Laribacter hongkongensis is a potential emerging pathogen associated with community-acquired gast... more Laribacter hongkongensis is a potential emerging pathogen associated with community-acquired gastroenteritis and traveler's diarrhea. We report the isolation of L. hongkongensis from the stool of a patient who had no history of travel outside the United States. The organism was identified by phenotypic tests, mass spectrometry, and gene sequencing.
Experiments were performed to characterize plasma lipid transfer protein activity (LTA), and the ... more Experiments were performed to characterize plasma lipid transfer protein activity (LTA), and the rate of [3H]CE transfer from HDL to lower density lipoproteins in plasma of hamsters. Compared to rabbits, hamster plasma has about one-tenth the level of d greater than 1.21 LTA but a relatively high level of VLDL-triacylglycerols, and a higher fractional rate of HDL-[3H]CE transfer in plasma (in vitro) than predicted by the d greater than 1.21 LTA. Like the rat, hamster plasma contains an inhibitor(s) of LTA; the level of the inhibitor activity in d greater than 1.21 g/ml plasma was similar in normal and hyperlipoproteinemic hamsters. Hypertriglyceridemia in sucrose-fed hamsters did not affect LTA, cholesteryl ester transfer or the plasma level of HDL-CE. However, a comparable degree of hypercholesterolemia was associated with a 122% increase in plasma d greater than 1.21 LTA and a 63% increase in the fractional rate of [3H]CE transfer from HDL to lower density lipoproteins in plasma. ...
An effective treatment for fibromyalgia (FM) has yet to become available. To assess the efficacy ... more An effective treatment for fibromyalgia (FM) has yet to become available. To assess the efficacy ofa lifestyle program consisting of a modified elimination diet and a supplemental medical food on clinical symptoms of FM assessed by the Fibromyalgia Impact Questionnaire (FIQ), FibroQuest Symptoms Survey (FibroQuest), Medical Symptoms Questionnaire (MSQ), metallothionein mRNA expression, and urinary toxic element excretion. Eight women (aged 48-74 years) were enrolled in an 8-week pilot trial employing a sequential design. During the initial 4-week Program A (control), participants consumed a modified US Department of Agriculture food pyramid diet and a rice protein powder supplement that provided basic macronutrient support. During the second 4-week Program B (intervention), participants consumed a modified elimination diet and a phytonutrient-rich medical food. Compared to baseline, both programs showed trends toward lower mean FIQ total score, MSQ total score, and FibroQuest total ...
These studies were performed to determine the role of plasma lipid transfer activity in the regul... more These studies were performed to determine the role of plasma lipid transfer activity in the regulation of plasma total and lipoprotein cholesterol in vivo. Partially purified human lipid transfer activity was injected into rats at a level similar to that of normal rabbit plasma, d greater than 1.21. The disappearance of exogenous lipid transfer activity from rat plasma was biphasic, with a 70% loss within 6 h. The remaining 30% was lost with a half-time of about 14 h. In the rat, short-term exposure (6 h) to high levels of lipid transfer activity resulted in a net transfer of cholesteryl esters from high density to d less than 1.019 lipoproteins, without affecting plasma total cholesterol. However, the lipid transfer activity-induced changes in lipoprotein cholesterol were not evident after 24 h, despite the fact that the lipid transfer activity of rat plasma d greater than 1.21 was similar to that of human plasma d greater than 1.21 during the preceding 18 h.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 1988
Human and rabbit plasma contains a lipid transfer protein that transfers cholesteryl esters and t... more Human and rabbit plasma contains a lipid transfer protein that transfers cholesteryl esters and triglycerides among the plasma lipoproteins and may also have a role in the movement of lipids into and out of cells. Little is known about the regulation of the activity of the lipid transfer protein, but in the rabbit, hypercholesterolemia is associated with increased plasma lipid transfer activity (LTA). Perfused rabbit livers secrete LTA, and hepatic cholesterol secretion is increased in rabbits with diet-induced hypercholesterolemia. Thus, experiments were performed with rabbits to determine if LTA is regulated by a concerted hepatic secretion of lipoprotein protein cholesterol and LTA. Rabbits were fed chow or chow plus coconut oil (14% wt/wt), and plasma lipids, LTA, and the rate of secretion of cholesterol into plasma were determined. Coconut oil feeding increased plasma cholesterol by 68%, LTA by 42%, and hepatic cholesterol secretion by 69%. Mevinolin (75 mg/day), an inhibitor o...
