MINFLUX reveals dynein stepping in live neurons.

Dynein is the primary molecular motor responsible for retrograde intracellular transport of a variety of cargoes, performing successive nanometer-sized steps within milliseconds. Due to the limited spatiotemporal precision of established methods for molecular tracking, current knowledge of dynein stepping is essentially limited to slowed-down measurements in vitro. Here, we use MINFLUX fluorophore localization to directly track CRISPR/Cas9-tagged endogenous dynein with nanometer/millisecond precision in living primary neurons. We show that endogenous dynein primarily takes 8 nm steps, including frequent sideways steps but few backward steps. Strikingly, the majority of direction reversals between retrograde and anterograde movement occurred on the time scale of single steps (16 ms), suggesting a rapid regulatory reversal mechanism. Tug-of-war-like behavior during pauses or reversals was unexpectedly rare. By analyzing the dwell time between steps, we concluded that a single rate-limiting process underlies the dynein stepping mechanism, likely arising from just one adenosine 5'-triphosphate hydrolysis event being required during each step. Our study underscores the power of MINFLUX localization to elucidate the spatiotemporal changes underlying protein function in living cells.

Nicotine or marijuana vaping exposure during pregnancy and altered immune responses in offspring.

Electronic nicotine delivery systems (ENDS) - which include electronic cigarettes or e-cigarettes, or simply e-cigs, and marijuana vaping have become increasingly popular. ENDS devices have been established as one of the tobacco quit methods and promoted to be safer compared to traditional tobacco cigarettes. Emerging evidence demonstrates that e-cigarette and marijuana vape use can be harmful, with potential associations with cancer. Herein, we summarize the level of evidence to date for altered immune response, with a focus on cancer risks in the offspring after maternal use of, or aerosol exposures from, ENDS or marijuana vape during pregnancy. From 27 published articles retrieved from PubMed, we sought to find out identified carcinogens in ENDS aerosols and marijuana vapor, which cross the placental barrier and can increase cancer risk in the offspring. Carcinogens in vaping aerosols include aldehydes, metals, tobacco-specific nitrosamines, tobacco alkaloids, polycyclic aromatic hydrocarbons, and volatile organic compounds. Additionally, there was only one passive vaping exposure case study on a human fetus, which noted that glycerol, aluminum, chromium, nickel, copper, zinc, selenium, and lead crossed from the mother to the offspring's cord blood. The carcinogens (metals) in that study were at lower concentrations compared to the mother's biological matrices. Lastly, we observed that in utero exposures to ENDS-associated chemicals can occur in vital organs such as the lungs, kidneys, brain, bladder, and heart. Any resulting DNA damage increases the risk of tumorigenesis. Future epidemiological studies are needed to examine the effects of passive aerosol exposures from existing and emerging electronic nicotine and marijuana products on developing offspring to cancer.

GRIN3A: A biomarker associated with a cribriform pattern and poor prognosis in prostate cancer.

Prostate cancer with a cribriform pattern, including invasive cribriform carcinoma (ICC) and/or intraductal carcinoma (IDC) is associated with a poor prognosis, and the underlying mechanisms are unclear. Therefore, we aimed to identify biomarkers for this feature. Using a radical prostatectomy cohort, we performed within-patient differential expression analyses with RNA sequencing data to compare samples with a cribriform pattern to those with non-cribriform Gleason pattern 4 (NcGP4; n=13). ACSM1, GRIN3A, PCDHB2, and REG4 were identified as differentially expressed, and validation was performed using real-time reverse transcription polymerase chain reaction (n=99; 321 RNA samples) and RNA in situ hybridization on tissue microarrays (n=479; 2047 tissue cores). GRIN3A was significantly higher expressed in cribriform pattern vs. NcGP4, when assessed within the same patient (n=27; p=0.005) and between different patients (n=83; p=0.001). Tissue cores with IDC more often expressed GRIN3A compared to ICC, NcGP4, and benign tissue (52 % vs. ≤ 32 %). When IDC and NcGP4 was compared within the same patient (173 pairs of tissue cores; 54 patients), 38 (22 %) of the tissue microarray core pairs had GRIN3A expression in only IDC, 33 (19 %) had expression in both IDC and NcGP4, 14 (8 %) in only NcGP4 and 88 (51 %) were negative in both entities (p=0.001). GRIN3A was as well associated with biochemical recurrence (log-rank, p=0.002). In conclusion, ectopic GRIN3A expression is an RNA-based biomarker for the presence of cribriform prostate cancer, particularly for IDC.

A care coordination program to support patients with hepatitis B virus at Kaiser Permanente Mid-Atlantic States.

