Circadian relations among cardiovascular variables of young adults.

Every 4 hours for 24 hours, 14 clinically healthy young individuals (6 women and 8 men), 26 +/- 4 years of age, measured systolic (S) and diastolic (D) blood pressure (BP) by sphygmomanometer and heart rate by ECG and did impedance cardiography under usual living conditions. Stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) were calculated. Time series of SBP, DBP, HR, SV, CO and TPR were analyzed by single and population-mean cosinor. A circadian cardiovascular rhythm is demonstrated by rejection of the zero amplitude assumption in the population-mean cosinor test for SBP, DBP, HR, SV, CO and TPR (P < 0.01). TPR peaks around 0400 (-61 degrees from local midnight), in antiphase with all other variables, their acrophase occurring around 1600 (-240 degrees). A circadian rhythm of statistical significance or of borderline statistical significance is found for all variables except TPR in women. Circadian rhythm characteristics were otherwise mostly similar in men and women with a statistically significant gender difference found by parameter tests only for the MESOR and amplitude of SBP.     

Incremental lines of dental cementum in biological age estimation

The aim of this study is to evaluate the use of counting incremental lines of dental root cementum for biological age determination, and to compare it with alternative methods. Two samples were taken: 51 teeth from 49 individuals of known age obtained at the Stomatological Clinic, Vilnius University, as well as the canine teeth from the remains of 48 individuals from the mass graves of Tuskulenai in Vilnius (inhumed 1944-47). In the latter sample, the chronological age of 43 individuals was known through personal identification. Undecalcified teeth were sectioned with the Leica SP 1600 microtome diamond saw, and incremental line count as a blind test was made on sections of 35 to 100 microns thickness. Incremental line count was possible in 82-86 percent of cases. The results of three independent counts showed that intra-observer bias has no significant impact. Biological age was estimated by adding incremental line number to the average age of tooth eruption. It was found that mean absolute error was 6.46 years for the 1st sample, 6.27 years for the 2nd sample, and in some cases exceeded 10 years. For the 2nd sample, the results were compared to those of other methods such as endocranial suture ossification, pubic symphysis morphology and the "combined" method of Nemeskéri. All four methods yield a similar correlation in regard to an individual's chronological age. The highest correlation was found for the combined method, and the lowest one for public symphysis morphology. All correlations had a similar standard error. Thus our assessment is less enthusiastic than in some past studies; it is suggested that the incremental lines rather have a similar use as other methods.     

Probabilistic approach to age estimation of children by dental maturation

Two probabilist methods of age prediction in children are proposed: they are both based on the radiological presence of erupted teeth or germs. Using an apprenticeship sample of known age and sex, we established several discriminant models (+/- 13, +/- 16, +/- 18 years old). We also evaluated a Bayesian model with the following age groups: < 13, [13-16[, [16-18[, > or = 18 years old, or [X and Y] years old. When applied on a known test sample, Fisher's linear functions presented a success rate greater than 90%, above 13 years threshold, and below 16 and 18 years thresholds, and Bayesian approach, greater than 85%. Therefore, these methods provide an interesting alternative for children age determination that can be applied in biological and forensic anthropology, too.     

Significance of microhaematuria in young adults.

The medical records of 1000 asymptomatic male air force personnel were examined retrospectively for the results of 15 yearly examinations of urinary sediment. The study covered the period 1968-82, beginning with the subjects aged 18-33 years. The cumulative incidence of two to four or more red blood cells per high power field found at one or more examinations was 38.7% after an average of 12.2 yearly examinations per person. In 161 subjects two to four or more red blood cells per high power field were found at two or more yearly examinations within a five year period. Intravenous pyelography in 58 cases disclosed asymptomatic nephrolithiasis in six. Cystoscopy performed in 11 cases identified one patient with urethritis, one with a vesical calculus, and one with transitional cell carcinoma of the bladder. Two years before diagnosis the patient with carcinoma had had a single transient finding of 10-12 red blood cells per high power field which was not investigated further. Cystoscopy was performed after an episode of macroscopic haematuria. Renal biopsy in one subject with recurrent microhaematuria and trace proteinuria disclosed focal glomerulonephritis. None of the remaining subjects with microhaematuria developed hypertension or proteinuria, and at the end of the study period all were active and free of urinary symptoms. The observed cumulative incidence of urological neoplasms at 15 years (0.1%) was consistent with that expected in Israeli men aged 18-40 (0.09%). Hence microhaematuria detected during a screening examination probably should not be regarded as a specific sign of a significant lesion and does not of itself warrant urological investigation in adults aged 40 or less.     

Genetic analysis of ecologically relevant morphological variability in Plantago lanceolata L.

Summary Morphological variability was studied in two populations of Plantago lanceolata using diallel analysis. In each population, reciprocal crosses between all possible pairs of ten plants were made. In the greenhouse, six members of each family were grown and many characters were measured. Using the model of Cockerham and Weir, the contributions of the different genetic variance components were calculated. From earlier papers it was postulated in advance to what extent and by which effect the characters in both populations were genetically determined. The populations had been differentiated for life history and morphological characters, and varied also in the relative contribution of genetic components to variability. In the Merrevliet (Me) population, where strong biotic selection was assumed, low levels of additive-genetic variability were present and the relative dominance appeared to be high. The contrasting population, Westduinen (Wd), which is abiotically controlled and shows strong environmental variability, possessed higher levels of additive-genetic variability and lower levels of relative dominance. It is possible that differential natural selection has diminished additive-genetic variability to different extents in both populations: plasticity and environmental heterogeneity prevented the loss of additive-genetic variability in Wd, whereas in the stable population, Me, natural selection had the opportunity of not only changing the means of the characters but also of diminishing additive-genetic variability to a great extent.Grassland Species Research Group Publication No. 146     

Genetic analysis of ecological relevant morphological variability in Plantago lanceolata L.

