Methods were established for the detection of parvovirus DNA in human serum using single-stranded RNA probes. The sensitivity of detection of virus using 32P-radiolabelled RNA versus non-radiolabelled biotinylated RNA probes using a streptavidin-polyalkaline phosphatase detection system was compared. Virus was detected using 32P-labelled and biotinylated RNA probes at serum dilutions of 10(-3), equivalent to approx. 3 pg of viral DNA. Using biotinylated RNA probes and a dot-blot system, diagnosis of numerous serum samples could be performed within 8 h of receipt of samples, using an RNA probe which was synthesised and stored at -20 degrees C for up to 12 months without loss of sensitivity. Our work demonstrates the potential of biotinylated RNA probes in the routine analysis of viral sequences in serum.

DNA, Viral↗

PubMedDate not supplied

Kinematics of arm movements in elderly humans.

Changes in the kinematics of arm movements with age were studied. "Young" (aged 21-23) and "elderly" (aged 68-95) subjects performed a visually guided, step tracking task. Each subject performed movements of eight different amplitudes (10-80 deg) at two volitionally determined speeds ("own speed," "fast and accurate"). Movement durations and maximum velocities were similar for both groups and increased with movement amplitude under all conditions. The young subjects made movements in which approximately the same length of time was spent in accelerating as in decelerating the movement. In contrast, movements by the elderly subjects were temporally asymmetrical, the deceleration phase being longer than the acceleration phase. The ratio of maximum to average velocities (Vm/Vav) was markedly different between the young and elderly subjects, particularly in the smaller amplitude movements (less than 40 deg). Values of this parameter ranged from 1.5 to 6 in the elderly subjects. Movements made by the elderly subjects were more variable than those of the young subjects, particularly so at smaller amplitudes. Variability was most apparent in the deceleratory phase of movement where the elderly subjects often showed hypermetria. Some elderly subjects also showed movement decomposition, the movements being made as a series of discrete submovements. Thus, the elderly subjects displayed some of the characteristics classically described as arising from cerebellar dysfunction.

Adult↗

PubMedDate not supplied

Lung function in older humans: the contribution of body composition, physical activity and smoking.

An allometric model was used to determine the important factors related to the decline in forced expiratory volume (FEV1.0) across ages 55-86 years in independently living men and women. Measurements were available from a randomized sample of 181 men and 203 women residing in London, Ontario, Canada. The effects of height, age, sex, adiposity, fat free mass (FFM), grip strength and physical activity (PA) on FEV1.0 were assessed using an allometric model to test the hypothesis that sex differences in lung function would be due in part to sex-related differences in the aforementioned variables and would therefore be eliminated by our analysis. The following model was linearized and parameters were identified using standard multiple regression: FEV1.0 = height(beta1) x FFM(beta2) x grip strength(beta3) x PA(beta4) x exp(beta0 + beta5age + beta6sex + beta7smoking + beta8%body fat) x epsilon. Results indicate that the amount of FFM and heavy intensity physical activity participated in by the elderly may be more important in influencing forced expiratory function than previously recognized. In addition, results from this study have confirmed the importance of age and height in the prediction of FEV1.0 and demonstrated a negative effect of smoking on lung function. Individuals with a greater FFM and physical activity level tended to be associated with an above average lung function performance. The cross-sectional rate of decline in FEV1.0 determined from our model was approximately 12% per decade.

Aged↗

PubMedDate not supplied

Body mass indices and skeletal size in 394 Canadians aged 55-86 years.

Demispan (finger web to midline) is the preferred index of stature in the study of the elderly where height is unreliable because of age-related loss or distortion. As a consequence, two alternative mass indices, Demiquet (male mass. demispan-2) and Mindex (female mass. demispan-1), have been proposed for use in the elderly, in place of body mass index calculated from height, which might be suspect. These gender-specific indices reflect the squared and linear relationship of height to mass in men and women respectively. To assess the independence of Demiquet and Mindex from stature and the reliability of demispan, height, demispan (second fingerweb to midline), and mass were recorded in a random sample of independent Canadian men (182) and women (212) aged 55-86 years. Both Demiquet and Mindex were highly correlated with mass, r = 0.81 (p = 0.001) and r = 0.96 (p = 0.001), respectively. In both gender groups these mass indices were independent of height and demispan. The demispan within- and between-observer errors were small -0.04(-0.16 to 0.08)cm and -0.09(-0.22 to 0.03) cm and the between-observer intraclass correlation estimate of reliability was 0.96 (lower-bound one-sided 95% CI 0.90). Demispan is a reliable and reproducible measure of stature in the elderly. Demiquet and Mindex are useful mass indices, independent of stature and suitable for use in the study of the elderly where the use of mass indices based on height may be questionable.

Aged↗

PubMedDate not supplied

Cardiovascular fitness in a selected group of dentists.

Thirty-three dentists were studied as part of an exercise rehabilitation clinic in order to evaluate their cardiovascular capacity and coronary prone risk factors. Measurements were made of their physical work capacity, predicted maximal oxygen uptake, fatness, serum lipids and uric acid levels, pulmonary peak flow rates and personality Type A or B. The group as a whole exhibited a moderately high level of fitness and a very active life style which probably reflected their presence at a clinic of this type. Cardiovascular fitness varibles increased with age. This increase may be due to a need and desire on the part of the dentists to maintain their physical fitness as they become older. This need for improved self image may also be a factor in their joining an exercise rehabilitation clinic.

Adult↗

PubMedDate not supplied

An outcome measure to quantify passive stiffness of the ankle.

The primary aim of this research project was to develop a method to quantify a specific variable of neuromuscular function, passive stiffness of the ankle. It was then used to determine if values for the outcome measure varied with age and sex in a sample of elderly men and women between 55 and 85 years old. Subjects were screened for medical conditions contraindicative to testing, e.g. severe arthritis, other history of bone or muscle disorders, ankle fracture, neural disorder causing spasticity or contracture. A rotatable footplate which recorded position and resistive torque with a potentiometer and strain gauge, respectively, was linked to an electric, computer-controlled torque motor. Passive elastic stiffness, defined as the slope of the passive resistance curve at 10 degrees dorsiflexion (in N.m/degree), was greater in males, (p < .001), and increased with age (p = .002). There was a significant effect of age group on passive range of motion (ROM) values for ankle dorsiflexion (p < .001), but also a significant sex by age interaction (p = .001). Females showed a large drop from a mean of 19.3 degrees +/- 3.2 in the youngest group (55-60 yr) to 12.1 degrees +/- 5.5 in the 81 to 85 yr olds. Corresponding mean values for the middle-aged males were 15.4 degrees +/- 4.3 versus 13.1 degrees +/- 3.5 of dorsiflexion in the group of 81 to 85 yr old men. It was concluded that passive ROM of the ankle into dorsiflexion showed decreases in the elderly, which seemed to reflect less complaint tissue structures.

Aged↗

PubMedDate not supplied

Clinical value of krypton-81m and technetium-99m perfusion lung scanning.

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Humans↗