Evaluation of an alternative skeletal muscle index for skeletal muscle mass assessment in a group of Australian women.

BACKGROUND: Sarcopenia is assessed by several methods, including dual energy X-ray absorptiometry (DEXA), which provide a height-adjusted skeletal muscle index (H-SMI). A SMI 2 standard deviation below the young adult reference [1] combined with low muscle strength or performance is used to identify sarcopenia. As height declines with age, H-SMI may underestimate low skeletal muscle mass in the older population. Our study aims to evaluate an alternative SMI and to examine its relationship to grip strength in a group of Australian women. METHODS: Women from two cohorts were analysed. 2041 women had body composition data (112 had calf circumference, 137 had leg length measurements) without grip strength, and 49 women had grip strength measured (40 had body composition data).The relationship between leg length-adjusted SMI (LL-SMI) to grip strength and anthropometric variables to skeletal muscle mass by DEXA were examined by linear regression analysis. RESULTS: Cohort 1: Older women were compared to younger women. Older women were shorter but leg length did not differ between different age groups. H-SMI was not different between groups (P = 0.528). LL-SMI was lower in older women (P = 0.002). Cohort 2: LL-SMI was significantly associated with grip strength (P = 0.048) after adjustment for age. CONCLUSION: Older women were shorter, while leg length did not differ from the younger group. H-SMI may obscure and may underestimate low muscle mass in older individuals. LL-SMI may be a better measure of skeletal muscle mass in older individuals. These alternate SMI would benefit from further exploration in older individuals.

Mental health diagnoses in adults with phenylketonuria: a retrospective systematic audit in a large UK single centre.

BACKGROUND: Recently published European Society for Phenylketonuria (ESPKU) guidelines have recommended a lifelong diet with phenylalanine (Phe) control ≤ 600 µmol/L for phenylketonuria (PKU) patients. This study aimed to identify whether PKU adult patients are at a higher risk of mental health diagnoses if their 2-year average Phe level is higher than the ESPKU European guidelines. Published studies identified by a literature review showed that related studies have been published in American and European PKU study populations but not in the United Kingdom (UK) study populations. Previous studies also involved a smaller number of participants due to this being a rare disease. RESULTS: We undertook a retrospective audit at a single large PKU centre in the UK. 244 adult PKU patients at the centre were included, 220 of which had a recorded Phe level. Approximately 75% of the patients in this study did not meet the ESPKU European guidelines for Phe control. A systematic search of the electronic patient record was undertaken looking for mental health diagnoses. Compared to two-year average Phe levels ≤ 600 µmol/L, PKU adult patients with two-year average Phe levels > 600 µmol/L were more likely to have diagnoses of low mood, depression, anxiety, or mood swings, but only low mood reached statistical significance (p < 0.05). CONCLUSIONS: PKU patients with two-year average Phenylalanine levels greater than ESPKU guidelines may be at greater risk of mental health diagnoses and symptoms. Many of these adult PKU patients will be lost to follow-up, and therefore may be receiving treatment for mental health conditions in the community. Multicentre UK studies and international collaborations are required to overcome low participant numbers in the study of this rare disease.

Multicomponent density models for body composition: Review of the dual energy X-ray absorptiometry volume approach.

Accurate and precise body composition estimates, notably of total body adiposity, are a vital component of in vivo physiology and metabolic studies. The reference against which other body composition approaches are usually validated or calibrated is the family of methods referred to as multicomponent "body density" models. These models quantify three to six components by combining measurements of body mass, body volume, total body water, and osseous mineral mass. Body mass is measured with calibrated scales, volume with underwater weighing or air-displacement plethysmography, total body water with isotope dilution, and osseous mineral mass by dual-energy X-ray absorptiometry. Body density is then calculated for use in model as body mass/volume. Studies over the past decade introduced a new approach to quantifying body volume that relies on dual-energy X-ray absorptiometry measurements, an advance that simplifies multicomponent density model development by eliminating the need for underwater weighing or air-displacement plethysmography systems when these technologies are unavailable and makes these methods more accessible to research and clinical programs. This review critically examines these new dual-energy X-ray approaches for quantifying body volume and density, explores their shortcomings, suggests alternative derivation approaches, and introduces ideas for potential future research studies.

