Revisited: the inertia tensor as a proprioceptive invariant in humans

A multitude of tasks that we perform on a daily basis require precise information about the orientation of our limbs with respect to the environment and the objects located within it. Recent studies have suggested that the inertia tensor, a physical property whose values are time- and co-ordinate-indepenclent, may be an important informational invariant used by the proprioceptive system to control the movements of our limbs (Pagano et al., Ecol. Psychol. 8 (1996) 43; Pagano and Turvey, Percept. Psychophys. 52 (1992) 617; Pagano and Turvey, J. Exp. Psychol. Hum. Percept. Perform. 21 (1995) 1070). We tested this hypothesis by recording the angular errors made by subjects when pointing to virtual targets in the dark. Close examination of the pointing errors made did not show any significant effects of the inertia tensor modifications on pointing accuracy. The kinematics of the pointing movements did not indicate that any on-line adjustments were being made to compensate for the inertia tensor changes. The implications of these findings with respect to the functioning of the proprioceptive system are discussed.

Demonstration of glycated insulin in human diabetic plasma and decreased biological activity assessed by euglycemic-hyperinsulinemic clamp technique in humans

The presence and biological significance of circulating glycated insulin has been evaluated by high-pressure liquid chromatography (HPLC), electrospray ionization mass spectrometry (ESI-MS), radioimmunoassay (RIA), receptor binding, and hyperinsulinemic-euglycemic clamp techniques. ESI-MS analysis of an HPLC-purified plasma pool from four male type 2 diabetic subjects (HbA(1e) 8.1 +/- 0.2%, plasma glucose 8.7 +/- 1.3 mmol/l [means +/- SE]) revealed two major insulin-like peaks with retention times of 14-16 min. After spectral averaging, the peak with retention time of 14.32 min exhibited a prominent triply charged (M+3H)(3+) species at 1,991.1 m/z, representing monoglycated insulin with an intact M-r of 5,970.3 Da. The second peak (retention time 15.70 min) corresponded to native insulin (M-r 5,807.6 Da), with the difference between the two peptides (162.7 Da) representing a single glucitol adduct (theoretical 164 Da). Measurement of glycated insulin in plasma of type 2 diabetic subjects by specific RIA gave circulating levels of 10.1 +/- 2.3 pmol/l, corresponding to -9% total insulin. Biological activity of pure synthetic monoglycated insulin (insulin B-chain Phe(1)-glucitol adduct) was evaluated in seven overnight-fasted healthy nonobese male volunteers using two-step euglycemic-hyperinsulinemic clamps (2 h at 16.6 mug (.) kg(-1) (.) min(-1), followed by 2 h at 83.0 mug (.) kg(-1) (.) min(-1); corresponding to 0.4 and 2.0 mU (.) kg(-1) (.) min(-1)). At the lower dose, the exogenons glucose infusion rates required to maintain euglycemia during steady state were significantly lower with glycated insulin (P

The sites of neural adaptation induced by resistance training in humans

Although it has long been supposed that resistance training causes adaptive changes in the CNS, the sites and nature of these adaptations have not previously been identified. In order to determine whether the neural adaptations to resistance training occur to a greater extent at cortical or subcortical sites in the CNS, we compared the effects of resistance training on the electromyographic (EMG) responses to transcranial magnetic (TMS) and electrical (TES) stimulation. Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle of 16 individuals before and after 4 weeks of resistance training for the index finger abductors (n=8), or training involving finger abduction-adduction without external resistance (n=8). TMS was delivered at rest at intensities from 5% below the passive threshold to the maximal output of the stimulator. TMS and TES were also delivered at the active threshold intensity while the participants exerted torques ranging from 5 to 60% of their maximum voluntary contraction (MVC) torque. The average latency of MEPs elicited by TES was significantly shorter than that of TMS MEPs (TES latency=21.5+/-1.4 ms; TMS latency=23.4+/-1.4 ms; P

Dietary antioxidant and mineral intake in humans is associated with reduced risk of esophageal adenocarcinoma but not reflux esophagitis or Barrett's esophagus

