Skeletal muscle disorders associated with selenium deficiency in humans

Plasma selenium, zinc, copper and lipid levels in postmenopausal Turkish women and their relation with osteoporosis

It has been shown that the trace elements and lipids play role in the growth, development and maintenance of bones. We aimed to investigate serum selenium (Se), zinc (Zn), copper (Cu) and lipid (total cholesterol, triglyceride (TG), high density lipoprotein-cholesterol, low-density lipoprotein-cholesterol) levels in postmenopausal women with osteoporosis, osteopenia and in healthy controls, and to determine the relationship between Se, Zn, Cu and lipid parameters and bone mineral density (BMD). The study included 107 postmenopausal women; 35 healthy (group 1), 37 osteopenic (group 2) and 35 osteoporotic (group 3). The women in all three groups were carefully matched for body mass index (BMI). Serum concentrations of Se, Zn and Cu were measured by atomic absorption spectrophotometry. Plasma Se, Cu, Zn and lipid levels were similar in all groups (p > 0.05). When we combined the women in each of the three groups, and considered them as one group (n = 107) we found a positive correlation between BMI and lumbar vertebra BMD, femur neck BMD, femur total BMD; a positive correlation between TG and femur neck BMD, femur total BMD; a positive correlation between Zn and lumbar vertebra BMD (total T score) (p < 0.05). There was no correlation between Se, Cu, Zn, P and lipid parameters (p > 0.05). Although BMI has a positive effect on BMD, trace elements and lipids, except Zn and TG, did not directly and correlatively influence BMD. Further studies are needed to clarify the role and relationship of trace elements and lipid parameters in postmenopausal osteoporosis.

Effects of dietary selenium on selenoprotein W gene expression in the chicken immune organs

Selenoprotein W (SelW) is expressed in the immune systems of mammals. However, its pattern of expression in the immune organs of birds is still unclear. To investigate the distribution of SelW and effects of dietary Se levels on the SelW mRNA expression in the immune organs of birds, 1-day-old male chickens were fed either a commercial diet or an Se-supplemented diet containing 0.601, 1.058, 1.514, or 2.427 mg Se per kilogram, and 1.0, 2.0, 3.0 or 5.0 mg sodium selenite per kilogram for 90 days. The immune organs (spleen, thymus, and bursa of Fabricius) were collected and examined for Se content and SelW mRNA levels. The mRNA expression of SelW was detected in all the tissues. Although Se content was the highest in the spleen, the remarkable stability of the SelW mRNA level was observed in this organ during different times of dietary Se supplementation. Se-supplemented diet can make the SelW expression levels higher within a certain range in thymus and bursa of Fabricius. The present study demonstrates that SelW is widely expressed in immune organs of birds and that Se-supplementation of the feed increases SelW expression in the thymus and the bursa of Fabricius.

Adaptive dysfunction of selenoproteins from the perspective of the triage theory: why modest selenium deficiency may increase risk of diseases of aging

The triage theory proposes that modest deficiency of any vitamin or mineral (V/M) could increase age-related diseases. V/M-dependent proteins required for short-term survival and/or reproduction (i.e., "essential") are predicted to be protected on V/M deficiency over other "nonessential" V/M-dependent proteins needed only for long-term health. The result is accumulation of insidious damage, increasing disease risk. We successfully tested the theory against published evidence on vitamin K. Here, we review about half of the 25 known mammalian selenoproteins; all of those with mouse knockout or human mutant phenotypes that could be used as criteria for a classification of essential or nonessential. Five selenoproteins (Gpx4, Txnrd1, Txnrd2, Dio3, and Sepp1) were classified as essential and 7 (Gpx1, Gpx 2, Gpx 3, Dio1, Dio2, Msrb1, and SelN) nonessential. On modest selenium (Se) deficiency, nonessential selenoprotein activities and concentrations are preferentially lost, with one exception (Dio1 in the thyroid, which we predict is conditionally essential). Mechanisms include the requirement of a special form of tRNA sensitive to Se deficiency for translation of nonessential selenoprotein mRNAs except Dio1. The same set of age-related diseases and conditions, including cancer, heart disease, and immune dysfunction, are prospectively associated with modest Se deficiency and also with genetic dysfunction of nonessential selenoproteins, suggesting that Se deficiency could be a causal factor, a possibility strengthened by mechanistic evidence. Modest Se deficiency is common in many parts of the world; optimal intake could prevent future disease.