Selective Loss of Levator Ani and Leg Muscle Volumes in Men Undergoing Androgen Deprivation Therapy.

CONTEXT: Androgen deprivation therapy (ADT) for prostate cancer (PCa) leads to a selective loss of leg muscle function during walking. Rodent models of ADT have demonstrated that the levator ani is exquisitely androgen sensitive. OBJECTIVE: To determine whether the high androgen responsiveness of the levator ani muscle documented in rodents is evolutionarily conserved and ADT is associated with a selective loss in leg muscle volume. DESIGN: Prospective longitudinal case-control study. SETTING: Tertiary referral hospital. PARTICIPANTS: Thirty-four men newly beginning ADT and 29 age-matched controls with PCa. MAIN OUTCOME MEASURES: The muscle volumes in liters of the levator ani and primary muscles involved in walking (iliopsoas, quadriceps, gluteus maximus, gluteus medius, calf). RESULTS: Compared with controls, during a 12-month period, men receiving ADT experienced a mean reduction in total testosterone from 14.1 to 0.4 nmol/L and demonstrated greater decreases in levator ani [mean adjusted difference (MAD), -0.005 L; 95% CI, -0.007 to -0.002; P = 0.002; -16% of initial median value], gluteus maximus (MAD, -0.032 L; 95% CI, -0.063 to -0.002; P = 0.017; -5% of initial median value), iliopsoas (MAD, -0.005 L; 95% CI, -0.001 to 0.000; P = 0.013; -5% of initial median value), and quadriceps (MAD, -0.050 L; 95% CI, -0.088 to -0.012; P = 0.031; -3% of initial median value). No substantial differences were observed in the gluteus medius and calf muscles. CONCLUSIONS: The androgen responsiveness of the levator ani appears to be evolutionarily conserved in humans. ADT selectively decreases the volume of muscles that support body weight. Interventional strategies to reduce ADT-related sarcopenia and sexual dysfunction should assess whether targeting these muscle groups, including the pelvic floor, will improve clinical outcomes.

Measuring visceral fat, subcutaneous fat and skeletal muscle area changes by computed tomography in acute pancreatitis: a retrospective, single-centre study.

OBJECTIVE: To show that body composition of intensive care unit patients can be analysed with existing computed tomography (CT) images. We planned to describe changes in visceral fat area (VFA), subcutaneous fat area (SFA) and muscle area (MA) on analysis of specific CT images during acute pancreatitis requiring an ICU admission. DESIGN, SETTING AND PARTICIPANTS: Retrospective analysis of body composition using existing CT images, in an ICU of a tertiary university-affiliated hospital 2005-2010, examining 21 patients with acute pancreatitis and CT imaging on two separate occasions within their hospital admission. MAIN OUTCOME MEASURES: VFA, SFA, VFA:SFA ratio and MA. Medical records were hand searched to identify ICU and hospital mortalities and other clinical outcomes. RESULTS: Three women and 18 men had 84 CT scans analysed, from the level of the right renal hilum and L3 vertebra. The median patient age was 52 years. The median time between CT scans was 9.4 days and the mean Acute Physiology and Chronic Health Evaluation II score was 20.2. ICU mortality was 9%. Analysis showed a decrease in VFA from a median of 229.2 cm2 to 202.1 cm2 (P < 0.01) and a decrease in VFA:SFA ratio from a median of 1.20 to 1.05 (P < 0.01) during the acute illness. MA did not change significantly. CONCLUSIONS: The body composition of ICU patients can be analysed through existing CT images. Pancreatitis requiring ICU admission causes a 12% decrease in VFA.

