Oral zinc supplementation improves hepatic encephalopathy. Results of a randomised controlled trial

22 cirrhotic patients with chronic encephalopathy were given oral zinc supplementation or placebo in a double-blind randomised trial. In the group which received zinc acetate 600 mg a day for 7 days, serum zinc had been restored to normal by day 8. On day 8 hepatic encephalopathy, as assessed by a trailmaking test, was improved in the supplemented group but not in the placebo group. There was also a significant increase in blood urea nitrogen in the supplemented group. Short-term oral zinc supplementation probably improved hepatic encephalopathy by correcting the zinc deficiency that compromises conversion of ammonia to urea. The duration of this improvement requires further investigation.

Hemodynamic changes in patients with portal venous obstruction

Splanchnic and systemic hemodynamics were evaluated in five adult patients with portal hypertension due to portal venous obstruction and were compared with those of patients with cirrhosis and those of a control group. In patients with portal venous obstruction, the gradient between wedged and free hepatic venous pressures ranged from 2 to 3 mm Hg, as in the control group, and was significantly lower than in patients with cirrhosis. Hepatic blood flow averaged 0.521 +/- 0.127 liter per min per m2 (mean +/- S.D.) and was significantly lower than that measured in cirrhotic and normal patients. Cardiac index averaged 3.788 +/- 0.629 liters per min per m2; this high value for cardiac index was not significantly different from that measured in cirrhotic patients, but was significantly higher than in patients of the control group. It is suggested that a hyperkinetic circulatory state may result from the development of portal-systemic venous collateral circulation in patients with portal venous obstruction having normal liver and hepatic venous pressures.

Acute effects of captopril on systemic and renal hemodynamics and on renal function in cirrhotic patients with ascites

The reduction of angiotensin II production by captopril--an angiotensin-converting enzyme inhibitor--could suppress hyperaldosteronism without impairment of renal function and could thereby be useful in the treatment of ascites in patients with cirrhosis. Systemic and renal hemodynamics and renal function were studied in 6 nonazotemic patients with cirrhosis and ascites with a low-sodium diet before and after oral administration of 25 mg of captopril. Cardiac output and renal blood flow did not change significantly after administration of captopril, whereas mean arterial pressure significantly decreased. Systemic and renal vascular resistances were significantly reduced. There was a statistically significant reduction of glomerular filtration rate, filtration fraction, and urinary output. Plasma renin activity significantly increased in all patients after administration of captopril. A statistically significant correlation was found between the decrease in mean arterial pressure and the reduction of glomerular filtration, but no relationship was found between basal values of plasma renin activity and the other observed variations. We concluded that captopril mainly induces hypotension due to an increase in renal vasodilatation in ascitic patients with cirrhosis.

Strontium isotopes (87 Sr/86 Sr) in terrestrial ecological and palaeoecological research: empirical efforts and recent advances in continental-scale models

Strontium (Sr) isotope analysis can provide detailed biogeographical and ecological information about modern and ancient organisms. Because Sr isotope ratios (⁸⁷ Sr/⁸⁶ Sr) in biologically relevant materials such as water, soil, vegetation, and animal tissues predominantly reflect local geology, they can be used to distinguish geologically distinct regions as well as identify highly mobile individuals or populations. While the application of Sr isotope analysis to biological research has been steadily increasing, high analytical costs have prohibited more widespread use. Additionally, accessibility of this geochemical tool has been hampered due to limited understanding of (i) the degree to which biologically relevant materials differ in their spatial averaging of ⁸⁷ Sr/⁸⁶ Sr ratios, and (ii) how these differences may be affected by lithologic complexity. A recently developed continental-scale model that accounts for variability in bedrock weathering rates and predicts Sr isotope ratios of surface water could help resolve these questions. In addition, if this 'local water' model can accurately predict ⁸⁷ Sr/⁸⁶ Sr ratios for other biologically relevant materials, there would be reduced need for researchers to assess regional Sr isotope patterns empirically. Here, we compile ⁸⁷ Sr/⁸⁶ Sr data for surface water, soil, vegetation, and mammalian and fish skeletal tissues from the literature and compare the accuracy with which the local water model predicts Sr isotope data among these five materials across the contiguous USA. We find that measured Sr isotope ratios for all five materials are generally close to those predicted by the local water model, although not with uniform accuracy. Mammal skeletal tissues are most accurately predicted, particularly in regions with low variability in ⁸⁷ Sr/⁸⁶ Sr predicted by the local water model. Increasing regional geologic heterogeneity increases both the offset and variance between modelled and empirical Sr isotope ratios, but its effects are broadly similar across materials. The local water model thus provides a readily available source of background data for predicting ⁸⁷ Sr/⁸⁶ Sr for biologically relevant materials in places where empirical data are lacking. The availability of increasingly high-quality modelled Sr data will dramatically expand the accessibility of this geochemical tool to ecological applications.