BACKGROUND: Eliminating hepatitis B virus (HBV) is a significant worldwide challenge requiring innovative approaches for vaccination, screening, disease management, and the prevention of related conditions. Programs that support patients in accessing needed clinical services can help optimize access to preventive services and treatment resources for hepatitis B. METHODS: Here, we outline a coordinator-supported program (HBV Pathway) that connects patients infected with HBV to laboratory testing, imaging, and specialty care for treatment initiation and/or liver cancer surveillance (screening of high-risk patients for liver cancer). This study describes the HBV Pathway steps and reports sociodemographic factors of patients by initiation and completion. RESULTS: Results showed a 72.5% completion rate (defined as completing all Pathway steps including the final specialty visit) among patients who initiated the Pathway. Differences in completion were observed by age, race, ethnicity, and service area, with higher rates for younger ages, Asian race, non-Hispanic ethnicity, and lower rates for patients within one service area. Of those who completed the specialty visit, 59.5% were referred for hepatocellular carcinoma surveillance. CONCLUSIONS: The HBV Pathway offers dual benefits- care coordination support for patients to promote Pathway completion and a standardized testing and referral program to reduce physician burden. This program provides an easy and reliable process for patients and physicians to obtain updated clinical information and initiate treatment and/or liver cancer screening if needed.

Bactericidal/permeability-increasing protein instructs dendritic cells to elicit Th22 cell response.

Neutrophil-derived bactericidal/permeability-increasing protein (BPI) is known for its bactericidal activity against gram-negative bacteria and neutralization of lipopolysaccharide. Here, we define BPI as a potent activator of murine dendritic cells (DCs). As shown in GM-CSF-cultured, bone-marrow-derived cells (BMDCs), BPI induces a distinct stimulation profile including IL-2, IL-6, and tumor necrosis factor expression. Conventional DCs also respond to BPI, while M-CSF-cultivated or peritoneal lavage macrophages do not. Subsequent to BPI stimulation of BMDCs, CD4+ T cells predominantly secrete IL-22 and, when naive, preferentially differentiate into T helper 22 (Th22) cells. Congruent with the tissue-protective properties of IL-22 and along with impaired IL-22 induction, disease severity is significantly increased during dextran sodium sulfate-induced colitis in BPI-deficient mice. Importantly, physiological diversification of intestinal microbiota fosters BPI-dependent IL-22 induction in CD4+ T cells derived from mesenteric lymph nodes. In conclusion, BPI is a potent activator of DCs and consecutive Th22 cell differentiation with substantial relevance in intestinal homeostasis.

Optimal objective measurement of physical function and its predictive capacity for mortality among community-dwelling older women.

AIM: Objective measurements of physcial function, including gait speed, handgrip strength, and the chair stand test, have been shown to have predictive capacity for negative health-related outcomes. The aim of this study was to examine campariatively which of these common assessments may be optimal in terms of their predictive capacity for mortality. METHODS: A total of 9834 community-dwelling older women aged 65-89 years from the Study of Osteoporotic Fractures (SOF) were followed for 20 years. Gait speed, handgrip strength, and the chair stand test were measured every 2-4 years on up to 9 visits. All deaths were adjudicated. RESULTS: All three measurements of physical function were significantly associated with overall, cardiovascular disease and other mortality. Gait speed had the greatest magnitude of hazard ratios (HRs) for all outcomes of interest. A one-unit standard deviation increase in gait speed was associated with a 33% (HR = 0.67, 95% confidence interval [95% CI]: 0.64-0.70) lower risk for overall mortality, a 31% (HR = 0.69, 95% CI: 0.64-0.73) lower risk for cardiovascular disease mortality, a 15% (HR = 0.85, 95% CI: 0.78-0.92) lower risk for cancer mortality and a 42% (HR = 0.58, 95% CI: 0.55-0.62) lower risk for other mortality. Further examination of gait speed identified two cut-points (0.9 and 0.7 m/s) that were strongly indicative of increased mortality risk. CONCLUSION: Our large prospective study indicates that gait speed possesses a better prediction of mortality among older women compared with handgrip strength or the chair stand test. Using cut-points of 0.9 and 0.7 m/s can help identify older women at higher mortality risk, who may benefit from physical function improvement interventions. Geriatr Gerontol Int 2023; 23: 715-721.

Microfluidic Platform for Profiling of Extracellular Vesicles from Single Breast Cancer Cells.