Suppose a firm faces a “timing problem” in its capacity decision: it must acquire capacity, a str... more Suppose a firm faces a “timing problem” in its capacity decision: it must acquire capacity, a strict upper bound on production, and set its price before quantity demanded for its product is known. The paper shows that the uncertainty capacity is greater than the certainty capacity when the marginal cost of capacity is low; the reverse holds for high marginal
The relationship between the concentration of plasma cholesterol and the lipid transfer activity ... more The relationship between the concentration of plasma cholesterol and the lipid transfer activity (LTA) of lipoprotein-deficient plasma (d greater than 1.21) was studied in two models of pregnancy in the rabbit. Plasma cholesterol and the protein-mediated transfer of cholesteryl ester and triglyceride were monitored throughout gestation, 48 hr after parturition, and during lactation in New Zealand white (NZW) and heterozygous WHHL rabbits. Lipoprotein cholesterol was determined prior to and 48 hr after parturition. For both NZW and heterozygous WHHL rabbits, the progressive hypocholesterolemia of gestation was associated with parallel changes in LTA. Similarly, the rapid postpartum increase in plasma cholesterol was paralleled by increased LTA for both strains. In relation to basal values, the relative changes in plasma cholesterol and LTA were virtually identical. These data provide further evidence that in the rabbit plasma cholesterol and LTA are closely related.
The potential utility of an animal model of hyperalphalipoproteinemia for examining the role of h... more The potential utility of an animal model of hyperalphalipoproteinemia for examining the role of high density lipoprotein (HDL) in atherogenesis prompted the current studies. Preliminary data indicated that in rabbits high-coconut oil feeding for 30 days doubled plasma HDL-cholesterol levels, but did not affect lower density lipoproteins (LDL) (d less than 1.063 g/ml). Experiments were performed to examine the composition of these HDL and to determine the mechanism for the diet-induced increase in plasma HDL. Rabbits were fed commercial chow or chow plus 14% (w/w) coconut oil and blood samples were collected 18 h after feeding. Compared to chow-fed rabbits, peak levels of HDL-cholesterol were attained within 2 weeks, and coconut oil feeding doubled the plasma levels of HDL-cholesterol, phospholipids and protein for up to 4 months without affecting HDL lipid and apoprotein composition. After 3 months the diet also increased VLDL- (107%) and LDL-cholesterol (40%) levels, but the absolute increases in each of these lipoprotein fractions was less than half of that of HDL. Isotope kinetic studies of 125I-HDL protein indicated a doubled rate of production of HDL and no change in the efficiency of removal of HDL from plasma. These studies demonstrate that in the rabbit high-coconut oil feeding doubles the rate of production and turnover of apparently normal HDL particles. It is proposed that such an animal model could be utilized to examine directly the role of HDL in atherogenesis.
Studies were performed in the rabbit to investigate the relationship between plasma lipids and th... more Studies were performed in the rabbit to investigate the relationship between plasma lipids and the cholesteryl ester/triglyceride transfer activity of lipoprotein-deficient plasma (d greater than 1.21). The time courses for diet-induced changes in plasma lipids and the lipid (cholesteryl ester/triglyceride) transfer activity of lipoprotein-deficient plasma (LTA) were determined in rabbits fed a variety of hyperlipidemic diets. LTA was not altered within 36 h after a single high-cholesterol/oil meal despite a near doubling of the concentration of plasma cholesterol. With high cholesterol and/or high-fat feeding, LTA increased and reached new steady state levels within about 10 days with little additional change for up to 87 days even when plasma cholesterol continued to increase. For all diets, the greatest increments in LTA occurred about 5 days after initiation of experimental feeding. A low-cholesterol (0.05-0.2%, w/w) diet and a cholesterol-free, high-coconut oil diet (14%, w/w) were associated with comparable increases in both plasma cholesterol and LTA. A marked, concomitant increase in plasma triglycerides was not associated with a further increase in LTA in hypercholesterolemic rabbits. These data indicate that in the rabbit LTA increases in a parabolic manner with moderate and gross, diet-induced increases in plasma cholesterol, and the time courses for the diet-induced changes in LTA are similar for a variety of hyperlipidemic diets.
