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Biomedical subjects

P Rother

Publications and source records attributed to P Rother.

At least 19 recordsLinked to original sources
PubMed1990

[Quantitative analysis of cell density and pattern of chondrocytes in transitory hyaline cartilage anlagen of human tarsal bones].

Changes in the distribution patterns of chondrocytes in the embryonic transitory hyaline cartilage of the tarsus were studied using 56 sagittal section of tarsi from 28 human embryos, with a vertex-foot length from 7.0 to 44.0 cm. The os naviculare and os cuboideum were not sliced in all sections. A total of 93,931 cells were transferred via a mirror to paper, and the resulting patterns were analyzed. Determinations included the numerical surface and volume density of the chondrocytes and the cell distribution patterns using the dispersion index. In the case of the calcaneus, talus, os naviculare and os cuboideum, the number of sliced cells found over a constant area decreases at a continuous linear rate in the course of the embryonic period. In all tarsal primordia the distribution pattern developed from regular to random. Particular conditions prevail immediately below the perichondrium and near the ossification centers which can be found in the calcaneus from the 6th month onwards.

Ankle↗
PubMed1990

[Behavior of adiposity indices in relation to body weight and height between the ages of 3 and 17 years].

We studied the coefficients of correlation between weight and height and four adiposity indices (weight/height 0,5; weight/height; weight/height2; weight/height3), year to year, in 1676 schoolchildren of both sexes (663 boys and 1,013 girls), aged between 3 and 17 years. Weight-for-height index should be uncorrelated with height and highly correlated with weight. In our study, Quetelet index (w/h2) in females and Rohrer index (w/h3) in males, are independent from height. Between two indices, Quetelet index had better correlations with weight.

Adipose Tissue↗
PubMed1990

[Morphological studies of postnatal changes of the sound transport apparatus in the middle ear of humans and rabbits].

The dimensions of the tympanic membrane and middle ear ossicles, respectively, were measured, in order to investigate the postnatal development of sound transport function. In human we observed only a small increase of the tympanic membrane area between the 7th postconceptional month and the 32nd year of life. This growth has no functional effect on the sound transport. In contrast, in rabbits all measured parameters with the exception of the stapes plate area show an increase until the 12th day of life. Thus, the amplification factor doubles in this species during the first 2 weeks of life. The temporal parallelism of the middle ear development with the ontogenesis of the acoustic function seems to exist in humans, but does not in rabbits.

Adolescent↗
PubMed1989

[Comparison of three histometric methods for the comprehension of stimulating effects on the rat thyroid gland].

There exist some histometric methods for the morphological quantification of different strongly stimulating effects on the thyroid gland induced by drugs and/or other chemical substances in dependence upon dose and duration of application. But in respect of technical and temporal expense and also diagnostic statement, there are considerable differences between these recording procedures. Therefore we examined the 3 mostly used methods synchronously (i.e. determination of thyroid epithelial cell height, nuclear volume in thyrocytes, and estimation of relative volume parts in the thyroid gland by the point counting method) by investigating the thyroid glands of methylthiouracil-(MTU)-stimulated rats and corresponding controls in order to compare the diagnostic value and temporal expense. The largest temporal expense was required in the nuclear volume determination, the smallest in the point-counting method. On principle, all 3 procedures allow the determination of hypertrophic alterations but only by help of the point-counting method, also hyperplastic changes are recognizable. By nuclear volume determination, we found significant differences between central and peripheral parts of the thyroid gland. Therefore, to avoid the subjective error, it will be necessary to measure a large number of nuclei in many planes of the gland. Also the determination of epithelial cell high reinforces the subjective error because of the heterological structure especially in unstimulated thyroid gland. If the number of counting points is exactly determined and, full of sense, limited, the point-counting method allows a nearly complete measuring of the whole object to be tested within an acceptable investigation time. In this way, the heterological structure of thyroid gland will be regarded, and comparability and reproducibility are guaranteed on an high level.

Animals↗
PubMed1989

[Age changes of functional nuclear swelling and classes of nuclei in human hepatocytes].

The aim of the study was to describe aging changes in the functional nuclear edema and the classification of human hepatocyte nuclei, by determining three parameters--the size of the nucleus, the relative DNA quantity and the number of chromocenters. For this purpose, karyometry and DNA cytophotometry were performed on 10 human liver preparations. The data obtained was subjected to correlation, cluster and discriminance analysis. The results indicated a reduction in the capacity of liver cells for functional nuclear edema as aging progressed. Whereas at a young age there is only a loose correlation between nuclear size and DNA content, it becomes much stricter later on, partly caused by polyploidization. Cluster analysis, followed by discriminance analysis, is well suited for dividing the nuclei of human hepatocytes into two or three statistical populations provided the nuclear area, DNA quantity and number of chromocenters are all used as characteristics simultaneously. When allowance is made for functional edema, the biological interpretation of clusters from young liver preparations permits meaningful conclusions, but it appears problematic for old preparations. Here it might be more practical to analyze the mixed distributions resulting from a determination of the DNA quantity or nuclear size alone.

Aging↗
PubMed1989

[Random sample planning in morphometry].