Triple sulfur-oxygen-strontium isotopes probabilistic geographic assignment of archaeological remains using a novel sulfur isoscape of western Europe

Sulfur isotope composition of organic tissues is a commonly used tool for gathering information about provenance and diet in archaeology and paleoecology. However, the lack of maps predicting sulfur isotope variations on the landscape limits the possibility to use this isotopic system in quantitative geographic assignments. We compiled a database of 2,680 sulfur isotope analyses in the collagen of archaeological human and animal teeth from 221 individual locations across Western Europe. We used this isotopic compilation and remote sensing data to apply a multivariate machine-learning regression, and to predict sulfur isotope variations across Western Europe. The resulting model shows that sulfur isotope patterns are highly predictable, with 65% of sulfur isotope variations explained using only 4 variables representing marine sulfate deposition and local geological conditions. We used this novel sulfur isoscape and existing strontium and oxygen isoscapes of Western Europe to apply triple isotopes continuous-surface probabilistic geographic assignments to assess the origin of a series of teeth from local animals and humans from Brittany. We accurately and precisely constrained the origin of these individuals to limited regions of Brittany. This approach is broadly transferable to studies in archaeology and paleoecology as illustrated in a companion paper (Colleter et al. 2021).

Round-trip across the Sahara: Afrotropical Painted Lady butterflies recolonize the Mediterranean in early spring

The Palearctic-African migratory circuit has been typically associated with birds. Very few insects are known to endure annual trans-Saharan circuits, but the Painted Lady butterfly (Vanessa cardui) is an exception. While it was demonstrated that this species massively migrates from Europe to the Afrotropics during the autumn, the existence of a reverse migration from the Afrotropics to Europe in the early spring remains hypothetical. Here, we analysed wing stable hydrogen isotope values (δ²H) of V. cardui migrants collected from February to April across the circum-Mediterranean region. We assessed their region of natal origin by comparing their wing isotope signature predicted δ²H values (isoscape). The results unambiguously demonstrate a sub-Saharan origin for many individuals, especially those collected in February, representing the first tangible evidence for a reverse northwards trans-Saharan migration in spring. This work supports the view that the Afrotropics (mostly exploited from September to February) is key in the V. cardui Palearctic-African population dynamics. This species relies on both temperate and tropical habitats to complete their multigenerational cycle, an unprecedented adaptation for butterflies and for most migratory insects. Such a migratory circuit has strong parallelisms with those of migratory birds.

Assessment of beta-adrenergic blockade with propranolol in patients with cirrhosis

Fourteen patients with cirrhosis and bleeding esophageal varices were treated with propranolol. The dose of propranolol was determined by decreasing the resting heart rate by 25% 12 hr after an oral dose of propranolol which was given twice a day. Significant decreases in the hepatic venous pressure gradient and cardiac output after 1 month of propranolol administration was observed. To assess beta-adrenergic blockade, the isoproterenol test and plasma propranolol levels were evaluated. Increasing doses of isoproterenol were injected to increase the resting heart rate 25 beats per minute (chronotropic dose 25 or CD25 ). Plasma propranolol concentrations were measured in blood samples drawn 4 hr after the last oral dose. The mean CD25 was 5 +/- 2 micrograms before and 146 +/- 84 micrograms after 1 month of propranolol administration. The plasma propranolol level after 1 month of drug administration was 0.69 +/- 0.47 microM per liter i.e. 2.33 +/- 1.59 micrograms per ml. A significant correlation was found between the CD25 measured after continuous propranolol administration and plasma propranolol level. In conclusion, the efficacy of beta-adrenergic blockade was estimated by the isoproterenol test which correlates with the plasma propranolol level in patients with cirrhosis. This study suggests that the isoproterenol test is useful in assessing beta-adrenergic blockade with propranolol in patients with cirrhosis.