Alternative medicine review : a journal of clinical therapeutic, 1998
Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associa... more Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associated with the slow accumulation of toxic metals are multiple and rather nondescript, and overt expression of toxic effects may not appear until later in life. The sulfhydryl-reactive metals (mercury, cadmium, lead, arsenic) are particularly insidious and can affect a vast array of biochemical and nutritional processes. The primary mechanisms by which the sulfhydryl-reactive metals elicit their toxic effects are summarized. The pro-oxidative effects of the metals are compounded by the fact that the metals also inhibit antioxidative enzymes and deplete intracellular glutathione. The metals also have the potential to disrupt the metabolism and biological activities of many proteins due to their high affinity for free sulfhydryl groups. Cysteine has a pivotal role in inducible, endogenous detoxication mechanisms in the body, and metal exposure taxes cysteine status. The protective effects of ...
Alternative medicine review : a journal of clinical therapeutic, 2001
Trace element analysis in biological samples has improved significantly over the last 40 years. I... more Trace element analysis in biological samples has improved significantly over the last 40 years. Improvements in instrumentation such as inductively coupled plasma-mass spectrometry and microwave digestion have resulted in improved precision, accuracy, reliability, and detection limits. The analysis of human scalp hair has benefited significantly from these improvements. A recent article in the Journal of the American Medical Association found significant inter-laboratory variation amongst several laboratories performing trace metal hair testing. It concluded that standardization was necessary to improve inter-laboratory comparability, and an accompanying commentary described the characteristics of a laboratory that should be used in performing hair analysis. The objective of this study is to demonstrate that good laboratory practices will generate precise, accurate, and reliable results. A method for establishing reference ranges and specific data on an analytical method will also b...
Lipoprotein lipase (LPL) activities of skeletal muscles, heart and adipose tissue were investigat... more Lipoprotein lipase (LPL) activities of skeletal muscles, heart and adipose tissue were investigated during feeding, prolonged food restriction, and refeeding. The influence of the duration of starvation on adipose tissue LPL activity was to cause it to decrease throughout starvation, whereas heart LPL activity increased during the first 24 hours of fasting and then declined for the remainder of the fast. Starvation of 10-week-old female, lean and obese rats to 80% of initial body weight required 5 and 9 days, respectively. In fed controls, no differences between phenotypes were found for any tissue in the LPL activities expressed per gram tissue. However, obese rats exhibited significantly smaller muscle mass and a resulting 29% lower total skeletal muscle LPL activity. No phenotype differences were detected for tissue LPL activities during starvation or refeeding. During caloric restriction, the LPL activities were reduced in heart (-18%) and adipose (-52%) tissues, but skeletal mu...
The plasma total cholesterol (TC) and lipoprotein cholesterol concentrations of sedentary young m... more The plasma total cholesterol (TC) and lipoprotein cholesterol concentrations of sedentary young men (n = 23) were determined during 4 wk of controlled feeding and 6 wk of supervised aerobic conditioning. Subjects were assigned to dietary treatments of 400 mg cholesterol per day (M) or 1400 mg cholesterol per day (H); both diets had a P/S ratio of about 0.6. Dietary groups M and H were subdivided into exercise (MX and HX) and sedentary (MS and HS) groups. Compared to the sedentary groups, MX and HX exhibited significant (p less than 0.01) improvements in cardiorespiratory fitness. After 2 and 4 wk of high cholesterol feeding, group HS exhibited significant (p less than 0.05) elevations in TC (+30 +/- 7 and +32 +/- 9 mg/dl) with nonsignificant increases in very low-density lipoprotein cholesterol and low-density lipoprotein cholesterol. Group HX exhibited consistent weekly increases in high-density lipoprotein cholesterol (HDL-C) (from 46 +/- 3 mg/dl, the base level, to 53 +/- 4 mg/dl...
