LYM2-dependent chitin perception limits molecular flux via plasmodesmata

Chitin acts as a pathogen-associated molecular pattern from fungal pathogens whose perception triggers a range of defense responses. We show that LYSIN MOTIF DOMAIN-CONTAINING GLYCOSYLPHOSPHATIDYLINOSITOL-ANCHORED PROTEIN 2 (LYM2), the Arabidopsis homolog of a rice chitin receptor-like protein, mediates a reduction in molecular flux via plasmodesmata in the presence of chitin. For this response, lym2-1 mutants are insensitive to the presence of chitin, but not to the flagellin derivative flg22. Surprisingly, the chitin-recognition receptor CHITIN ELCITOR RECEPTOR KINASE 1 (CERK1) is not required for chitin-induced changes to plasmodesmata flux, suggesting that there are at least two chitin-activated response pathways in Arabidopsis and that LYM2 is not required for CERK1-mediated chitin-triggered defense responses, indicating that these pathways are independent. In accordance with a role in the regulation of intercellular flux, LYM2 is resident at the plasma membrane and is enriched at plasmodesmata. Chitin-triggered regulation of molecular flux between cells is required for defense responses against the fungal pathogen Botrytis cinerea, and thus we conclude that the regulation of symplastic continuity and molecular flux between cells is a vital component of chitin-triggered immunity in Arabidopsis.     

Über eine Methode der qualitativen Bestimmung von Giftwirkungen auf Fermentsysteme der Zellatmung

Ohne ZusammenfassungMit 1 Textabbildung.Unter Leitung von Prof. Dr. Wilhelm Doerr.     

Recent Advances in Archaeological Science Techniques Special Feature: Dating the emergence of dairying by the first farmers of Central Europe using 14C analysis of fatty acids preserved in pottery vessels

Direct, accurate, and precise dating of archaeological pottery vessels is now achievable using a recently developed approach based on the radiocarbon dating of purified molecular components of food residues preserved in the walls of pottery vessels. The method targets fatty acids from animal fat residues, making it uniquely suited for directly dating the inception of new food commodities in prehistoric populations. Here, we report a large-scale application of the method by directly dating the introduction of dairying into Central Europe by the Linearbandkeramik (LBK) cultural group based on dairy fat residues. The radiocarbon dates (n = 27) from the 54th century BC from the western and eastern expansion of the LBK suggest dairy exploitation arrived with the first settlers in the respective regions and were not gradually adopted later. This is particularly significant, as contemporaneous LBK sites showed an uneven distribution of dairy exploitation. Significantly, our findings demonstrate the power of directly dating the introduction of new food commodities, hence removing taphonomic uncertainties when assessing this indirectly based on associated cultural materials or other remains.

