Vitamin D-binding protein gene microsatellite polymorphism influences BMD and risk of fractures in men.

UNLABELLED: Here we report the results of a vitamin D-binding protein gene microsatellite polymorphism study in 170 men, comprising healthy male subjects and men with osteoporosis-related symptomatic vertebral fractures. We confirm the results of an earlier study in a different cohort, showing relationship between certain genotypes of (TAAAn)-Alu repeats and reduced BMD and vertebral fractures. INTRODUCTION: Vitamin D-binding protein (DBP) plays a critical role in the transport and metabolism of metabolites of vitamin D, including the key calciotropic hormone 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3). METHODS: We have investigated intra-intronic variable tandem (TAAA)n-Alu repeat expansion in the DBP gene in 170 men, comprising healthy male subjects and men with idiopathic osteoporosis and low trauma fractures. RESULTS AND CONCLUSIONS: The predominant DBP-Alu genotype in the control subjects was 10/10 (frequency 0.421), whereas the frequency of this genotype in men with osteoporosis was 0.089. DBP-Alu alleles *10, *8 and *9, respectively, were the three commonest in both healthy subjects and men with osteoporosis. Allele *10 was associated with a lower risk of osteoporosis (OR 0.39, 95% CI 0.25-0.64; p < 0.0005), as was allele *11 (odds ratio 0.09, 95% CI 0.01-0.67; p < 0.007). Logistic regression gave similar results, showing that individuals with genotype 10/10 and 19-20 repeats (genotypes 9/10, 9/11, 10/10,) are protected from fracture or osteoporosis. Overall, there was a relationship between DBP Alu genotype and BMD, suggesting that DBP-Alu genotype may influence fracture risk. This effect may be mediated by changes in the circulating concentrations of DBP which influences free concentrations of vitamin D.

Objective evidence of cognitive complaints in Chronic Fatigue Syndrome: a BOLD fMRI study of verbal working memory.

Individuals with Chronic Fatigue Syndrome (CFS) often have difficulties with complex auditory information processing. In a series of two Blood Oxygen Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) studies, we compared BOLD signal changes between Controls and individuals with CFS who had documented difficulties in complex auditory information processing (Study 1) and those who did not (Study 2) in response to performance on a simple auditory monitoring and a complex auditory information processing task (mPASAT). We hypothesized that under conditions of cognitive challenge: (1) individuals with CFS who have auditory information processing difficulties will utilize frontal and parietal brain regions to a greater extent than Controls and (2) these differences will be maintained even when objective difficulties in this domain are controlled for. Using blocked design fMRI paradigms in both studies, we first presented the auditory monitoring task followed by the mPASAT. Within and between regions of interest (ROI), group analyses were performed for both studies with statistical parametric mapping (SPM99). Findings showed that individuals with CFS are able to process challenging auditory information as accurately as Controls but utilize more extensive regions of the network associated with the verbal WM system. Individuals with CFS appear to have to exert greater effort to process auditory information as effectively as demographically similar healthy adults. Our findings provide objective evidence for the subjective experience of cognitive difficulties in individuals with CFS.

Real-time assessment of postprandial fat storage in liver and skeletal muscle in health and type 2 diabetes.

Liver and skeletal muscle triglyceride stores are elevated in type 2 diabetes and correlate with insulin resistance. As postprandial handling of dietary fat may be a critical determinant of tissue triglyceride levels, we quantified postprandial fat storage in normal and type 2 diabetes subjects. Healthy volunteers (n = 8) and diet-controlled type 2 diabetes subjects (n = 12) were studied using a novel 13C magnetic resonance spectroscopy protocol to measure the postprandial increment in liver and skeletal muscle triglyceride following ingestion of 13C-labeled fatty acids given with a standard mixed meal. The postprandial increment in hepatic triglyceride was rapid in both groups (peak increment controls: +7.3 +/- 1.5 mmol/l at 6 h, P = 0.002; peak increment diabetics: +10.8 +/- 3.4 mmol/l at 4 h, P = 0.009). The mean postprandial incremental AUC of hepatic 13C enrichment between the first and second meals (0 and 4 h) was significantly higher in the diabetes group (6.1 +/- 1.4 vs. 1.7 +/- 0.6 mmol x l(-1) x h(-1), P = 0.019). Postprandial increment in skeletal muscle triglyceride in the control group was small compared with the diabetic group, the mean 24-h postprandial incremental AUC being 0.2 +/- 0.3 vs. 1.7 +/- 0.4 mmol x l(-1) x h(-1) (P = 0.009). We conclude that the postprandial uptake of fatty acids by liver and skeletal muscle is increased in type 2 diabetes and may underlie the elevated tissue triglyceride stores and consequent insulin resistance.

