Improving stable isotopic interpretations made from human hair through reduction of growth cycle error

Discovery of a novel and highly selective JAK3 inhibitor as a potent hair growth promoter

JAK-STAT signalling pathway inhibitors have emerged as promising therapeutic agents for the treatment of hair loss. Among different JAK isoforms, JAK3 has become an ideal target for drug discovery because it only regulates a narrow spectrum of γc cytokines. Here, we report the discovery of MJ04, a novel and highly selective 3-pyrimidinylazaindole based JAK3 inhibitor, as a potential hair growth promoter with an IC50 of 2.03 nM. During in vivo efficacy assays, topical application of MJ04 on DHT-challenged AGA and athymic nude mice resulted in early onset of hair regrowth. Furthermore, MJ04 significantly promoted the growth of human hair follicles under ex-vivo conditions. MJ04 exhibited a reasonably good pharmacokinetic profile and demonstrated a favourable safety profile under in vivo and in vitro conditions. Taken together, we report MJ04 as a highly potent and selective JAK3 inhibitor that exhibits overall properties suitable for topical drug development and advancement to human clinical trials.

The DNA-Buster: The evaluation of an alternative DNA recovery approach

Touch DNA recovery techniques can have limitations, as their effectiveness depends on the substrate on which the DNA of a person of interest can be found. In this study, an in-house dry-vacuuming device, the DNA-Buster, was compared to traditional methods for its DNA recovery performance from items typically examined in forensic casework. The aim was to evaluate whether this dry-vacuuming approach can recover DNA efficiently, potentially complementing the well-established recovery strategies. For this, the performances of swabbing, taping, wet- (M-Vac®) and dry-vacuuming (DNA-Buster) were investigated quantitatively and qualitatively for touch DNA deposited on carpet, cotton sweater, stone, tile and wood. For the sweater, both vacuuming methods outperformed the other collection tools quantitatively. While the highest DNA amounts for the carpet were yielded by swabbing and taping, dry-vacuuming was equally good in reaching full DNA profiles, whereas less complete profiles were observed for the M-Vac®. For stone and tile, swabbing was optimal, whereas dry-vacuuming clearly underperformed for these substrates. Taping was the best recovery method for wood. Despite applying single donor DNA after thoroughly cleaning the items, undesired DNA mixtures were detected for all recovery techniques and all substrates. The overall research findings show first that the novel dry-vacuuming method is suited for DNA recovery from textiles. Secondly, they indicate that more attention should be paid to the substrate-collection dependency to ensure best practices in recovering genetic material in a precise, confident and targeted manner from the variety of forensic casework material.

Migration and maize in the Virú Valley: Understanding life histories through multi-tissue carbon, nitrogen, sulfur, and strontium isotope analyses

OBJECTIVES

Stable isotope analysis can provide crucial insight into the function and development of early state-level societies on the north coast of Peru.

MATERIALS AND METHODS

Multi-tissue (bone collagen, tooth enamel, hair, nail, skin, and tendon) stable isotope analyses (carbon, nitrogen, sulfur, and strontium) were conducted for 13 individuals from the lower Virú Valley.

RESULTS

Non-seasonal changes in a predominantly C₄ -based terrestrial diet, with minimal inputs of marine foods were identified. One individual (Burial 5), however, had a stable isotope signature unlike any previously found on the north coast of Peru, indicating both a large contribution of C₃ -terrestrial resources to their diet and an ⁸⁷ Sr/⁸⁶ Sr value suggestive of highland residence during childhood.

DISCUSSION

This research provides the first strong stable isotope evidence of a highland individual within a coastal burial in northern Peru, new insight into the ritual killing event at Huaca Santa Clara during the late middle horizon and supporting evidence of the importance of C₄ terrestrial resources to the developing Virú polity during the early intermediate period.

