Ignacio Vives Ponseti (1914-2009)

Ignacio Vives Ponseti (1914-2009)Ignacio Vives Ponseti developed a noninvasive method for treating congenital club foot in the US during the late 1940s. Congenital club foot is a birth deformity in which one or both of an infant's feet are rotated inward beneath the ankle, making normal movement rigid and painful. Ponseti developed a treatment method, later called the Ponseti method, that consisted of a series of manipulations and castings of the club foot performed in the first few months of life. The Ponseti method provided a non-surgical treatment that generally resulted in better long-term outcomes than the surgical procedures that doctors used prior to Ponseti's work. Ponseti's method for treating congenital club foot improved the quality of life for patients born with the deformity, and his work led researchers to study fetal foot tissues.

Harald zur Hausen's Experiments on Human Papillomavirus Causing Cervical Cancer (1976–1987)

Harald zur Hausen's Experiments on Human Papillomavirus Causing Cervical Cancer (1976–1987)From 1977 to 1987, Harald zur Hausen led a team of researchers across several institutions in Germany to investigate whether the human papillomavirus (HPV) caused cervical cancer. Zur Hausen's first experiment tested the hypothesis that HPV caused cervical cancer rather than herpes simplex virus type 2 (HSV-2), the then accepted cause. His second and third experiments detailed methods to identify two previously unidentified HPV strains, HPV 16 and HPV 18, in cervical cancer tumor samples. The experiments showed that HPV 16 and 18 DNA were present in cervical tumor samples. Zur Hausen concluded that HPV, not HSV-2, caused cervical cancer, which enabled researchers to develop preventions, such as the HPV vaccine.

Agent Orange Birth Defects

Agent Orange Birth Defects Editor's Note: This article replaces the previous article on this topic, which was published in this encyclopedia in 2012. The 2012 article may be found at http://hdl.handle.net/10776/4202.

"Presence of Fetal DNA in Maternal Plasma and Serum" (1997), by Dennis Lo, et al.

Fetal DNA in Maternal Plasma, (1997)In the late 1990s researchers Yuk Ming Dennis Lo and his colleagues isolated fetal DNA extracted from pregnant woman’s blood. The technique enabled for more efficient and less invasive diagnoses of genetic abnormalities in fetuses, such as having too many copies of chromosomes. Lo’s team published their results in their 1997 article "Presence of Fetal DNA in Maternal Plasma and Serum." The results led to developments of clinical tests that can access fetal genetic information and detect genetic abnormalities before birth without the risks associated with invasive genetic testing techniques of potentially harming the fetus.

Hermann Joseph Muller's Study of X-rays as a Mutagen, (1926-1927)

Hermann Joseph Muller's Study of X-rays as a Mutagen, (1926-1927) Hermann Joseph Muller conducted three experiments in 1926 and 1927 that demonstrated that exposure to x-rays, a form of high-energy radiation, can cause genetic mutations, changes to an organism's genome, particularly in egg and sperm cells. In his experiments, Muller exposed fruit flies (Drosophila) to x-rays, mated the flies, and observed the number of mutations in the offspring. In 1927, Muller described the results of his experiments in "Artificial Transmutation of the Gene"

Hydrocephalus During Infancy

Hydrocephalus During InfancyHydrocephalus is a congenital or acquired disorder characterized by the abnormal accumulation of cerebrospinal fluid within the cavities of the brain, called ventricles. The accumulation of cerebrospinal fluid, the clear fluid surrounding the brain and spinal cord, causes an abnormal widening of the ventricles. The widening creates potentially harmful pressure on the tissues of the brain that can result in brain damage or death. The most obvious sign of hydrocephalus is the rapid increase in head circumference or an unusual large head size due to the accumulation of cerebrospinal fluid in the brain. In infants, hydrocephalus can be caused by congenital factors such as malformations

Arthur Earl Walker (1907-1995)

Arthur Earl Walker (1907-1995) Arthur Earl Walker was a medical researcher and physician who studied the brain and neurosurgery in the United States during the twentieth century. Walker examined the connections of the thalamus to the rest of the brain and how the thalamus coordinates sensory signals. The thalamus is a cluster of nerve cells located between the two hemispheres of the brain and it is responsible for consciousness and sensory interpretation. While studying the thalamus, Walker noted that cerebral spinal fluid, the clear fluid surrounding the brain and spinal cord, sometimes became obstructed in certain parts of the brain in infants. Scientists linked the cerebral spinal fluid obstruction with a congenital brain malformation, later called Dandy-Walker Syndrome. Walker's work on the brain and cerebral

Edward Charles Dodds (1899-1973)

Edward <a href="/search?text=Charles%20Dodds" title="" class="lexicon-term">Charles Dodds</a> (1899-1973)Edward Charles Dodds researched the function and effects of natural and artificial hormones on the endocrine system in England during the twentieth century. Though he first worked with hormones such as insulin, Dodds focused on the effects of estrogen in the body and how to replicate those effects with artificial substances. In 1938, along with chemist Robert Robinson, Dodds synthesized the first synthetic estrogen called diethylstilbestrol.

Julia Barlow Platt's Embryological Observations on Salamanders' Cartilage (1893)

Julia Barlow Platt's Embryological Observations on Salamanders' Cartilage (1893)In 1893, Julia Barlow Platt published her research on the origins of cartilage in the developing head of the common mudpuppy (Necturus maculosus) embryo. The mudpuppy is an aquatic salamander commonly used by embryologists because its large embryonic cells and nuclei are easy to see. Platt followed the paths of cells in developing mudpuppy embryos to see how embryonic cells migrated during the formation of the head. With her research, Platt challenged then current theories about germ layers, the types of cells in an early embryo that develop into adult cells. In most organisms' development, three types of germ layers are responsible for the formation of tissues and organs. The

Golgi Staining Technique

Golgi Staining TechniqueThe Golgi staining technique, also called the black reaction after the stain's color, was developed in the 1870s and 1880s in Italy to make brain cells (neurons) visible under the microscope. Camillo Golgi developed the technique while working with nervous tissue, which required Golgi to examine cell structure under the microscope. Golgi improved upon existing methods of staining, enabling scientists to view entire neurons for the first time and changing the way people discussed the development and composition of the brain's cells. Into the twenty-fist century, Golgi's staining method continued to inform research on the nervous system, particularly regarding embryonic development.