Selenium deficiency and HIV infection

Selenium is a non-metallic chemical element of great important to human health. Low selenium levels in humans are associated with several pathological conditions and are a common finding in HIV infected individuals. We conducted a review of the literature to assess if selenium deficiency or selenium supplementation could play a role in modifying the clinical course of HIV disease. Several studies investigated the role of selenium in disease progression, morbidity and mortality in HIV infected individuals. Larger studies were conducted in countries with poor economic resources and limited access to HAART. According to the majority of published studies low selenium levels appear to have an association with mortality, and selenium supplementation appears to play a beneficial role on survival or on slowing disease progression among HIV infected individuals. The role of selenium supplementation on preventing hospital admission among HIV outpatients was also noticed. The literature suggests an association between selenium deficiency and development of HIV associated cardiomyopathy and furthermore, selenium supplementation appears to improve the cardiac function in HIV infected individuals with cardiomyopathy. However, there is conflicting evidence regarding the role selenium in modifying HIV viral load and immune status in HIV infection.

Biochemical markers of muscular damage

Muscle tissue may be damaged following intense prolonged training as a consequence of both metabolic and mechanical factors. Serum levels of skeletal muscle enzymes or proteins are markers of the functional status of muscle tissue, and vary widely in both pathological and physiological conditions. Creatine kinase, lactate dehydrogenase, aldolase, myoglobin, troponin, aspartate aminotransferase, and carbonic anhydrase CAIII are the most useful serum markers of muscle injury, but apoptosis in muscle tissues subsequent to strenuous exercise may be also triggered by increased oxidative stress. Therefore, total antioxidant status can be used to evaluate the level of stress in muscle by other markers, such as thiobarbituric acid-reactive substances, malondialdehyde, sulfhydril groups, reduced glutathione, oxidized glutathione, superoxide dismutase, catalase and others. As the various markers provide a composite picture of muscle status, we recommend using more than one to provide a better estimation of muscle stress.

Diagnostic and Therapeutic Significance of the Oxidative Stress Parameters in Children

Pharmacotherapy of pediatric diseases represents a major challenge considering that the majority of medicines in everyday practice have not been pediatrically evaluated. The efficacy of therapy depends to a large extent on the knowledge of pathophysiological processes in the children organism at different ages. Therefore, research in that direction is of the utmost importance. An imbalance in the production of free oxygen/nitrogen species and parameters of antioxidative protection is a significant factor in many diseases (e.g. heart failure, pulmonary hypertension, asthma, neonatal sepsis, cancer etc.) in children of different age groups. Reactive oxygen/nitrogen species serve as cell signaling molecules for normal biologic processes. An increase in their generation can cause damages which can disrupt normal physiological cellular processes and eventually cause cell death. This review outlines the previous assessments of oxidative stress parameters in children of different ages for some diseases. Also, the potential diagnostic and therapeutic possibilities for the oxydative stress parameters in children have been considered.

Selenoproteins and protection against oxidative stress: selenoprotein N as a novel player at the crossroads of redox signaling and calcium homeostasis

Healthy cells continually produce low levels of reactive oxygen species (ROS), which are buffered by multiple antioxidant systems. Imbalance between ROS production and elimination results in oxidative stress, which has been implicated in aging and in numerous human diseases, including cancer and diabetes. Selenoproteins are a family of proteins that contain the amino acid selenocysteine, encoded by an in-frame UGA. Those selenoproteins whose function is identified are catalytically active in redox processes, representing one of the main enzymatic antioxidant systems and important mediators of the beneficial role of selenium in human health. Nevertheless, the function of most selenoproteins remains unknown; this included Selenoprotein N (SelN), the only selenoprotein directly associated with a human genetic disease. Mutations of the SelN gene cause SEPN1-related myopathy, a particular early-onset muscle disorder. Recent studies have identified SelN as a key protein in cell protection against oxidative stress and redox-related calcium homeostasis. Furthermore, an effective ex vivo treatment of SelN deficiency has been identified, paving the way to a clinical therapy. In this review we discuss the physiological and pathophysiological role of SelN and the interest of SEPN1-related myopathy as a model paradigm to understand and target therapeutically other selenoproteins involved in human health and disease.