Serum adrenal androgens in women with primary operable breast cancer and their relationship with age and body mass index.

Several studies have found elevated levels of adrenal androgens in postmenopausal women and depressed levels in premenopausal women with breast cancer, suggesting a role for adrenal androgens in the aetiology of breast cancer. We have measured serum dehydroepiandrosterone sulphate and androstenedione in 81 women with primary operable breast cancer and 62 age-matched controls. Results showed that serum levels of both adrenal androgens fell significantly with age in women with breast cancer (P=0.003). However, no relationship was observed between serum adrenal androgen levels and body mass index in either women with breast cancer or controls. Dehydroepiandrosterone sulphate levels were elevated in postmenopausal women with breast cancer compared to controls, and this was not due to preoperative stress. No differences were observed in androstenedione levels between premenopausal or postmenopausal women with breast cancer and controls, nor were dehydroepiandrostenedione sulphate levels significantly different between premenopausal women with breast cancer and controls. These results suggest that dehydroepiandrosterone sulphate has a role in the aetiology of postmenopausal breast cancer.

Moderate-intensity muscle pain can be produced and sustained during cycle ergometry.

PURPOSE: The aim of this experiment was to determine whether moderate-intensity quadriceps muscle pain could be produced and sustained during cycle ergometry. METHODS: 12 women volunteers completed a peak cycle ergometry test during which quadriceps muscle pain-intensity ratings were obtained using a 0-10 scale. On a subsequent day, participants cycled for 20 min beginning at the power output associated with quadriceps muscle pain threshold during the peak test. Participants manipulated power output during the first 10 s of each minute to produce and sustain moderate-intensity quadriceps muscle pain. During the last 20 s of each minute, VO2, ratings of quadriceps muscle pain intensity, and ratings of perceived exertion (Borg 6-20) were obtained. RESULTS: Moderate-intensity quadriceps pain ratings were achieved within 4 min, during which time the average power output was increased from 124 to 138 W. Pain-intensity ratings were unchanged from minutes 4 to 20 (F = 0.94; df = 16, 176; P = 0.52; eta2 = 0.079). Quadriceps RPE responses mimicked the pain responses. To sustain a moderate-intensity quadriceps pain participants reduced power output significantly (F = 7.75; df = 16, 176; P < 0.001; eta2 = 0.413) and in a linear fashion by 21.7 W (15.7%). The changes in % VO2peak were similar in pattern to the changes in power output but smaller in magnitude. CONCLUSIONS: 1) College women can produce and sustain a moderate-intensity quadriceps muscle pain during cycle ergometry, 2) moderate-intensity quadriceps muscle pain is sustained by reducing power output, and 3) sustaining moderate-intensity quadriceps muscle pain during short duration cycling is associated with a "hard" perceptual effort and 69-74% VO2peak.

Relationship of brain MRI abnormalities and physical functional status in chronic fatigue syndrome.

Chronic Fatigue Syndrome (CFS) is an unexplained illness that is characterized by severe fatigue. Some have suggested that CFS is a "functional somatic syndrome" in which symptoms of fatigue are inappropriately attributed to a serious illness. However, brain magnetic resonance imaging (MRI) data suggest that there may be an organic abnormality associated with CFS. To understand further the significance of brain MRI abnormalities, we examined the relationship between MRI identified brain abnormalities and self-reported physical functional status in 48 subjects with CFS who underwent brain MR imaging and completed the Medical Outcomes Study SF-36. Brain MR images were examined for the presence of abnormalities based on 5 general categories previously shown to be sensitive to differentiating CFS patients from healthy controls. There were significant negative relationships between the presence of brain abnormalities and both the physical functioning (PF) (rho=-.31, p=.03), and physical component summary PCS (rho=-.32, p=.03) subscales of the SF-36. CFS patients with MRI identified brain abnormalities scored significantly lower on both PF (t(1,46) =2.3, p=.026) and the PCS (t(1,41) =2.4, p=.02) than CFS subjects without an identified brain abnormality. When adjusted for age differences only the PF analysis remained significant. However, the effect sizes for both analyses were large indicating meaningful differences in perceived functional status between the groups. These results demonstrate that the presence of brain abnormalities in CFS are significantly related to subjective reports of physical function and that CFS subjects with MRI brain abnormalities report being more physically impaired than those patients without brain abnormalities.