The Afrotropical breeding grounds of the Palearctic-African migratory painted lady butterflies (Vanessa cardui)

Migratory insects are key players in ecosystem functioning and services, but their spatiotemporal distributions are typically poorly known. Ecological niche modeling (ENM) may be used to predict species seasonal distributions, but the resulting hypotheses should eventually be validated by field data. The painted lady butterfly (Vanessa cardui) performs multigenerational migrations between Europe and Africa and has become a model species for insect movement ecology. While the annual migration cycle of this species is well understood for Europe and northernmost Africa, it is still unknown where most individuals spend the winter. Through ENM, we previously predicted suitable breeding grounds in the subhumid regions near the tropics between November and February. In this work, we assess the suitability of these predictions through i) extensive field surveys and ii) two-year monitoring in six countries: a large-scale monitoring scheme to study butterfly migration in Africa. We document new breeding locations, year-round phenological information, and hostplant use. Field observations were nearly always predicted with high probability by the previous ENM, and monitoring demonstrated the influence of the precipitation seasonality regime on migratory phenology. Using the updated dataset, we built a refined ENM for the Palearctic-African range of V. cardui. We confirm the relevance of the Afrotropical region and document the missing natural history pieces of the longest migratory cycle described in butterflies.

Multi-isotopes in human hair: A tool to initiate cross-border collaboration in international cold-cases

Unidentified human remains have historically been investigated nationally by law enforcement authorities. However, this approach is outdated in a globalized world with rapid transportation means, where humans easily move long distances across borders. Cross-border cooperation in solving cold-cases is rare due to political, administrative or technical challenges. It is fundamental to develop new tools to provide rapid and cost-effective leads for international cooperation. In this work, we demonstrate that isotopic measurements are effective screening tools to help identify cold-cases with potential international ramifications. We first complete existing databases of hydrogen and sulfur isotopes in human hair from residents across North America by compiling or analyzing hair from Canada, the United States (US) and Mexico. Using these databases, we develop maps predicting isotope variations in human hair across North America. We demonstrate that both δ2H and δ34S values of human hair are highly predictable and display strong spatial patterns. Multi-isotope analysis combined with dual δ2H and δ34S geographic probability maps provide evidence for international travel in two case studies. In the first, we demonstrate that multi-isotope analysis in bulk hair of deceased border crossers found in the US, close to the Mexico-US border, help trace their last place of residence or travel back to specific regions of Mexico. These findings were validated by the subsequent identification of these individuals through the Pima County Office of the Medical Examiner in Tucson, Arizona. In the second case study, we demonstrate that sequential multi-isotope analysis along the hair strands of an unidentified individual found in Canada provides detailed insights into the international mobility of this individual during the last year of life. In both cases, isotope data provide strong leads towards international travel.

Black pigments in the liver related to gold and titanium deposits. A report of four cases

Black pigments are rarely described in the liver. We report four patients with chronic cholestasis and black pigments described on liver histological examination. Energy-dispersive X-ray analysis identified these black pigments as gold particles in the first three patients and titanium particles in the fourth. The origin of the gold deposits was unknown in this first patient and related to gold salts therapy in the two others. Titanium deposits was associated with hepatic granulomas and related to total knee replacement.

Continental igneous rock composition: A major control of past global chemical weathering

The composition of igneous rocks in the continental crust has changed throughout Earth's history. However, the impact of these compositional variations on chemical weathering, and by extension on seawater and atmosphere evolution, is largely unknown. We use the strontium isotope ratio in seawater [(87Sr/86Sr)seawater] as a proxy for chemical weathering, and we test the sensitivity of (87Sr/86Sr)seawater variations to the strontium isotopic composition (87Sr/86Sr) in igneous rocks generated through time. We demonstrate that the 87Sr/86Sr ratio in igneous rocks is correlated to the epsilon hafnium (εHf) of their hosted zircon grains, and we use the detrital zircon record to reconstruct the evolution of the 87Sr/86Sr ratio in zircon-bearing igneous rocks. The reconstructed 87Sr/86Sr variations in igneous rocks are strongly correlated with the (87Sr/86Sr)seawater variations over the last 1000 million years, suggesting a direct control of the isotopic composition of silicic magmatism on (87Sr/86Sr)seawater variations. The correlation decreases during several time periods, likely reflecting changes in the chemical weathering rate associated with paleogeographic, climatic, or tectonic events. We argue that for most of the last 1000 million years, the (87Sr/86Sr)seawater variations are responding to changes in the isotopic composition of silicic magmatism rather than to changes in the global chemical weathering rate. We conclude that the (87Sr/86Sr)seawater variations are of limited utility to reconstruct changes in the global chemical weathering rate in deep times.

