Journal of Toxicology and Environmental Health, Part B, 2010
... Health A , 73: 187–207. [Taylor & Francis Online], [PubMed] View all references, 2010b13.... more ... Health A , 73: 187–207. [Taylor & Francis Online], [PubMed] View all references, 2010b13. Krewski, D., Chambers, A., Ransom Stern, B., Aggett, PJ, Plunkett, L. and Rudenko, L. 2010b. ... Hung, YH,Bush, AI and Cherny, RA 2010. Copper in the brain and Alzheimer's disease. ...
Numerous studies support the concept that a major cause of pregnancy complications can be subopti... more Numerous studies support the concept that a major cause of pregnancy complications can be suboptimal embryonic and fetal nutrition. Although the negative effects of diets low in energy on pregnancy outcome are well documented, less clear are the effects of diets that are low in one or more essential micronutrients. However, several observational and intervention studies suggest that diets low
The objective of this experiment was to determine whether changes in liver cholesterol content, p... more The objective of this experiment was to determine whether changes in liver cholesterol content, plasma lipids and lipoprotein composition result from dietary manganese (Mn) deficiency in the Sprague-Dawley (SD) and the Wistar (W) rat. Weanling rats of both strains were fed Mn-deficient (1 ppm Mn) or Mn-adequate (45 ppm Mn) diets for 10 wk. After the 10-wk period rats were killed and plasma, liver, kidney and heart were collected. Liver, kidney and heart Mn concentrations were significantly lower in the rats fed the Mn-deficient diet than in controls. Plasma high density lipoprotein (HDL) (density 1.050-1.1963) was isolated by sequential ultracentrifugation. Plasma cholesterol levels were similar for all groups. HDL protein, cholesterol and apo E levels were significantly reduced with Mn deficiency. A shift to a smaller HDL particle was associated with Mn deficiency, based on gradient gel electrophoresis. The shift in size was more pronounced in the SD strain. Liver concentrations of...
Intense training for long-distance running has been associated with reduced hemoglobin (Hb) level... more Intense training for long-distance running has been associated with reduced hemoglobin (Hb) levels and low iron stores. Whether iron supplementation helps prevent this "runner's anemia" remains controversial. To determine the relationship between iron status and the early stage of reduced Hb levels in male runners, we examined hematologic variables in 15 healthy men (ages 25 to 47 yrs) who ran twice their regular training distance in 20 days during a 500-km road race. Nine of the runners took iron-containing tablets which provided an average of 36 mg/d of iron, while the other six did not take iron supplements. Only one of the 15 subjects had a low Hb concentration (less than 14 g/dl) before the race. After 10 days (285 km), low Hb levels (p less than 0.001) were found in 12/15; six of these runners took iron supplements. However, following a 2-day rest period and five more days of running, only 5/15 and 7/15, respectively, had low Hb levels. Serum iron, ferritin, total iron binding capacity, and percent transferrin saturation values remained within normal limits and did not change significantly. Reticulocyte counts progressively increased, becoming 8-fold higher than at baseline (p less than 0.001), irrespective of the use of iron supplements. "Runner's anemia" developed in 11/15 (73%) of the subjects, independently of their iron status and iron intake. The reductions in Hb were accompanied by parallel decreases in RBC count and hematocrit, and by a significant reticulocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Although a number of cases of hepatotoxicity are associated with the use of Hydroxycut weight man... more Although a number of cases of hepatotoxicity are associated with the use of Hydroxycut weight management products, it has been alleged that their effects are primarily due to the presence of hydroxycitric acid (HCA, as Super CitriMax) in the formulations. However, while these products contain up to 20 different ingredients, some do not contain HCA. Case studies reported to date have not considered in depth the literature on the numerous animal and human studies that have been conducted on the safety and efficacy of HCA. No HCAassociated hepatotoxicity or treatment-related adverse effects have been reported in these studies, and thus it is premature to make the assumptions presented in the recent case studies regarding Hydroxycut. If it is established in well controlled studies that the use of these formulations with and/or without HCA can result in the occurrence or progression of hepatotoxicity, additional studies should be conducted to characterize the causative factor(s). . No evidence demonstrating hepatotoxicity associated with hydroxycitric acid. World J Gastroenterol 2009; 15(32)
Age-related macular degeneration (ARMD) may result from events initiated by reactive oxygen speci... more Age-related macular degeneration (ARMD) may result from events initiated by reactive oxygen species. Blood samples from 18 patients with ARMD and 18 similarly aged controls were analysed for activities of important antioxidants. Blood glutathione reductase activity was lower in patients with ARMD compared with controls (p = 0.035). The activities of glutathione peroxidase (p = 0.18) and erythrocyte superoxide dismutase (p = 0.29) were similar between the two groups by a Student's two sample t test. Logistic regression was used to determine which enzyme activities were associated with ARMD after adjusting for possible confounding variables: smoking history, age, multivitamin use, and cardiovascular disease. Glutathione reductase activity (p = 0.05) and glutathione peroxidase activity (p = 0.065) were significantly associated with ARMD by this analysis. The relation of glutathione reductase and glutathione peroxidase activity to ARMD merits further study.