A Multidisciplinary Review of the Inka Imperial Resettlement Policy and Implications for Future Investigations

The rulers of the Inka empire conquered approximately 2 million km2 of the South American Andes in just under 100 years from 1438-1533 CE. Inside the empire, the elite conducted a systematic resettlement of the many Indigenous peoples in the Andes that had been rapidly colonised. The nature of this resettlement phenomenon is recorded within the Spanish colonial ethnohistorical record. Here we have broadly characterised the resettlement policy, despite the often incomplete and conflicting details in the descriptions. We then review research from multiple disciplines that investigate the empirical reality of the Inka resettlement policy, including stable isotope analysis, intentional cranial deformation morphology, ceramic artefact chemical analyses and genetics. Further, we discuss the benefits and limitations of each discipline for investigating the resettlement policy and emphasise their collective value in an interdisciplinary characterisation of the resettlement policy.

Hydrogen isotopes in serial hair samples record season of death in a mummified child from 19th century San Francisco, CA

BACKGROUND

The mummified body of a small child was found in a sealed Barstow cast iron casket during construction activity in San Francisco in 2016. Using historical records and ancient DNA the child was determined to be Edith H. Cook. She was born 28 November, 1873 in the city of San Francisco, and died of "marasmus" on 13 October, 1876 also in San Francisco.

AIMS

Currently, there are few techniques for estimating human season of death in archaeological cases. Hydrogen isotope ratios (δ2H) in hair keratin is known to strongly correlate with drinking water. We explore δ2H in serial hair samples as a potential technique to estimate season of death by comparing the δ2H record from hair to the known date of death.

MATERIALS & METHODS

Approximately 50 hairs were removed from the scalp, aligned from the root, and cut into 5cm serial sections, each representing approximately 2 weeks of growth, and the total sequence a total of 1 year of growth. δ2H was measured on each 5cm segment and compared to previously-reported δ13C, δ15N, and δ34S values.

RESULTS

δ2H in the serial hair samples ranged between -56‰ and -48‰, consistent with her water values recorded in surface waters from San Francisco, and follow a sinusoidal pattern. Decreasing δ2H in terminal samples before death suggest Fall as the season of death, consistent with the known date of death.

DISCUSSION

This test case shows that archaeological hair preserves a seasonal signature in the form of changing keratin δ2H values that correlate to changing δ2H in surface drinking water. Terminal values in root record water ingested during the final week(s) before death.

CONCLUSIONS

We argue that this technique can be used to estimate season of death in future archaeological or forensic cases where hair has been preserved but date of death is unknown.

Assessing geographic controls of hair isotopic variability in human populations: A case-study in Canada

Studying the isotope variability in fast-growing human tissues (e.g., hair, nails) is a powerful tool to investigate human nutrition. However, interpreting the controls of this isotopic variability at the population scale is often challenging as multiple factors can superimpose on the isotopic signals of a current population. Here, we analyse carbon, nitrogen, and sulphur isotopes in hair from 590 Canadian resident volunteers along with demographics, dietary and geographic information about each participant. We use a series of machine-learning regressions to demonstrate that the isotopic values in Canadian residents' hair are not only influenced by dietary choices but by geographic controls. First, we show that isotopic values in Canadian residents' hair have a limited range of variability consistent with the homogenization of Canadian dietary habits (as in other industrialized countries). As expected, some of the isotopic variability within the population correlates with recorded individual dietary choices. More interestingly, some regional spatial patterns emerge from carbon and sulphur isotope variations. The high carbon isotope composition of the hair of eastern Canadians relative to that of western Canadians correlates with the dominance of corn in the eastern Canadian food-industry. The gradient of sulphur isotope composition in Canadian hair from coast to inland regions correlates with the increasing soil pH and decreasing deposition of marine-derived sulphate aerosols in local food systems. We conclude that part of the isotopic variability found in the hair of Canadian residents reflects the isotopic signature associated with specific environmental conditions and agricultural practices of regional food systems transmitted to humans through the high consumption rate of intra-provincial food in Canada. Our study also underscores the strong potential of sulphur isotopes as tracers of human and food provenance.