Summary Morphological variability was analysed in an F₂-generation derived from crosses between two ecotypes of Plantago lanceolata L. Six allozyme loci, localised in five linkage groups, were used as markers. For two marker loci, Got-2 and Gpi-1, segregations did not fit monogenic ratios. In the linkage groups to which these two loci belonged, male sterility genes appeared to be present. In these crosses, male sterility (type 3, as described by Van Damme 1983) may be determined by two recessive loci located in the linkage groups of Got-2 and of Gpi-1. Many correlations of morphological and life history characters with allozyme markers were observed. The quantitative trait loci did not appear to be concentrated in major gene complexes. Often many loci were involved, sometimes with effects opposite to those expected from the population values. Main effects of the linkage groups appeared to be more important than interaction effects in determining variability. It also appeared that there is a positive correlation between the number of heterozygous allozyme loci and generative growth.Grassland Species Research Group Publication No. 115     

Genetic analysis of ecological relevant morphological variability in Plantago lanceolata L.

Summary Plants of an F₂ generation derived from crosses between two ecotypes of Plantago lanceolata L. had previously been studied in a greenhouse. In the present experiment, F₂ plants were transplanted into their original habitats (a hayfield and a pasture). Six allozyme loci were used as markers in the analysis of survival and performance of the segregating genotypes. Fitness differences between the plants were large enough to detect natural selection. In both transplantation sites selection appeared to operate, though in different ways. In the hayfield habitat directional selection was hypothesized and both survival and performance of the plants were related to genotype, with the genotypes originating from the hayfield almost always performing better. In the pasture habitat where the habitat is not uniform and unpredictable hazardous droughts occur, survival was nearly genotype independent and environmentally determined, whereas performance of the plants was genotype dependent. The expression of two morphological characteristics, number of leaves and leaf length, was often not in concordance with the greenhouse results and was contradictory in both sites. Expression of both characters in the field, therefore, appeared to be strongly dependent on the general performance and growth conditions of the plant and not on the genotype.Grassland Species Research Group Publication no. 143     

Improved age determination of blood and teeth samples using a selected set of DNA methylation markers

Age estimation from DNA methylation markers has seen an exponential growth of interest, not in the least from forensic scientists. The current published assays, however, can still be improved by lowering the number of markers in the assay and by providing more accurate models to predict chronological age. From the published literature we selected 4 age-associated genes (ASPA, PDE4C, ELOVL2, and EDARADD) and determined CpG methylation levels from 206 blood samples of both deceased and living individuals (age range: 0–91 years). This data was subsequently used to compare prediction accuracy with both linear and non-linear regression models. A quadratic regression model in which the methylation levels of ELOVL2 were squared showed the highest accuracy with a Mean Absolute Deviation (MAD) between chronological age and predicted age of 3.75 years and an adjusted R² of 0.95. No difference in accuracy was observed for samples obtained either from living and deceased individuals or between the 2 genders. In addition, 29 teeth from different individuals (age range: 19–70 years) were analyzed using the same set of markers resulting in a MAD of 4.86 years and an adjusted R² of 0.74. Cross validation of the results obtained from blood samples demonstrated the robustness and reproducibility of the assay. In conclusion, the set of 4 CpG DNA methylation markers is capable of producing highly accurate age predictions for blood samples from deceased and living individuals     

Can there be age determination on the basis of the dental cementum also in older individuals as a significant context between histological and real age determination

The aim of this study is to test the cementum annulation technique for its reliability used on individuals of higher ages. Two samples were taken. The first consists of teeth from 34 individuals with known ages between 57 and 90 years. A second sample of 24 teeth from younger individuals between 21 and 45 years was taken as control group. The results show, that there is a greater divergence between predicted and actual age in older persons. The present study shows how great this divergence is and drives attention to possible reasons. Furthermore, it is shown if there is a difference between men and women and between modern teeth and teeth from the 19th century.     

Comparative morphological and histochemical aspects of selected arteries in the chicken and rat.

Morphologic and histochemical characteristics of selected portions of normal arteries from two species known to differ in susceptibility to vascular disease were examined. Arteries were classified as predominantly elastic, muscular or complex. Species differences in the structural organization of the abdominal aortic segment were observed. Arterial mucopoly-saccharides were stained more intensely in the tunica intima and media of chicken vessels than within those of the rat, and tended to be most concentrated in proximity of the internal elastic membrane. Histochemical procedures for the demonstration of enzymatic activity revealed inter-and intraspecies variations in vascular metabolism. Pronounced differences in reaction intensity for hydroxybutyrate dehydrogenase and malic enzyme, affecting chicken and rat coronary arteries, were noted. In contrast, theses vessels displayed only minimal activity for acid phosphatase. Marked endothelial deposition of alkaline phosphatase reaction products in the arteries of the chicken was demonstrated, while this enzyme's activity in the vessels of the rat was restricted to the tunica adventitia. The implications of these structural and histochemical factors with regard to vascular susceptibility to disease were discussed.     

Comparison of a Bone Criterion and a dental Criterion for estimation of age at death in the study of an Ancient Cemetery

Two methods, a visual method based on the appearance of the auricular surface of the ilium and a metric method based on two dental criteria, were used in conjunction for estimation of skeletal age at death in paleodemographic study of an ancient cemetery, and were found to be coherent. However, the paleodemographic profiles differed according to sex, indicating a sexual difference in the evolution of the sacroiliac joint.