Improved vascular function after the incorporation of walnuts into controlled or high-fat diets h... more Improved vascular function after the incorporation of walnuts into controlled or high-fat diets has been reported; however, the mechanism(s) underlying this effect of walnuts is(are) poorly defined. The objective of the current study was to evaluate the acute and short-term effects of walnut intake on changes in microvascular function and the relationship of these effects to plasma epoxides, the cytochrome-P450-derived metabolites of fatty acids. Thirty-eight hypercholesterolemic postmenopausal women were randomized to 4 weeks of 5 g or 40 g of daily walnut intake. All outcomes were measured after an overnight fast and 4 h after walnut intake. Microvascular function, assessed as the reactive hyperemia index (RHI), was the primary outcome measure, with serum lipids and plasma epoxides as secondary measures. Compared to 5 g of daily walnut intake, consuming 40 g/d of walnuts for 4 weeks increased the RHI and Framingham RHI. Total cholesterol and low- and high-density cholesterol did n...
We reported previously that feeding zinc-deficient diets for 14 d altered the oxidant defense sys... more We reported previously that feeding zinc-deficient diets for 14 d altered the oxidant defense system in the testes of young male rats and increased levels of lipid, protein and DNA oxidation in this tissue. In this study, we investigated the early involvement of oxidative stress in zinc deficiency-induced testicular pathology. Weanling male rats (17 d old) were given free access
The effect of dietary iron on the development of copper-deficiency anemia in the growing rat was ... more The effect of dietary iron on the development of copper-deficiency anemia in the growing rat was investigated. For up to 80 d, female rats (75 g) were fed purified diets containing adequate, marginal or low levels of iron, and either 0.7 or 10 ppm copper. Hemoglobin levels and factors postulated to affect liver iron mobilization, including ferroxidase (Fox) I and II, ascorbate and liver xanthine dehydrogenase (XDH) were assayed. By d 7, Fox I activity in the copper-deficient groups was 10% that of the copper-sufficient groups; thereafter, Fox I activity remained low, and was not affected by dietary iron. Fox II activity in the copper-deficient groups after d 28 was 50-75% of values from rats adequate in copper. On d 49, hemoglobin levels in the copper-deficient groups were lower than in the copper-sufficient groups fed low and marginal levels of iron, but were similar to those fed adequate iron. Liver iron was similar in both groups fed adequate iron, but was higher in the copper-de...
