Search PubMed⌕ Search

Biomedical subjects

E A Yount

Publications and source records attributed to E A Yount.

11 recordsLinked to original sources
PubMed1987

Applications of the MEGADATS database system in medical genetics.

The MEGADATS relational database system has many useful applications in the field of medical genetics. Some of these applications include storage, retrieval, and display of pedigree information; retrieval of sets of individuals, sibships, or families who meet given criteria; storage of necessary information for mailing lists, clinic data, etc; and combination of pedigree information and genotype information into the format needed for linkage analysis packages.

Genetics, Medical↗
PubMed1987

The use of relational database commands in retrieval of pedigree information.

Genetic research frequently requires retrieval of information about families afflicted with some genetic disease. These queries may involve simple retrieval of information on individuals with particular attributes or finding data from sibships or families who meet some set of criteria. Although the former case may be handled by almost any file management system, the latter case cannot be easily managed since family relationships are necessary to the query. These family relationships are normally stored by means of a pointer system that links the record of each individual with those of his parents. Given such a pointer system, the standard commands of a relational database system can be used to perform such retrievals, thus diminishing the need for special programs to perform such queries.

Database Management Systems↗
PubMed1985

Automating data manipulation for genetic analysis using a data base management system.

Inefficient coding and manipulation of pedigree data have often hindered the progress of genetic studies. In this paper we present the methodology for interfacing a data base management system (DBMS) called MEGADATS with a linkage analysis program called LIPED. Two families that segregate a dominant trait and one test marker were used in a simulated exercise to demonstrate how a DBMS can be used to automate tedious clerical steps and improve the efficiency of a genetic analysis. The merits of this approach to data management are discussed. We conclude that a standardized format for genetic analysis programs would greatly facilitate data analysis.

Genetics, Medical↗
PubMed1984

Huntington's disease research roster data base support with MEGADATS-3M.

This paper describes the MEGADATS (MEdical Genetics Acquisition and DAta Transfer System) data base development project for collecting, storing, retrieving, and plotting human family pedigrees. The newest system, MEGADATS-3M, is described. The microcomputer version of MEGADATS-3M and the use of MEGADATS-3M in the support of the Huntington's disease research roster project are emphasized. Examples of data input and pedigree plotting are shown.

Computers↗
PubMed1982

Comparison of the metabolic and toxic effects of 2-chloropropionate and dichloroacetate.

The metabolic and toxic effects of 2-chloropropionate and dichloroacetate, activators of the pyruvate dehydrogenase complex, were compared. In 4-hr fasted mice, the oral LD50 values for 2-chloropropionate and dichloroacetate were 15.4 +/- 0.1 and 32.1 +/- 1.1 mmol/kg, respectively. In suckling rats, both compounds effectively lowered blood lactate and glucose levels and increased blood ketone bodies. Although comparable effects were brought about by both compounds on other metabolites, dichloroacetate caused a greater increase in blood ketone bodies. In a prolonged oral toxicity study using male rats, both compounds decreased growth rate and food consumption and caused neurotoxic effects. Both compounds brought about hind limb weakness, slower nerve conduction velocities and decreased diameter of tibial nerves. 2-Chloropropionate treatment caused testicular abnormalities manifested by testicular maturation arrest and degeneration of germ cells. 2-Chloropropionate-treated rats had significantly lower plasma triacylglycerol levels than control or dichloroacetate-treated rats. In mature rats, total serum ketone bodies were increased by dichloroacetate but not significantly elevated by 2-chloropropionate. Although 2-chloropropionate may lack sufficient safety to warrant chronic use in humans, it is a useful research tool for studying the metabolic effects of activation of the pyruvate dehydrogenase complex. Since 2-chloropropionate is not converted to oxalate and is not as ketogenic as dichloroacetate, 2-chloropropionate may be useful clinically in situations requiring only short-term therapy.

Acetates↗
PubMed1980

Studies on the inhibition of gluconeogenesis by oxalate.

Oxalate was shown to enter isolated rat hepatocytes and to inhibit gluconeogenesis from lactate, pyruvate, and alanine, but not from glutamine, proline, propionate or dihydroxyacetone. Oxalate apparently acts by inhibiting pyruvate carboxylase (EC 6.4.1.1.). It is known to inhibit the isolated enzyme, and inhibition of gluconeogenesis was much greater in a bicarbonate-deficient medium where pyruvate carboxylase activity limits the overall rate of the pathway. A slight inhibition of gluconeogenesis from asparagine was observed, suggesting that oxalate may also inhibit gluconeogenesis at another site. Chelation of extracellular Ca2+ does not contribute to the inhibition of gluconeogenesis. Compared to oxalate, other Ca2+ chelators have little effect upon gluconeogenesis. Also, oxalate inhibits gluconeogenesis effectively both in low Ca2+ medium and in medium containing 2.6 mM Ca2+. Chelation of intracellular Ca2+ also appears to be of little importance, since oxalate does not block the glycogenolytic effects of epinephrine, vasopressin, and angiotensin which are thought to act via Ca2+ as the second messenger. The inhibition of gluconeogenesis could conceivably contribute to the toxic actions of oxalate and to the hypoglycemic action of dichloroacetate, a compound that is metabolized to oxalate. However, oxalate did not cause hypoglycemia in the suckling rat, a model in vivo system very dependent upon gluconeogenesis for maintenance of normal blood glucose levels. Thus, inhibition of gluconeogenesis is probably of little importance in oxalate toxicity and the hypoglycemic effects of dichloroacetate.

Angiotensins↗
PubMed1976

Development of guanylylimidodiphosphate-dependent activation of adenylate cyclase by glucagon in the neonatal rat heart.

The basal adenylate cyclase activity of the rat heart increases with the age of the animal. By itself, 10(-5) M glucagon activates only adenylate cyclase activity from adult rat hearts. In contrast, 10(-5) M glucagon in the presence of 10(-4)M 5'-guanylylimidodiphosphate (GMP-PNP) clearly activates adenylates cyclase activity in the 14-day-old rat heart, with some activation being evident in hearts of 7-day-old animals. GMP-PNP, 10(-4) M, activates adenylate cyclase activity by itself at ages of 14 days and older, but to a far lesser degree than in combination with 10(-5) M glucagon. Activity elicited by NaF increases throughout the neonatal period. The ratio of NaF-stimulated activity to basal activity increases from 6.3 at 2 days to 10.0 in the adult, a change which is not statistically significant. We conclude that a cardiac receptor for glucagon is present early in neonatal period of the rat, but this receptor cannot effect activation of adenylate cyclase and an increase in heart rate, or depletion of glycogen. Even in the presence of 10(-4) GMP-PNP, the response to glucagon by cardiac adenylate cyclase depends on the age of the rat. In heart cells from a 7-day-old rat, the response is barely measurable but the magnitude of the response increases each week.

Adenylyl Cyclases↗