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Plant-pathogenic bacteria are one of the major constraints on agricultural yield. In order to selectively treat these bacteria, it is essential to understand the molecular structure of their cell membrane. Previous studies have focused on analyzing hydrolyzed fatty acids (FA) due to the complexity of bacterial membrane lipids. These studies have highlighted the occurrence of branched-chain fatty acids (BCFA) alongside normal-chain fatty acids (NCFA) in many bacteria. As several FA are bound in the intact phospholipids of the bacterial membrane, the presence of isomeric FA complicates lipid analysis. Furthermore, commercially available reference standards do not fully cover potential lipid isomers. To address this issue, we have developed a reversed-phase high-performance liquid chromatography (RP-HPLC) method with tandem mass spectrometry (MS/MS) to analyze the phospholipids of various plant-pathogenic bacteria with a focus on BCFA containing phospholipids. The study revealed the separation of three isomeric phosphatidylethanolamines (PE) depending on the number of bound BCFA to NCFA. The validation of the retention order was based on available reference standards in combination with the analysis of hydrolyzed fatty acids through gas chromatography with mass spectrometry (GC/MS) after fractionation. Additionally, the transferability of the retention order to other major lipid classes, such as phosphatidylglycerols (PG) and cardiolipins (CL), was thoroughly examined. Using the information regarding the retention behavior, the phospholipid profile of six plant-pathogenic bacteria was structurally elucidated. Furthermore, the developed LC-MS/MS method was used to classify the plant-pathogenic bacteria based on the number of bound BCFA in the phospholipidome., (© 2024. The Author(s).)

Background: Lipidomics studies require rapid separations with accurate and reliable quantification results to further elucidate the role of lipids in biological processes and their biological functions. Supercritical fluid chromatography (SFC), in particular, can provide this rapid and high-resolution separation. The combination with trapped ion mobility spectrometry (TIMS) has not yet been applied, although the post-ionization separation method in combination with liquid chromatography or imaging techniques has already proven itself in resolving isomeric and isobaric lipids and preventing false identifications. However, a multidimensional separation method should not only allow confident identification but also provide quantitative results to substantiate studies with absolute concentrations., Results: A SFC method was developed and the hyphenation of SFC and TIMS was further explored towards the separation of different isobaric overlaps. Furthermore, lipid identification was performed using mass spectrometry (MS) and parallel accumulation serial fragmentation (PASEF) MS/MS experiments in addition to retention time and collision cross section (CCS). Quantification was further investigated with short TIMS ramps and performed based on the ion mobility signal of lipids, since TIMS increases the sensitivity by noise filtering. The final method was, as an exemplary study, applied to investigate the function of different ceramide synthases (CerS) in the nematode and model organism Caenorhabditis elegans (C. elegans). Loss of three known CerS hyl-1, hyl-2 and lagr-1 demonstrated different influences on and alterations in the sphingolipidome., Significance: This method describes for the first time the combination of SFC and TIMS-MS/MS, which enables a fast and sensitive quantification of lipids. The results of the application to C. elegans samples prove the functionality of the method and support research on the metabolism of sphingolipids in nematodes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In prior research, hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) has demonstrated applicability for characterizing regioisomers in lipidomics studies, including phosphatidylglycerols (PG) and bis(monoacyl)glycerophosphates (BMP). However, there are other lipid regioisomers, such as phosphatidylethanolamines (PE) and lyso- N -acyl-PE (LNAPE), that have not been studied as extensively. Therefore, hyphenated mass spectrometric methods are needed to investigate PE and LNAPE regioisomers individually. The asymmetric structure of LNAPE favors isomeric species, which can result in coelution and chimeric MS/MS spectra. One way to address the challenge of chimeric MS/MS spectra is through mobility-resolved fragmentation using trapped ion mobility spectrometry (TIMS). Therefore, we developed a multidimensional HILIC-TIMS-MS/MS approach for the structural characterization of isomeric phosphatidylethanolamines in both negative and positive ionization modes. The study revealed the complementary fragmentation pattern and ion mobility behavior of LNAPE in both ionization modes, which was confirmed by a self-synthesized LNAPE standard. With this knowledge, a distinction of regioisomeric PE and LNAPE was achieved in human plasma samples. Furthermore, regioisomeric LNAPE species containing at least one unsaturated fatty acid were noted to exhibit a change in collision cross-section in positive ionization mode, leading to a lipid characterization with respect to fatty acyl positional level. Similar mobility behavior was also observed for the biological LNAPE precursor N -acyl-PE (NAPE). Application of this approach to plasma and cereal samples demonstrated its effectiveness in regioisomeric LNAPE and NAPE species' elucidation.