Isotope geochemistry reveals ontogeny of dispersal and exchange between main-river and tributary habitats in smallmouth bass Micropterus dolomieu

Radiogenic strontium isotope ratios (⁸⁷ Sr:⁸⁶ Sr) in otoliths were compared with isotope ratios predicted from models and observed in water sampling to reconstruct the movement histories of smallmouth bass Micropterus dolomieu between main-river and adjacent tributary habitats. A mechanistic model incorporating isotope geochemistry, weathering processes and basin accumulation reasonably predicted observed river ⁸⁷ Sr:⁸⁶ Sr across the study area and provided the foundations for experimental design and inferring fish provenance. Exchange between rivers occurred frequently, with nearly half (48%) of the 209 individuals displaying changes in otolith ⁸⁷ Sr:⁸⁶ Sr reflecting movement between isotopically distinct rivers. The majority of between-river movements occurred in the first year and often within the first few months of life. Although more individuals were observed moving from the main river into tributaries, this pattern did not necessarily reflect asymmetry in exchange. Several individuals made multiple movements between rivers over their lifetimes; no patterns were found, however, that suggest seasonal or migratory movement. The main-river sport fishery is strongly supported by recruitment from tributary spawning, as 26% of stock size individuals in the main river were spawned in tributaries. The prevailing pattern of early juvenile dispersal documented in this study has not been observed previously for this species and suggests that the process of establishing seasonal home-range areas occurs up to 2 years earlier than originally hypothesized. Extensive exchange between rivers would have substantial implications for management of M. dolomieu populations in river-tributary networks.

The last battle of Anne of Brittany: Solving mass grave through an interdisciplinary approach (paleopathology, biological anthropology, history, multiple isotopes and radiocarbon dating)

Mass graves are usually key historical markers with strong incentive for archeological investigations. The identification of individuals buried in mass graves has long benefitted from traditional historical, archaeological, anthropological and paleopathological techniques. The addition of novel methods including genetic, genomic and isotopic geochemistry have renewed interest in solving unidentified mass graves. In this study, we demonstrate that the combined use of these techniques allows the identification of the individuals found in two Breton historical mass graves, where one method alone would not have revealed the importance of this discovery. The skeletons likely belong to soldiers from the two enemy armies who fought during a major event of Breton history: the siege of Rennes in 1491, which ended by the wedding of the Duchess of Brittany with the King of France and signaled the end of the independence of the region. Our study highlights the value of interdisciplinary approaches with a particular emphasis on increasingly accurate isotopic markers. The development of the sulfur isoscape and testing of the triple isotope geographic assignment are detailed in a companion paper [13].

Historical Landscape Use of Migratory Caribou: New Insights From Old Antlers

Accumulations of shed caribou antlers (Rangifer tarandus) are valuable resources for expanding the temporal scope with which we evaluate seasonal landscape use of herds. Female caribou shed their antlers within days of giving birth, thus marking calving ground locations. Antler geochemistry (87Sr/86Sr) reflects the isotopic signature of regions used during antler growth, thereby providing data on a second component of seasonal landscape use. Here, we evaluate shed caribou antlers from the Coastal Plain of the Arctic National Wildlife Refuge, Alaska. The Central and Eastern regions of the Coastal Plain are calving grounds for the Porcupine Caribou Herd, while the Western Coastal Plain supports calving by the Central Arctic Herd. We found that antler 87Sr/86Sr from the Central and Eastern Coastal Plain were isotopically indistinguishable, while antler 87Sr/86Sr from the Western Coastal Plain was significantly smaller. For each region, we compared isotopic data for “recent” antlers, which overlap the bulk of standardized state and federal caribou monitoring (early 1980s and younger), with “historical” antlers shed in years predating these records (from the 1300s to the 1970s). For Porcupine Herd females calving in the Arctic Refuge, comparisons of antler 87Sr/86Sr through time indicate that summer ranges have been consistent since at least the 1960s. However, changes between historical and recent antler 87Sr/86Sr for the Central Arctic Herd indicate a shift in summer landscape use after the late 1970s. The timing of this shift is coincident with multiple factors including increased infrastructural development in their range related to hydrocarbon extraction. Accumulations of shed caribou antlers and their isotope geochemistry extend modern datasets by decades to centuries and provide valuable baseline data for evaluating potential anthropogenic and other influences on caribou migration and landscape use.