The objective of this study was to assess the levels of 39 toxic metals and essential minerals in... more The objective of this study was to assess the levels of 39 toxic metals and essential minerals in hair samples of children with autism spectrum disorders and their mothers compared to controls. Inductively coupled plasma-mass spectrometry was used to analyze the elemental content of the hair of children with autism spectrum disorders (n=51), a subset of their mothers (n=29), neurotypical children (n=40), and a subset of their mothers (n=25). All participants were recruited from Arizona. Iodine levels were 45% lower in the children with autism (p=0.005). Autistic children with pica had a 38% lower level of chromium (p=0.002). Autistic children with low muscle tone had very low levels of potassium (-66%, p=0.01) and high zinc (31%, p=0.01). The mothers of young children with autism had especially low levels of lithium (56% lower, p=0.005), and the young children (ages 3-6 yr) with autism also had low lithium (-30%, p=0.04). Low iodine levels are consistent with previous reports of abn...
This study investigates both the level of toxic metals in children with autism and the possible a... more This study investigates both the level of toxic metals in children with autism and the possible association of those toxic metals with autism severity. This study involved 55 children with autism ages 5-16 years compared to 44 controls with similar age and gender. The study included measurements of toxic metals in whole blood, red blood cells (RBC), and urine. The autism group had higher levels of lead in RBC (+41 %, p = 0.002) and higher urinary levels of lead (+74 %, p = 0.02), thallium (+77 %, p = 0.0001), tin (+115 %, p = 0.01), and tungsten (+44 %, p = 0.00005). However, the autism group had slightly lower levels of cadmium in whole blood (-19 %, p = 0.003). A stepwise, multiple linear regression analysis found a strong association of levels of toxic metals with variation in the degree of severity of autism for all the severity scales (adjusted R(2) of 0.38-0.47, p < 0.0003). Cadmium (whole blood) and mercury (whole blood and RBC) were the most consistently significant varia...
Expected values, reference ranges, or reference limits are necessary to enable clinicians to appl... more Expected values, reference ranges, or reference limits are necessary to enable clinicians to apply analytical chemical data in the delivery of health care. Determination of references ranges is not straightforward in terms of either selecting a reference population or performing statistical analysis. In light of logistical, scientific, and economic obstacles, it is understandable that clinical laboratories often combine approaches in developing health associated reference values. A laboratory may choose to:
ABSTRACT Influences of exercise and changes in dietary carbohydrate and fat on tissue lipoprotein... more ABSTRACT Influences of exercise and changes in dietary carbohydrate and fat on tissue lipoprotein lipase (LPL) activities were studied in 40 female Sprague-Dawley rats. Rats were trained to run (n=20) on a treadmill 6 days/week, 60 minutes/day at 28 m/min on an 8° incline for 8 wk or remained sedentary (n=20). All rats were fed a control high carbohydrate diet (12% kcals fat) for 5 weeks and then one-half of the trained and nontrained groups were assigned to a high fat (HF) diet. The HF (73% kcals fat) fed rats were pair fed to be isocaloric and isonitrogenous with the animals receiving the control diet. Animals were fasted 12–14 hours before sacrifice. Feeding the HF diet increased body weight, fat pad weight and plasma TG levels, but had no effect on muscle weight or muscle TG content. Training at least doubled the LPL activivity of the red gastrocnemius muscle. The combination of HF feeding and exercise produced an elevation in the LPL activity of the red (135%) and white (80%) gastrocnemius muscles compared to control feeding and no exercise. The additive effect of the HF diet and exercise training also increased LPL activity of renal adipose tissue (43%) versus control feeding and no exercise. Feeding the HF diet reduced glycogen depletion in liver and skeletal muscle during exercise. This study demonstrates that skeletal muscle LPL activity is sensitive to the individual and combined effects of dietary fat and exercise.
The relationship between relative metabolic disturbances and developmental disorders is an emergi... more The relationship between relative metabolic disturbances and developmental disorders is an emerging research focus. This study compares the nutritional and metabolic status of children with autism with that of neurotypical children and investigates the possible association of autism severity with biomarkers.