This report tries to explain principles and presuppositions of planning sample sizes. The aim is estimation of the optimal, that means minimally necessary sample size, justifying an investigation ethically and economically. The problems are complicated because of the necessity of nested sampling or samples within samples. We describe the most important presuppositions using an example of mean value estimation. These are: establishing of demands for exactness, of error probability, and knowledge of variance of the parameters. It is explained in detail by means of binomially distributed variables as we find them in the point counting method.

Humans↗
PubMed1989

[Quantitative analysis of chondrocyte distribution patterns in hyaline cartilage tissue--a comparison of different models].

The purpose of our investigations were aging changes in hyaline cartilage of the trachea and of the larynx. 42 samples of carina tracheae and 29 samples of arytenoid cartilage were used in both organs from the newborn age up to the age of 91 a. We have examined patterns of cell distribution with the help of the computer programme "Dichte" ("density") using the following methods of stochastic geometry: product density, L function, and others. Product density allows for a reliable destination between a regular pattern of cells (hard-core distribution), a random pattern (soft-core distribution), and a typical clustering of chondrocytes. 2 examples of arytenoid cartilage have been selected to demonstrate the possibilities of interpretation of product density supported by the L function. Soft-core and in few cases hard-core distribution have been found both with the carina tracheae and the cartilago arytaenoidea in the 1st decade of life. Beginning with the 2nd decade of life, the typical clustering of chondrocytes have been confirmed with both organs.

Aging↗
PubMed1986

[Biostatistical models in experimental gerontology].

Morphometric measuring values present themselves in a definite distribution which changes in the ageing process. This change of distribution can be clarified by distribution analyses. Another task within the analysis of frequency distributions is the decomposition of mixed distributions, as they may appear in various parameters in the course of life. The linear regression analysis is, for instance, to be used in the verification of sexual divergencies in the process of ageing. An adaptation of non-linear exponential functions to series of measuring values serves, among others, to make evidence concerning the ageing rapidity of the tissues. When in gerontological inquiries at the same time many different characteristics are determined also the degree of their ageing dependency is of interest. This is to be established by means of a special transformation within the factor analysis. Finally the study shows instances for the application of contingency tables in qualitative characteristics and the investigation of their frequency in the process of ageing as well as for the use of the cluster analysis.

Adolescent↗
PubMed1986

[Discussion of errors and measuring strategies in morphometry using analysis of variance].

Statistical techniques known as the analysis of variance make it possible for the morphologist to plan work in such a way as to get quantitative data with the greatest possible economy of effort. This paper explains how to decide how many measurements to make per micrograph, how many micrographs per tissue block or organ, and how many organs or individuals are necessary for getting an exactness of sufficient quality of the results. The examples furnished have been taken from measuring volume densities of mitochondria in heart muscle cells and from cell counting in lymph nodes. Finally we show, how to determine sample sizes, if we are interested in demonstration of significant differences between mean values.

Analysis of Variance↗
PubMed1986

[Computerized tomography studies of normal morphology and volumetry of parenchymatous epigastric organs in humans].

Variations in the area and dimensions of the liver and spleen in the craniocaudal direction show a similar behaviour despite individual differences in the size and shape of the organs. The liver has its largest areal extent in the upper half of the organ. In the case of the spleen, it is not possible for the largest areal extent to be assigned to a particular region of the organ. The 5-type liver classification of FROMMHOLD and KOISCHWITZ (1982) provided the basis for a study of the frequency distribution of those types among a total of 116 organs. Type 2 (location of the greater part of the liver to the right of the vertebral column) was found to be the most frequent type, whereas type 5 (left lobe of the liver larger than the right one) could not be found. Of the 183 splenic organs included in these studies, 21% showed lobulation and 6%, an accessory spleen. The morphological studies of 334 adrenal glands enabled the most frequent variants of form to be represented summarily. The determination of liver dimensions, which was done on 37 organs, yielded a mean value of 16.6 cm for the craniocaudal extent, 15.5 cm for the dorsoventral extent, and 16.6 cm for the lateromedial extent. From the examinations performed on 38 individuals it was possible to determine a mean value of 11.1 cm for the craniocaudal extent of the spleen, 11.8 cm for the anatomical length of the spleen, 10.4 cm for the width of the spleen, and 4.2 cm for the thickness of the spleen. The mean value of the width of pancreas was 20.5 mm at the head, 19.6 mm at the corpus, and 18 mm at the tail. The mean length of pancreas was of the order of 129 mm. These results were obtained from examinations made on 96 pancreatic organs. Evaluation of a total of 200 computer tomograms yielded mean values of 22 mm for the length. 14 mm for the width, and 5 mm for the leg thickness of the left adrenal gland. The respective mean values obtained for the right adrenal gland were 28 mm, 9 mm, and 4 mm respectively. Determination of the volume of liver on 37 organs yielded a mean value of 1,331 cm3. For the spleen, examinations performed on 38 organs showed the mean volume to be in the order of 169 cm3. For the volume of pancreas, a mean value of 40.4 cm3 was determined.

Adrenal Glands↗
PubMed1985

[Types of error and error propagation in morphometry].

