Frank J. Rühli

A dissection and computer tomograph study of tarsal coalitions in 100 cadaver feet

Most of the clinical studies report the incidence of tarsal coalitions (TC) as less than 1% but they disregard the asymptomatic coalitions. TC have been associated with degenerative arthritic changes. After X‐rays, computer tomography (CT) is the most commonly used diagnostic test in the detection of TC.

Direct evidence of milk consumption from ancient human dental calculus

Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenlands medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15th century CE.

Intraskeletal isotopic compositions (δ13C, δ15N) of bone collagen: Nonpathological and pathological variation

Paleodiet research traditionally interprets differences in collagen isotopic compositions (δ(13) C, δ(15) N) as indicators of dietary distinction even though physiological processes likely play some role in creating variation. This research investigates the degree to which bone collagen δ(13) C and δ(15) N values normally vary within the skeleton and examines the influence of several diseases common to ancient populations on these isotopic compositions. The samples derive from two medieval German cemeteries and one Swiss reference collection and include examples of metabolic disease (rickets/osteomalacia), degenerative joint disease (osteoarthritis), trauma (fracture), infection (osteomyelitis), and inflammation (periostitis). A separate subset of visibly nonpathological skeletal elements from the German collections established normal intraindividual variation. For each disease type, tests compared bone lesion samples to those near and distant to the lesions sites. Results show that normal (nonpathological) skeletons exhibit limited intraskeletal variation in carbon- and nitrogen-isotope ratios, suggesting that sampling of distinct elements is appropriate for paleodiet studies. In contrast, individuals with osteomyelitis, healed fractures, and osteoarthritis exhibit significant intraskeletal differences in isotope values, depending on whether one is comparing lesions to near or to distant sites. Skeletons with periostitis result in significant intraskeletal differences in nitrogen isotope values only, while those with rickets/osteomalacia do not exhibit significant intraskeletal differences. Based on these results, we suggest that paleodiet researchers avoid sampling collagen at or close to lesion sites because the isotope values may be reflecting both altered metabolic processes and differences in diet relative to others in the population.

Technical note: Terahertz imaging of ancient mummies and bone

Ancient mummified soft-tissues are a unique source to study the evolution of disease. Diagnostic imaging of such historic tissues is of foremost interest in paleoanthropology or paleopathology, with conventional x-ray and computed tomography (CT) being the gold-standard. Longer wavelength radiation in the far-infrared or Terahertz region allows diagnostic close-to-surface tissue differentiation of bone morphology while being harmless to human cells. The aim of this study is to show the feasibility and the morpho-diagnostic impact of THz imaging of historic remains. Images of an artificially embalmed ancient Egyptian human mummy hand, an artificially embalmed ancient Egyptian mummified fish and a macerated human lumbar vertebra were obtained by THz-pulse imaging and compared with conventional X-ray and CT images. Although conventional x-ray imaging provides higher spatial resolution, we found that THz-imaging is well-suited for the investigation of ancient mummified soft tissue and embalming-related substances / wrappings. In particular, bone and cartilaginous structures can be well differentiated from surrounding soft-tissues and bandage-wrappings by THz imaging. Furthermore, THz-pulse imaging also measures the time-delay of the pulsed signal when passing through the sample, which provides supplementary information on the optical density of the sample that is not obtained by X-ray and CT. Terahertz radiation provides a completely non-invasive diagnostic imaging modality for historic dry specimens. We anticipate this modality also to be used for detection of hidden objects in historic samples such as funerary amulets still in situ in wrapped mummies, as well as potentially for the identification of spectral signatures from chemical substances, e.g., in embalming essences.

Variability of Human Foramen Magnum Size

The foramen magnum is an important landmark of the skull base and is of particular interest for anthropology, anatomy, forensic medicine, and other medical fields. Despite its importance, few osteometric studies of the foramen magnum have been published so far. A total of 110 transverse and 111 sagittal diameters from Central European male and female dry specimens dating from the Pleistocene to modern times were measured, and related to sex, age, stature, ethnicity, and a possible secular trend. Only a moderate positive correlation between the transverse and the sagittal diameter of the foramen magnum was found. Surprisingly, neither sexual dimorphism, individual age‐dependency, nor a secular trend was found for either diameter. Furthermore, the relationship between the individual stature and foramen magnum diameters was weak: thus foramen magnum size cannot be used as reliable indicator for stature estimation. Further consideration of possible factors influencing the variability of human foramen magnum size shall be explored in larger and geographically more diverse samples, thus serving forensic, clinical, anatomical, and anthropological interests in this body part. Anat Rec, 2009.

Ancient DNA analysis reveals high frequency of European lactase persistence allele (T-13910) in medieval Central Europe

