Amino acid transport in hepatoma cell cultures during tyrosine aminotransferase induction     

E L Krawitt  E F Baril  J E Becker  V R Potter 《Science (New York, N.Y.)》1970,169(942):294-296

Alpha-aminoisobutyric acid transport in hepatoma cells in culture was increased by insulin but not by hydrocortisone. Both of these agents induce tyrosine aminotransferase activity in this system. The apparent increase in alpha-aminoisobutyric acid transport and tyrosine aminotransferase activity produced by glucagon is probably caused by insulin contamination. Insulin did not increase transport in this system until after tyrosine aminotransferase activity had reached maximum levels. The mechanisms underlying increased alpha-aminoisobutyric acid transport appear to differ from those for tyrosine aminotransferase induction with hydrocortisone despite their close association in previous whole animal experiments.  相似文献   

Macroglobulin-producing plasma-cell tumor in mice: identification of a new light chain   总被引：12，自引：0，他引：12  

K R McIntire  R M Asofsky  M Potter  E L Kuff 《Science (New York, N.Y.)》1965,150(694):360-363

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Newsgathering     

Hirschberg E  Joseph Fu SC  Frisell WR  Farber E  Potter VR  Rusch HP  Saffiotti U  Shimkin MB  Brennan MJ  Nowell PC  Creech HJ  Taylor RM  Schabel FM  Frei E  Lepage GA  Weinhouse S  Hall TC 《Science (New York, N.Y.)》1972,176(4041):1288-1289

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Molecular biology and the nature of man     

Potter VR 《Science (New York, N.Y.)》1966,153(3732):121

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Pattern of genetic diversity of cultivated and non-cultivated mashua, <Emphasis Type="Italic">Tropaeolum tuberosum</Emphasis>, in the Cusco region of Perú     

O. R. Ortega  E. Duran  C. Arbizu  R. Ortega  W. Roca  D. Potter  C. F. Quiros 《Genetic Resources and Crop Evolution》2007,54(4):807-821

This paper analyzes the genetic diversity of mashua cultivars grown in six communities in the Cusco region of Perú, of non-cultivated forms collected in the same region, and a sample of cultivars from the germplasm collection at the International Potato Center (CIP). From the DNA fingerprinting generated by SRAP markers, it is clear that mashua is a genetically variable crop with a range of similarity ranging from 65 to 99%. The widest range of variation was found for the most isolated community, Sayllafaya. Another important finding was that most of the non-cultivated accessions are likely feral races resulting from escape to cultivation rather than wild relatives. In general the range of variation of the cultivars from the communities and their feral relatives are not represented in the cultivars sampled of the collection maintained at the International Potato Center, Perú.  相似文献   

Utilization of the genetic resources of wild species to create a nontransgenic high flavonoid tomato     

Willits MG  Kramer CM  Prata RT  De Luca V  Potter BG  Steffens JC  Graser G 《Journal of agricultural and food chemistry》2005,53(4):1231-1236

Flavonoids represent a large and important group of plant natural products that are ubiquitous in the plant kingdom. Epidemiological studies have shown the health benefits of a diet high in flavonoids. However, the dietary intake of flavonoids in most western populations is limited, creating a need to find alternative food sources for these polyphenolic secondary metabolites. The domestication of many of our cultivated food crops has resulted in alterations in the biosynthetic pathways of many essential micronutrients and vitamins through inadvertent counterselection against nutritional traits in favor of agronomic ones. Flavonoids are nearly absent from fruits of cultivated tomato (Lycopersicon esculentum Mill.), a major vegetable in human diets. Previous attempts to restore the flavonoid pathway in tomato fruits have been limited to transgenic strategies, suggesting that the problem was intractable through traditional methods. Here, we describe for the first time a nontransgenic metabolic engineering approach to developing a high flavonoid tomato using a wild tomato species (Lycopersicon pennelliiv. puberulum) and demonstrate the opportunities for restoring functional pathways using the genetic resources of wild species, resulting in production of healthier foods.  相似文献   

Factors affecting the dissolution and degradation of oriental mustard-derived sinigrin and allyl isothiocyanate in aqueous media   总被引：2，自引：0，他引：2  

Tsao R  Yu Q  Friesen I  Potter J  Chiba M 《Journal of agricultural and food chemistry》2000,48(5):1898-1902