The activities of two liver gluconeogenic enzymes, pyruvate carboxylase (PC) and phosphoenolpyruv... more The activities of two liver gluconeogenic enzymes, pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK), as well as liver glycogen and plasma glucose, insulin, and glucagon were measured in first- and second-generation, manganese-sufficient (control) and manganese-deficient (Mn-) adult rats. Pyruvate carboxylase activity of first generation male Mn- rats was higher than that of controls in both the fed and fasted states. In contrast, PC activity in second generation male Mn- rats was lower than control levels. In female rats, PC activity was lower than controls in both fed, first- and second-generation Mn- rats; in the fasted state, PC activity was either the same or higher than controls. Phosphoenolpyruvate carboxykinase activity was lower in male first generation Mn- rats than in controls, but there was no difference in PEPCK activity in second-generation animals. Phosphoenolpyruvate carboxylase activity was lower in both fed and fasted Mn- female rats than in c...
Experimental biology and medicine (Maywood, N.J.), 2007
There has been considerable work on the relationships between nutrition and the immune response, ... more There has been considerable work on the relationships between nutrition and the immune response, particularly on studies that have focused on adaptive responses. There is increasing recognition of the importance of innate immunity in host protection and initiation of cytokine networks. In this study, we examined the effect of select cocoa flavanols and procyanidins on innate responses in vitro. Peripheral blood mono-nuclear cells (PBMCs), as well as purified monocytes and CD4 and CD8 T cells, were isolated from healthy volunteers and cultured in the presence of cocoa flavanol fractions that differ from another by the degree of flavanol polymerization: short-chain flavanol fraction (SCFF), monomers to pentamers; and long-chain flavanol fraction (LCFF), hexamers to decamers. Parallel investigations were also done with highly purified flavanol monomers and procyanidin dimers. The isolated cells were then challenged with lipopolysaccharide (LPS) with quantitation of activation using CD6...
Epidemiologic studies have linked flavonoid-rich foods with a reduced risk of cardiovascular mort... more Epidemiologic studies have linked flavonoid-rich foods with a reduced risk of cardiovascular mortality. Some cocoas are flavonoid-rich and contain the monomeric flavanols (-)-epicatechin and (+)-catechin and oligomeric procyanidins formed from these monomeric units. Both the monomers and the oligomers have shown potential in favorably influencing cardiovascular health in in vitro and preliminary clinical studies. Although previous investigations have shown increasing concentrations of (-)-epicatechin in human plasma after cocoa consumption, no information is available in the published literature regarding the presence of procyanidins in human plasma. This study sought to determine whether procyanidins can be detected and quantified in human plasma after acute consumption of a flavanol-rich cocoa. Peripheral blood was obtained from 5 healthy adult subjects before (baseline, 0 h) and 0.5, 2, and 6 h after consumption of 0.375 g cocoa/kg body wt as a beverage. Plasma samples were analy...
... Z Clin. Nutr. 72, 30 (2000). 5o AL Waterhouse, JR Shirley, and JL Donovan, Lancet 348, 834 (1... more ... Z Clin. Nutr. 72, 30 (2000). 5o AL Waterhouse, JR Shirley, and JL Donovan, Lancet 348, 834 (1996). ... At a concentration of 1 txM, all compounds tested inhibited copper-catalyzed LDL oxidation (Fig. 3). The monomer and dimer inhibited oxidation by approximately 33%. ...
Diets that are rich in plant foods have been associated with a decreased risk for specific diseas... more Diets that are rich in plant foods have been associated with a decreased risk for specific disease processes and certain chronic diseases. In addition to essential macronutrients and micronutrients, the flavonoids in a variety of plant foods may have health-enhancing properties. Chocolate is a food that is known to be rich in the flavan-3-ol epicatechin and procyanidin oligomers. However, the bioavailability and the biological effects of the chocolate flavonoids are poorly understood. To begin to address these issues, we developed a method based on HPLC coupled with electrochemical (coulometric) detection to determine the physiological levels of epicatechin, catechin and epicatechin dimers. This method allows for the determination of 20 pg (69 fmol) of epicatechin, which translates to plasma concentrations as low as 1 nmol/L. We next evaluated the absorption of epicatechin, from an 80-g semisweet chocolate (procyanidin-rich chocolate) bolus. By 2 h after ingestion, there was a 12-fo...
Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in conne... more Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons an...
