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The traditional way of taking a drug, such as a pill or injection, often results in plasma drug levels that cycle between too high and too low. To better maintain drug levels in the effective range, scientists have developed a variety of systems to optimize drug release. In his first talk, Bob Langer gives an overview of many of these controlled drug release technologies, including polymer and pump systems. Langer begins Part 2 with the story of how he became interested in drug release technologies, which is also a story of the power of perseverance. As a post-doc with Judah Folkman, and after much trial and error, Langer developed a polymer system that provided a slow and constant release of an anti-angiogenesis factor. Initially, his results were met with skepticism, by both scientists and the patent office. Today, many, many companies have developed peptide delivery systems based on that original work. Langer also describes ongoing research in areas such as targeted drug delivery and externally controlled microchips designed for drug delivery. In Part 3, Langer focuses on the materials used in drug delivery and medical devices. Many of the original materials used in medicine were adapted from completely unrelated uses and often generated their own problems. Langer describes work by his lab and others to make polymers designed for specific medical uses. For instance, a porous polymer can be shaped into an ear or nose and act as a scaffold onto which a patient’s cells can be seeded to grow a new structure. Different polymers have been successfully used as scaffolds to grow new blood vessels or artificial skin for burn victims.
- Subjects:
- Health Technology and Informatics and Health Sciences
- Keywords:
- Drugs -- Controlled release Controlled release technology
- Resource Type:
- Video
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Video
Human population growth and urbanization have accelerated dramatically in recent centuries, providing unprecedented opportunities for microbes that use our bodies as vehicles for their own propagation and transmission. These conditions have led to the emergence of virulent new pathogens and the increased prevalence of “classic” scourges, such as Mycobacterium tuberculosis. This tenacious microbe is transmitted via infectious aerosols produced by individuals with pulmonary tuberculosis. Infection is lifelong and symptomatic tuberculosis may develop following a period of clinical latency lasting for months, years, or decades. The first part of this lecture provides an overview of the natural history of TB infection and the global impact of TB on human health. Tuberculosis remains one of the most important causes of human disease and death despite the introduction of vaccination in 1921 and chemotherapy in 1952. Although these interventions are inexpensive and widely available their impact is limited. The effectiveness of vaccination is unclear; in clinical trials, the protection conferred by vaccination has been variable and generally poor. Although chemotherapy can be highly effective, multiple drugs must be administered for 6-9 months to provide a reliable cure; the majority of tuberculosis patients are unable or unwilling to complete such a demanding regimen unless closely supervised. The second part of this lecture will discuss the challenges facing development of more effective vaccines and drugs for prevention and treatment of tuberculosis. The principal obstacle to successful treatment of tuberculosis is the lengthy duration of current regimens, which require administration of multiple drugs for 6-9 months. The requirement for prolonged therapy is attributed to sub-populations of bacillary “persisters” that are refractory to antimicrobials. The persisters are not drug-resistant in the conventional (heritable) sense and it is a mystery why they are spared whilst their genetically identical siblings are killed. The third part of this lecture describes recent work in our laboratory using microfluidics and time-lapse microscopy to analyze the behavior of drug-stressed bacteria at single-cell resolution. These studies challenge conventional views of how antimicrobials kill (or fail to kill) bacteria. All pathogens must acquire and assimilate nutrients from their hosts in order to grow and multiply — our tissues are literally their food — yet surprisingly little is known about this fundamental aspect of the pathogenic lifestyle. Accumulating evidence suggests that M. tuberculosis might utilize fatty acids as its principal carbon and energy source during infection. The fourth part of this lecture describes work in our laboratory that is focused on identifying the metabolic pathways that are essential for growth and persistence of M. tuberculosis in vivo. Some of these pathways are potentially interesting targets for antimicrobial drug development, as they are not found in human cells.
- Subjects:
- Public Health and Health Sciecnes
- Keywords:
- Tuberculosis Public health
- Resource Type:
- Video
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Video
Easy access to nutrients has contributed to the increase in obesity in the human population. But, what is obesity and why isn’t everybody fat? Dr. Stephen O’Rahilly provides a biomedical perspective of obesity, and evaluates which genes could potentially shift the balance towards obesity. As he explains, one becomes obese when the balance between energy intake and energy spent is shifted. Surprisingly, mutations that lead to obesity in humans aren’t in genes involved in metabolism and energy storage, but failure in satiety signals in the brain that result in people eating too much. The excess of energy intake over energy expenditure leads to obesity. What is the consequence of obesity in human health? Physically, obesity can result in lower mobility and sleeping disorders. But, in humans, the link between obesity and metabolic diseases isn’t straightforward. For example, not everyone that’s obese becomes insulin resistant. As O’Rahilly explains, the probability of an obese individual to have a metabolic disease is linked to the capacity of adipose tissue to store the extra fat. Mutations that decrease fat storage in adipose tissue increase the chance of metabolic diseases, like insulin resistance, even when the person is not obese.
- Subjects:
- Health Sciences and Biology
- Keywords:
- Obesity -- Genetic aspects
- Resource Type:
- Video
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Video
Microglia are the primary immune cells in the central nervous system. In the brain, they play central roles in proper development and function, as well as dysfunction and disease. In her first talk, Dr. Beth Stevens provides an overview of the many ways microglia cells operate, and how they can both harm and protect the brain. Fairly recent advances in the study of microglia through imaging have allowed researchers to identify different microglia states and study their dynamic roles at different stages of development. In her second second talk, Dr. Stevens dives deeper into the mechanisms that allow microglia to shape the network of connections between neurons in the brain. She provides an introduction to the role of microglia in synaptic pruning, the process of eliminating extra synapses in healthy developing brains. She then goes on to explain how the reactivation of this process affects aging and diseased brains.
- Subjects:
- Medical Laboratory Science
- Keywords:
- Microglia Brain -- Diseases
- Resource Type:
- Video