Laribacter hongkongensis is a potential emerging pathogen associated with community-acquired gast... more Laribacter hongkongensis is a potential emerging pathogen associated with community-acquired gastroenteritis and traveler&amp;amp;#39;s diarrhea. We report the isolation of L. hongkongensis from the stool of a patient who had no history of travel outside the United States. The organism was identified by phenotypic tests, mass spectrometry, and gene sequencing.
Experiments were performed to characterize plasma lipid transfer protein activity (LTA), and the ... more Experiments were performed to characterize plasma lipid transfer protein activity (LTA), and the rate of [3H]CE transfer from HDL to lower density lipoproteins in plasma of hamsters. Compared to rabbits, hamster plasma has about one-tenth the level of d greater than 1.21 LTA but a relatively high level of VLDL-triacylglycerols, and a higher fractional rate of HDL-[3H]CE transfer in plasma (in vitro) than predicted by the d greater than 1.21 LTA. Like the rat, hamster plasma contains an inhibitor(s) of LTA; the level of the inhibitor activity in d greater than 1.21 g/ml plasma was similar in normal and hyperlipoproteinemic hamsters. Hypertriglyceridemia in sucrose-fed hamsters did not affect LTA, cholesteryl ester transfer or the plasma level of HDL-CE. However, a comparable degree of hypercholesterolemia was associated with a 122% increase in plasma d greater than 1.21 LTA and a 63% increase in the fractional rate of [3H]CE transfer from HDL to lower density lipoproteins in plasma. ...
An effective treatment for fibromyalgia (FM) has yet to become available. To assess the efficacy ... more An effective treatment for fibromyalgia (FM) has yet to become available. To assess the efficacy ofa lifestyle program consisting of a modified elimination diet and a supplemental medical food on clinical symptoms of FM assessed by the Fibromyalgia Impact Questionnaire (FIQ), FibroQuest Symptoms Survey (FibroQuest), Medical Symptoms Questionnaire (MSQ), metallothionein mRNA expression, and urinary toxic element excretion. Eight women (aged 48-74 years) were enrolled in an 8-week pilot trial employing a sequential design. During the initial 4-week Program A (control), participants consumed a modified US Department of Agriculture food pyramid diet and a rice protein powder supplement that provided basic macronutrient support. During the second 4-week Program B (intervention), participants consumed a modified elimination diet and a phytonutrient-rich medical food. Compared to baseline, both programs showed trends toward lower mean FIQ total score, MSQ total score, and FibroQuest total ...
These studies were performed to determine the role of plasma lipid transfer activity in the regul... more These studies were performed to determine the role of plasma lipid transfer activity in the regulation of plasma total and lipoprotein cholesterol in vivo. Partially purified human lipid transfer activity was injected into rats at a level similar to that of normal rabbit plasma, d greater than 1.21. The disappearance of exogenous lipid transfer activity from rat plasma was biphasic, with a 70% loss within 6 h. The remaining 30% was lost with a half-time of about 14 h. In the rat, short-term exposure (6 h) to high levels of lipid transfer activity resulted in a net transfer of cholesteryl esters from high density to d less than 1.019 lipoproteins, without affecting plasma total cholesterol. However, the lipid transfer activity-induced changes in lipoprotein cholesterol were not evident after 24 h, despite the fact that the lipid transfer activity of rat plasma d greater than 1.21 was similar to that of human plasma d greater than 1.21 during the preceding 18 h.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 1988
Human and rabbit plasma contains a lipid transfer protein that transfers cholesteryl esters and t... more Human and rabbit plasma contains a lipid transfer protein that transfers cholesteryl esters and triglycerides among the plasma lipoproteins and may also have a role in the movement of lipids into and out of cells. Little is known about the regulation of the activity of the lipid transfer protein, but in the rabbit, hypercholesterolemia is associated with increased plasma lipid transfer activity (LTA). Perfused rabbit livers secrete LTA, and hepatic cholesterol secretion is increased in rabbits with diet-induced hypercholesterolemia. Thus, experiments were performed with rabbits to determine if LTA is regulated by a concerted hepatic secretion of lipoprotein protein cholesterol and LTA. Rabbits were fed chow or chow plus coconut oil (14% wt/wt), and plasma lipids, LTA, and the rate of secretion of cholesterol into plasma were determined. Coconut oil feeding increased plasma cholesterol by 68%, LTA by 42%, and hepatic cholesterol secretion by 69%. Mevinolin (75 mg/day), an inhibitor o...