Ruminant milk and dairy products are important food resources in many European, African, and Middle Eastern societies. These regions are also associated with derived genetic variants for lactase persistence. In mammals, lactase, the enzyme that hydrolyzes the milk sugar lactose, is normally down-regulated after weaning, but at least five human populations around the world have independently evolved mutations regulating the expression of the lactase-phlorizin-hydrolase gene. These mutations result in a dominant lactase persistence phenotype and continued lactase tolerance in adulthood. A single nucleotide polymorphism (SNP) at C/T-13910 is responsible for most lactase persistence in European populations, but when and where the T-13910 polymorphism originated and the evolutionary processes by which it rose to high frequency in Europe have been the subject of strong debate. A history of dairying is presumed to be a prerequisite, but archaeological evidence is lacking. In this study, DNA was extracted from the dentine of 36 individuals excavated at a medieval cemetery in Dalheim, Germany. Eighteen individuals were successfully genotyped for the C/T-13910 SNP by molecular cloning and sequencing, of which 13 (72%) exhibited a European lactase persistence genotype: 44% CT, 28% TT. Previous ancient DNA-based studies found that lactase persistence genotypes fall below detection levels in most regions of Neolithic Europe. Our research shows that by AD 1200, lactase persistence frequency had risen to over 70% in this community in western Central Europe. Given that lactase persistence genotype frequency in present-day Germany and Austria is estimated at 71–80%, our results suggest that genetic lactase persistence likely reached modern levels before the historic population declines associated with the Black Death, thus excluding plague-associated evolutionary forces in the rise of lactase persistence in this region. This new evidence sheds light on the dynamic evolutionary history of the European lactase persistence trait and its global cultural implications.

Harris lines revisited: Prevalence, comorbidities, and possible etiologies

Objectives: The occurrence of transverse radiopaque lines in long bones—Harris lines (HLs)—is correlated with episodes of temporary arrest of longitudinal growth and has been used as an indicator of health and nutritional status of modern and historical populations. However, the interpretation of HLs as a stress indicator remains debatable. The aim of this article is to evaluate the perspectives and the limitations of HLs analyses and to examine their reliability as a stress indicator.

BMI distribution/social stratification in Swiss conscripts from 1875 to present.

Background/Objectives:We aimed to extend the actual overweight discussion with new unbiased Swiss conscript data from 2005 to 2006, and to present for the first time Swiss data on body mass index (BMI) before 1950 and for the late-nineteenth century.Subjects/Methods:For this study, 19-year-old Swiss male conscripts (draft army; Cantons Bern, Zurich, Basel-Stadt and Basel-Land) from the census of 1875–1879, 1933–1939 and 2005–2006 (N=28 033; 2005–2006 census) were included. BMI distribution (World Health Organization (WHO) classification) and social stratification (International Labour Organization classification) were main outcome measures.Results:Mean BMI of 19-year-old men in Switzerland increased in the 50 years between the 1870s and the 1930s by 0.80 kg/m2 and between the 1930s and 2005 by 1.45 kg/m2. The modern BMI sample is much more right skewed and s.d. is higher. Obesity prevalence (according to modern WHO classification) has increased by a factor of 105 from 1870s until present. Over 23% of our representative sample of Swiss men in 2005–2006 had a BMI of over 25 kg/m2. In 2005–2006, contrary to the nineteenth century, unskilled workers had articulately higher BMI values at the 75th, 90th and 95th percentile than students; 12% of unskilled workers were obese against 2% of students.Conclusions:It thus seems that BMI relations between the upper and the lower end of the socio-economic strata changed inversely from the late-nineteenth century to 2005–2006. We further propose that the phenomenon of massive right-skewing BMI distribution between the 1930s and 2005–2006 affected the lower socio-economic strata to a far greater extent than the higher socio-economic group.

Preservation of cell structures in a medieval infant brain: A paleohistological, paleogenetic, radiological and physico-chemical study

Cerebral tissues from archaeological human remains are extremely rare findings. Hereby, we report a multidisciplinary study of a unique case of a left cerebral hemisphere from a 13th century AD child, found in north-western France. The cerebral tissue-reduced by ca. 80% of its original weight-had been fixed in formalin since its discovery. However, it fully retained its gross anatomical characteristics such as sulci, and gyri; the frontal, temporal and occipital lobe as well as grey and white matter could be readily recognised. Neuronal remains near the hippocampus area and Nissl bodies from the motor cortex area were observed (Nissl, Klüver-Barrera staining). Also, computed tomography (CT) and magnetic resonance imaging (T1, proton density, ultra short echo time sequences) were feasible. They produced high quality morpho-diagnostic images. Both histological and radiological examinations could not confirm the pathologists previously suggested diagnosis of cerebral haemorrhage as the cause of death. Reproducible cloned mtDNA sequences were recovered from the skeleton but not from the brain itself. This was most likely due to the combined effect of formaldehyde driven DNA-DNA and/or DNA-protein cross-linking, plus hydrolytic fragmentation of the DNA. The chemical profile of the brain tissue, from gas-chromatography/mass-spectroscopy analysis, suggested adipocerous formation as the main aetiology of the mummification process. The hereby presented child brain is a unique paleo-case of well-preserved neuronal cellular tissue, which is a conditio sine qua non for any subsequent study addressing wider perspectives in neuroscience research, such as the evolution of brain morphology and pathology.

New perspectives on evolutionary medicine: the relevance of microevolution for human health and disease

Evolutionary medicine (EM) is a growing field focusing on the evolutionary basis of human diseases and their changes through time. To date, the majority of EM studies have used pure theories of hominin macroevolution to explain the present-day state of human health. Here, we propose a different approach by addressing more empirical and health-oriented research concerning past, current and future microevolutionary changes of human structure, functions and pathologies. Studying generation-to-generation changes of human morphology that occurred in historical times, and still occur in present-day populations under the forces of evolution, helps to explain medical conditions and warns clinicians that their current practices may influence future humans. Also, analyzing historic tissue specimens such as mummies is crucial in order to address the molecular evolution of pathogens, of the human genome, and their coadaptations.