A mineral-rich extract from the red marine algae Lithothamnion calcareum preserves bone structure and function in female mice on a Western-style diet

The purpose of this study was to determine whether a mineral-rich extract derived from the red marine algae Lithothamnion calcareum could be used as a dietary supplement for prevention of bone mineral loss. Sixty C57BL/6 mice were divided into three groups based on diet: the first group received a high-fat Western-style diet (HFWD), the second group was fed the same HFWD along with the mineral-rich extract included as a dietary supplement, and the third group was used as a control and was fed a low-fat rodent chow diet (AIN76A). Mice were maintained on the respective diets for 15 months. Then, long bones (femora and tibiae) from both males and females were analyzed by three-dimensional micro-computed tomography (micro-CT) and (bones from female mice) concomitantly assessed in bone strength studies. Tartrate-resistant acid phosphatase (TRAP), osteocalcin, and N-terminal peptide of type I procollagen (PINP) were assessed in plasma samples obtained from female mice at the time of sacrifice. To summarize, female mice on the HFWD had reduced bone mineralization and reduced bone strength relative to female mice on the low-fat chow diet. The bone defects in female mice on the HFWD were overcome in the presence of the mineral-rich supplement. In fact, female mice receiving the mineral-rich supplement in the HFWD had better bone structure/function than did female mice on the low-fat chow diet. Female mice on the mineral-supplemented HFWD had higher plasma levels of TRAP than mice of the other groups. There were no differences in the other two markers. Male mice showed little diet-specific differences by micro-CT.

Pediatric parenteral nutrition: putting the microscope on macronutrients and micronutrients

Parenteral nutrition can be a life-saving therapy, but its benefits need to be balanced with a unique set of risks and complications. Methods of practice vary because there is a dearth of research in the area of pediatric parenteral nutrition. This article reviews the available literature on parenteral nutrition in children and provides suggestions on prevention and management of parenteral nutrition-associated liver disease. Some of the issues discussed in this article include glucose infusion rates, cycling of parenteral nutrition, copper and manganese toxicity, and the provision of glutamine, selenium, and carnitine.

Magnesium, Zinc, Copper, Manganese, and Selenium Levels in Postmenopausal Women with Osteoporosis. Can Magnesium Play a Key Role in Osteoporosis?

Introduction: There has been a resurgence of interest in studies concerning the role of elements in the development and maintenance of the skeleton. The aim of the study was to assess the plasma and red blood concentrations of some elements in postmenopausal women with osteoporosis. Materials and Methods: Seventy-seven postmenopausal women with osteoporosis aged 61 years (median interquartile range, 7.5; range, 46 to 74) and 61 age- and BMI-matched healthy postmenopausal women aged 60 years (median interquartile range, 8.0; range, 44 to 76) were included in the study. Element concentrations in plasma and red blood cells including magnesium (Mg), zinc, copper, manganese, and selenium were measured by atomic absorption spectrophotometry in both postmenopausal women with osteoporosis and healthy postmenopausal women. Results: Only statistically significant difference between the osteoporotic (51.51 [15.40] μg/mL) and healthy subjects (54.54 [15.42] μg/mL) was observed in red blood cell (RBC) magnesium concentration (Z = -2.07, P = 0.039). However, no significant difference was found between patient and control groups, both in plasma and in red blood concentrations, for zinc, copper, manganese, and selenium. Conclusion: Mg levels in red blood cells are significantly lower in postmenopausal women with osteoporosis. It is concluded that Mg transport mechanism(s) into the cell could be affected in patients with osteoporosis. Key words: Copper, Magnesium, Manganese, Osteoporosis, Selenium, Zinc