Suppose a firm faces a “timing problem” in its capacity decision: it must acquire capacity, a str... more Suppose a firm faces a “timing problem” in its capacity decision: it must acquire capacity, a strict upper bound on production, and set its price before quantity demanded for its product is known. The paper shows that the uncertainty capacity is greater than the certainty capacity when the marginal cost of capacity is low; the reverse holds for high marginal
The relationship between the concentration of plasma cholesterol and the lipid transfer activity ... more The relationship between the concentration of plasma cholesterol and the lipid transfer activity (LTA) of lipoprotein-deficient plasma (d greater than 1.21) was studied in two models of pregnancy in the rabbit. Plasma cholesterol and the protein-mediated transfer of cholesteryl ester and triglyceride were monitored throughout gestation, 48 hr after parturition, and during lactation in New Zealand white (NZW) and heterozygous WHHL rabbits. Lipoprotein cholesterol was determined prior to and 48 hr after parturition. For both NZW and heterozygous WHHL rabbits, the progressive hypocholesterolemia of gestation was associated with parallel changes in LTA. Similarly, the rapid postpartum increase in plasma cholesterol was paralleled by increased LTA for both strains. In relation to basal values, the relative changes in plasma cholesterol and LTA were virtually identical. These data provide further evidence that in the rabbit plasma cholesterol and LTA are closely related.
The potential utility of an animal model of hyperalphalipoproteinemia for examining the role of h... more The potential utility of an animal model of hyperalphalipoproteinemia for examining the role of high density lipoprotein (HDL) in atherogenesis prompted the current studies. Preliminary data indicated that in rabbits high-coconut oil feeding for 30 days doubled plasma HDL-cholesterol levels, but did not affect lower density lipoproteins (LDL) (d less than 1.063 g/ml). Experiments were performed to examine the composition of these HDL and to determine the mechanism for the diet-induced increase in plasma HDL. Rabbits were fed commercial chow or chow plus 14% (w/w) coconut oil and blood samples were collected 18 h after feeding. Compared to chow-fed rabbits, peak levels of HDL-cholesterol were attained within 2 weeks, and coconut oil feeding doubled the plasma levels of HDL-cholesterol, phospholipids and protein for up to 4 months without affecting HDL lipid and apoprotein composition. After 3 months the diet also increased VLDL- (107%) and LDL-cholesterol (40%) levels, but the absolute increases in each of these lipoprotein fractions was less than half of that of HDL. Isotope kinetic studies of 125I-HDL protein indicated a doubled rate of production of HDL and no change in the efficiency of removal of HDL from plasma. These studies demonstrate that in the rabbit high-coconut oil feeding doubles the rate of production and turnover of apparently normal HDL particles. It is proposed that such an animal model could be utilized to examine directly the role of HDL in atherogenesis.
Studies were performed in the rabbit to investigate the relationship between plasma lipids and th... more Studies were performed in the rabbit to investigate the relationship between plasma lipids and the cholesteryl ester/triglyceride transfer activity of lipoprotein-deficient plasma (d greater than 1.21). The time courses for diet-induced changes in plasma lipids and the lipid (cholesteryl ester/triglyceride) transfer activity of lipoprotein-deficient plasma (LTA) were determined in rabbits fed a variety of hyperlipidemic diets. LTA was not altered within 36 h after a single high-cholesterol/oil meal despite a near doubling of the concentration of plasma cholesterol. With high cholesterol and/or high-fat feeding, LTA increased and reached new steady state levels within about 10 days with little additional change for up to 87 days even when plasma cholesterol continued to increase. For all diets, the greatest increments in LTA occurred about 5 days after initiation of experimental feeding. A low-cholesterol (0.05-0.2%, w/w) diet and a cholesterol-free, high-coconut oil diet (14%, w/w) were associated with comparable increases in both plasma cholesterol and LTA. A marked, concomitant increase in plasma triglycerides was not associated with a further increase in LTA in hypercholesterolemic rabbits. These data indicate that in the rabbit LTA increases in a parabolic manner with moderate and gross, diet-induced increases in plasma cholesterol, and the time courses for the diet-induced changes in LTA are similar for a variety of hyperlipidemic diets.