How isotopic signatures relate to meat consumption in wild chimpanzees: A critical reference study from Taï National Park, Côte d'Ivoire

The roots of human hunting and meat eating lie deep in our evolutionary past shared with chimpanzees (Pan troglodytes). From the few habituated wild populations, we know that there is considerable variation in the extent to which chimpanzees consume meat. Expanding our knowledge of meat eating frequencies to more, yet unhabituated, populations requires noninvasive, indirect quantitative techniques. We here evaluate the use of stable isotopes to reconstruct meat-eating behavior in wild chimpanzees. We present hair isotope data (n = 260) of two western chimpanzee (P. troglodytes verus) groups from Taï forest (Côte d'Ivoire) and relate them to directly observed amounts of meat consumed, sex/female reproductive state, and group, while controlling for differences between individuals, seasons, and observation efforts. Succeeding seven months of hunting observations, we collected hair of 25 individuals for sequential analysis of δ¹⁵N and δ¹³C. Hunting success in the 7-month study period varied between the groups, with 25 successful hunts in the East group and only 8 in the North group. However, our models only found a direct relationship between amounts of meat consumed and variation within individual hair δ¹⁵N values in the East group, but not in the North group and not when comparing between individuals or groups. Although on average East group individuals consumed more than double the amount of meat than North group individuals, their δ¹⁵N values were significantly lower, suggesting that differences in microhabitat are substantial between group territories. The effect of sex/female reproductive state was significant in δ¹⁵N and δ¹³C, suggesting it related to access to food or feeding preferences. We conclude that several factors additional to diet are influencing and thus obscuring the isotope ratios in wild chimpanzee hair, particularly when comparing between sexes and social groups.

Linking isotope analysis and paleopathology: An andean perspective

This paper reviews the significant advances in isotopic investigations in Andean South America and directs scholars to explore new theoretical and analytical directions, specifically the applicability of isotope data to paleopathology. Excellent preservation and large skeletal collections of human remains make the Central Andes ideal for biogeochemical reconstructions and advancements in isotopic methods. Our aims are twofold: first, we present a meta-analysis of stable and radiogenic isotope research in the Central Andes since 1985, and highlight those that combine analyses of isotope ratios and pathological conditions. Second, we discuss useful directions for incorporating stable isotope analysis more explicitly in studies of paleopathology in the Andes more in the future. Principle research foci have described dietary variation and regional population mobility since the 1980s, where early methodological explorations identified significant trends in isotopic variation. For the years 1980-2017, we identified 96 scholarly publications through a meta-data analysis of major peer-reviewed journals, book chapters, and conference proceedings. These demonstrate specific trends in topical and methodological preferences across the Andean region and a shift from 10 publications pre-1997 to 67 in the last 10 years. However, combined isotope and paleopathology studies in this region remain sparse; given the ecological, geological, and cultural complexity of the Central Andes, analyses of pathological conditions in different regions would significantly benefit from the information on diet, mobility, and local ecology that isotope ratios provide. Isotope analysis requires destruction of archaeological tissues, and interpreting isotope data can be complex, but it can also provide unique insights into the pathogenesis of multifactorial conditions and assist differential diagnosis. Therefore, we also discuss research designs for pairing isotopic and paleopathological variables that will allow researchers to better capture disease ecologies in archaeological samples and their variation across different regions, within related sites, and within individual lifespans.

Prenatal effects of maternal nutritional stress and mental health on the fetal movement profile

Purpose

Prenatal sub-optimal nutrition and exposure to maternal stress, anxiety and depression in pregnancy have been linked to increased postnatal morbidity and mortality. Fetal growth is most vulnerable to maternal dietary deficiencies, such as those evident in hyperemesis gravidarum (HG), early in pregnancy. The purpose of this pilot study was to examine the effects of HG on fetal movement profiles as a measure of fetal healthy development in the 3rd trimester of pregnancy, and to assess whether nutritional stress on the mother can be evaluated using isotopic analysis of hair.

Method

We analyzed fetal movement profiles using 4D ultrasound scans at 32- and 36-weeks' gestation. Fetuses of women (N = 6) diagnosed with HG, having lost more than 10% of their body weight in the first trimester of pregnancy were compared to a healthy group (N = 6), controlling for stress, depression and anxiety. We tested carbon and nitrogen isotope ratios in maternal hair as a measure of both diet and nutritional changes due to catabolism of body proteins and fats.

