Physical activity improves gaze and posture control in the elderly

Ageing is associated with a decrease in the quality of balance regulation, in particular through dysfunctions of gaze control and postural stabilization, which results in an increased risk of falling. Conversely, the practice of physical and sporting activities has been shown to improve every level of postural regulation. This study is to assess the effects of the practice of physical activities on vestibulospinal reflex and ocular movements of visual and vestibular origins in elderly people. Gaze control and posture stabilization were evaluated in 13 healthy aged women who regularly practised physical activities and in 13 healthy aged sedentary women of a similar age, by dynamic posturographic test with electromyography, as well as electronystagmography with caloric and rotational vestibular tests, ocular saccades, smooth pursuit and optokinetic tests. The gaze and posture control performance of the active group was better; the proprioceptive and vestibular sensitivities were higher, visual detection quality was good, and reaction time was low. Regular physical activity develops or maintains the efficiency of the reflexes involved in postural control, especially through adequate neurosensorial information, which allows the central integrative structures to generate a more appropriate motor response.     

Physical activity, aerobic fitness, and seven-year changes in adiposity in the Canadian population.

Associations among baseline physical activity, aerobic fitness, changes in physical activity, and 7-y changes in adiposity were determined. The sample consisted of 602 males and 644 females, aged 20-69 y, from the 1981 Canada Fitness Survey and the 1988 Campbell's Survey. Questionnaire-derived measures of physical activity level consisted of activity energy expenditure (AEE) and time spent on physical activity. Participants were grouped into physical activity level categories by AEE and physical activity intensity (based on MET values), and physical activity level changes were determined from movement between tertiles of AEE from baseline to follow-up. Aerobic fitness levels at baseline were determined using the Canadian Aerobic Fitness Test. Changes in body mass, the sum of five skinfolds (SF5), and waist circumference (WC) were used as indicators of adiposity change. ANCOVA and multiple regression analyses indicated that neither baseline physical activity levels, intensity, physical activity change categories, nor aerobic fitness levels were significant predictors of changes in adiposity. In conclusion, physical activity was not predictive of 7-y changes in indicators of adiposity in this sample.     

Trophic action of pharmacological substances with a guanidine group on mouse neuroblastoma cells and chick ganglionic neurons in culture

A series of substances (designated CTQ compounds) with a guanidine group have been synthesized and tested for their ability to promote neuronal survival and neurite outgrowth. Mouse neuroblastoma clonal cell lines grown in serum-containing medium for 10 days as well as primary cultures of embryonic chicken ganglion neurons grown in serum-free defined medium for 1 or 2 days have been used for the experiments. Among the various CTQ compounds (CTQ1–CTQ20) tested, only CTQ8 exerted positive neurotrophic effects on these peripheral neuronal cells. At a concentration of 10⁻⁴ M, CTQ8 enhanced neuritogenesis of neuroblastoma cells. However, the most striking influence of CTQ8 was its promoting effect (6- to 10-fold) on the survival of chicken ciliary and dorsal root ganglionic neurons at concentrations ranging from 10⁻³ M to 5×10⁻⁴ M.     

An “all-season” mammoplasty

A reduction mammoplasty must produce a reduction in volume, a natural lasting shape, and minimal residual scarring. Many attempts to achieve this goal have been developed in recent years. The author described, in 1970, a vertical technique achieving an important reduction and a good shape but with the appearance of the end of the vertical scar below the brassiere line. In 1977, the author [3] modified the technique by the adjunction of a small horizontal scar to eliminate the inconvenience of the visible part of the vertical scar. In this article the author describes his technique which appears to be suitable for most types of breast deformities.     

Penetration of teniposide (VM-26) into human intracerebral tumors

Thirty-four consenting patients received VM-26 50–100 mg/m² I.V. before surgical resection of intracerebral tumor, and drug was measured using a high pressure liquid chromatographic technique. Sufficient tumor for analysis was obtained from 29 patients. Brain metastases (13 patients) had higher concentrations of V M-26 than did gliomas (13 patients). Concentrations were comparable in brain metastases and meningiomas (3 patients). Prolonged (24 h) infusion of V M-26 did not appear to result in higher tumor drug concentrations in 5 patients than did rapid (1 h) infusion in 24 patients. Pretreatment with Amphotericin-B 10 mg/m² 12 h and 1 h before VM-26 did not appear to have any effect on VM-26 uptake into 4 intracerebral tumors, although data were limited, and VM-26 concentrations were very high in 1 metastasis. Pretreatment with oral glycerol 500 mg/kg 18 h, 12 h, 6 h, and immediately before I.V. VM-26 may have resulted in increased penetration of VM-26 into 9 tumors, although confirmation is required. Amphotericin-B, glycerol, and operative conditions did not appear to alter VM-26 plasma pharmacokinetics.VM-26 4-demethylepipodophyllotoxin 9-(4-6-O-thenylidene-B-D-glucopyranoside) - VP-16 4-demethylepipodophyllotoxin 9-(4-6-O-ethylidene-B-D-glucopyranoside) Presented in Part at the 74th Annual Meeting of the American Association for Cancer Research, San Diego, California, May 25–28, 183(1).     

Dopamine in the conscious dog with chronic heart-block

Summary The chronotropic effects of dopamine were studied in the conscious dog with chronic A-V block. Dopamine at 12.5–200 g/kg and 12.5–50 g/kg/min lowered atrial rate independently of dose. After blockade of muscarine receptors or alpha-adrenoceptors, it raised atrial rate. After blockade of dopamine receptors, dopamine still lowered atrial rate, and did so dose-relatedly after blockade of beta-adrenoceptors. It raised ventricular rate, and at high doses also induced ventricular rhythm disorders. Blockade of muscarine receptors enhanced the ventricular cardioaccelerator effect of dopamine (P<0.025) at 100 g/kg, while blockade of alpha-adrenoceptors reduced it (P<0.05). Blockade of dopamine receptors did not modify this effect, but blockade of beta-adrenoceptors reversed it. Dopamine at 25–200 g/kg raised mean blood pressure. This effect was enhanced by blockade of muscarine receptors, reversed by blockade of alpha-adrenoceptors, and was unaffected by blockade of beta-adrenoceptors or dopamine receptors. These results show that the atrial cardiomoderator effect of dopamine is a vagal reflex response to its hypertensive action, and that it is limited by its direct beta-adrenergic stimulating action. They also show that the ventricular cardioaccelerator effect of dopamine is attenuated by a reflex vagal depressor effect consequent to the induced hypertension. No evidence was found for the existence of positive chronotropic dopamine receptors in either atria or ventricles.A preliminary report of these findings was presented at the Symposium on Peripheral Dopaminergic Receptors, July 1978, in Strasbourg, France (Boucher et al. 1979b)