Muscle pain perception and sympathetic nerve activity to exercise during opioid modulation.

The purpose of this experiment was to examine the effects of the endogenous opioid system on forearm muscle pain and muscle sympathetic nerve activity (MSNA) during dynamic fatiguing exercise. Twelve college-age men (24 +/- 4 yr) performed graded (1-min stages; 30 contractions/min) handgrip to fatigue 1 h after the ingestion of either 60 mg codeine, 50 mg naltrexone, or placebo. Pain (0-10 scale) and exertion (0-10 and 6-20 scales) intensities were measured during the last 15 s of each minute of exercise and every 15 s during recovery. MSNA was measured continuously from the peroneal nerve in the left leg. Pain threshold occurred earlier [1.8 +/- 1, 2. 2 +/- 1, 2.2 +/- 1 J: codeine, naltrexone, and placebo, respectively] and was associated with a lower rating of perceived exertion (RPE) (2.7 +/- 2, 3.6 +/- 2, 3.8 +/- 2: codeine, naltrexone, and placebo, respectively) in the codeine condition compared with either the naltrexone or placebo conditions. There were no main effects (i.e., drugs) or interaction (i.e., drugs x time) for either forearm muscle pain or RPE during exercise [pain: F (2, 22) = 0.69, P = 0.51]. There was no effect of drug on MSNA, heart rate, or blood pressure during baseline, exercise, or recovery. Peak exercise MSNA responses were 21 +/- 1, 21 +/- 2.0, and 21 +/- 2.0 bursts/30 s for codeine, naltrexone, and placebo conditions, respectively. Peak mean arterial pressure responses were 135 +/- 4, 131 +/- 3, and 132 +/- 4 mmHg for codeine, naltrexone, and placebo conditions, respectively. It is concluded that neither 60 mg codeine nor 50 mg naltrexone has an effect on forearm muscle pain, exertion, or MSNA during high- intensity handgrip to fatigue.

Sex differences in naturally occurring leg muscle pain and exertion during maximal cycle ergometry.

This investigation examined the role of sex in perceptions of leg muscle pain during exercise. Males (N = 26; age = 23.2 +/- 3.9) and females (N = 26; age = 21.9 +/- 3.5) matched on weekly energy expenditure completed a ramped maximal cycle ergometry test. Leg muscle pain thresholds were determined and pain intensity ratings as well as ratings of perceived exertion were obtained during and after exercise. The power output at pain threshold was lower in females (129.9 +/- 46.5 watts) compared to males (148.2 +/- 56.6 watts). Peak power output and peak pain intensity ratings were lower (P < 0.001) in females (211.3 +/- 39.1 watts; 5.5 +/- 2.9) compared to males (303.6 +/- 27.5 watts; 8.5 +/- 2.3). A Sex X Relative Intensity (i.e., % peak power output) ANOVA revealed that females reported lower pain ratings at each relative intensity examined (F = 17.7; df = 1.50; p < 0.001). The primary conclusion of this investigation is that females rate naturally occurring leg muscle pain as less intense than males when data are relativized to peak power output.

Anxiolytic and blood pressure effects of acute static compared to dynamic exercise.

