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Biomedical subjects

J J Koval

Publications and source records attributed to J J Koval.

17 recordsLinked to original sources
PubMed1992

Age and sex effects on mobility of the human ankle.

We investigated whether values for passive resistive torque, dorsiflexion strength, and active mobility of the ankle joint varied with age in a randomly selected sample of middle-aged and elderly males and females. The main effects of sex and age group were significant, without an interaction effect, on values for passive resistive torque and voluntary strength. The trends indicated that females had lower values for both variables and that passive torque increased and strength decreased with respect to age. Dorsiflexion range of motion also showed a highly significant trend to decrease across age groups, and more so for females than males. Mean values for middle-aged men vs old men went from 20.0 to 13.5 degrees, while corresponding values for women decreased from 20.7 degrees of dorsiflexion to 10.1. Functional ankle movement thus becomes limited with age, but could be improved by strengthening weak dorsiflexor muscles.

Aged↗
PubMed1992

Forced expiratory volume, height, and demispan in Canadian men and women aged 55-86.

In a random cross-sectional study in London, Canada, forced expiratory volume in 1 second (FeV1.0), height, and demispan (fingerweb to central sternal notch) were measured on 182 men and 212 women of mean ages 70.4 (SD 8.5) and 71.3 (8.2). The mean FeV1.0 for men was 2.55 (0.66) l, and for women 1.80 (0.48) l and declined 29 ml.year-1 and 25 ml.year-1, respectively. The mean FeV1.0 standardized for measured height and calculated height for men was 2.54 (0.61) l and 2.55 (0.62) l in men, and 1.80 (0.46) l and 1.79 (0.45) l in women. There was no significant difference between the two methods of standardization, and the relationship of height to demispan in this independent elderly population was constant across age for both men (2.16) and women (2.17). Linear and proportional regression coefficients to predict FeV1.0 from height and demispan have been generated for this random sample aged 55 to 86 years.

Aged↗
PubMed1992

Response rates in a survey of physical capacity among older persons.

A representative sample of 420 subjects aged 55 to 84 was sought for participation in a study of the relationship between physical activity and health. A stratified random sample with 35 subjects in each of 12 age-gender categories was designed, using lists generated consecutively until the target number for each category was reached. Although the protocol required walking and treadmill tests, 60.3 percent of those eligible participated, a figure comparable to that of NHANES II and superior to that of the Canada Fitness Survey. Participants were younger, more likely to be male, less likely to be currently married, and more likely to have had a white-collar job and some postsecondary education than were nonparticipants. Difficulties of obtaining subjects and methods for avoiding these difficulties include offering many opportunities to attend and determining accurately the reason for nonparticipation.

Age Factors↗
PubMed1984

Testing the effect of sex differences on sib-sib correlations.

Procedures for testing the effect of sex differences on sib-sib correlations are studied. It is demonstrated that a simple procedure for testing the equality of a pair of brother-brother and sister-sister correlations (the modified Z test) is comparable in power to the likelihood ratio test in moderately large samples drawn from sibship-size distributions that are likely to occur in practice. In small samples, the modified Z test is preferable to the likelihood ratio test, since the latter tends to be anti-conservative.

Biometry↗
PubMed1983

Clinical correlates of the spectrum of lung microvascular injury in human noncardiac edema.

We measured the clearance from blood to pulmonary edema fluid of a small molecular weight hydrophilic radiotracer, Indium-111-DTPA (In-DTPA) and a larger molecular weight radiotracer, Iodine-125-HSA (I-HSA), in patients with pulmonary edema on either a cardiac or noncardiac (permeability) basis. In previous investigations, we had noted an apparent relationship between the magnitude of clearance of I-HSA across the alveolocapillary membrane and the severity of noncardiac pulmonary edema. In this study, we were able to distinguish at least 2 distinct groups of patients with noncardiac pulmonary edema. Patients with the greatest damage to the alveolo-capillary exchanging membrane, defined by the flux of I-HSA from blood to edema fluid, were significantly differentiated from those with a lesser microvascular injury on the basis of higher mean heart rate (HR), temperature, cardiac index (CI), pulmonary artery pressures, right ventricular stroke work index (RVSWI), and a lower mean total white blood cell count (WBC), among others. Therefore, noncardiac pulmonary edema is characterized by a spectrum of permeability injury to the pulmonary microvasculature which seems to parallel other measurable indices of the severity of the systemic response to the illness.

Cell Membrane Permeability↗
PubMed1983

Variance-component estimation from human sibship data.