Results

HG and catabolism were significantly correlated (p = 0.02). Furthermore, at 32-weeks' gestation movement profiles of fetuses of mothers with HG differed significantly from the movement profiles of fetuses of healthy mothers. Fetuses of mothers suffering from HG showed a significantly increased ratio of fine-grained movements at 32 weeks (p = 0.008); however, there were no significant differences detectable at 36-weeks' gestation.

Conclusion

The effect of HG on fetal development as expressed by variations in fetal movement profiles in this pilot study suggest that prenatal effects of HG can be measured using movement profiles. Isotope analysis of hair can supplement this with information on nutritional imbalances early in pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s00404-020-05571-w) contains supplementary material, which is available to authorized users.

Economic and demographic predictors of dietary variation and nutritional indicators in Nicaragua

OBJECTIVES

We measured carbon and nitrogen isotopic ratios in a contemporary population, and tested how the isotopic variability relates to measures of socioeconomic status (e.g., household wealth) and anthropometric measures (e.g., standardized height-for-age and weight-for-age z-scores).

METHODS

Hair samples from individuals living in the Bosawas Biosphere Reserve in Nicaragua were analyzed for δ¹³ C and δ¹⁵ N, and these data were examined in relation to individual (e.g., age, sex, anthropometrics) and household (e.g., household size, wealth) variables.

RESULTS

We found through mixed-effects modeling that δ¹³ C and δ¹⁵ N varied predictably with individual age and household wealth. δ¹³ C and δ¹⁵ N did not, however, improve models predicting variation in individual anthropometric measures.

CONCLUSION

These results indicate that, although there is a relationship between diet (δ¹³ C and δ¹⁵ N) and socioeconomic variables, these dietary differences are not the main cause of health differences in this population.

Stable C and N isotope analysis of hair suggest undernourishment as a factor in the death of a mummified girl from late 19th century San Francisco, CA

The chance discovery of a 1.5–3.5 years old mummified girl presents a unique opportunity to further our understanding of health and disease among children in 19^th Century San Francisco. This study focuses on carbon and nitrogen stable isotope signatures in serial samples of hair that cover the last 14 months of her life. Results suggest an initial omnivorous diet with little input from marine resources or C4 plants. Around six months before death δ¹⁵N starts a steady increase, with a noticeable acceleration just two months before she died. The magnitude of δ¹⁵N change, +1.5‰ in total, is consistent with severe undernourishment or starvation. Cemetery records from this time period in San Francisco indicate high rates of infant and child mortality, mainly due to bacterial-borne infectious diseases, about two orders of magnitude higher than today. Taken together, we hypothesize that the girl died after a prolonged battle with such an illness. Results highlight the tremendous impacts that modern sanitation and medicine have had since the 1800s on human health and lifespan in the United States.

Do we excrete what we eat? Analysis of stable nitrogen isotope ratios of human urinary urea

RATIONALE

Natural stable nitrogen isotope ratios (δ¹⁵ N) are frequently used for the determination of provenance and dietary assessment of recent and ancient humans. Although individual δ¹⁵ N values typically correspond to the dietary δ¹⁵ N composition, they are also affected by metabolic conditions. Preferred matrices for the measurement of human δ¹⁵ N values have been hair, nail or blood. The goal of this study was to validate a novel approach for the assessment of the δ¹⁵ N values from urinary urea, the principal end-product of human N metabolism.

METHODS

The method, which involves the precipitation of urea from urine using xanthydrol, was validated using fortified urea solutions. Intra- and inter-individual variance of the δ¹⁵ N values of urinary urea was determined from samples obtained from multiple human subjects.

RESULTS

Precipitation with xanthydrol did not alter the δ¹⁵ N values of urea. The mean δ¹⁵ N value in urinary urea from human subjects from Germany was +4.4 ± 0.6 ‰, which corresponds to the estimated dietary composition. It falls below previously reported δ¹⁵ N values for human tissue and blood samples. Longitudinal analyses over 7 days illustrate short-time changes linked to varying protein intake.

CONCLUSIONS

Our results indicate that δ¹⁵ N values can be measured reliably from human urine and that the method is suitable to monitor rapid dietary and metabolic changes of an individual. Our findings further confirm that urinary urea is depleted in ¹⁵ N compared with human tissue but within the range of the δ¹⁵ N composition of the diet. Copyright © 2017 John Wiley & Sons, Ltd.