Journal of Toxicology and Environmental Health, Part B, 2010
... Health A , 73: 187–207. [Taylor & Francis Online], [PubMed] View all references, 2010b13.... more ... Health A , 73: 187–207. [Taylor & Francis Online], [PubMed] View all references, 2010b13. Krewski, D., Chambers, A., Ransom Stern, B., Aggett, PJ, Plunkett, L. and Rudenko, L. 2010b. ... Hung, YH,Bush, AI and Cherny, RA 2010. Copper in the brain and Alzheimer's disease. ...
Numerous studies support the concept that a major cause of pregnancy complications can be subopti... more Numerous studies support the concept that a major cause of pregnancy complications can be suboptimal embryonic and fetal nutrition. Although the negative effects of diets low in energy on pregnancy outcome are well documented, less clear are the effects of diets that are low in one or more essential micronutrients. However, several observational and intervention studies suggest that diets low
The objective of this experiment was to determine whether changes in liver cholesterol content, p... more The objective of this experiment was to determine whether changes in liver cholesterol content, plasma lipids and lipoprotein composition result from dietary manganese (Mn) deficiency in the Sprague-Dawley (SD) and the Wistar (W) rat. Weanling rats of both strains were fed Mn-deficient (1 ppm Mn) or Mn-adequate (45 ppm Mn) diets for 10 wk. After the 10-wk period rats were killed and plasma, liver, kidney and heart were collected. Liver, kidney and heart Mn concentrations were significantly lower in the rats fed the Mn-deficient diet than in controls. Plasma high density lipoprotein (HDL) (density 1.050-1.1963) was isolated by sequential ultracentrifugation. Plasma cholesterol levels were similar for all groups. HDL protein, cholesterol and apo E levels were significantly reduced with Mn deficiency. A shift to a smaller HDL particle was associated with Mn deficiency, based on gradient gel electrophoresis. The shift in size was more pronounced in the SD strain. Liver concentrations of...
Intense training for long-distance running has been associated with reduced hemoglobin (Hb) level... more Intense training for long-distance running has been associated with reduced hemoglobin (Hb) levels and low iron stores. Whether iron supplementation helps prevent this "runner's anemia" remains controversial. To determine the relationship between iron status and the early stage of reduced Hb levels in male runners, we examined hematologic variables in 15 healthy men (ages 25 to 47 yrs) who ran twice their regular training distance in 20 days during a 500-km road race. Nine of the runners took iron-containing tablets which provided an average of 36 mg/d of iron, while the other six did not take iron supplements. Only one of the 15 subjects had a low Hb concentration (less than 14 g/dl) before the race. After 10 days (285 km), low Hb levels (p less than 0.001) were found in 12/15; six of these runners took iron supplements. However, following a 2-day rest period and five more days of running, only 5/15 and 7/15, respectively, had low Hb levels. Serum iron, ferritin, total iron binding capacity, and percent transferrin saturation values remained within normal limits and did not change significantly. Reticulocyte counts progressively increased, becoming 8-fold higher than at baseline (p less than 0.001), irrespective of the use of iron supplements. "Runner's anemia" developed in 11/15 (73%) of the subjects, independently of their iron status and iron intake. The reductions in Hb were accompanied by parallel decreases in RBC count and hematocrit, and by a significant reticulocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Although a number of cases of hepatotoxicity are associated with the use of Hydroxycut weight man... more Although a number of cases of hepatotoxicity are associated with the use of Hydroxycut weight management products, it has been alleged that their effects are primarily due to the presence of hydroxycitric acid (HCA, as Super CitriMax) in the formulations. However, while these products contain up to 20 different ingredients, some do not contain HCA. Case studies reported to date have not considered in depth the literature on the numerous animal and human studies that have been conducted on the safety and efficacy of HCA. No HCAassociated hepatotoxicity or treatment-related adverse effects have been reported in these studies, and thus it is premature to make the assumptions presented in the recent case studies regarding Hydroxycut. If it is established in well controlled studies that the use of these formulations with and/or without HCA can result in the occurrence or progression of hepatotoxicity, additional studies should be conducted to characterize the causative factor(s). . No evidence demonstrating hepatotoxicity associated with hydroxycitric acid. World J Gastroenterol 2009; 15(32)
Age-related macular degeneration (ARMD) may result from events initiated by reactive oxygen speci... more Age-related macular degeneration (ARMD) may result from events initiated by reactive oxygen species. Blood samples from 18 patients with ARMD and 18 similarly aged controls were analysed for activities of important antioxidants. Blood glutathione reductase activity was lower in patients with ARMD compared with controls (p = 0.035). The activities of glutathione peroxidase (p = 0.18) and erythrocyte superoxide dismutase (p = 0.29) were similar between the two groups by a Student's two sample t test. Logistic regression was used to determine which enzyme activities were associated with ARMD after adjusting for possible confounding variables: smoking history, age, multivitamin use, and cardiovascular disease. Glutathione reductase activity (p = 0.05) and glutathione peroxidase activity (p = 0.065) were significantly associated with ARMD by this analysis. The relation of glutathione reductase and glutathione peroxidase activity to ARMD merits further study.