Alternative medicine review : a journal of clinical therapeutic, 1998
Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associa... more Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associated with the slow accumulation of toxic metals are multiple and rather nondescript, and overt expression of toxic effects may not appear until later in life. The sulfhydryl-reactive metals (mercury, cadmium, lead, arsenic) are particularly insidious and can affect a vast array of biochemical and nutritional processes. The primary mechanisms by which the sulfhydryl-reactive metals elicit their toxic effects are summarized. The pro-oxidative effects of the metals are compounded by the fact that the metals also inhibit antioxidative enzymes and deplete intracellular glutathione. The metals also have the potential to disrupt the metabolism and biological activities of many proteins due to their high affinity for free sulfhydryl groups. Cysteine has a pivotal role in inducible, endogenous detoxication mechanisms in the body, and metal exposure taxes cysteine status. The protective effects of ...
Alternative medicine review : a journal of clinical therapeutic, 2001
Trace element analysis in biological samples has improved significantly over the last 40 years. I... more Trace element analysis in biological samples has improved significantly over the last 40 years. Improvements in instrumentation such as inductively coupled plasma-mass spectrometry and microwave digestion have resulted in improved precision, accuracy, reliability, and detection limits. The analysis of human scalp hair has benefited significantly from these improvements. A recent article in the Journal of the American Medical Association found significant inter-laboratory variation amongst several laboratories performing trace metal hair testing. It concluded that standardization was necessary to improve inter-laboratory comparability, and an accompanying commentary described the characteristics of a laboratory that should be used in performing hair analysis. The objective of this study is to demonstrate that good laboratory practices will generate precise, accurate, and reliable results. A method for establishing reference ranges and specific data on an analytical method will also b...
Lipoprotein lipase (LPL) activities of skeletal muscles, heart and adipose tissue were investigat... more Lipoprotein lipase (LPL) activities of skeletal muscles, heart and adipose tissue were investigated during feeding, prolonged food restriction, and refeeding. The influence of the duration of starvation on adipose tissue LPL activity was to cause it to decrease throughout starvation, whereas heart LPL activity increased during the first 24 hours of fasting and then declined for the remainder of the fast. Starvation of 10-week-old female, lean and obese rats to 80% of initial body weight required 5 and 9 days, respectively. In fed controls, no differences between phenotypes were found for any tissue in the LPL activities expressed per gram tissue. However, obese rats exhibited significantly smaller muscle mass and a resulting 29% lower total skeletal muscle LPL activity. No phenotype differences were detected for tissue LPL activities during starvation or refeeding. During caloric restriction, the LPL activities were reduced in heart (-18%) and adipose (-52%) tissues, but skeletal mu...
The plasma total cholesterol (TC) and lipoprotein cholesterol concentrations of sedentary young m... more The plasma total cholesterol (TC) and lipoprotein cholesterol concentrations of sedentary young men (n = 23) were determined during 4 wk of controlled feeding and 6 wk of supervised aerobic conditioning. Subjects were assigned to dietary treatments of 400 mg cholesterol per day (M) or 1400 mg cholesterol per day (H); both diets had a P/S ratio of about 0.6. Dietary groups M and H were subdivided into exercise (MX and HX) and sedentary (MS and HS) groups. Compared to the sedentary groups, MX and HX exhibited significant (p less than 0.01) improvements in cardiorespiratory fitness. After 2 and 4 wk of high cholesterol feeding, group HS exhibited significant (p less than 0.05) elevations in TC (+30 +/- 7 and +32 +/- 9 mg/dl) with nonsignificant increases in very low-density lipoprotein cholesterol and low-density lipoprotein cholesterol. Group HX exhibited consistent weekly increases in high-density lipoprotein cholesterol (HDL-C) (from 46 +/- 3 mg/dl, the base level, to 53 +/- 4 mg/dl...