The role of antioxidants in the pathogenesis of reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) remains unknown. We evaluated the associations among dietary antioxidant intake and these diseases. We performed an assessment of dietary antioxidant intake in a case control study of RE (n = 219), BE (n = 220), EAC (n = 224), and matched population controls (n = 256) (the Factors Influencing the Barrett's Adenocarcinoma Relationship study) using a modification of a validated FFQ. We found that overall antioxidant index, a measure of the combined intake of vitamin C, vitamin E, total carotenoids, and selenium, was associated with a reduced risk of EAC [odds ratio (OR) = 0.57; 95% CI = 0.33-0.98], but not BE (OR = 0.95; 95% CI = 0.53-1.71) or RE (OR = 1.60; 95% CI = 0.86-2.98), for those in the highest compared with lowest category of intake. Those in the highest category of vitamin C intake had a lower risk of EAC (OR = 0.37; 95% CI = 0.21-0.66; P-trend = 0.001) and RE (OR = 0.46; 95% CI = 0.24-0.90; P-trend = 0.03) compared with those in the lowest category. Vitamin C intake was not associated with BE, and intake of vitamin E, total carotenoids, zinc, copper, or selenium was not associated with EAC, BE, or RE. In conclusion, the overall antioxidant index was associated with a reduced risk of EAC. Higher dietary intake of vitamin C was associated with a reduced risk of EAC and RE. These results suggest that antioxidants may play a role in the pathogenesis of RE and EAC and may be more important in terms of progression rather than initiation of the disease process.

Short-term consumption of phytoestrogen-rich foods in humans alters dietary macro- and micronutrient intake

The aim of this study was to determine bow nutrient intake is affected by a short-term phytoestrogen-rich diet. Ten healthy volunteers consumed 100 g soya chunks, 150 g lentils, and 250 g kidney beans daily for 3 days. Urine was collected during the 2 days before, 3 intervention days, and 2 days after the intervention and analyzed for phytoestrogen status. Subjects filled in food diaries throughout the study period. Urinary daidzein, but not equol and enterolactone, levels increased during the 7-day period. There was no change in energy, protein, sugar, or total fat intake, but an increase in carbohydrate, fiber, and starch intake. There was a change in the distribution of fat intake with a fall in saturated fat and cholesterol intake. Iron intake significantly increased, although vitamin B-12 fell significantly. The long-term effects of this diet and the associated health benefits of these changes require further study. (C) 2006 Elsevier Inc. All rights reserved.

Dogs as a diagnostic tool for ill-health in humans

Researchers have long reported that dogs and cats improve the physical and psychological health of their human caregivers, and while it is still inconclusive, a substantial amount of research now lends support for the commonly held view that "pets are good for us." Recently, studies have directed attention toward exploring the use of animals, most notably dogs, in the detection of disease and other types of health problems in people. This article reviews the evidence for dogs' ability to detect ill health in humans, focusing specifically on the detection of cancer, epileptic seizures, and hypoglycemia. The author describes the research carried out in this area and evaluates it in an effort to determine whether dogs have a role to play in modern health care as an "alert" tool or screening system for ill health. Where necessary, the author has highlighted weaknesses in the work and proposed directions for future studies.

Glucose and citrate reduce the permeability changes caused by indomethacin in humans

Nonsteroidal anti-inflammatory drug (NSAID)-induced increased intestinal permeability appears to be a prerequisite for NSAID enteropathy. It has been suggested that early metabolic events leading to the permeability changes may involve inhibition of glycolysis and the tricarboxylic acid cycle, in which case the coadministration of glucose and citrate (the substrates for these metabolic pathways) with indomethacin may afford some protection. The present study, using a combined intestinal absorption-permeability test including 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and [51Cr]ethylene-diaminetetraacetic acid (EDTA) as test probes and the differential urine excretion ratio of [51Cr]-EDTA/L-rhamnose, showed that indomethacin (50 + 75 mg) increased intestinal permeability. A formulation of indomethacin containing 15 mg glucose and 15 mg citrate to each milligram of indomethacin did not increase intestinal permeability significantly above baseline values. When given alone with indomethacin, neither glucose nor citrate (45 mg to each milligram of indomethacin) had any protective effects. Pharmokinetic studies showed that the effects of glucose and citrate cannot be explained on the basis of altered drug absorption. These results suggest a new approach to reducing the small intestinal side effects of NSAIDs.