Homosalate (HMS) is a UV filter used in sunscreens and personal care products as a mixture of cis- and trans-isomers. Systemic absorption after sunscreen use has been demonstrated in humans, and concerns have been raised about possible endocrine activity of HMS, making a general population exposure assessment desirable. In a previous study, it was shown that the oral bioavailability of cis-HMS (cHMS) is lower than that of trans-HMS (tHMS) by a factor of 10, calling for a separate evaluation of both isomers in exposure and risk assessment. The aim of the current study is the investigation of HMS toxicokinetics after dermal exposure. Four volunteers applied a commercial sunscreen containing 10% HMS to their whole body under regular-use conditions (18-40 mg HMS (kg bw) -1 ). Parent HMS isomers and hydroxylated and carboxylic acid metabolites were quantified using authentic standards and isotope dilution analysis. Further metabolites were investigated semi-quantitatively. Elimination was delayed and slower compared to the oral route, and terminal elimination half-times were around 24 h. After dermal exposure, the bioavailability of cHMS was a factor of 2 lower than that of tHMS. However, metabolite ratios in relation to the respective parent isomer were very similar to the oral route, supporting the applicability of the oral-route urinary excretion fractions for dermal-route exposure assessments. Exemplary calculations of intake doses showed margins of safety between 11 and 92 (depending on the approach) after single whole-body sunscreen application. Human biomonitoring can reliably quantify oral and dermal HMS exposures and support the monitoring of exposure reduction measures., (© 2024. The Author(s).)

Background: The placenta accreta spectrum is a complex disorder characterized by abnormal invasion of the placenta into the uterine wall, posing a significant risk of life-threatening haemorrhage for patients. Its incidence is on the rise, largely attributed to the increasing rates of caesarean sections. Management of this spectrum involves a multidisciplinary approach, although standardized protocols are not yet established. While caesarean hysterectomy remains the standard Gold, several adjunctive treatments have emerged in recent years to mitigate bleeding risk and associated morbidity. Among these, prophylactic occlusion balloons placed in the internal iliac arteries have shown promise. The aim of our study is to demonstrate the effect of prophylactic occlusion balloons in both uterine iliac arteries in the management of placental accreta spectrum disorders., Methods: A retrospective monocentric cohort study was conducted in the Department "C" of Gynaecology and Obstetrics at the Maternity Center of Tunis. The study spanned three years, from January 2nd, 2020, to December 31st, 2022. The study population consisted of two groups: Control Group (CG) comprised patients who underwent caesarean hysterectomy without internal-iliac prophylactic occlusion balloons, and Occlusion balloons of both internal iliac arteries Group (OBIIAG) included patients who underwent caesarean hysterectomy with internal-iliac prophylactic occlusion balloons., Results: A total of 38 patients were included in the study, all of whom exhibited similar epidemiological characteristics and comparable personal and obstetric histories. The most prevalent risk factor among the patients was a history of caesarean section (92%). On average, patients were diagnosed at 30 weeks of gestation, with third-trimester bleeding being the most common presentation (71% of cases). The median gestational age at delivery was between 36 and 37 weeks. We observed a significant difference in blood loss between the two groups (2888 ml in the control group and 1828 ml in the group with internal-iliac prophylactic occlusion balloons, p < 0.05). Implementation of this technique resulted in a reduced need for massive transfusions (p < 0.01) and shorter operating times (126 min for the control group and 92 min for the group with internal-iliac prophylactic occlusion balloons; p = 0.04). There were no significant differences in morbidity between the two groups., Conclusion: The intra-iliac prophylactic occlusion balloons can help reduce the risk of hemorrhage and the morbidities that come with the placenta accreta spectrum disorder., Competing Interests: The authors declare they have nothing to disclose., (© 2024 The Authors.)

To broaden the substrate scope of microbial cell factories towards renewable substrates, rational genetic interventions are often combined with adaptive laboratory evolution (ALE). However, comprehensive studies enabling a holistic understanding of adaptation processes primed by rational metabolic engineering remain scarce. The industrial workhorse Pseudomonas putida was engineered to utilize the non-native sugar D-xylose, but its assimilation into the bacterial biochemical network via the exogenous xylose isomerase pathway remained unresolved. Here, we elucidate the xylose metabolism and establish a foundation for further engineering followed by ALE. First, native glycolysis is derepressed by deleting the local transcriptional regulator gene hexR. We then enhance the pentose phosphate pathway by implanting exogenous transketolase and transaldolase into two lag-shortened strains and allow ALE to finetune the rewired metabolism. Subsequent multilevel analysis and reverse engineering provide detailed insights into the parallel paths of bacterial adaptation to the non-native carbon source, highlighting the enhanced expression of transaldolase and xylose isomerase along with derepressed glycolysis as key events during the process., (© 2024. The Author(s).)