The objective of this study was to assess the levels of 39 toxic metals and essential minerals in... more The objective of this study was to assess the levels of 39 toxic metals and essential minerals in hair samples of children with autism spectrum disorders and their mothers compared to controls. Inductively coupled plasma-mass spectrometry was used to analyze the elemental content of the hair of children with autism spectrum disorders (n=51), a subset of their mothers (n=29), neurotypical children (n=40), and a subset of their mothers (n=25). All participants were recruited from Arizona. Iodine levels were 45% lower in the children with autism (p=0.005). Autistic children with pica had a 38% lower level of chromium (p=0.002). Autistic children with low muscle tone had very low levels of potassium (-66%, p=0.01) and high zinc (31%, p=0.01). The mothers of young children with autism had especially low levels of lithium (56% lower, p=0.005), and the young children (ages 3-6 yr) with autism also had low lithium (-30%, p=0.04). Low iodine levels are consistent with previous reports of abn...
This study investigates both the level of toxic metals in children with autism and the possible a... more This study investigates both the level of toxic metals in children with autism and the possible association of those toxic metals with autism severity. This study involved 55 children with autism ages 5-16 years compared to 44 controls with similar age and gender. The study included measurements of toxic metals in whole blood, red blood cells (RBC), and urine. The autism group had higher levels of lead in RBC (+41 %, p = 0.002) and higher urinary levels of lead (+74 %, p = 0.02), thallium (+77 %, p = 0.0001), tin (+115 %, p = 0.01), and tungsten (+44 %, p = 0.00005). However, the autism group had slightly lower levels of cadmium in whole blood (-19 %, p = 0.003). A stepwise, multiple linear regression analysis found a strong association of levels of toxic metals with variation in the degree of severity of autism for all the severity scales (adjusted R(2) of 0.38-0.47, p < 0.0003). Cadmium (whole blood) and mercury (whole blood and RBC) were the most consistently significant varia...
Expected values, reference ranges, or reference limits are necessary to enable clinicians to appl... more Expected values, reference ranges, or reference limits are necessary to enable clinicians to apply analytical chemical data in the delivery of health care. Determination of references ranges is not straightforward in terms of either selecting a reference population or performing statistical analysis. In light of logistical, scientific, and economic obstacles, it is understandable that clinical laboratories often combine approaches in developing health associated reference values. A laboratory may choose to:
ABSTRACT Influences of exercise and changes in dietary carbohydrate and fat on tissue lipoprotein... more ABSTRACT Influences of exercise and changes in dietary carbohydrate and fat on tissue lipoprotein lipase (LPL) activities were studied in 40 female Sprague-Dawley rats. Rats were trained to run (n=20) on a treadmill 6 days/week, 60 minutes/day at 28 m/min on an 8° incline for 8 wk or remained sedentary (n=20). All rats were fed a control high carbohydrate diet (12% kcals fat) for 5 weeks and then one-half of the trained and nontrained groups were assigned to a high fat (HF) diet. The HF (73% kcals fat) fed rats were pair fed to be isocaloric and isonitrogenous with the animals receiving the control diet. Animals were fasted 12–14 hours before sacrifice. Feeding the HF diet increased body weight, fat pad weight and plasma TG levels, but had no effect on muscle weight or muscle TG content. Training at least doubled the LPL activivity of the red gastrocnemius muscle. The combination of HF feeding and exercise produced an elevation in the LPL activity of the red (135%) and white (80%) gastrocnemius muscles compared to control feeding and no exercise. The additive effect of the HF diet and exercise training also increased LPL activity of renal adipose tissue (43%) versus control feeding and no exercise. Feeding the HF diet reduced glycogen depletion in liver and skeletal muscle during exercise. This study demonstrates that skeletal muscle LPL activity is sensitive to the individual and combined effects of dietary fat and exercise.
The relationship between relative metabolic disturbances and developmental disorders is an emergi... more The relationship between relative metabolic disturbances and developmental disorders is an emerging research focus. This study compares the nutritional and metabolic status of children with autism with that of neurotypical children and investigates the possible association of autism severity with biomarkers.
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Papers by David Quig