Human Biology

This paper describes the setting up of a nature trail for educational purposes. It discusses the aims, methods of use, and possible evaluation techniques for such a trail. Some probable developments of the ‘trail’ concept at Hartsholme are reviewed. Examples are given of both school-based and leisure-learning activities.     

Surnames and the Y chromosome

A randomly ascertained sample of males with the surname "Sykes" was typed with four Y-chromosome microsatellites. Almost half the sample shared the same Y-chromosome haplotype, which has not been observed in control samples either from the same geographic region or from the United Kingdom as a whole. This points to a single surname founder for extant Sykes males, even though written sources had predicted multiple origins. The distribution of other Sykes Y-chromosome haplotypes were not significantly different from those in controls and may be accounted for by the historical accumulation of nonpaternity during the past 700 years, in which case the average rate estimate is 1.3%/generation. If this pattern is reproduced with other surnames, it may have important forensic and genealogical applications.     

Developmental Biology and Human Concerns

There is a large natural loss of human embryos in early gestation.Most conceptual losses occur before pregnancy has been diagnosedin the woman. It is now acknowledged that chromosomal aberrationsare the major etiologic agents responsible for spontaneous abortions.Fully 50 percent of naturally aborted embryos in the first trimesterhave an abnormal karyotype. Most of the chromosomal errors thathave been identified in abortuses are only rarely seen in livebirths.Natural in utero selection is relentless in eliminating 99 percentof the chromosomally abnormal conceptuses through spontaneousabortion. The birth of affected offspring that escape nature'sscreening mechanism can be averted by the option of prenataldiagnosis. The thrust of prenatal diagnosis is to prevent thetragic impact of debilitating genetic disorders. But notallat-risk parents wish to avail themselves of prenatal diagnosisbecause they are unwilling to accept the choice of therapeuticabortion. Prevention of a genetic disorder before implantationwould obviate the necessity of an abortion at a later stageof pregnancy. With this perspective, the correction of the basicgenetic flaw by replacing the faulty gene with a functioningallele is an attractive alternative. Notwithstanding the imprecisetechnology that presently serves to caution against immediateapplication, gene therapy is a reasonable and natural extensionof efforts to ameliorate the effects of severe inherited disorders.     

A Human Ex Vivo Atherosclerotic Plaque Model to Study Lesion Biology

Atherosclerosis is a chronic inflammatory disease of the vasculature. There are various methods to study the inflammatory compound in atherosclerotic lesions. Mouse models are an important tool to investigate inflammatory processes in atherogenesis, but these models suffer from the phenotypic and functional differences between the murine and human immune system. In vitro cell experiments are used to specifically evaluate cell type-dependent changes caused by a substance of interest, but culture-dependent variations and the inability to analyze the influence of specific molecules in the context of the inflammatory compound in atherosclerotic lesions limit the impact of the results. In addition, measuring levels of a molecule of interest in human blood helps to further investigate its clinical relevance, but this represents systemic and not local inflammation. Therefore, we here describe a plaque culture model to study human atherosclerotic lesion biology ex vivo. In short, fresh plaques are obtained from patients undergoing endarterectomy or coronary artery bypass grafting and stored in RPMI medium on ice until usage. The specimens are cut into small pieces followed by random distribution into a 48-well plate, containing RPMI medium in addition to a substance of interest such as cytokines or chemokines alone or in combination for defined periods of time. After incubation, the plaque pieces can be shock frozen for mRNA isolation, embedded in Paraffin or OCT for immunohistochemistry staining or smashed and lysed for western blotting. Furthermore, cells may be isolated from the plaque for flow cytometry analysis. In addition, supernatants can be collected for protein measurement by ELISA. In conclusion, the presented ex vivo model opens the possibility to further study inflammatory lesional biology, which may result in identification of novel disease mechanisms and therapeutic targets.     

Surnames in the Azores: analysis of the isonymy structure

Geographic isolation is a significant factor to consider when characterizing human populations. The knowledge of the genetic structure of isolated populations has been of great importance to disease-locus positioning and gene identification. To investigate the genetic structure of the Azorean population, we conducted a survey based on the frequencies of surnames listed in the 2001 telephone book. We calculated the following parameters: isonymy (I), the random component of inbreeding (F(ST)), genetic diversity according to Fisher (alpha), Karlin-McGregor's migration rate (v), and Nei's distance. For the 1,271 subscribers and 163 different surnames, Graciosa island presented the lowest value of abundance of surnames (alpha = 15.75), suggesting great genetic isolation compared to the other eight islands. Migration, calculated on the basis of the diversity of surnames within islands, ranged from 0.2747 (Corvo island) to 0.0026 (S?o Miguel island), indicating that people migrated preferentially toward the economically more developed islands. The value of the random component of inbreeding obtained for the whole population (F(ST) = 0.0039) indicates little genetic differentiation (Wright's F(ST) < 0.05). Moreover, isonymy similarity revealed using the UPGMA method shows three subclusters corresponding to the geographic distribution of the islands.