.

Format: Articles

Subject: Experiments

Using Digital PCR to Detect Fetal Chromosomal Aneuploidy in Maternal Blood (2007)

In 2007, Dennis Lo and his colleagues used digital polymerase chain reaction or PCR to detect trisomy 21 in maternal blood, validating the method as a means to detect fetal chromosomal aneuploidies, or an abnormal number of chromosomes in a cell. The team conducted their research at the Chinese University of Hong Kong in Hong Kong, Hong Kong, and at the Boston University in Boston, Massachusetts.

Format: Articles

Subject: Experiments

Viktor Hamburger's Study of Central-Peripheral Relations in the Development of Nervous System

An important question throughout the history of embryology is whether the formation of a biological structure is predetermined or shaped by its environment. If both intrinsic and environmental controls occur, how exactly do the two processes coordinate in crafting specific forms and functions? When Viktor Hamburger started his PhD study in embryology in the 1920s, few neuroembryologists were investigating how the central neurons innervate peripheral organs.

Format: Articles

Subject: Experiments

Temperature-Dependent Sex Determination in Reptiles

The sex of a reptile embryo partly results from the production of sex hormones during development, and one process to produce those hormones depends on the temperature of the embryo's environment. The production of sex hormones can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination, also called genetic or chromosomal sex determination, an organism's genes determine which hormones are produced.

Format: Articles

Subject: Experiments

Serial Cultivation of Human Diploid Cells in the Lab (1958–1961) by Leonard Hayflick and Paul S. Moorhead

From 1958 to 1961, Leonard Hayflick and Paul Moorhead in the US developed a way in the laboratory to cultivate strains of human cells with complete sets of chromosomes. Previously, scientists could not sustain cell cultures with cells that had two complete sets of chromosomes like normal human cells (diploid). As a result, scientists struggled to study human cell biology because there was not a reliable source of cells that represented diploid human cells. In their experiments, Hayflick and Moorhead created lasting strains of human cells that retained both complete sets of chromosomes.

Format: Articles

Subject: Experiments

Lysogenic Bacteria as an Experimental Model at the Pasteur Institute (1915-1965)

Lysogenic bacteria, or virus-infected bacteria, were the primary experimental models used by scientists working in the laboratories of the Pasteur Institute in Paris, France, during the 1950s and 1960s. Historians of science have noted that the use of lysogenic bacteria as a model in microbiological research influenced the scientific achievements of the Pasteur Institute's scientists.

Format: Articles

Subject: Organisms, Experiments