This experiment tested whether state anxiety and blood pressure responses to exercise were influenced by the type of muscular contraction performed. On testing day 1, 11 volunteers completed one-repetition maximums (1-RMs) separately for the right and left limbs: arm extension, arm flexion, leg extension and leg flexion (8 total exercises). On two subsequent days, which were randomly ordered, subjects completed 24 minutes of either static or dynamic exercise. Both the static and dynamic exercise conditions involved eight 3-min exercise periods performed at an intensity equal to 10% of 1-RM and separated by a 1-min rest period. In the dynamic exercise condition, exercise was performed at a rate of 20 contractions x min(-1). State anxiety and blood pressure were assessed immediately before as well as 3, 13, and 23 minutes following exercise. Heart rate was assessed continuously during exercise, and overall ratings of perceived exertion were obtained during the last 15 seconds of each 3-min exercise period. Two-way repeated measures ANOVAs revealed that state anxiety and systolic blood pressure were reduced to a similar degree following both static and dynamic exercise. It is concluded that anxiety and systolic blood pressure responses to acute exercise are not mediated by the type of muscle contraction performed.

A sandwich hybridization assay employing enzyme amplification for termination of specific ribosomal RNA from unpurified cell lysates.

We have employed the power of the cyclic NAD-based enzyme amplification system to the determination of 16S rRNA. This generally applicable system employs two oligonucleotide probes, one of which is captured on a microtiter well surface and the other labeled with alkaline phosphatase. The detection of very low levels of hybridization of the capture probe is then achieved by the means of the ultrasensitive enzyme-amplified assay system, resulting in a highly sensitive, convenient, and rapid technology which can be directly employed on unpurified samples. We have been able to demonstrate the detection of 20 amol (10(7) molecules) of pure rRNA, and specific signals from as few as 2000 bacterial cells have also been demonstrated. The total procedural time can be short-5 to 18 h-depending on the dynamic range and sensitivity required. RNA target in the range of 10(12)-10(8) molecules can be assayed within 5 h. Extending the substrate incubation time enables between 10(11) and 10(7) molecules to be determined within 18 h. The system has great potential use with respect to studying the distribution and physiological states of cellular organisms.

Naturally occurring muscle pain during exercise: assessment and experimental evidence.

The objectives were: (i) to present a method for assessing muscle pain during exercise, (ii) to provide reliability and validity data in support of the measurement tool, (iii) to test whether leg muscle pain threshold during exercise was related to a commonly used measure of pain threshold pain during test, (iv) to examine the relationship between pain and exertion ratings, (v) to test whether leg muscle pain is related to performance, and (vi) to test whether a large dose of aspirin would delay leg muscle pain threshold and/or reduce pain ratings during exercise. In study 1, seven females and seven males completed three 1-min cycling bouts at three different randomly ordered power outputs. Pain was assessed using a 10-point pain scale. High intraclass correlations (R from 0.88 to 0.98) indicated that pain intensity could be rated reliably using the scale. In study 2, 11 college-aged males (age 21.3 +/- 1.3 yr) performed a ramped (24 W.min-1) maximal cycle ergometry test. A button was depressed when leg muscle pain threshold was reached. Pain threshold occurred near 50% of maximal capacity: 50.3 (+/- 12.9% Wmax), 48.6 (+/- 14.8% VO2max), and 55.8 (+/- 12.9% RPEmax). Pain intensity ratings obtained following pain threshold were positively accelerating function of the relative exercise intensity. Volitional exhaustion was associated with pain ratings of 8.2 (+/- 2.5), a value most closely associated with the verbal anchor "very strong pain." In study 3, participants completed the same maximal exercise test as in study 2 as well as leg cycling at 60 rpm for 8 s at four randomly ordered power outputs (100, 150, 200, and 250 W) on a separate day. Pain and RPE ratings were significantly lower during the 8-s bouts compared to those obtained at the same power outputs during the maximal cycle test. The results suggest that noxious metabolites of muscle contraction play a role in leg muscle pain during exercise. In study 4, moderately active male subjects (N = 19) completed two ramped maximal cycle ergometry tests. Subjects drank a water and Kool-Aid mixture, that either was or was not (placebo) combined with a 20 mg.kg-1 dose of powdered aspirin 60 min before exercise. Paired t-tests revealed no differences between conditions for the measures of exercise intensity at pain threshold [aspirin vs placebo mean (+/- SD)]: power output: 150 (+/- 60.3 W) versus 153.5 (+/- 64.8 W); VO2: 21.3 (+/- 8.6 mL.kg-1.min-1) versus 22.1 (+/- 10.0 mL.kg-1.min-1); and RPE: 10.9 (+/- 3.1) versus 11.4 (+/- 2.9). Repeated measures ANOVA revealed no significant condition main effect or condition by trial interaction for pain responses during recovery or during exercise at 60, 70, 80, 90, and 100% of each condition's peak power output. It is concluded that the perception of leg muscle pain intensity during cycle ergometry: (i) is reliably and validly measured using the developed 10-point pain scale, (ii) covaries as a function of objective exercise stimuli such as power output, (iii) is distinct from RPE, (iv) is unrelated to performance of the type employed here, and (v) is not altered by the ingestion of 20 mg.kg-1 acetylsalicylic acid 1 h prior to the exercise bout.

