Search PubMed⌕ Search

Biomedical subjects

M J Roede

Publications and source records attributed to M J Roede.

7 recordsLinked to original sources
PubMed1978

Nuclear area and sex chromatin frequency in oral mucosa and hair root sheats of human females.

In 36 oral mucosa and in 25 hair root sheath slides nuclear area was measured in about 100 nuclei per slide. Within one slide no differences were found in nuclear area between nuclei with or without sex chromatin, or with a non-peripheral sex chromatin. No correlation was found between nuclear area and sex chromatin frequency, except for a weakly significant negative correlation between nuclear area and those nuclei without either peripheral or non-peripheral sex chromatin.

Adult↗
PubMed1977

A Monte Carlo test of weight as a critical factor in menarche, compared with bone age and measures of height, width, and sexual development.

The correlation coefficients for each of nine traits measured at menarche (bone age, pubic hair and breast stages, and five physical measurements) have been calculated. These have been compared with the corresponding correlation coefficients obtained by using a Monte Carlo technique, where the ages of menarche are randomly redistributed over the sample. The difference between the random and actual results are most pronounced for bone age, sitting height and the development of pubic hair and breasts, showing that these characteristics may indeed be critically related to menarche, while the same differences for weight, height, sitting height/height, and biacromial and bi-iliocristal diameters show that these latter are only moderately related to menarche. These results do not support the exclusivity of body weight as a critical factor in menarche (critical body weight hypothesis).

Adolescent↗
PubMed1977

Sex chromatin scores in oral mucosa and hair root sheaths of human females.

The preparation and the utility of oral mucosa and hair root sheaths for quantitative sex chromatin studies is discussed. In buccal smears requirements for reliable scoring are frequently not fulfilled. Counting is time-consuming and disturbing measurement errors cannot be avoided. On the other hand, hair root sheath slides can be quickly prepared, the method yields preparations of good quality, and sex chromatin is displayed with considerable clarity. This procedure thus provides a high degree of accuracy and simplicity and counting can be quickly done with a relatively small measurement error. The incidence of sex chromatin in hair nuclei is observed to be about 20 per cent higher than in oral mucosa of the same female. In hair root sheaths non-peripheral sex chromatin can easily be recognized; including these into the scores significantly increases the actual incidence of sex chromatin positive nuclei.

Adult↗
PubMed1976

Estimation of growth velocities from individual longitudinal data.

Since the construction of growth velocity curves using the simple increment method (i.e., plotting the increments deltaxt vs, time, t) involves a number of methodological problems, when mathematical curves are fit, they are generally fit to the "distance traveled", plot (of xt vs. t) and the corresponding velocity curve is then obtained by differentiation. However, most of the traditional methods for accomplishing this (e.g., fitting the Gompertz or logistic curves) require that the course of growth be studied over a sufficiently long time period to allow accurate determinations of the upper and lower asymptotes of these S-shaped functions. This is not always feasible in practice: a case in point being the mixed-longitudinal Nijmegen Growth Study where each of the cohorts comprising the sample is followed for but a five-year period. In such situations, alternative approaches to the problem of constructing growth velocity curves may be of considerable practical as well as theoretical interest. One such approach is developed in this paper and its use is illustrated on some data collected as part of the Nijmegen Growth Study. These results are then compared with those obtained using the increment method on the same data.

Adolescent↗