The large-sample relative efficiencies of the analysis-of-variance (ANOVA) estimators of variance components and the intraclass correlation coefficient rho are investigated for the unbalanced single classification in the context of family studies. The efficiency of an analysis based on the method of unweighted group means is also investigated. From a Monte Carlo study which generates the group sizes from typical family-size distributions it is found that the relative efficiency of the ANOVA estimators of the between-group variance component exceeds 95% for values of .2 less than or equal to rho less than or equal to .4, but can fall below 60% for values of rho that are very close to zero. For the estimation of the between-group variance component the method of unweighted means tends to be preferable to the ANOVA method only if rho greater than .5.

Analysis of Variance↗
PubMed1982

Design considerations in the estimation of intraclass correlation.

The design of family studies to estimate the value of an intraclass correlation coefficient p is considered when ni individuals are to be selected from each of k families, i = 1, 2, ..., k. In particular, the accuracy of a balance design (ni = n, i = 1, 2, ..., k) for estimating p is compared with the accuracy of an unbalanced "natural" design, in which the ni are sampled at random from family size distributions that tend to occur in practice. It is found for two different estimators of p that the balanced design is usually preferable, but only to a small degree if the number of families sampled is greater than 50.

Epidemiologic Methods↗
PubMed1982

The effectiveness of an electro-ionizing toothbrush in the control of dentinal hypersensitivity.

The object of the investigation was to test the value of the 3M Brand Electro-Ionizing Toothbrush in the treatment of dentinal hypersensitivity. Eighty-eight volunteers were divided into three groups, each using different methods: (I) stannous fluoride dentifrice and 3M brush without a battery; (II) stannous fluoride dentifrice and 3M brush with a 1 1/2 volt battery; and (III) strontium chloride dentifrice and 3M brush without a battery. The volunteers brushed their teeth for 3 minutes twice a day for 12 weeks using one of the three test agents. The subjects were tested at weeks 0, 2, 4, 8 and 12 by means of a cold water spray quantitated by a temperature probe. All three groups experienced improvement and by week 12 Groups II and III displayed much less sensitivity than did Group I. At the end of the 12 weeks the subjects were questioned as to benefit of treatment. The questionnaire revealed that stannous fluoride with the ionizing brush provided significantly greater relief than did the stannous fluoride alone.

Adult↗
PubMed1981

A multivariate analysis of family data.

The authors describe the application of multivariate analysis to the problem of estimating intra-family correlations and testing them for statistical significance. This is illustrated by a re-analysis of survey data collected by Miall and Oldham (Clin Sci 1958;17:459-87) on the familial aggregation of blood pressure. The multivariate analysis provides collective tests of significance for parent-child and child-child correlations based on likelihood ratio theory, and maximum likelihood estimates for individual intra-family correlations.

Blood Pressure↗
PubMed1978

The effect of chemical fixatives on cell walls of Bacillus subtilis.

Cell walls of Bacillus subtilis were treated with several chemical fixatives which are commonly used preparatory to electron microscopy; i.e., osmium tetroxide, formaldehyde, acrolein, crotonaldehyde, and glutaraldehyde. Dimensional analysis was performed on thin sections of fixed walls from plastic embeddings and, by means of the statistical technique of multiple comparisons, significant differences were found between wall thicknesses from the various fixations. These differences varied with the fixation time and the type of fixative used in the reaction. When compared to embedded walls which had been stained before fixation, the overall effect was a reduction in wall thickness which was attributed to fixative action and not to the embedding or staining processes. The reduction of wall thickness was even more apparent when dimensions of fixed walls were compared to published dimensions of both frozen sections and freeze-etch profiles. Since these fixatives bind to reactive sites within the wall fabric, a change in electrochemical charge density is effected which can be monitored in terms of heavy-metal-binding capacity. Most monoaldehyde fixatives and osmium tetroxide render the wall as reactive, or less reactive, to uranyl acetate as unfixed walls, whereas glutaraldehyde can significantly increase the binding capacity.

Acrolein↗
PubMed1977

The relation of clinical and laboratory findings to the survival of patients with macroglobulinaemia.

The relation of clinical and laboratory findings at the time clinical presentation to subsequent survival was investigated in 204 patients with macroglobulinaemia. It was found that the ten following clinical and laboratory parameters were of prognostic significance and a further twelve were not. The best prognoses were found amongst male patients, patients aged 50-69 years and those with serum IgM paraprotein concentrations of 20-39 g/1, type lambda paraproteins, no Bence-Jones proteinuria or cryoglobulinaemia, only one paraprotein, serum cold haemagglutinin activity, serum albumin above 40 g/1 and serum urea below 10 mmol/1.

Adolescent↗
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↗