The introduction of new food commodities into the human diet at the very beginnings of plant and animal domestication is one of the most critical questions in the Neolithization process, having far reaching consequences for human evolution and environmental change. Of major importance is milk exploitation, as it relates to animal domestication but also the ability of adult humans to digest lactose (1, 2). Clearly, identifying the beginnings of the exploitation of domesticated animals for their secondary products (i.e., those obtained during the life of animals, such as milk, wool, or blood) as opposed to primary products (i.e., those obtained by the death of the animal such as meat, skin, teeth, or horn) makes it extremely important to establish when and how dairying began (3, 4). Directly dating the introduction of a new food commodity is nonetheless challenging.Evidence for dairy exploitation in prehistory can be interpreted from iconography, diagnostic ceramics, or domesticated animal slaughter patterns based on sex and ages (3, 4). Additionally, direct evidence for dairy exploitation can be derived from lipid analyses of food residues preserved in pottery vessels. By determining the stable carbon isotope values of the two fatty acids (FAs) (C_16:0 and C_18:0) characteristic of degraded animal fats, dairy products can be distinguished from carcass products (5). Recent combined lipid residue analyses of pottery vessels and animal management assessments based on faunal remains (stable isotopes, butchery practices, kill-off patterns, and calving patterns) have provided invaluable knowledge of early dairying practices at archaeological sites. Currently, the earliest evidence for milk use from lipid residues and faunal assemblages recovered during the Neolithic was found in Anatolia during the 7th millennium BC (6), from several regions in the Balkans, eastern Europe, and the Mediterranean during the 6th millennium BC (7–12), in Saharan Africa (Libya and Algeria) during the 5th millennium BC (13–15), from the beginning of the Neolithic in Britain, Ireland, and Scandinavia during the 4th millennium BC (5, 16–19), and in the Baltic countries during the 3rd millennium BC (16). The dates of the introduction of dairying in these regions have been established largely indirectly based on associated materials (e.g., animal bone collagen, charcoal, charred seeds, etc.) recovered from the same archaeological contexts as the pottery yielding milk fat residues. However, uncertainties exist with indirect dating due to possible intrusion or residuality of datable materials, resulting from the disturbance of archaeological layers and the requirement for the datable materials to be short-lived and truly contemporaneous in date with the pottery vessels containing the dairy residues.Thus, the application of recently developed methods for the direct dating of lipids from pottery food residues offers a unique approach to obtain accurate and precise dates for the introduction of new food commodities. The direct ¹⁴C dating of dairy fat residues avoids all the aforementioned uncertainties, offering an unprecedented opportunity to accurately date the start of dairying practices. At the University of Bristol, United Kingdom, we recently reported a method for radiocarbon dating pottery vessels from their absorbed food residues. Our compound-specific radiocarbon analysis (CSRA) approach is based on the isolation of the C_16:0 and C_18:0 FAs from the clay matrix and freeing them from exogenous organic contaminants (20, 21). We have successfully applied this approach to a small number of dairy residues from the Libyan Sahara and Central Europe, with one of the oldest dated dairy residues coming from the 6th millennium in the Balkans (11, 22). Hence, this dating method offers the opportunity to directly date residues identified as dairy fats based on the compound-specific δ¹³C values of the C_16:0 and C_18:0 FAs, avoiding taphonomic uncertainties arising from dating-associated materials.In this paper, we focus on the Linearbandkeramik (LBK) culture, the first farming society in Central Europe, which emerged and expanded over much of northern Europe in the middle of the 6th millennium BC (23). This culture has been divided into five main phases: Earliest (I), Early (II), Middle (III), Late (IV), and Final (V) LBK, known as the Meier-Arendt chronology, whose timing and evolution differed in the different regions of the LBK (24). Hence, the ceramic phases discussed in the remainder of this paper use the regional and site classifications for the chronology of earliest, early, middle, and Late LBK, which are not necessarily contemporaneous. For example, phase I in Poland and phase I in Cuiry-lès-Chaudardes refer to the Earliest and Late LBK phases, respectively, in the Meier-Arendt chronology.Dairy residues were identified in varying quantities at LBK sites across Central Europe. Some sites show only a weak dairy signal (1 to 2 potsherds only), while others display much higher recovery, with over 20% of the residues displaying dairy fat molecular and carbon isotope characteristics. These results emphasize the spatial disparity in the exploitation of cattle and caprines for their milk in this period. We do not exclude the possibility that the use of organic containers other than clay vessels for dairy products at some sites may affect the overall dairy lipid recovery observed. Diachronic studies in certain regions also revealed dairy practices evolving from being nonexistent or at very low levels at LBK sites but becoming much more abundant in the following Middle Neolithic cultures [e.g., the Rössen culture in Lower Alsace, France (22) or Funnel Beaker culture at the site of Kopydłowo, Poland (25)]. Dating of dairy residues recovered from the earliest phases of the sites would provide calendar ages for the emergence of dairying between LBK regions based directly on the commodity itself rather than on associated materials. Critically, some sites cannot be dated by conventional materials due to their poor preservation, while at other sites where dairy evidence is scarce, the possibility exists for false-positive signal arising due to stratigraphic perturbations. In reporting here the application of our recently developed CSRA method to a wide range of potsherds, we begin to resolve the timing of appearance of dairying practices by LBK farmers during the Neolithic in the diverse regions of the settlements.     

Predictive Factors for Bilateral Disease in Papillary Microcarcinoma: A Retrospective Cohort Study

Background: Based on risk stratification, the therapeutic options in papillary microcarcinoma (PTMC) can be active surveillance or surgery. Multifocal tumor occurrence can be decisive in determining the treatment strategy. The objective of this study was to identify risk factors for bilateral tumor occurrence in PTMC to enable individual therapy planning. Methods: A total of 545 PTMC patients who underwent thyroidectomy from 2008 to 2020 were retrieved. Univariate and multivariate analyses were performed to evaluate risk factors for bilateral PTMC. Results: 25.1% (n = 137) of all patients had multifocal PTMC, and 13.2% (n = 72) bilateral PTMC, respectively. In contrast to the maximum tumor size, the total tumor size significantly influenced a bilateral tumor manifestation (median total tumor size 5 mm versus 8.5 mm for bilateral PTMC, p < 0.001). A cut-off level for the total tumor size of >10 mm resulted in a sensitivity and specificity of 29.2% and 94.7%, respectively, in predicting a bilateral tumor manifestation, AUC 0.680 (95% CI, 0.611–0.748, p < 0.001). A cut-off of >4 tumors showed a sensitivity of 99.4% and a specificity of 97.5%, AUC 0.897 (95% CI, 0.870–0.924, p < 0.001) in predicting bilaterality. Conclusion: We could demonstrate for the first time that a total tumor size of >10 mm and more than four tumors significantly increased the risk of bilateral PTMC tumor involvement. These findings enable a risk-adjusted patient treatment.     