Homosalate (HMS) is an organic UV filter used in sunscreens and personal care products. Despite its widespread use and detection in environmental matrices, little is known regarding its exposure in humans. HMS is used as a mixture of cis - and trans -isomers, and we recently revealed major differences in human toxicokinetics, indicating the need to consider these isomers separately in exposure and risk assessments. In the course of these previous investigations of human HMS toxicokinetics, we identified two trans -HMS-specific and one cis -HMS-specific biomarker candidates. However, the latter lacks sensitivity due to only low amounts excreted in urine, prompting the search for another cis -HMS-specific biomarker. Our toxicokinetic investigations revealed a total of five isomers of HMS carboxylic acid metabolites (HMS-CA). Of these, only one was specifically formed from cis -HMS (HMS-CA 5), but its full identity in terms of constitution and configuration had, so far, not been elucidated. Here, we describe the synthesis of three HMS-CA isomers, of which the isomer (1 R ,3 S ,5 S )/(1 S ,3 R ,5 R )-3-((2-hydroxybenzoyl)oxy)-1,5-dimethylcyclohexane-1-carboxylic acid turned out to be HMS-CA 5. Taken together with two previously synthesized HMS-CA isomers, we were able to identify the constitution and configuration of all five HMS-CA isomers observed in human metabolism. We integrated the newly identified cis -HMS-specific metabolite HMS-CA 5 into our previously published human biomonitoring LC-MS/MS method. Intra- and interday precisions had coefficients of variation below 2% and 5%, respectively, and the mean relative recovery was 96%. The limit of quantification in urine was 0.02 μg L -1 , enabling the quantification of HMS-CA 5 in urine samples for at least 96 h after sunscreen application. The extended method thus enables the sensitive and separate monitoring of cis - and trans -HMS in future human biomonitoring studies for exposure and risk assessment.

Objectives: To investigate the feasibility, safety, and efficiency after application of a cervical tourniquet during caesarian hysterectomy owing to placenta accreta., Study Design: It was a monocentric prospective observational study for 3 years. Patients were allocated into two group: Group Tourniquet: (TG) in which a cervical tourniquet was systematically applied during hysterectomy, control group (CG) when the caesarian hysterectomy was performed without., Results: 20 patients in the TG and 23 patients in the CG. Tourniquet application significantly reduced per operative estimated blood loss volume (TG: 530 ± 135 vs 940 ± 120 ml in the CG, p = 0.0074), ΔHB (0.6 [0.3-1.9] vs 2.5[2.5-3.6] g/dl in the CG, p = 0.006) RBC transfusion requirements' (TG: 2 ± 1.7 vs 4.3 ± 2.1 units in the CG, p = 0.046) procedure duration (TG: 98 ± 21 vs 137 ± 33 min in the CG, p = 0.015), clotting disorders (TG: 1 (5%) vs 6 (26,1%) in the CG, p = 0.013) and the incidence of bladder wounds (TG: 1 (5%) vs 5 (21,7%) in the CG, p = 0.048). There was no significant difference regarding ICU transfer rate (TG: 16 (80%) vs 20 (86.9%) in the CG, p = 0.53) or length of stay (TG: 1.4 [2,3] vs 2.3 [1-4] days in the CG, p = 0.615) and digestive wound (TG: 0 vs 2 (8,7%) in the CG, p = 0.641)., Conclusion: In case of a radical management of placenta accreta. A strategy that involves the application of a cervical Tourniquet should be considered as a feasible, safe and above all efficient alternative to prevent blood spoliation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Acetamiprid (ACE) and imidacloprid (IMI) are insecticides of global importance and are used as spray and watering agents for ornamental plants to control biting and sucking insects or as topical medications on pets to remove and control fleas. Human biomonitoring data on ACE and IMI exposures when applying these products are limited. We investigated exposures to ACE and IMI in male volunteers after the domestic application of either an ACE-containing agent or an IMI-containing spot-on medication. Complete and consecutive urine samples were collected for up to 56 h after application. Urine samples were analyzed for ACE, IMI, and their respective metabolites ( N -desmethyl-ACE, IMI-olefin, and sum of 4-/5-hydroxy-IMI) by liquid chromatography-tandem mass spectrometry. Fairly uniform concentrations of N -desmethyl-ACE could be observed before and after orchid treatment, so that an ACE exposure associated with orchid treatment can most likely be excluded. In contrast, after the application of the IMI-containing medication, elevated concentrations of IMI, 4-/5-hydroxy-IMI, and IMI-olefin were quantified in urine samples post-20 h with maximum concentrations of 3.1, 14.9, and 8.0 μg/g creatinine, respectively, well above general background levels. Nevertheless, the IMI intake (10.6 μg/kg bw), calculated from the excreted amounts, was around five times below the current European acceptable daily intake. Based on the case results here, household exposures to ACE and IMI after spray treatment of ornamental plants and anti-flea treatment of dogs can be regarded as low and safe. However, people regularly applying neonicotinoid-containing formulations, such as professional gardeners and employees in animal shelters, should be studied in more detail., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wrobel, Koslitz, Bury, Hayen, Koch, Brüning and Käfferlein.)