Refining Stable Oxygen and Hydrogen Isoscapes for the Identification of Human Remains in Mississippi

Isoscape refinement is an essential component for accurately predicting region-of-origin in forensic investigations involving isotope analysis of unidentified human remains. Stable oxygen (δ¹⁸ O) and hydrogen (δ² H) isotopes were measured from 57 tap water samples collected across Mississippi to model refined isoscapes for the state. A tap water conversion equation, δ¹⁸ O_tw =1.64 δ¹⁸ Op-31.35, was developed for the southeastern USA to test the prediction accuracy of the δ¹⁸ O_tw isoscape using individuals with known residential histories. A local Mississippi resident (USAFA-134) was assigned with 90% probability to the correct region-of-origin reported by the participant. Assignments for Georgia residents (USAFA-118 and USAFA-205) had variable results, predicting USAFA-118 from Mississippi and USAFA-205 as a nonlocal resident. Stable isotope values often overlap geographically and a multi-isotope approach should be used when narrowing region(s)-of-origin(s). This study demonstrates the utility of refining isoscapes and the importance of tissue calibration in prediction assignments of human remains.

Comparative isotope ecology of African great apes

The isotope ecology of great apes is a useful reference for palaeodietary reconstructions in fossil hominins. As extant apes live in C₃-dominated habitats, variation in isotope signatures is assumed to be low compared to hominoids exploiting C₄-plant resources. However, isotopic differences between sites and between and within individuals are poorly understood due to the lack of vegetation baseline data. In this comparative study, we included all species of free-ranging African great apes (Pan troglodytes, Pan paniscus, Gorilla sp.). First, we explore differences in isotope baselines across different habitats and whether isotopic signatures in apes can be related to feeding niches (faunivory and folivory). Secondly, we illustrate how stable isotopic variations within African ape populations compare to other extant and extinct primates and discuss possible implications for dietary flexibility. Using 701 carbon and nitrogen isotope data points resulting from 148 sectioned hair samples and an additional collection of 189 fruit samples, we compare six different great ape sites. We investigate the relationship between vegetation baselines and climatic variables, and subsequently correct great ape isotope data to a standardized plant baseline from the respective sites. We obtained temporal isotopic profiles of individual animals by sectioning hair along its growth trajectory. Isotopic signatures of great apes differed between sites, mainly as vegetation isotope baselines were correlated with site-specific climatic conditions. We show that controlling for plant isotopic characteristics at a given site is essential for faunal data interpretation. While accounting for plant baseline effects, we found distinct isotopic profiles for each great ape population. Based on evidence from habituated groups and sympatric great ape species, these differences could possibly be related to faunivory and folivory. Dietary flexibility in apes varied, but temporal variation was overall lower than in fossil hominins and extant baboons, shifting from C₃ to C₄-resources, providing new perspectives on comparisons between extinct and extant primates.

The Steady State Great Ape? Long Term Isotopic Records Reveal the Effects of Season, Social Rank and Reproductive Status on Bonobo Feeding Behavior

Dietary ecology of extant great apes is known to respond to environmental conditions such as climate and food availability, but also to vary depending on social status and life history characteristics. Bonobos (Pan paniscus) live under comparatively steady ecological conditions in the evergreen rainforests of the Congo Basin. Bonobos are an ideal species for investigating influences of sociodemographic and physiological factors, such as female reproductive status, on diet. We investigate the long term dietary pattern in wild but fully habituated bonobos by stable isotope analysis in hair and integrating a variety of long-term sociodemographic information obtained through observations. We analyzed carbon and nitrogen stable isotopes in 432 hair sections obtained from 101 non-invasively collected hair samples. These samples represented the dietary behavior of 23 adult bonobos from 2008 through 2010. By including isotope and crude protein data from plants we could establish an isotope baseline and interpret the results of several general linear mixed models using the predictors climate, sex, social rank, reproductive state of females, adult age and age of infants. We found that low canopy foliage is a useful isotopic tracer for tropical rainforest settings, and consumption of terrestrial herbs best explains the temporal isotope patterns we found in carbon isotope values of bonobo hair. Only the diet of male bonobos was affected by social rank, with lower nitrogen isotope values in low-ranking young males. Female isotope values mainly differed between different stages of reproduction (cycling, pregnancy, lactation). These isotopic differences appear to be related to changes in dietary preference during pregnancy (high protein diet) and lactation (high energy diet), which allow to compensate for different nutritional needs during maternal investment.