Molecular and cellular events in alcohol-induced muscle disease

Alcohol consumption induces a dose-dependent noxious effect on skeletal muscle, leading to progressive functional and structural damage of myocytes, with concomitant reductions in lean body mass. Nearly half of high-dose chronic alcohol consumers develop alcoholic skeletal myopathy. The pathogenic mechanisms that lie between alcohol intake and loss of muscle tissue involve multiple pathways, making the elucidation of the disease somewhat difficult. This review discusses the recent advances in basic and clinical research on the molecular and cellular events involved in the development of alcohol-induced muscle disease. The main areas of recent research interest on this field are as follows: (i) molecular mechanisms in alcohol exposed muscle in the rat model; (ii) gene expression changes in alcohol exposed muscle; (iii) the role of trace elements and oxidative stress in alcoholic myopathy; and (iv) the role of apoptosis and preapoptotic pathways in alcoholic myopathy. These aforementioned areas are crucial in understanding the pathogenesis of this disease. For example, there is overwhelming evidence that both chronic alcohol ingestion and acute alcohol intoxication impair the rate of protein synthesis of myofibrillar proteins, in particular, under both postabsorptive and postprandial conditions. Perturbations in gene expression are contributory factors to the development of alcoholic myopathy, as ethanol-induced alterations are detected in over 400 genes and the protein profile (i.e., the proteome) of muscle is also affected. There is supportive evidence that oxidative damage is involved in the pathogenesis of alcoholic myopathy. Increased lipid peroxidation is related to muscle fibre atrophy, and reduced serum levels of some antioxidants may be related to loss of muscle mass and muscle strength. Finally, ethanol induces skeletal muscle apoptosis and increases both pro- and antiapoptotic regulatory mechanisms.

Serum selenium, vitamin E, and sialic acids concentrations in lambs with white muscle disease

The aim of this study was to determine the serum concentrations of selenium, vitamin E, and total- and lipid-bound sialic acid (LBSA) in lambs with white muscle disease (WMD) before and after treatment with a commercial preparation containing selenite and vitamin E. Fifteen lambs with WMD and ten control animals were used as research materials. Blood samples were collected from both groups before- and 1 month after treatment for Se analysis by fluorimetry, whereas vitamin E and sialic acid were measured by HPLC and spectrophotometry, respectively. Compared to controls, in the diseased animals, there was a significant increase of serum total sialic acid (TSA) and LBSA, together with significant decreases of serum Se and vitamin E concentrations (p < 0.001). One month after treatment, a reversal of trend was observed with decreases of TSA and LBSA and increases of Se and vitamin E concentrations. The TSA and LBSA levels, however, remained significantly higher than those of the controls, p < 0.05 and 0.001, respectively. The Se and vitamin E concentrations of the treated animals were the same as those of controls. This is the first study on total and LBSA concentrations in lambs with WMD, showing that these markers can be used in the prognosis of the disease.

Clinical features of selenium deficiency in infants receiving long-term nutritional support

OBJECTIVE

Selenium deficiency is a known complication in patients requiring long-term nutritional support; however, the clinical features of selenium deficiency in infants have not been completely described. We describe the clinical features of selenium deficiency in infants.

METHODS

Six infants with selenium deficiency were studied retrospectively, with a focus on the period of nutritional support, the clinical symptoms, and the chronologic changes in serum selenium concentrations before and after the administration of selenite.

RESULTS

The onset of selenium deficiency in five patients occurred at <6 mo of age; selenium deficiency occurred in one patient 14 mo after birth. One patient received parenteral nutrition for 15 mo after birth; the other five patients primarily received an elemental diet for 2-6 mo. In all patients, growth retardation and alopecia with pseudoalbinism were the characteristic symptoms of selenium deficiency. At the time of diagnosis, the serum selenium level in four patients was <2.0 microg/dL and serum selenium levels in two patients were 3.2 and 3.3 microg/dL, respectively. The resolution of hair symptoms corresponded to the level of serum selenium after 1-2 mo and a rapid improvement in growth occurred in all patients after the administration of selenite.

CONCLUSION

The early clinical symptoms of selenium deficiency in infants include growth retardation and alopecia with pseudoalbinism, which are reversible if the patients are treated with adequate amounts of selenite. Clinicians who manage infants receiving long-term nutritional support, including an elemental diet, should be aware of the symptoms associated with selenium deficiency.

Association of low plasma selenium concentrations with poor muscle strength in older community-dwelling adults: the InCHIANTI Study

BACKGROUND

Although selenium plays an important role in muscle function, the relation between circulating selenium and muscle strength in elderly adults has not been characterized.

OBJECTIVE

The objective was to examine the hypothesis that low plasma selenium is associated with poor muscle strength in older adults.

DESIGN

We measured plasma selenium and hip, grip, and knee strength in a cross-sectional study of 891 men and women aged >or=65 y from the Invecchiare in Chianti (InCHIANTI) Study, a population-based cohort study in Tuscany (Italy). Poor muscle strength was defined as the lowest quartile of hip flexion, grip, and knee extension strength.