Fat-free mass depletion in cystic fibrosis: associated with lung disease severity but poorly detected by body mass index.

OBJECTIVE: Malnutrition in cystic fibrosis (CF) is associated with poorer survival, but the determinants of fat-free mass (FFM) depletion are not well-characterized. It is unknown whether routine nutritional indicators, including body mass index (BMI), are adequate for detecting FFM depletion. This study aimed to determine the prevalence of FFM depletion in adults with CF, to compare fat-free mass index (FFMI) with BMI, and to identify predictors of FFM depletion. METHODS: This was a prospective cross-sectional study of 86 adults with CF (19-59 y old). Body composition was assessed using dual-energy X-ray absorptiometry to determine FFMI and BMI. FFMI percentiles and Z-scores were derived from a reference population of 156 healthy adults. FFM depletion was defined as an FFMI below the fifth percentile for age and gender and low BMI as <18.5 kg/m(2). Univariate and multivariate analyses identified predictors of FFMI and FFMI Z-score. RESULTS: Mean FFMIs were 18.3+/-1.9 kg/m(2) in men with CF and 15.8+/-1.1 kg/m(2) in women with CF (P<0.0005). FFM depletion was found in 14% of adults with CF, and low BMI was found in 18.6%. The sensitivity of BMI for detecting FFM depletion was 42%. Forced expiratory volume in 1 s as a percentage of predicted was independently associated with FFMI in women (r=0.62, P<0.0001) and men (r=0.28, P=0.045) and FFMI Z-score (r=0.41, P<0.0001). CONCLUSION: FFM depletion was found in 14% of adults with CF, but was undetectable by BMI in 58% of these patients. These findings, together with the association of FFMI with forced expiratory volume in 1 s predicted, suggest a role for body composition assessment in adult CF care.

Testosterone enhances estradiol's effects on postmenopausal bone density and sexuality.

To investigate the role of androgens in increasing bone density and improving low libido in postmenopausal women, we have studied the long-term effects of estradiol and testosterone implants on bone mineral density and sexuality in a prospective, 2 year, single-blind randomised trial. Thirty-four postmenopausal volunteers were randomised to treatment with either estradiol implants 50 mg alone (E) or estradiol 50 mg plus testosterone 50 mg (E&T), administered 3-monthly for 2 years. Cyclical oral progestins were taken by those women with an intact uterus. Thirty-two women completed the study. BMD (DEXA) of total body, lumbar vertebrae (L1-L4) and hip area increased significantly in both treatment groups. BMD increased more rapidly in the testosterone treated group at all sites. A substantially greater increase in BMD occurred in the E&T group for total body (P < 0.008), vertebral L1-L4 (P < 0.001) and trochanteric (P < 0.005) measurements. All sexual parameters (Sabbatsberg sexual self-rating scale) improved significantly in both groups. Addition of testosterone resulted in a significantly greater improvement compared to E for sexual activity (P < 0.03), satisfaction (P < 0.03), pleasure (P < 0.01), orgasm (P < 0.035) and relevancy (P < 0.05). Total cholesterol and LDL-cholesterol fell in both groups as did total body fat. Total body fat-free mass (DEXA, anthropometry, impedance) increased in the E&T group only. We concluded that in postmenopausal women, treatment with combined estradiol and testosterone implants was more effective in increasing bone mineral density in the hip and lumbar spine than estradiol implants alone. Significantly greater improvement in sexuality was observed with combined therapy, verifying the therapeutic value of testosterone implants for diminished libido in postmenopausal women. The favourable estrogenic effects on lipids were preserved in women treated with T, in association with beneficial changes in body composition.

Smaller hip circumference is associated with dyslipidemia and the metabolic syndrome in obese women.

