Experiential Learning : Experience as the Source of Learning and Development

Detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III)

The mechanisms that balance food intake and energy expenditure determine who will be obese and who will be lean. One of the molecules that regulates energy balance in the mouse is the obese (ob) gene. Mutation of ob results in profound obesity and type II diabetes as part of a syndrome that resembles morbid obesity in humans. The ob gene product may function as part of a signalling pathway from adipose tissue that acts to regulate the size of the body fat depot.

Positional cloning of the mouse obese gene and its human homologue

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Hyperhomocysteinaemia has been identified as a risk factor for cerebrovascular, peripheral vascular and coronary heart disease. Elevated levels of plasma homocysteine can result from genetic or nutrient-related disturbances in the trans-sulphuration or re-methylation pathways for homocysteine metabolism. 5, 10-Methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, the predominant circulatory form of folate and carbon donor for the re-methylation of homocysteine to methionine. Reduced MTHFR activity with a thermolabile enzyme has been reported in patients with coronary and peripheral artery disease. We have identified a common mutation in MTHFR which alters a highly-conserved amino acid; the substitution occurs at a frequency of approximately 38% of unselected chromosomes. The mutation in the heterozygous or homozygous state correlates with reduced enzyme activity and increased thermolability in lymphocyte extracts; in vitro expression of a mutagenized cDNA containing the mutation confirms its effect on thermolability of MTHFR. Finally, individuals homozygous for the mutation have significantly elevated plasma homocysteine levels. This mutation in MTHFR may represent an important genetic risk factor in vascular disease.

/pdf/a-candidate-genetic-risk-factor-for-vascular-disease-a-28fnjdqen2.pdf

A candidate genetic risk factor for vascular disease: a common mutation in methylenetetrahydrofolate reductase

The Metabolic basis of inherited disease

THE Committee on Nutrition of the American Academy of Pediatrics has strongly endorsed the use of milk and infant formula products as primary vehicles for vitamin D supplementation to ensure a total vitamin D intake of 400 I.U. per day by all infants and children. Although in the United States there are significant regional differences with respect to dairy practices in fortifying fluid milk, almost three-fourths of all whole milk sold at retail is fortified with vitamin D, and almost all evaporated milk and infant formula products contain 400 I. U. of vitamin D per reconstituted quart. In addition, vitamin D is readily available in vitamin supplements, and, undoubtedly as a result of the wide distribution and ready availability of vitamin D, the incidence of infantile rickets in the United States has remained at a very low level.

This report draws attention to the lack of vitamin D in nonfat dry milk, a product used in significantly increasing amounts for preparing milk for home use for children, and possibly for infants. The use of nonfat dry milk has been accelerated recently by the increase in prices of fluid milk. For example, in 1965, the last year for which figures are available, consumer sales of nonfat dry milk amounted to 2.5 billion pounds of fluid equivalent, or about 5% of the total national consumption of milk. This total reflects an increase in consumption of almost 70% over the past 10 years.

The lack of vitamin D in certain major sources of milk for the population invites the reappearance of rickets.

https://pediatrics.aappublications.org/content/pediatrics/40/3/455.full.pdf

Committee on nutrition

Phenylalanine hydroxylase deficiency

Monogenic traits are not simple: lessons from phenylketonuria

1. Collect 5 ml of blood in a vacutainer tube (Becton Dickinson) containing EDTA and mix. 2. Make volume up to 10 ml with solution 1 (10 mM Tris pH 7.6; 10 mM KC1; 10 mM MgCy. 3. Add 120 /il Nonidet P40 (BDH) to lyse the cells. Mix well by inverting several times. 4. Spin down the nuclear pellet at 2000 rpm for 10 mins. 5. Pour off the supernatant without dislodging the pellet. The pellets can be stored frozen. 6. Gently resuspend pellet well in 800 /il of solution 2 (10 mM Tris pH 7.6; 10 mM KC1; 10 mM MgCl2; 0.5 M NaCl; 0.5% SDS; 2 mM EDTA). Solution 2 will lyse the nuclei so be careful not to shear the DNA. Transfer to a 1.5 ml microcentrifuge tube. 7. Add 400 /il of distilled phenol (saturated with 1 M Tris pH 8.0) and mix well. 8. Microfuge for 1 min at 12000 rpm. Transfer upper phase to a clean microfuge tube. Do not worry about transferring a little of the interface. 9. Add 200 /tl of phenol and 200 /il of chloroform :isoamyl alcohol (24:1). Mix well by inverting. 10. Spin for 1 min at 12000 rpm. Transfer upper phase to a clean microfuge tube. 11. Add 700 /tl of chloroform:isoamyl alcohol and extract as above. 12. Transfer upper aqueous phase to a small clean container. Avoid removing the interface. Add 2 volumes of ice cold ethanol and mix to precipitate the DNA*. 13. With the sealed tip of a pasture pipette, transfer the DNA fibres to a microcentrifuge tube containing 1 ml of 70% ethanol. Mix well to wash the DNA. 14. Spin for 5 mins at full speed. Discard the ethanol and dry pellet in a speed vac. Resuspend DNA in sterile water at 65°C. Do not over-dry genomic DNA or it will be difficult to resuspend. SIZE A / /Kb Hindll l

/pdf/a-rapid-procedure-for-extracting-genomic-dna-from-leukocytes-4a8dfzpvcb.pdf

Charles R. Scriver

Papers

The Metabolic basis of inherited disease

Committee on nutrition

Phenylalanine hydroxylase deficiency

Monogenic traits are not simple: lessons from phenylketonuria

A rapid procedure for extracting genomic DNA from leukocytes