Sinigrin, the predominant glucosinolate in the oriental mustard Brassica juncea, is mainly degraded upon the enzymatic action of myrosinase under normal conditions to give allyl isothiocyanate (AITC) in an aqueous media. Because AITC is considered to be the principal nematicidal ingredient in B. juncea, its stability in aqueous media is an important issue in achieving efficient nematode control. Pure sinigrin and AITC were found to be relatively stable in buffered water in the pH range of 5.00-7.00 but less stable at pH 9.00. Both sinigrin and AITC were more stable in soil water (supernatant of a 1:1 water/air-dried soil mixture) than in buffered water at the same pH range of 5.00-9.00. Sinigrin dissolved from the mustard bran or ground seed into water very quickly and was degraded by codissolved myrosinase to AITC. The AITC that formed from the degradation of sinigrin was found to be more stable in the soil water than in the buffered water. Buffer capacity was considered to be one of the factors that contributed to the stabilization of AITC in the soil water, but other unknown factors from both bran or seed and soil may also have contributed to the stabilization.  相似文献   

Digestible energy requirements for work and maintenance of horses fed conventional and fat-supplemented diets     

G.D. Potter  S.P. Webb  J.W. Evans  G.W. Webb   《Journal of Equine Veterinary Science》1990,10(3)

A control and a 10% fat-supplemented diet were fed to exercising horses maintained in two different body conditions, during both temperate and hot weather, to determine the efficacy of fat as dietary aid to reduced energy requirements for thermal regulation in exercising horses. Horses were worked 7.2 km daily, 5 d/w, and in each season were fed sufficient energy to maintain constant body weight and body fat content at each assigned level of body condition. In both seasons and in both body conditions, digestible energy intake was lower (P<.01) when the horses were fed the fat-supplemented diet than when fed the control diet. Digestible energy intake was partitioned into requirements for work and maintenance. Since work levels were similar, digestible energy requirements for work were similar when horses were fed both experimental diets. However, the digestible energy requirements for maintenance were significantly lower (P<.01) when the horses were fed the fat-supplemented diet. Thus, it appears that feeding fat to exercising horses reduces the thermal load and resulting digestible energy requirements for maintenance in both temperate and hot weather.  相似文献   

Evaluation of crab meal as a dietary ingredient for young Turkeys     

L. M. Potter  J. R. Shelton 《British poultry science》1973,14(3):257-261

Adding 3 or 6% crab meal to the diets of turkeys between 1 d and 4 weeks of age resulted in their average body weight being increased by 5.2 or 6.8% and food consumption by 4.2 or 5.8%. Efficiency of food utilisation was not significantly changed. However, the addition of 5% crab meal to the diets of turkeys between 4 and 8 weeks of age resulted in average body weight gain and food consumption being increased by 1.4 and 1.3% respectively (P>0.05).

By adding 5% herring fish meal to the diets of poults from 4 to 8 weeks, body weight gain was increased by 2.0% (0.05<P<0.1), but food consumption was decreased by 2.3% and efficiency of food utilisation was increased by 4.2% indicating that fish meal contains a larger quantity of metabolisable energy than crab meal.

The addition of erythromycin at a rate of 13.5 or 20.4 mg/kg increased body weight gain by 4.5% and efficiency of food utilisation by 4.4% during the period between 4 and 8 weeks of age. No significant interactions among the dietary factors on the measurements studied in these experiments were observed.  相似文献   

Nitrogen metabolism in mature horses at varying levels of work     

D W Freeman  G D Potter  G T Schelling  J L Kreider 《Journal of animal science》1988,66(2):407-412

Nitrogen metabolism was measured in five mature geldings performing varying levels of work that simulated race training. Following an initial maintenance period without forced exercise, workload was increased in succeeding 18-d periods by doubling the distance the horses were galloped in each period from period 2 through 4. A 4-d N balance experiment was conducted at the end of each 18-d period. The maximum distance galloped daily, which was in period 4, was repeated in period 5. Then, workloads were decreased through period 7. Nitrogen balance was determined in two additional periods, 8 and 9, while the geldings were at maintenance with no forced exercise. Geldings were fed diets containing similar protein-to-calorie ratios in all periods. Nitrogen retention increased (P less than .05) as workload increased from period 1 to period 3 and remained elevated throughout the rest of the experiment. Nitrogen retention did not (P greater than .05) decrease from highest values, observed at maximum workload during periods 4 and 5, until period 9, which was 34 d postexercise during a maintenance period. Nitrogen retention was higher (P less than .05) following training than before training.  相似文献