Infant feeding practices and childhood diet at Apollonia Pontica: Isotopic and dental evidence

OBJECTIVE

This study analyzes deciduous dental pathology and stable isotopes to investigate the relationship between diet, feeding practices, and oral health in a subadult skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (mid-5th to mid-3rd Centuries BC).

METHODS

Stable carbon and nitrogen isotope analysis was conducted on 74 bone collagen samples, and the deciduous dentitions of 85 individuals aged 8.5 months to 11 years were examined for evidence of caries, calculus, antemortem tooth loss, abscesses, and occlusal tooth wear.

RESULTS

δ(13) C and δ(15) N values of the collagen samples indicate that weaning began between the ages of 6 months and 1 year, and was complete for most individuals by the age of 3. The isotopic data are consistent with a mixed diet of primarily terrestrial C3 resources. The dental pathology data indicate that complementary foods provided to young children had an impact on their oral health early on. Four outliers exhibited elevated δ(15) N values compared with the adult female range and lower levels of tooth wear than other members of their age groups. Possible explanations include prolonged breastfeeding, the consumption of diets elevated in (15) N, and physiological/nutritional stress.

CONCLUSIONS

The deciduous dental data correlate well with the isotopic data and are consistent with later textual sources regarding the timing and duration of weaning, and the composition of complementary foods. The results of this research demonstrate the value of combining isotopic and dental evidence to investigate the dietary practices of infants and young children and the impact of these practices on oral health.

Moulting matters: the importance of understanding moulting cycles in bats when using fur for endogenous marker analysis

Endogenous markers are a valuable indicator of individual animal ecology, but data interpretation requires a detailed understanding of the timing of tissue formation. Fur is commonly used in bat research using endogenous markers, but the moulting cycles of most bat species are not well documented. In this review, we (i) describe methods of investigating bat moulting; (ii) summarize the current literature on bat moulting cycles, highlighting broad trends; (iii) discuss knowledge gaps; and (iv) make recommendations for optimal fur sampling protocols. Three characteristics may indicate moulting in bats: changing skin pigmentation; visible fur growth and colour changes; and endogenous markers. Most studies reported new fur growth once annually during summer–fall, although there were exceptions. The timing of new fur growth varies among species, sexes, and age classes. Individuals commonly experience asynchronous new fur growth, with dorsal fur growth occurring before ventral. Specific moult progressions vary among species. Knowledge gaps include moulting cycles in tropical species and in subadult and yearling bats; migration during new fur growth; and the timing of fur growth compared with shedding. We recommend that fur samples taken dorsally from adult males are the most likely to be representative of the bat’s site of summer residency.

The diet-body offset in human nitrogen isotopic values: a controlled dietary study

The "trophic level enrichment" between diet and body results in an overall increase in nitrogen isotopic values as the food chain is ascended. Quantifying the diet-body Δ(15) N spacing has proved difficult, particularly for humans. The value is usually assumed to be +3-5‰ in the archaeological literature. We report here the first (to our knowledge) data from humans on isotopically known diets, comparing dietary intake and a body tissue sample, that of red blood cells. Samples were taken from 11 subjects on controlled diets for a 30-day period, where the controlled diets were designed to match each individual's habitual diet, thus reducing problems with short-term changes in diet causing isotopic changes in the body pool. The Δ(15) N(diet-RBC) was measured as +3.5‰. Using measured offsets from other studies, we estimate the human Δ(15) N(diet-keratin) as +5.0-5.3‰, which is in good agreement with values derived from the two other studies using individual diet records. We also estimate a value for Δ(15) N(diet-collagen) of ≈6‰, again in combination with measured offsets from other studies. This value is larger than usually assumed in palaeodietary studies, which suggests that the proportion of animal protein in prehistoric human diet may have often been overestimated in isotopic studies of palaeodiet.