RESULTS

Overall, mean (+/-SD) plasma selenium was 0.95 +/- 0.15 mumol/L. After adjustment for age, sex, education, total energy intake, body mass index, and chronic disease, participants in the lowest versus the highest quartile of plasma selenium were at higher risk of poor hip strength [odds ratio (OR): 1.69; 95% CI: 1.02, 2.83; P = 0.04, P for linear trend = 0.04], knee strength (OR: 1.94; 95% CI: 1.18, 3.19; P = 0.009, P for linear trend = 0.01), and grip strength (OR: 1.94; 95% CI: 1.19, 3.16; P = 0.008, P for linear trend = 0.08).

CONCLUSIONS

Low plasma selenium is independently associated with poor skeletal muscle strength in community-dwelling older adults in Tuscany.

Low serum selenium concentrations are associated with poor grip strength among older women living in the community

Aging is associated with a loss of muscle strength, and, in turn, loss of muscle strength has been associated with increased risk of frailty, disability and mortality. The factors that contribute to loss of muscle strength with aging have not been well characterized. Selenium is important in normal muscle function because of its role in selenoenzymes that protect muscle against oxidative damage. We hypothesized that low serum selenium concentrations were associated with poor grip strength. We examined the association between serum selenium and hand grip strength among 676 moderately to severely disabled community-dwelling women in the Women's Health and Aging Study I in Baltimore, Maryland. After adjusting for age, race, body mass index, Mini-Mental Status Examination score, current smoking, hypertension, congestive heart failure and depression, serum selenium was associated with grip strength (P=0.04). This study supports the idea that selenium is important to muscle strength in older women.

An unusual myopathy: Speckled muscle fibers due to enlarged mitochondria

We report a 52-year-old woman who presented with a 6-month history of proximal muscle weakness, elevated serum creatine kinase, and myopathic pattern on electromyography (EMG). Histology of the muscle shows a speckled pattern due to clustering of enlarged mitochondria. The pathology resembles that of selenium deficiency. The patient was found to have borderline low serum selenium and also low vitamin D and thyroid-stimulating hormone. The cause of this unusual myopathy is probably multifactorial. This case is important because the unusual pathological picture represents a potentially treatable myopathy. In addition, we hope that publication of the complex clinical and biochemical abnormalities of this case, in conjunction with other case reports, may facilitate future elucidation of muscle mitochondrial function and dysfunction.

Decreased beta-adrenoceptor chronotropic response in selenium-deficient mice: negative crosstalk between iNOS activity and cAMP accumulation

With the aim to study if selenium (Se) deficiency affects the basal frequency and cardiac response to isoproterenol (ISO), mice were fed a Se-deficient diet (Se-) or the same diet supplemented with 0.2 ppm Se as sodium selenite (Se+) for 4 wk. Atria frequency, cyclic AMP (cAMP) accumulation, nitric oxide synthase (NOS) activity, and beta-adrenoceptor-binding assay were then examined. Results showed that Se-mice have both a reduction in atria frequency as well as in cAMP content but higher NOS activity levels either at basal or after ISO stimulation. These differences were suppressed by feeding Se-mice with a Se-supplemented diet for 1 wk or by inhibition of inducible nitric oxide synthase (iNOS). Alterations observed after ISO stimulation in atria of Se-mice were not related to a beta-adrenoceptor expression modification because specific radioligand-binding parameters in cardiac membranes from Se-mice and Se+ mice were similar. The reduced response on rate and cAMP in atria from Se-mice to direct adenylate cyclase (AC) stimulation by forskolin and the shifted upward levels present in 2-amino-4-methylpyridine-treated Se-mice is in agreement with a negative crosstalk between iNOS activity and AC activity in Se-mice.

Understanding the importance of selenium and selenoproteins in muscle function

Selenium is an essential trace element. In cattle, selenium deficiency causes dysfunction of various organs, including skeletal and cardiac muscles. In humans as well, lack of selenium is associated with many disorders, but despite accumulation of clinical reports, muscle diseases are not generally considered on the list. The goal of this review is to establish the connection between clinical observations and the most recent advances obtained in selenium biology. Recent results about a possible role of selenium-containing proteins in muscle formation and repair have been collected. Selenoprotein N is the first selenoprotein linked to genetic disorders consisting of different forms of congenital muscular dystrophies. Understanding the muscle disorders associated with selenium deficiency or selenoprotein N dysfunction is an essential step in defining the causes of the disease and obtaining a better comprehension of the mechanisms involved in muscle formation and maintenance.

