Embryo Project Encyclopedia

According to the US National Institutes of Health (NIH), the standard American source on stem cell research, three characteristics of stem cells differentiate them from other cell types: (1) they are unspecialized cells that (2) divide for long periods, renewing themselves and (3) can give rise to specialized cells, such as muscle and skin cells, under particular physiological and experimental conditions. When allowed to grow in particular environments, stem cells divide many times. This ability to proliferate can yield millions of stem cells over several months. As long as the stem cells remain unspecialized, meaning they lack tissue-specific structures, they are able to sustain long-term self-renewal.

Hans Peter Dietz and Judy Simpson published, “Levator Trauma is Associated with Pelvic Organ Prolapse,” in the journal BJOG: An International Journal of Obstetrics and Gynecology in 2008. In their article, Dietz and Simpson estimated the risk of pelvic organ prolapse in women who attained injuries to the pelvic levator muscles. The levator muscles, also known as the levator ani, are a major muscle group that comprise the pelvic floor. Along with other muscles, the pelvic floor supports organs in a woman’s pelvis, such as the bladder, uterus, and rectum. Vaginal childbirth can cause a weakening of the pelvic muscles. That can lead to pelvic organ prolapse, which results in the descent of the pelvic organs towards a woman’s vaginal opening. In, “Levator Trauma is Associated with Pelvic Organ Prolapse,” Dietz and Simpson found that women were more likely to have pelvic organ prolapse if they had levator trauma, and called for further research to understand the relationship between levator ani trauma and pelvic organ prolapse.

In 1997, physicians and researchers Ambre Olsen, Virginia Smith, John Bergstrom, Joyce Colling, and Amanda Clark published, “Epidemiology of Surgically Managed Pelvic Organ Prolapse and Urinary Incontinence,” in the journal Obstetrics and Gynecology. In their article, the authors retrospectively analyzed data from patients who underwent surgery for pelvic organ prolapse or urinary incontinence two years prior in 1995. Often due to a weakening of or damage to their pelvic muscles, women with pelvic organ prolapse can experience a descent of pelvic organs into the lower pelvis and vagina. People with urinary incontinence can experience bladder control issues and urinary leaks. According to the authors, an estimated fifty percent of women who have previously given birth have had a prolapse. In their article, Olsen and colleagues analyze factors such as race, age, and weight in women who had surgery to treat pelvic organ prolapse and ultimately advocate for a standard assessment for the severity of those conditions.

In 1996, a team of researchers associated with the International Continence Society published “The Standardization of Terminology of Female Pelvic Organ Prolapse and Pelvic Floor Dysfunction” in American Journal of Obstetrics and Gynecology. Pelvic organ prolapse is characterized by the descent of the pelvic organs into the lower portion of the pelvis and is often caused by a weakening of the muscles and ligaments that normally hold the organs in place. The authors concluded that physicians and researchers needed to develop a system of standardized terms to use to describe the anatomical position of pelvic organ prolapse in women. They propose using terms that emphasize the location of the prolapse rather than just the involved organ. They also suggest that the system utilizes a series of examinations and imaging to uniformly describe and quantify pelvic organ prolapse. The article by Bump and colleagues was one of the first to call for a standardized system using specific terms to communicate findings about pelvic organ prolapse systematically across clinical and academic research settings.

In 2007, physicians John Jelovsek, Christopher Maher, and Matthew Barber published, “Pelvic Organ Prolapse,” in The Lancet. In their article, Jelovsek and colleagues provided an overview of pelvic organ prolapse in women and described the epidemiology, risk factors, symptoms, and management of the condition. Pelvic organ prolapse occurs when a woman’s pelvic floor is weakened or damaged from stress or trauma such as vaginal childbirth. The pelvic floor is a group of muscles that provides support to organs within the lower abdominal region of the body, including the bladder, uterus, and rectum. Disorders of the pelvic floor disrupt its normal function, often causing a feeling of uncomfortable pressure or pain, and incontinence, which is involuntary leakage of urine or feces. In their article, Jelovsek and colleagues reviewed the known information about pelvic organ prolapse as of 2007 and research teams who further studied the causes and management of pelvic organ prolapse in women later used the article as a reference.