Improved vascular function after the incorporation of walnuts into controlled or high-fat diets h... more Improved vascular function after the incorporation of walnuts into controlled or high-fat diets has been reported; however, the mechanism(s) underlying this effect of walnuts is(are) poorly defined. The objective of the current study was to evaluate the acute and short-term effects of walnut intake on changes in microvascular function and the relationship of these effects to plasma epoxides, the cytochrome-P450-derived metabolites of fatty acids. Thirty-eight hypercholesterolemic postmenopausal women were randomized to 4 weeks of 5 g or 40 g of daily walnut intake. All outcomes were measured after an overnight fast and 4 h after walnut intake. Microvascular function, assessed as the reactive hyperemia index (RHI), was the primary outcome measure, with serum lipids and plasma epoxides as secondary measures. Compared to 5 g of daily walnut intake, consuming 40 g/d of walnuts for 4 weeks increased the RHI and Framingham RHI. Total cholesterol and low- and high-density cholesterol did n...
We reported previously that feeding zinc-deficient diets for 14 d altered the oxidant defense sys... more We reported previously that feeding zinc-deficient diets for 14 d altered the oxidant defense system in the testes of young male rats and increased levels of lipid, protein and DNA oxidation in this tissue. In this study, we investigated the early involvement of oxidative stress in zinc deficiency-induced testicular pathology. Weanling male rats (17 d old) were given free access
The effect of dietary iron on the development of copper-deficiency anemia in the growing rat was ... more The effect of dietary iron on the development of copper-deficiency anemia in the growing rat was investigated. For up to 80 d, female rats (75 g) were fed purified diets containing adequate, marginal or low levels of iron, and either 0.7 or 10 ppm copper. Hemoglobin levels and factors postulated to affect liver iron mobilization, including ferroxidase (Fox) I and II, ascorbate and liver xanthine dehydrogenase (XDH) were assayed. By d 7, Fox I activity in the copper-deficient groups was 10% that of the copper-sufficient groups; thereafter, Fox I activity remained low, and was not affected by dietary iron. Fox II activity in the copper-deficient groups after d 28 was 50-75% of values from rats adequate in copper. On d 49, hemoglobin levels in the copper-deficient groups were lower than in the copper-sufficient groups fed low and marginal levels of iron, but were similar to those fed adequate iron. Liver iron was similar in both groups fed adequate iron, but was higher in the copper-de...