Effects of baseline serum levels of Se on markers of eccentric exercise-induced muscle injury

Inflammation and oxidative stress have been implicated in the mechanism of eccentric exercise-induced muscle injury. This study examined whether baseline serum levels of selenium (Se), a trace element that participates in both antioxidant and anti-inflammatory systems, affects the overall response to injury. Thirteen males performed 36 maximal eccentric actions with the elbow flexors of the non-dominant arm on a motorized dynamometer. Venous blood samples were collected immediately before and after exercise at 2, 24, 48, 72 and 96 hours. Established indicators of muscle damage such as maximum isometric torque (MIT), range of motion (ROM), relaxed arm angle (RANG), flexed arm angle (FANG), arm circumference (CIRC), muscle soreness and serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) were determined at the same time points. Baseline serum levels of Se were also measured. Complementary data regarding assessment of Se status were retrieved by the use of a semi-quantitative food frequency questionnaire. All measures changed significantly (p<0.05) after exercise. The main finding of this study was that baseline Se serum levels were associated inversely with CK, LDH and FANG and positively with MIT and ROM (p<0.05). These data suggest that beyond overt Se deficiency, suboptimal Se status possibly worsens muscle functional decrements subsequent to eccentric muscle contractions.

Complications musculaires de l’infection par le virus de l’immunodéficience humaine (VIH) à l’ère des trithérapies

Introduction of highly active antiretroviral therapy (HAART) has dramatically modified the natural history of HIV disease, but lengthening the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions. Muscular complications of HIV infection are classified as follows: (1) HIV-associated myopathies and related conditions including polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitis, myasthenic syndromes, and chronic fatigue; (2) iatrogenic conditions including mitochondrial myopathies, HIV-associated lipodystrophy syndrome, and immune restoration syndrome; (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. These features are described in the present review.

Skeletal muscle involvement in human immunodeficiency virus (HIV)-infected patients in the era of highly active antiretroviral therapy (HAART)

Skeletal muscle involvement can occur at all stages of human immunodeficiency virus (HIV) infection, and may represent the first manifestation of the disease. Myopathies in HIV-infected patients are classified as follows: (1) HIV-associated myopathies and related conditions, including HIV polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitic processes, myasthenic syndromes, and chronic fatigue; (2) muscle complications of antiretroviral therapy, including zidovudine and toxic mitochondrial myopathies related to other nucleoside-analogue reverse-transcriptase inhibitors (NRTIs), HIV-associated lipodystrophy syndrome, and immune restoration syndrome related to highly active antiretroviral therapy (HAART); (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. Introduction of HAART has dramatically modified the natural history of HIV disease by controlling viral replication, but, in turn, lengthening of the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions.

Body-composition alterations consistent with cachexia in children and young adults with Crohn disease

BACKGROUND

Crohn disease (CD) in children is associated with low body mass index (BMI), poor growth, and delayed maturation; alterations in lean and fat mass, however, are poorly characterized.

OBJECTIVE

The objective was to quantify lean and fat mass in children and young adults with CD and in healthy control subjects, relative to height and pubertal maturation.

DESIGN

This cross-sectional study assessed whole-body lean and fat mass by using dual-energy X-ray absorptiometry in 104 subjects with CD and in 233 healthy control subjects aged 4-25 y. Linear regression was used to determine the effect of CD on body composition and to generate sex-specific SD scores (z scores) for lean and fat mass relative to height.

RESULTS

Subjects with CD had lower height-for-age and BMI-for-age z scores (P < 0.001 for both) than did control subjects. CD was associated with significant deficits in lean mass after adjustment for height, age, race, and Tanner stage (P = 0.003); deficits in fat mass were not observed. The mean (+/-SD) lean mass-for-height and fat mass-for-height z scores in the subjects with CD were -0.61 +/- 0.92 and -0.04 +/- 0.86, respectively. Within the control group, fat mass-for-height was positively correlated with lean mass-for height (r = 0.41, P < 0.0001); this association was absent in the subjects with CD.