BACKGROUND: There is great need for simple anthropometric measures that predict risk. The authors explored the relationship between body composition measures and features of the metabolic syndrome (MtS) in women aged between 20 and 50 years with class I obesity. METHODS: This is a cross-sectional study of 49 obese (BMI 30-35) women recruited into a weight management randomized trial. An analysis was conducted of the baseline weight, anthropometric measures, skin-fold thickness, bioelectrical impedance, whole body dual-energy x-ray absorptiometry (DEXA), and their relationships with the features of the MtS. RESULTS: All women but one (n=48) had a population risk waist circumference of >88 cm. 16 of the 49 (33%) fulfilled the criteria of the metabolic syndrome. Simple anthropometric measures provided the strongest correlations with the presence of the MtS. Cut-off values were selected using receiver operator characteristics. Waist circumference of >100 cm and hip circumference <115cm was associated with odds ratios of 5.2 (95% CI, 1.4-20) and 12.3 (95% CI, 3.0-51) respectively for the MtS. Regional DEXA analysis showed that lower leg fat mass rather than fat-free mass was associated with the MtS. The dyslipidemia of the MtS was associated with a lower leg fat mass, while higher HbAlc levels and HOMA, an indirect measure of insulin resistance, were seen with increased trunk fat. Percentage fat as measured by skin-fold thickness and bioelectrical impedance were not related to any features. Women with the metabolic syndrome were found to have lower bone mineral content as measured by DEXA. CONCLUSION: Weight distribution is highly predictive of metabolic risk. Smaller hip and larger waist circumference provided independent effect. BMI adjusted anthropometric measures may be of value.

Body composition of children with chronic and end-stage renal failure.

AIM: Protein energy malnutrition is common in children with chronic renal failure (CRF) and may negatively impact on clinical outcome. Although the aetiology of malnutrition is multifactorial, descriptive information on body composition may guide nutritional interventions aimed at optimising nutritional status. METHODS: This prospective cohort study in children with CRF was conducted from April 1999 to November 2000. Patients were categorised according to their glomerular filtration rate (GFR) into CRF and end-stage renal failure (ESRF). Body composition was assessed based on anthropometry, total body potassium (TBK), total body protein (TBP) and dual X-ray absorptiometry (DEXA). RESULTS: Fifteen patients (10 male, 5 female; mean age: 13.4 +/- 4.3 years) were studied, including eight patients with CRF (mean GFR: 17.0 +/- 7.2 mL/min/1.73 m(2)) and seven patients with ESRF (mean GFR: 6.4 +/- 1.7 mL/min/1.73 m(2)). Patients in both groups (n = 15) had deficits in height and TBP (mean z-score height-for-age: -1.19 +/- 1.05, P < 0.01; mean z-score TBP: -0.71 +/- 0.71, P < 0.05). There were no significant differences in weight, height, fat-free mass, TBK and TBP between patients with CRF and ESRF. CONCLUSIONS: Linear growth impairment and decreased TBP are common in children with chronic and ESRF. TBK and DEXA may underestimate the degree of malnutrition in these patients.

Changes in body composition with weight loss: obese subjects randomized to surgical and medical programs.

OBJECTIVE: To assess changes in body composition with weight loss in obese subjects randomized to a laparoscopic adjustable gastric band surgical program or a medical program using a very-low-energy diet and orlistat. RESEARCH METHODS AND PROCEDURES: Using body composition measurements by DXA, neutron activation for total body nitrogen, and whole body gamma counting for total body potassium, we studied changes in fat mass, fat distribution, fat-free mass, total bone mineral content, total body protein, and body cell mass at 6 (n = 61 paired) and 24 months (n = 53 paired) after randomization. RESULTS: At 24 months, the surgical group had lost significantly more weight (surgical, 20.3 +/- 6.5 kg; medical, 5.9 +/- 8.0 kg). There was favorable fat-free mass to fat mass loss ratios for both groups (surgical, 1:5.5; medical, 1:5.9). Changes in total body nitrogen or potassium were favorable in each group. A small reduction in mean bone mineral content occurred throughout the study but was not associated with extent of weight loss or treatment group. At 6 months, weight loss for both groups was similar (surgical, 14.1 +/- 4.5 kg; medical, 13.3 +/- 7.3 kg). The medical program subjects lost less fat-free mass and skeletal muscle and had increased total body protein. The proportion of body fat to limb fat remained remarkably constant throughout the study. DISCUSSION: Weight loss programs used in this study induced fat loss without significant deleterious effects on the components of fat-free mass.

