The “independent breath” algorithm: assessment of oxygen uptake during exercise

European Journal of Applied Physiology - Reduction of noise of breath-by-breath gas-exchange data is crucial to improve measurements. A recently described algorithm (“independent...     

The detection of tremor during slow alternating movements performed by patients with early Parkinson’s disease

The present study demonstrates that tremor can be detected during slow alternating movements (SAM) performed by patients with early Parkinsons disease (PD) and that its relative amplitude is strongly correlated with patients rest and postural hand tremor amplitudes (Rho = 0.80 and 0.61, respectively, P<0.05). However, the tremor detected during SAM did not influence the accuracy of patients because of its relatively low amplitude. These results imply that the presence of tremor during movement is not restricted to advanced PD, but can also be detected in patients with early PD having relatively low amplitude tremor. Evidence that the tremor detected at rest, during posture and during voluntary movement share similar or overlapping neural substrates is also presented.     

“The quiet necrosis”: An early medieval case of multifocal juvenile osteochondritis dissecans of the knee

Background

osteochondritis dissecans (OCD) is an ancient disease with few well-described cases in paleopathological records. Here, we report a very rare case of OCD on both lateral femoral condyles and on the lateral condyle of the right tibia in an early medieval human skeleton.

Prefrontal asymmetry in depression? The long-term effect of unilateral brain lesions

The proposal that a functional asymmetry in prefrontal cortex (PFC) may play a role in the pathophysiology of depression has sparked vigorous debate and investigation. One particularly contentious issue of clinical and theoretical importance is whether left PFC lesions are associated with the development of depression, and whether any such lesion-depression association is stable over time. To address this issue, we assessed the long-term depressive symptomotology of Vietnam veterans who had acquired left PFC lesions (n = 21), right PFC lesions (n = 18), non-PFC lesions (n = 38), or no brain lesions (n = 31) during the Vietnam War. Depressive symptoms were assessed at two different timepoints, approximately 15 and 35 years after lesion onset, respectively. There was no significant effect of PFC lesion laterality on overall depression severity at either timepoint. These data converge with previous stroke studies to suggest that PFC lesion laterality has no long-term systematic effect on vulnerability to depression.     

Instability of the “steady state” during exercise

Summary The steady state of exercise is only relatively steady; considerable fluctuation in the rate of oxygen consumption occurs from minute to minute. The standard deviations expressed in per cent of mean O₂ consumption are smallest with a moderate work load which requires a certain effort and concentration of the subject; they are greater at either extreme of work load. The instability of the steady state of exercise appears to be a normal phenomenon.This investigation was supported by research grant GM-08013 (Principal Investigator: Dr.Verne T.Inman) from the National Institutes of Health, U. S. Public Health Service.     

Does weight gain during pregnancy influence postpartum depression?

The goal of this study was to determine if weight gain during pregnancy has an effect on postpartum depression (PPD). Data were collected in a web survey from 238 women who had recently given birth. The data were analyzed for the total sample and also by body weight category before pregnancy. Findings revealed that weight gain was inversely associated with PPD for the obese women in our sample. For these women, the less weight they gained, the more likely they were to experience PPD. History of depression, partner support, and age were also predictors of PPD.     

The activity of thalamus and cerebral cortex neurons in rabbits during “slow wave-spindle” EEG complexes

“Slow wave-spindle” complexes were studied during slow wave sleep in rabbits at the thalamic (medial thalamus) and cortical (upper and lower layers of the sensorimotor cortex) levels. Slow wave complexes are biphasic positive-negative complexes or triphasic complexes with a predominantly negative component. Spindles have characteristics close to those of spontaneous sleep spindles. Complexes arise singly, as though inserted into the rhythm of spontaneous sleep spindles, or in series with periods similar to the spindle rhythm. Medial thalamus neurons and some cortical neurons had the same activity during waves as during spindles: if the neuron decreased (increased) its spike frequency in a spindle, then decreases (increases) in frequency were also seen in slow waves; if the neuron produced trains of discharges during spindles, then trains of activity were also seen from the slow-wave part of “slow wave-spindle” complexes. The membrane potential changed in a similar fashion: on a background of hyperpolarization which started at the slow wave, individual depolarization oscillations appeared in the EEG wave rhythm; these oscillations were not always accompanied by spike trains. The slow wave mechanisms, the rhythms of isolated complexes and simultaneous complexes and spontaneous sleep spindles may share a common underlying mechanism: slow, cyclical variations in excitability in thalamocortical neuronal networks, which have previously been demonstrated for spindle-likes activity. The possibility that there are common mechanisms for slow waves in complexes and other EEG slow waves, particularly δ activity, remains hypothetical. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 84, No. 3, pp. 182–190, March, 1998.     

The suppression of the μ rhythm during the creation of imagery representation of movement

The aim of this study was to answer the following question: are there differences between the attenuation of μ rhythms, recorded with EEG in the parietal area during observation of movement and the creation of its imaginative representation? In addition, we checked the extent to which the μ rhythm suppression depends on whether the observed and the imagined movement is performed by a human or is artificial. As a result of the experiment a significant difference in μ rhythm suppression between the conditions “Observation,” “Imagery,” and “White noise” was recorded. It did not matter whether the motion was carried out by a human being or performed by a machine. The results are discussed in the light of findings which relate to the mirror neuron system.