CONCLUSIONS

Children and young adults with CD had significant deficits in lean mass but preserved fat mass, which is consistent with cachexia. Further research is needed to identify physical activity, nutritional, and antiinflammatory interventions to improve body composition in persons with CD.

Body-composition alterations consistent with cachexia in children and young adults with Crohn disease

BACKGROUND

Crohn disease (CD) in children is associated with low body mass index (BMI), poor growth, and delayed maturation; alterations in lean and fat mass, however, are poorly characterized.

OBJECTIVE

The objective was to quantify lean and fat mass in children and young adults with CD and in healthy control subjects, relative to height and pubertal maturation.

DESIGN

This cross-sectional study assessed whole-body lean and fat mass by using dual-energy X-ray absorptiometry in 104 subjects with CD and in 233 healthy control subjects aged 4-25 y. Linear regression was used to determine the effect of CD on body composition and to generate sex-specific SD scores (z scores) for lean and fat mass relative to height.

RESULTS

Subjects with CD had lower height-for-age and BMI-for-age z scores (P < 0.001 for both) than did control subjects. CD was associated with significant deficits in lean mass after adjustment for height, age, race, and Tanner stage (P = 0.003); deficits in fat mass were not observed. The mean (+/-SD) lean mass-for-height and fat mass-for-height z scores in the subjects with CD were -0.61 +/- 0.92 and -0.04 +/- 0.86, respectively. Within the control group, fat mass-for-height was positively correlated with lean mass-for height (r = 0.41, P < 0.0001); this association was absent in the subjects with CD.

CONCLUSIONS

Children and young adults with CD had significant deficits in lean mass but preserved fat mass, which is consistent with cachexia. Further research is needed to identify physical activity, nutritional, and antiinflammatory interventions to improve body composition in persons with CD.

Medicinal mushroom modulators of molecular targets as cancer therapeutics

Empirical approaches to discover anticancer drugs and cancer treatments have made limited progress in the past several decades in finding a cure for cancer. The expanded knowledge of the molecular basis of tumorigenesis and metastasis, together with the inherently vast structural diversity of natural compounds found in mushrooms, provided unique opportunities for discovering new drugs that rationally target the abnormal molecular and biochemical signals leading to cancer. This review focuses on mushroom low-molecular-weight secondary metabolites targeting processes such as apoptosis, angiogenesis, metastasis, cell cycle regulation, and signal transduction cascades. Also discussed in this review are high-molecular-weight polysaccharides or polysaccharide-protein complexes from mushrooms that appear to enhance innate and cell-mediated immune responses, exhibit antitumor activities in animals and humans, and demonstrate the anticancer properties of selenium compounds accumulated in mushrooms.

Better osteoblast adhesion on nanoparticulate selenium— A promising orthopedic implant material

Apart from problems such as poor osseointegration, stress shielding, and wear debris-associated bone cell death, a major concern of metallic orthopedic implants is that they slowly corrode under in vivo environments. It is possible that continuous tissue exposure to metallic corrosion products limits orthopedic implant efficacy; this is especially true for patients receiving implants due to bone cancer. To date, there is no metallic orthopedic implant available in the market that specifically deals with the prevention and/or recurring cancer that may happen in these patients. The objective of this study was to deal with these problems in an integrated way by introducing a new biomaterial to the orthopedic community with anticancer chemistry: selenium (Se). In this study, six types of Se compacts were tested for bone cell (osteoblast) adhesion under in vitro conditions. Two types of cylindrical compacts were made with conventional Se metal particles in the micron (6.539 +/- 1.364-microm diameter) and submicron (0.963 +/- 0.139-microm diameter) range. These two types of compacts were chemically etched with different concentrations of NaOH to create two additional types of Se particles in each category: conventional size particles with nanosurface roughness and nanometer particles (0.204- to 0.264-microm diameter). Results showed for the first time, enhanced osteoblast adhesion on particulate surfaces of the compacts made from conventional Se compared with reference nonparticulate wrought titanium sheets. More importantly, this study provided the first evidence that osteoblast density was further increased on the surfaces of the Se compacts with nanometer particles. These initial findings indicate that there may be a promising future for nanoparticulate Se as an anticancer biocompatible orthopedic material.