Extracellular vesicles (EVs) are considered as valuable biomarkers to discriminate healthy from diseased cells such as cancer. Passing cytosolic and plasma membranes before their release, EVs inherit the biochemical properties of the cell. Here, we determine protein profiles of single EVs to understand how much they represent their cell of origin. We use a microfluidic platform which allows to immobilize EVs from completely isolated single cells, reducing heterogeneity of EVs as strongly seen in cell populations. After immunostaining, we employ four-color total internal reflection fluorescence microscopy to enumerate EVs and determine their biochemical fingerprint encoded in membranous or cytosolic proteins. Analyzing single cells derived from pleural effusions of two different human adenocarcinoma as well as from human embryonic kidney (SkBr3, MCF-7 and HEK293, respectively), we observed that a single cell secretes enough EVs to extract the respective tissue fingerprint. We show that overexpressed integral plasma membrane proteins are also found in EV membranes, which together with populations of colocalized proteins, provide a cell-specific, characteristic pattern. Our method highlights the potential of EVs as a diagnostic marker and can be directly employed for fundamental studies of EV biogenesis.

The fate of germ cells in cryptorchid testis.

Cryptorchidism in males constitutes a notable risk factor for both infertility and testicular cancer. Infertility in adulthood is closely linked to the germ cell status in childhood. Furthermore, the significance of germ cell status is important as more than 95% of all reported testicular malignancies are germ cell tumors. The review aims to elucidate the pathogenesis of germ cells in cryptorchid testes concerning their association with infertility and testicular malignancies. Impaired germ cell numbers are evident in cryptorchid testes even during antenatal and neonatal stages. In cryptorchidism there is a rapid decline in germ cell number within the first year of life, partially attributed to physiologic gonocyte apoptosis. Additionally, germ cells fail to differentiate normally during mini-puberty leading to reduced germ cell proliferation and delayed clearance of gonocytes from the seminiferous epithelium. Absence of germ cells in testicular biopsies occurs already 10 months of age and germ cell deterioration progressively worsens with approximately 50% of persisting cryptorchid testes lacking germ cells during puberty. The deficient germ cell maturation and proliferation leads to later infertility. Elevated temperature in the cryptorchid testes and also hormonal deficiency contribute to this phenomenon. Germ cell neoplasia in situ (GCNIS) originating during fetal development may manifest in rare cases associated with disorders of sexual development, chromosomal abnormalities in boys, specific syndromes, and teratomas that include cryptorchidism. In adults, the presence of GCNIS predominantly represents a new histology pattern before invasive germ cell cancer is demonstrated and is neither congenital nor related to abnormal gonocyte transformation.

Thirdhand vaping exposures are associated with pulmonary and systemic inflammation in a mouse model.

Thirdhand smoke (THS) is the accumulation of secondhand smoke on surfaces that ages with time. THS exposure is a potential health threat to children, partners of smokers, and workers in environments with current or past smoking, and needs further investigation. In this study, we hypothesized that thirdhand Electronic Nicotine Delivery Systems (ENDS) exposures elicit lung and systemic inflammation due to resuspended particulate matter (PM) and inorganic compounds that remain after active vaping has ceased. To test our hypothesis, we exposed C57BL/6J mice to cotton towels contaminated with ENDS aerosols from unflavored vape fluid (6 mg nicotine in 50/50 propylene glycol/vegetable glycerin) for 1h/day, five days/week, for three weeks. We assessed protein levels in serum and bronchoalveolar lavage fluid (BALF) using a multiplex protein assay. The mean ± sd for PM10 and PM2.5 measurements in exposed mouse cages were 8.3 ± 14.0 and 4.6 ± 7.5 µg/m3, compared to 6.1 ± 11.2 and 3.7 ± 6.6 µg/m3 in control cages respectively. Two compounds, 4-methyl-1, 2-dioxolane and 4-methyl-cyclohexanol, were detected in vape fluid and on ENDS-contaminated towels, but not on control towels. Mice exposed to ENDS-contaminated towels had lower levels of serum Il-7 (P = 0.022, n = 7), and higher levels of Il-13 in the BALF (P = 0.006, n = 7) than those exposed to control towels (n = 6). After adjusting for sex and age, Il-7 and Il-13 levels were still associated with thirdhand vaping exposure (P = 0.010 and P = 0.017, respectively). This study provides further evidence that thirdhand ENDS aerosols can contaminate surfaces, and subsequently influence lung and systemic health upon exposure.

TissueGrinder, a novel technology for rapid generation of patient-derived single cell suspensions from solid tumors by mechanical tissue dissociation.