Single frequency bioelectrical impedance is a poor method for determining fat mass in moderately obese women.

BACKGROUND: The primary aim of weight loss intervention in obesity is the loss of fat mass (FM). Hence, determinations of changes in FM and fat free mass (FFM) during weight loss are of clinical value. The authors compared the clinical utility of SkinFold Thickness (SKF), tetrapolar bioelectrical impedance analysis (BIA) and a body mass index (BMI) based calculation, in determining changes in percentage of fat mass (delta%FM). METHODS: Using dual X-ray absorptiometry (DEXA) measurements of %FM as a standard, BIA, SKF and BMI were compared in 41 moderately obese women (BMI 30-35) before and after significant weight loss (-13.9 +/- 5.8 kg). RESULTS: When measuring fat mass loss, SKF was precise and accurate with a bias of +0.86 +/- 6.16 %, while the BMI-based estimation had a systematic bias of +6.36 +/- 6.04 % (r2 = 0.791, P < 0.001). BIA using the Lukaski formula had a bias of +5.22 % and limits of agreement that approached the magnitude of the measurement (+/- 20.82 %), thus providing no information. In contrast, BIA using the Segal formula had a systematic bias of +7.81% (r2 = 0.636, P < 0.001) and gave narrower limits of agreement (+/- 8.34 %). CONCLUSION: For measuring changes in %FM with weight loss, BIA has no clinical value using the Lukaski formula, and using the Segal formula BIA provided no additional information to that given by BMI. We show that BIA instrument variables confound the estimates of %FM achieved by the BMI component of the Lukaski and Segal formulas.

Near normalisation of lumbar spine bone density in young women with osteopenia recovered from adolescent onset anorexia nervosa: a longitudinal study.

To investigate the effect of the progression of adolescent onset anorexia nervosa (AN) on bone parameters we followed two cohorts (Disease cohort and recovered cohort) of adolescents for a total of 5.2 years. In the 'Disease' cohort (n = 18), lumbar spine bone density (BMD) was reduced by 0.6 SD after 0.8 years of disease and was reduced a further 1.0 SD after a total 2.5 years of disease (p < 0.001). At the third lumbar vertebra there was bone loss (-3.7%, p < 0.05) resulting in reduced volumetric BMD (-5.1%, p < 0.08). In the 'recovered' cohort, lumbar spine BMD was reduced by 1.9 SD after 1.7 years of disease, and increased by 1.5 SD after 2.7 years of recovery (p < 0.001). At the third lumbar vertebra there was an increase in bone mass (20.5%, p < 0.001) and bone volume (14.1%, p < 0.001), resulting in increased volumetric BMD (6.3%, p < 0.08). Normalisation of lumbar spine BMD may be achieved in patients with adolescent onset AN when the successful recovery of body weight is combined with the return of regular menses.

The relationship between body composition and knee cartilage volume in healthy, middle-aged subjects.

