National Institutes of Health

About: National Institutes of Health is a government organization based out in Bethesda, Maryland, United States. It is known for research contribution in the topics: Population & Gene. The organization has 149298 authors who have published 297896 publications receiving 21337431 citations. The organization is also known as: NIH & U.S. National Institutes of Health.

Brefeldin A: insights into the control of membrane traffic and organelle structure.

Abstract: THE definition of cellular organelles has evolved over the last hundred years largely driven by morphologic observations, but more recently has been supplemented and complemented by functional and biochemical studies (Palade, 1975) . Thus, organelles are now identified both by their morphology and by the set ofcomponents that comprise them . Determining how organelle identity is established and maintained and how newly synthesized protein and membrane are sorted to different organelles are the central issues of organellogenesis . Essential to the many cellular functions that take place within the central vacuolar system (which consists ofthe ER, Golgi apparatus, secretory vesicles, endosomes, and lysosomes) is membrane traffic which mediates the exchange of components between different organelles . There are two critical characteristics of membrane traffic . First, only certain sets oforganelles exchange membrane and the patterns of this exchange define what are called membrane pathways . Second, multiple pathways intersect at specific points within the central vacuolar system . For specific components to "choose" the correct pathway at such points of crossing, mechanisms exist to impose choices on specific molecules . This process is called sorting . The characteristicsofeachorganelle within the central vacuolar system are likely to be intimately tied to the properties ofmembrane traffic . An imbalance in the magnitude ofmembrane input into and egress from an organelle would have profound effects on the size ofthat compartment . In addition, failures in sorting or aberrations in targeting pathways would be expected to profoundly affect the identity of individual organelles . Recently, the relationship between the control of membrane traffic and the maintenance of organelle structure has been investigated with the use ofa remarkable drug, brefeldin A (BFA).' In this review we will summarize recent findings with BFA and propose some speculative models concerning the mechanism and regulation ofmembrane traffic within the central vacuolar system .

The Ames Salmonella/microsome mutagenicity assay

Abstract: The Ames Salmonella/microsome mutagenicity assay (Salmonella test; Ames test) is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances that can produce genetic damage that leads to gene mutations. The test employs several histidine dependent Salmonella strains each carrying different mutations in various genes in the histidine operon. These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms. When the Salmonella tester strains are grown on a minimal media agar plate containing a trace of histidine, only those bacteria that revert to histidine independence (his(+)) are able to form colonies. The number of spontaneously induced revertant colonies per plate is relatively constant. However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner. The Ames test is used world-wide as an initial screen to determine the mutagenic potential of new chemicals and drugs. The test is also used for submission of data to regulatory agencies for registration or acceptance of many chemicals, including drugs and biocides. International guidelines have been developed for use by corporations and testing laboratories to ensure uniformity of testing procedures. This review provides historical aspects of how the Ames was developed and detailed procedures for performing the test, including the design and interpretation of results.

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

Abstract: Blood pressure is a heritable trait(1) influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (>= 140 mm Hg systolic blood pressure or >= 90 mm Hg diastolic blood pressure)(2). Even small increments in blood pressure are associated with an increased risk of cardiovascular events(3). This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.

Role of diabetes in congestive heart failure: the Framingham study.

Abstract: The incidence of congestive heart failure was determined in relation to prior diabetic status in 5,209 men and women aged 30 to 62 years followed up for 18 years in the Framingham study Men aged 45 to 74 years had more than twice the frequency of congestive failure as their nondiabetic cohorts, and diabetic women had a fivefold increased risk This excessive risk appears to be caused by factors other than accelerated atherogenesis and coronary heart disease Even when patients with prior coronary or rheumatic heart disease were excluded, the diabetic subjects had a four- to fivefold increased risk of congestive heart failure In women (but not men) with prior coronary disease, diabetes also imposed a threefold increased risk of congestive failure Furthermore, the increased risk of heart failure in the diabetic patients persisted after taking into account age, blood pressure, weight and cholesterol values as well as coronary heart disease Women with diabetes appeared to be especially vulnerable and, irrespective of coronary disease status, had twice the frequency of congestive heart failure as men The excessive risk of heart failure among diabetic subjects was confined to those treated with insulin The data suggest that diabetes is another discrete cause of congestive heart failure and that some form of cardiomyopathy is associated with diabetes, as a result of either small vessel disease or metabolic disorders