Body image in adulthood: a projective approach.

A sample of 210 persons varying by age (young adults, middle-aged, older adults), gender, and relationship status (single or involved) were administered the Holtzman Inkblot Technique (HIT) and Geriatric Draw-A-Person (G-DAP) to ascertain projectively assessed aspects of body image in adulthood. Results suggested that both the HIT and G-DAP were sensitive to the effects of age and gender, wherein young adults scored higher on both HIT Barrier and Penetration than both middle-aged or older adults. In addition, G-DAP scores favored young adults. HIT Penetration scores varied by both age and relationship status.

Eating disorder symptoms in former female college gymnasts: relations with body composition.

The purpose of this investigation was to describe eating disorder symptoms in 36.6 +/- 3.8-y-old former college gymnasts as well as relations between body dissatisfaction and body composition. Former college gymnasts (n = 22) and age-(mean +/- SE difference: 0.05 +/- 0.26 y), height-(0.47 +/- 0.75 cm), and weight-matched (2.20 +/- 0.30 kg) control subjects (n = 22) participated. Current and past symptoms were assessed by using the Eating Disorders Inventory-2 (EDI-2) and visual analog scales. EDI-2 body-dissatisfaction scores were correlated with assessments of body composition by dual-energy X-ray absorptiometry. Weight preoccupation was stable across the life span for control subjects but was lower before former gymnasts had begun gymnastics training and higher for former gymnasts when they were participating in college gymnastics (P = 0.03). Current levels of body dissatisfaction were more strongly related to actual minus ideal body-weight discrepancy scores (r = 0.77) than to percentage fat (r = 0.50) for the former gymnasts whereas the opposite was true for the control subjects (r = 0.51 and 0.77, respectively). These results suggest that symptoms of eating disorders abate after retirement from gymnastics and that concerns about achieving an ideal body may be a more important determinant of body dissatisfaction than percentage body fat for gymnasts.

Post-exercise analgesia: replication and extension.

This study was designed to investigate whether post-exercise analgesia occurs following an ad lib exercise routine. All of the 17 male participants exercised on a regular basis. In an exercise setting (student gymnasium) they participated in 20 min of self-selected exercise, while in the neutral setting (laboratory) they rested quietly for 20 min. Pain was induced via the gross pressure device. Pain threshold and pain tolerance were measured twice, with an interval of 20 min, in both the exercise and the neutral setting. Pain threshold was stable in the exercise setting. A significant increase in pain tolerance followed the 20 min bout of exercise, indicating a post-exercise analgesic response. These results support the prediction that the analgesic effect of exercise is not limited to controlled experimental conditions, but generalizes to naturally occurring situations.

Advances in immunoassay technology.

Major developments continue to be reported in key areas of immunoassay technology. Following the development of excellent signal generation methods, attention has shifted to the development of immunochemical methods and instrumentation to provide convenient systems of high performance. Important advances have been made in the design of immunochemical approaches that permit the replacement of competitive format assays for small molecules, such as drugs, metabolites and pollutants, with non-competitive formats, bringing advantages previously seen only with large molecular analytes. Bispecific antibodies and recombinant proteins are also beginning to impact immunodiagnostics, with the promise of even more highly specified reagents. Improvements in automation have brought the facility of homogeneous systems to high-throughput and high-performance heterogeneous systems. Similarly, 'point of need' testing continues to progress. Through all of these advances, systems are evolving according to the needs of users in terms of operator convenience, accuracy, specificity, speed, robustness, and sensitivity.