The activities of two liver gluconeogenic enzymes, pyruvate carboxylase (PC) and phosphoenolpyruv... more The activities of two liver gluconeogenic enzymes, pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK), as well as liver glycogen and plasma glucose, insulin, and glucagon were measured in first- and second-generation, manganese-sufficient (control) and manganese-deficient (Mn-) adult rats. Pyruvate carboxylase activity of first generation male Mn- rats was higher than that of controls in both the fed and fasted states. In contrast, PC activity in second generation male Mn- rats was lower than control levels. In female rats, PC activity was lower than controls in both fed, first- and second-generation Mn- rats; in the fasted state, PC activity was either the same or higher than controls. Phosphoenolpyruvate carboxykinase activity was lower in male first generation Mn- rats than in controls, but there was no difference in PEPCK activity in second-generation animals. Phosphoenolpyruvate carboxylase activity was lower in both fed and fasted Mn- female rats than in c...
Experimental biology and medicine (Maywood, N.J.), 2007
There has been considerable work on the relationships between nutrition and the immune response, ... more There has been considerable work on the relationships between nutrition and the immune response, particularly on studies that have focused on adaptive responses. There is increasing recognition of the importance of innate immunity in host protection and initiation of cytokine networks. In this study, we examined the effect of select cocoa flavanols and procyanidins on innate responses in vitro. Peripheral blood mono-nuclear cells (PBMCs), as well as purified monocytes and CD4 and CD8 T cells, were isolated from healthy volunteers and cultured in the presence of cocoa flavanol fractions that differ from another by the degree of flavanol polymerization: short-chain flavanol fraction (SCFF), monomers to pentamers; and long-chain flavanol fraction (LCFF), hexamers to decamers. Parallel investigations were also done with highly purified flavanol monomers and procyanidin dimers. The isolated cells were then challenged with lipopolysaccharide (LPS) with quantitation of activation using CD6...
Epidemiologic studies have linked flavonoid-rich foods with a reduced risk of cardiovascular mort... more Epidemiologic studies have linked flavonoid-rich foods with a reduced risk of cardiovascular mortality. Some cocoas are flavonoid-rich and contain the monomeric flavanols (-)-epicatechin and (+)-catechin and oligomeric procyanidins formed from these monomeric units. Both the monomers and the oligomers have shown potential in favorably influencing cardiovascular health in in vitro and preliminary clinical studies. Although previous investigations have shown increasing concentrations of (-)-epicatechin in human plasma after cocoa consumption, no information is available in the published literature regarding the presence of procyanidins in human plasma. This study sought to determine whether procyanidins can be detected and quantified in human plasma after acute consumption of a flavanol-rich cocoa. Peripheral blood was obtained from 5 healthy adult subjects before (baseline, 0 h) and 0.5, 2, and 6 h after consumption of 0.375 g cocoa/kg body wt as a beverage. Plasma samples were analy...
... Z Clin. Nutr. 72, 30 (2000). 5o AL Waterhouse, JR Shirley, and JL Donovan, Lancet 348, 834 (1... more ... Z Clin. Nutr. 72, 30 (2000). 5o AL Waterhouse, JR Shirley, and JL Donovan, Lancet 348, 834 (1996). ... At a concentration of 1 txM, all compounds tested inhibited copper-catalyzed LDL oxidation (Fig. 3). The monomer and dimer inhibited oxidation by approximately 33%. ...
Diets that are rich in plant foods have been associated with a decreased risk for specific diseas... more Diets that are rich in plant foods have been associated with a decreased risk for specific disease processes and certain chronic diseases. In addition to essential macronutrients and micronutrients, the flavonoids in a variety of plant foods may have health-enhancing properties. Chocolate is a food that is known to be rich in the flavan-3-ol epicatechin and procyanidin oligomers. However, the bioavailability and the biological effects of the chocolate flavonoids are poorly understood. To begin to address these issues, we developed a method based on HPLC coupled with electrochemical (coulometric) detection to determine the physiological levels of epicatechin, catechin and epicatechin dimers. This method allows for the determination of 20 pg (69 fmol) of epicatechin, which translates to plasma concentrations as low as 1 nmol/L. We next evaluated the absorption of epicatechin, from an 80-g semisweet chocolate (procyanidin-rich chocolate) bolus. By 2 h after ingestion, there was a 12-fo...
Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in conne... more Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons an...
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Papers by Carl Keen