Pelvic organ prolapse is a common condition in women that causes the pelvic organs to descend, often resulting from a weakened pelvic floor. Pelvic organs supported by the pelvic floor, such as the bladder, bowel, or uterus, can descend to such a degree that they project out from a woman’s body typically via the vagina. Pelvic floor stress or trauma, like vaginal childbirth, can cause pelvic organ prolapse. Women with pelvic organ prolapse also often experience other conditions, such as incontinence or the involuntary leakage of urine or fecal matter. As a result, while many women experience pressure or fullness from the prolapse itself, other common symptoms of pelvic organ prolapse are those involving the bladder or the bowel. Treatments for prolapse depend on the woman’s symptoms, and include pessaries, surgery, and pelvic floor exercises. As of 2021, researchers and physicians continue to study pelvic organ prolapse to determine how different treatments can be tailored to specific causes or symptoms.

In November 1998, two independent reports were published concerning the first isolation of pluripotent human stem cells, one of which was "Derivation of Pluripotent Stem Cells from Cultured Human Primordial Germ Cells." This paper, authored by John D. Gearhart and his research team - Michael J Shamblott, Joyce Axelman, Shunping Wang, Elizabeith M. Bugg, John W. Littlefield, Peter J. Donovan, Paul D. Blumenthal, and George R. Huggins - was published in Proceedings of the National Academy of Science soon after James A. Thomson and his research team published "Embryonic Stem Cell Lines Derived from Human Blastocysts" in Science. Gearhart 's paper suggested that pluripotent human stem cells, which have the ability to develop into all cell types that make up the body, could be derived from primordial germ cells, which are precursors of fully differentiated germ cells, isolated from embryos. At the time, Gearhart was a professor of obstetrics and gynecology at Johns Hopkins University School of Medicine. With a background in genetics, he had devoted the majority of his research to how genes regulate tissue and embryo formation. However, the successful isolation of mice embryonic stem cells encouraged Gearhart to pursue the isolation of similar cells in humans. The principal difference between human embryonic stem (ES) cells, which Thomson 's team derived, and human embryonic germ (EG) cells, which Gearhart 's team derived, is that human embryonic germ cells are derived from early germ cells. Nonetheless, they are thought to share similar properties to human embryonic stem cells.

James Alexander Thomson, affectionately known as Jamie Thomson, is an American developmental biologist whose pioneering work in isolating and culturing non-human primate and human embryonic stem cells has made him one of the most prominent scientists in stem cell research. While growing up in Oak Park, Illinois, Thomson's rocket-scientist uncle inspired him to pursue science as a career. Born on 20 December 1958, Thomson entered the nearby University of Illinois Urbana-Champaign nineteen years later as a National Merit Scholar majoring in biophysics. He became fascinated with development via the encouragement and influence of Fred Meins, one of his undergraduate professors. After graduating as a Phi Beta Kappa scholar, Thomson took his interest in biology to the University of Pennsylvania where he earned two doctorate degrees: one in veterinary medicine, completed in 1985, and the other in molecular biology, completed in 1988. It was during his graduate years that Thomson began working with embryonic stem cells.

In 2011, Cristian Persu, Christopher Chapple, Victor Cauni, Stefan Gutue, and Petrisor Geavlete published “Pelvic Organ Prolapse Quantification System (POP-Q) – A New Era in Pelvic Prolapse Staging,” in the Journal of Medicine and Life. In their article, the authors explain the need for a reliable diagnostic method for describing the state of a pelvic organ prolapse, or a condition that can result from weakness or damage to the muscles that support the pelvic organs, sometimes leading to bladder, bowel, and sexual dysfunction. Persu and colleagues describe a previous diagnostic method, the Baden-Walker Halfway Scoring System, comparing it to the newer system, the Pelvic Organ Prolapse Quantification System, referred to also as POP-Q. By examining the benefits and drawbacks of each pelvic organ prolapse measurement and diagnostic system, the authors proposed a universal acceptance of the POP-Q system, based on its accuracy and reliability.

On 2 December 2007, Science published a report on creating human induced pluripotent stem (iPS) cells from human somatic cells: "Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells." This report came from a team of Madison, Wisconsin scientists: Junying Yu, Maxim A. Vodyanik, Kim Smuga-Otto, Jessica Antosiewicz-Bourget, Jennifer L. Frane, Shulan Tian, Jeff Nie, Gudrun A. Jonsdottir, Victor Ruotti, Ron Stewart, Igor I. Slukvin, and James A. Thomson. Earlier that year Shinya Yamanaka at Kyoto University, Japan published a similar paper,"Generation of Germline-Competent Induced Pluripotent Stem Cells," in Nature. Both papers independently identified four genes used to reprogram human somatic cells to pluripotent stem cells, which are cells that have the ability to develop into any specialized cell type making up the body. The reprogrammed somatic cells were referred to as iPS cells and they exhibit fundamental qualities of human embryonic stem (ES) cells.