OBJECTIVE: Although obesity is widely accepted as a risk factor for knee osteoarthritis, it is not clear whether individual components of body composition, such as the mass and distribution of muscle and fat, are associated with development of the disease. This study examined the effect of measures of body composition on the longitudinal change in tibial cartilage volume. METHODS: Body composition, assessed via dual x-ray absorptiometry, and tibial cartilage volume, assessed via magnetic resonance imaging, were measured in 86 healthy men and women who were mid-life in age. Change in tibial cartilage volume was assessed by imaging each knee 2 years after the baseline measurement and determining the difference from baseline in tibial cartilage volume. Correlations were determined between the muscle and fat mass of the arm, leg, and total body and the volume of the lateral- and medial-tibial cartilage, as well as the change in tibial cartilage volume over 2 years, after adjusting for confounders. RESULTS: There was a significant association between muscle mass and the medial-tibial cartilage volume, independent of age, sex, body mass index, tibial bone area, and level of physical activity. Although there was a positive association between muscle mass and the lateral-tibial cartilage volume, this did not persist after adjustment for confounders. Loss of muscle mass was associated with an increased loss of medial- and lateral-tibial cartilage over 2 years, after adjusting for confounders. No relationship was apparent between fat mass and either medial- or lateral-tibial cartilage volume, or between fat mass and change in either medial- or lateral-tibial cartilage volume over 2 years, after adjusting for confounders. CONCLUSION: Muscle mass is an independent predictor of medial-tibial cartilage volume in healthy people in mid-life and is associated with a reduction in the rate of loss of tibial cartilage. This suggests that increased muscle mass may be protective against the onset of osteoarthritis.

Determination of maternal body composition in pregnancy and its relevance to perinatal outcomes.

Three models and 10 specific methods for determining maternal body composition are discussed and their perinatal relevance reviewed. English language publications (1950 to January 2004) were searched electronically and by hand. Search terms included "body composition," "human," " pregnancy," "obesity," "adiposity," "regional," "2-, 3-, 4-component," "truncal," "peripheral," "central," "visceral" along with specific techniques and outcomes listed subsequently. Three models of body composition are described: 2-component being fat and fat-free mass; 3-component being fat, water, and protein; and 4-component being fat, water, protein, and osseous mineral. Ten techniques of body composition assessment are described: 1) anthropometric techniques including skinfold thicknesses and waist-hip ratio; 2) total body water (isotopically labeled); 3) hydrodensitometry (underwater weighing); 4) air-displacement plethysmography; 5) bio-impedance analysis (BIA); 6) total body potassium (TBK); 7) dual-energy x-ray absorptiometry (DEXA); 8) computed tomography (CT); 9) magnetic resonance imaging (MRI); and 10) ultrasound (USS). Most methods estimate total adiposity. Regional fat distribution-central (truncal) compared with peripheral (limb) or visceral compared with subcutaneous-is important because of regional variation in adipocyte metabolism. Skinfolds, DEXA, CT, MRI, or USS can distinguish central from peripheral fat. CT, MRI, or USS can further subdivide central fat into visceral and subcutaneous. Perinatal outcomes examined in relation to body composition include pregnancy duration, birth weight, congenital anomalies, gestational diabetes, gestational hypertension, and the fetal origins of adult disease. A few studies suggest that central compared with peripheral fat correlates better with birth weight, gestational carbohydrate intolerance, and hypertension. Means of accurately assessing maternal body composition remain cumbersome and impractical, but may more accurately predict perinatal outcomes than traditional assessments such as maternal weight.

Ninhydrin as a reversible protecting group of amino-terminal cysteine.

The proximity of the alpha-amine and beta-thiol of alpha-amino terminal-cysteine (NT-Cys) residues in peptides imparts unique chemical properties that have been exploited for inter- and intra-molecular ligation of unprotected peptides obtained through both synthetic and biological means. A reversible protecting group orthogonal to other protection strategies and reversible under mild conditions would be useful in simplifying the synthesis, cleavage, purification and handling of such NT-Cys peptides. It could also be useful for the sequential ligation of peptides. To this end, we explored tri-one chemistry and found that ninhydrin (indane-1,2,3 trione) reacted readily with cysteine or an NT-Cys-containing peptide on- or off-resin at pH 2-5 to form Ninhydrin-protected Cys (Nin-Cys) as a thiazolidine (Thz). The Thz ring, protecting both the amino and thiol groups in Nin-Cys, completely avoids the formylation and Thz side reactions found during hydrofluoric acid (HF) cleavage when N-pi-benzyloxymethyl histidine groups are present. Nin-Cys is stable during coupling reactions and various cleavage conditions with trifluoroacetic acid or HF, but is deprotected under thiolytic or reducing conditions. These properties enable a facile one-step deprotection and end-to-end-cyclization reaction of Nin-Cys peptides containing C-terminal thioesters.