Small-scale mobility fostering the interaction networks of Patagonian (Argentina) hunter-gatherers during the Late Holocene: Perspectives from strontium isotopes and exotic items

During the Late Holocene, hunter-gatherer interaction networks significantly grew in intensity and extension across Patagonia. Although this growth is evidenced by the increased flow of exotic items across the region, the mechanisms behind these strengthening social networks remain unclear. Since evidence suggests that some individuals might have performed long-distance trips, this article aims to address the potential relationship between these individuals and the flows of exotic items in North Patagonia. We analyzed 54 enamel teeth for strontium isotopes and reconstructed their probable mobility using mixed-effect models and isotope-based geographic assignments. We inferred population and individual mobility trends and compared them against the flow of exotic items built from a standardized compilation. Our results indicate that most individuals have isotopic composition compatible with residence within their burial and surrounding areas. However, a few individuals show isotopic composition incompatible with their burial areas, which suggests axes -from the burial location to the most likely isotope integration area- of extraordinary mobility. At the same time, the flows of exotic items overlap with these axes around the eastern sector of the study area suggesting that this location could have been a central point of convergence for people and items. We argue that small-scale socially driven mobility could have played a relevant role as a general mechanism of interaction that fostered and materialized Patagonian interaction networks during the Late Holocene.

Silver Linings at the Dawn of a “Golden Age”

Nearly four decades after the first applications of strontium isotope analyses in archaeology and paleoecology research, it could be said that we are entering a “Golden Age”. Here, we reflect on major past developments and current strengths in strontium isotope research, as well as speculate on future directions. We review (1) the currently limited number of (but much needed) controlled feeding experiments, (2) recent advances in isoscape mapping and spatial assignment, and (3) the strength of multi-proxy approaches (including both the integration of strontium isotopes with other isotope systems and complementary techniques such as ancient DNA analyses). We also explore the integration of strontium isotope research with other types of paleoecological or archaeology data, as well as with evidence and interpretative frameworks from other fields (such as conservation ecology, conservation paleobiology or history). This blending is critical as we seek to advance the field beyond simply distinguishing local or relatively sedentary individuals from those that were non-local or highly mobile. We finish with a call for future research centered on balancing methodological developments and novel applications with critical self-reflection, deeper theoretical considerations and cross-disciplinarity.

Costs and resource utilization patterns in surgical site infections: a pre-COVID-19 perspective from France, Germany, Spain, and the UK

BACKGROUND

Surgical site infections (SSIs), mainly caused by Staphylococcus aureus, pose a significant economic burden in Europe, leading to increased hospitalization duration, mortality, and treatment costs, particularly with drug-resistant strains such as meticillin-resistant S. aureus.

AIM

To conduct a case-control study on the economic impact of S. aureus SSI in adult surgical patients across high-volume centres in France, Germany, Spain, and the UK, aiming to assess the overall and procedure-specific burden across Europe.

METHODS

The SALT study is a multinational, retrospective cohort study with a nested case-control analysis focused on S. aureus SSI in Europe. The study included participants from France, Germany, Italy, Spain, and the UK who underwent invasive surgery in 2016 and employed a micro-costing approach to evaluate health economic factors, matching S. aureus SSI cases with controls.

FINDINGS

In 2016, among 178,904 surgical patients in five European countries, 764 developed S. aureus SSI. Matching 744 cases to controls, the study revealed that S. aureus SSI cases incurred higher immediate hospitalization costs (€8,810), compared to controls (€6,032). Additionally, S. aureus SSI cases exhibited increased costs for readmissions within the first year post surgery (€7,961.6 versus €5,298.6), with significant differences observed. Factors associated with increased surgery-related costs included the cost of hospitalization immediately after surgery, first intensive care unit (ICU) admission within 12 months, and hospital readmission within 12 months, as identified through multivariable analysis.

CONCLUSION

The higher rates of hospitalization, ICU admissions, and readmissions among S. aureus SSI cases highlight the severity of these infections and their impact on healthcare costs, emphasizing the potential benefits of evidence-based infection control measures and improved patient care to mitigate the economic burden.