It is in morphometry, too, that errors of measurement are liable to occur. This paper shows the types of error involved and how they may propagate when the primary measuring data are used for the calculation of further quantities of interest. Finally, there is shown the relation of inaccuracies due to measuring errors to the uncertainties of a particular result which have their origin in biological variability. The examples furnished have been taken from histological volumetry using the target method, from karyometry, and from osteometry.

Biometry↗
PubMed1985

[Proportions of the femur and humerus in relation to bone length].

Taking as a starting point the known fact that the vertical proportions of man are dependent upon stature, a study has been made to investigate if the relations between individual segments of long tubular bones are also dependent upon overall bone length. For these investigations, use was made of 356 human femurs of unknown sex, which were obtained from the bone collection of the Institute of Anatomy (Kurp 1979), and 70 human humeri of known sex (Kropf 1979), which were obtained from the Institute of Forensic Medicine and Criminology, Karl Marx University at Leipzig, and which had already been measured in connection with problems of forensic osteology. There were established relations between defined partial lengths, with the most suitable ones being selected and represented graphically. The severity of relationship was additionally determined by means of correlation and regression analyses, respectively. It was possible to show that the relative proportion of segment no. 4 (distance between the proximal point of the intercondylar fossa of the femur and the distal point of the medial condyle of the femur) and segment no. 5 (distance between the proximal point of the greater trochanter and the midpoint of the lesser trochanter) constantly decreases with the overall length of the femur. The quotient of diaphysial size and bone length decreases as the length of the humerus increases. The proportion of compacta in the total cross-sectional area in the mid-diaphysis becomes greater and greater as the length of the humerus increases. The total cross-sectional area and the compacta cross-section area in the middle of the humeral diaphysis tend to change with the overall bone length in that longer female and male humeri have larger total cross-sectional and compacta cross-section areas than shorter humeri of the same sex.

Anthropometry↗
PubMed1979

[Histometric volume determination in aging human thyroid glands and possible errors of this method].

We made histometric volume analyses of hematoxylin and eosin stained paraffin sections of 43 human thyroid lobes by means of the electric integrating apparatus Eltinor 4 A (Optische Werke Rathenow). We investigated ageing changes of the relative amounts of epithel, colloid and connective tissue in the total volume. The volume density of colloid rises up to the 3rd decade, thereafter it shows a small decrease. On the contrary, the amount of epithelial cells decreases until the 3rd decade. The data concerning connective tissue exhibit an increasing trend up to senility. During such measurements errors appear, which are called, among others, total error, systematic and statistic error. We estimated these errors and demonstrated possibilities of their diminution.

Adolescent↗
PubMed1978

[Investigations on the aging processes of the humerus by means of histomorphometry, regression and factor analysis (author's transl)].

Histomorphometric measurements were made on bone sections prepared from osseous material removed from the diaphysial center of 70 macerated humeri obtained from persons in their third to ninth decades of life. The diameters of osteons and Haversian canals, the densities of Haversian and Volkmann's canals and osteocytes, and the proportions by volume of special and interstitial lamellae were determined. The parameters were checked for age dependence and subjected, together with previously determined macroscopic dimensions of the same left humeri, to regression analyses. Influencing variables entering into the most suitable formula for age determination include the cross-sectional area of the medullary space in the diaphysial center as well as the smallest diameters of osteons and Haversian canals. Factor analysis of the complex structure of characteristics yielded 4 factors, namely, the age factor, size factor, structural factor, and nutritional factor. Also discussed are the processes of internal transformation of adult bones.

Adult↗
PubMed1978

[The aging changes of biological variability (author's transl)].

1. Examples are given to justify the concept that biological variability is dependent on age. 2. It appears possible that the variability of fundamental parameters of those with a strong genetic fixation increases toward the middle of the life span and decreases again in the senium. 3. The variability of most variables increases with age. The more complex the variables, the greater the increase. 4. Originally unitary statistical populations may split up into several populations in the course of life. These will then require separate statistical treatment. 5. Our considerations seem to have some significance for the economical planning of tests and the selection of test persons.

Adaptation, Biological↗
PubMed1977

[The determination of age and sex from measure of the humerus (author's transl)].

On a total of seventy left humeri of persons in their third to ninth decades of life thirty different bone dimensions were determined macroscoically and checked for age dependence. Strong dependence on age was shown only by the weight and volume of the humerus as well as by the areal and thickness dimensins of the center of the shaft. These were used to set up multidimensional linear regression functions by which it is possible for the age of persons past thirty to be estimated with defined accuracy. Also calculated were discriminant functions which allow the sex of a person to be identified to be determined from three dimensions of the left humeral head, and these are the size of the caput at the cartilage-to-bone interface, the transverse and vertical diameters of the caput humeri or head of the humerus. Of the 49 cases studied only three were found to be in the region of overlap of the dimensions used for calculation. Consequently, the formula would not allow unknown humeri or skeletons, respectively, to be identified as belonging to either male or female persons in 6 percent of the cases only. The results of additional examinations made of 198 right humeri were less accurate and showed a decrease of the sexual dimorphism of bone with age.

Adolescent↗