LacZ-expressing olfactory ensheathing cells do not associate with myelinated axons after implantation into the compressed spinal cord.

Studies have shown that implanting olfactory ensheathing cells (OECs) may be a promising therapeutic strategy to promote functional recovery after spinal cord injury. Several fundamental questions remain, however, regarding their in vivo interactions in the damaged spinal cord. We have induced a clip compression injury at the T10 level of the spinal cord in adult rats. After a delay of 1 week, OECs isolated from embryonic day 18 rats were implanted into the cystic cavity that had formed at the site of injury. Before implantation, OECs were infected with a LacZ-expressing retrovirus. At 3 weeks after implantation, LacZ-expressing OECs survived the implantation procedure and remained localized to the cystic cavity. At the electron microscopic level, the cystic cavity had clusters of LacZ-expressing OECs and numerous Schwann cells lacking LacZ expression. Although labeled OECs made no direct contact with axons, unlabeled Schwann cells were associated with either a single myelinated axon or multiple unmyelinated axons. Positively labeled OEC processes often enveloped multiple Schwann cell-axon units. These observations suggest that the role of OECs as the primary mediators of the beneficial effects on axon growth, myelination, and functional recovery after spinal cord injury may require re-evaluation.

Dietary carotenoid intake as a predictor of bone mineral density.

Our understanding of the influence of nutrition on bone health is limited because most studies concentrate on the role of calcium and protein, while other nutrients receive less attention. Recent evidence shows a positive link between fruit and vegetable consumption and bone health. In the present study, the relationships of dietary intakes of preformed retinol and carotenoids, one group of phytonutrients abundant in fruit and vegetables, were examined in an Anglo-Celtic Australian population of 68 men and 137 women. Bone mass of total body and lumbar spine were positively related to lycopene intake in men, and to lycopene and lutein/zeaxanthin intake in premenopausal women. In addition, a positive association of lumbar spine bone mass with dietary beta-carotene intake was observed in postmenopausal women. No relationship was found between dietary retinol intake and bone mineral status. The finding of the present study suggests a beneficial effect of fruit and vegetable consumption, as indicated by dietary carotenoid intake, on bone health, possibly via an antioxidant mechanism.

Glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor sustain the axonal regeneration of chronically axotomized motoneurons in vivo.

In contrast to injuries in the central nervous system, injured peripheral neurons will regenerate their axons. However, axotomized motoneurons progressively lose their ability to regenerate their axons, following peripheral nerve injury often resulting in very poor recovery of motor function. A decline in neurotrophic support may be partially responsible for this effect. The initial upregulation of glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) by Schwann cells of the distal nerve stump after nerve injury has led to the speculation that they are important for motor axonal regeneration. However, few experiments directly measure the effects of exogenous BDNF or GDNF on motor axonal regeneration. This study provided the first direct and quantitative evidence that long-term continuous treatment with exogenous GDNF significantly increased the number of motoneurons which regenerate their axons, completely reversing the negative effects of chronic axotomy. The beneficial effect of GDNF was not dose-dependent. A combination of exogenous GDNF and BDNF on motor axonal regeneration was significantly greater than either factor alone, and this effect was most pronounced following long-term continuous treatment. The ability of GDNF, either alone or in combination with BDNF, to increase the number of motoneurons that regenerated their axons correlated well with an increase in axon sprouting within the distal nerve stump. Thus long-term continuous treatment with neurotrophic factors, such as GDNF and BDNF, can be used as a viable treatment to sustain motor axon regeneration.