Gas Atomization of Duplex Stainless Steel Powder for Laser Powder Bed Fusion

Duplex stainless steel powders for laser additive manufacturing have not been developed extensively. In this study, the melts of a super duplex stainless steel X2CrNiMoCuWN25-7-4 (AISI F55, 1.4501) were atomized with different process gases (Ar or N₂) at different atomization gas temperatures. The process gas N₂ in the melting chamber leads to a higher nitrogen dissolution in the steel and a higher nitrogen content of the atomized powders. The argon-atomized powders have more gas porosity inside the particles than the nitrogen-atomized powders. In addition, the higher the atomization gas temperature, the finer the powder particles. The duplex stainless steel powders showed good processability during PBF-LB/M (Laser powder bed fusion). The gas entrapment in the powder particles, regardless of the gas chemistry and the gas content, appears to have a negligible effect on the porosity of the as-built parts.     

Sialendoscopy plus laser lithotripsy in sialolithiasis of the submandibular gland in 64 patients: A simple and safe procedure

ObjectiveTo demonstrate the safety and efficiency of holmium laser-assisted lithotripsy during sialendoscopy of the submandibular gland using a retrospective, interventional consecutive case series.MethodsWe performed 374 sialendoscopies between 2008 and 2015 and evaluated all patients regarding clinical symptoms, clinical findings, therapy and outcome. We performed 109 procedures of holmium laser-assisted lithotripsy in 64 patients whose sialoliths measured 5 mm or more in diameter. In addition to retrospective case note reviews, we performed telephone interviews of all patients in January 2017.ResultsWe performed 374 consecutive submandibular gland sialendoscopy procedures in 276 patients between 2008 to 2015. Sialolithiasis had either previously been diagnosed, or symptoms highly suggestive of sialolithiasis of the submandibular gland presented in 197 patients.Holmium laser-assisted Laser lithotripsy was performed in 109 cases (64.9%). Smaller mobile concrement was removed directly either by forceps or wire basket, or following marsupialisation of the submandibular duct. This was the case in 88 patients (29.1%). Three patients (0.8%) required surgical removal of the submandibular gland due to early abscess. The majority of patients (n = 374 procedures; 90.1%) remained symptom-free after two or more years following intervention. In the remaining procedures (n = 37 procedures; 9.9%), patients reported discreet postprandial problems but did not seek medical attention. In total, we managed to preserve the submandibular gland and avoid open surgery in 99% of patients through endoscopic management of submandibular concrement and duct stenosis.ConclusionHolmium laser-assisted lithotripsy is a simple, safe, and effective procedure for treating patients with sialolithiasis of the submandibular gland. Removal of the gland is rarely required, and removing the gland without prior sialendoscopy is no longer recommended. It should be offered to all patients with submandibular gland sialolithiasis, or such patients should be referred to the appropriate centre for sialendoscopy before submandibulectomy is considered.     

The effects of different lignans and isoflavones, tested as aglycones and glycosides, on hormone receptor-positive and -negative breast carcinoma cells in vitro

Purpose  

Phytooestrogens are known to cause anti-cancer effects on mamma carcinoma cells. In this study, the effects of the lignan secoisolariciresinol and the isoflavone glycosides and aglycones genistein, genistin, daidzein and daidzin were tested on MCF-7 and BT20 cells in vitro.     

Metabolic activation of 2‐amino‐1‐methyl‐6‐phenylimidazo [4,5‐b]pyridine and DNA adduct formation depends on p53: Studies in Trp53(+/+),Trp53(+/−) and Trp53(−/−) mice

The expression of the tumor suppressor p53 can influence the bioactivation of, and DNA damage induced by, the environmental carcinogen benzo[a]pyrene, indicating a role for p53 in its cytochrome P450 (CYP)‐mediated biotransformation. The carcinogen 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), which is formed during the cooking of food, is also metabolically activated by CYP enzymes, particularly CYP1A2. We investigated the potential role of p53 in PhIP metabolism in vivo by treating Trp53(+/+), Trp53(+/?) and Trp53(?/?) mice with a single oral dose of 50 mg/kg body weight PhIP. N‐(Deoxyguanosin‐8‐yl)‐2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP‐C8‐dG) levels in DNA, measured by liquid chromatography‐tandem mass spectrometry, were significantly lower in liver, colon, forestomach and glandular stomach of Trp53(?/?) mice compared to Trp53(+/+) mice. Lower PhIP‐DNA adduct levels in the livers of Trp53(?/?) mice correlated with lower Cyp1a2 enzyme activity (measured by methoxyresorufin‐O‐demethylase activity) in these animals. Interestingly, PhIP‐DNA adduct levels were significantly higher in kidney and bladder of Trp53(?/?) mice compared to Trp53(+/+) mice, which was accompanied by higher sulfotransferase (Sult) 1a1 protein levels and increased Sult1a1 enzyme activity (measured by 2‐naphthylsulfate formation from 2‐naphthol) in kidneys of these animals. Our study demonstrates a role for p53 in the metabolism of PhIP in vivo, extending previous results on a novel role for p53 in xenobiotic metabolism. Our results also indicate that the impact of p53 on PhIP biotransformation is tissue‐dependent and that in addition to Cyp1a enzymes, Sult1a1 can contribute to PhIP‐DNA adduct formation.