Introduction: Recent advances hold promise of making personalized medicine a step closer to implementation in clinical settings. However, traditional sample preparation methods are not robust and reproducible. In this study, the TissueGrinder, a novel mechanical semi-automated benchtop device, which can isolate cells from tissue in a very fast and enzyme-free way is tested for cell isolation from surgically resected tumor tissues. Methods: Thirty-three surgically resected tumor tissues from various but mainly pancreatic, liver or colorectal origins were processed by both novel TissueGrinder and explant method. An optimized processing program for tumors from pancreatic, liver or colorectal cancer was developed. The viability and morphological characteristics of the isolated cells were evaluated microscopically. Expression of pancreatic cancer markers was evaluated in cells isolated from pancreatic tumors. Finally, the effect of mechanical stress on the cells was evaluated by assessing apoptosis markers via western blotting. Results: TissueGinder was more efficient in isolating cells from tumor tissue with a success rate of 75% when compared to explant method 45% in terms of cell outgrowth six weeks after processing. Cells isolated with TissueGinder had a higher abundance and were more heterogeneous in composition as compared to explant method. Mechanical processing of the cells with TissueGrinder does not lead to apoptosis but causes slight stress to the cells. Discussion: Our results show that TissueGrinder can process solid tumor tissues more rapidly and efficiently and with higher success rate compared to the conventionally used explant method. The results of the study suggest that the TissueGrinder might be a suitable method for obtaining cells, which is important for its application in individualized therapy. Due to the great variance in different tumor entities and the associated individual tissue characteristics, a further development of the dissociation protocol for other types of tumors and normal tissue will be targeted.

Sodium-glucose cotransporter 2 (SGLT2) inhibitor initiation and hepatocellular carcinoma prognosis.

INTRODUCTION: Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a relatively new class of antidiabetic drugs. Emerging findings from laboratory studies indicate that SGLT2 inhibitors can improve liver function and suppress the proliferation of hepatocellular carcinoma (HCC) cells. The aim of this study was to test the hypothesis that initiation of SGLT2 inhibitors improves HCC prognosis in a human population. METHODS: We used National Surveillance, Epidemiology and End Results (SEER)-Medicare linked data in the United States to evaluate the role of SGLT2 inhibitor initiation on the survival of HCC patients. 3,185 HCC patients newly diagnosed between 2014 and 2017 aged 66 years or older with pre-existing type 2 diabetes were included and followed to the end of 2019. Information on SGLT2 inhibitor initiation was extracted from the Medicare Part D file. RESULTS: SGLT2 inhibitor initiation was associated with significantly lower mortality risk after adjusting for potential confounders (HR = 0.68, 95% CI = 0.54-0.86) with stronger association for longer duration of use (HR = 0.60, 95% CI = 0.41-0.88). Further, we found that SGLT2 inhibitor initiation was associated with a lower risk mortality risk ranging from 14% to 60% regardless of patient demographic variables, tumor characteristics, and cancer treatments. CONCLUSION: Our large SEER-Medicare linked data study indicates that SGLT2 inhibitor initiation was associated with improved overall survival of HCC patients with pre-existing type 2 diabetes compared with no SGLT2 inhibitor use. Further studies are needed to confirm our findings and elucidate the possible mechanisms behind the association.

Dual ProGlide versus ProGlide and FemoSeal for vascular access haemostasis after transcatheter aortic valve implantation.

BACKGROUND: Large-bore arteriotomy for transcatheter aortic valve implantation (TAVI) requires percutaneous vascular closure devices, but real-world data comparing different closure strategies are limited. AIMS: We sought to compare a dual ProGlide strategy vs a combination of one ProGlide and one FemoSeal for vascular closure after TAVI. METHODS: We retrospectively analysed 874 propensity score-matched patients undergoing TAVI at the Munich University Hospital from August 2018 to October 2020. From August 2018 to August 2019, a dual ProGlide strategy was used for vascular closure. From October 2019 to October 2020, a combination of one ProGlide and one FemoSeal was used. The primary endpoint was defined as access-related major vascular complications or bleeding ≥Type 2 according to Valve Academic Research Consortium 3 criteria. RESULTS: Patients in the dual ProGlide group (n=437) had a higher incidence of the primary endpoint than patients treated with one ProGlide and one FemoSeal (n=437; 11.4% vs 3.0%; p<0.001). Furthermore, they had a higher rate of closure device failure (2.7% vs 0.9%; p=0.044) and more often required unplanned surgery or endovascular treatment (3.9% vs 0.9%; p=0.004). The incidence of death did not differ significantly between groups (3.4% vs 1.6%; p=0.08). CONCLUSIONS: A combined ProGlide and FemoSeal strategy might have the potential to reduce access-related vascular complications following TAVI.

Comparison of muscle fat fraction measurements in the lower spine musculature with non-contrast-enhanced CT and different MR imaging sequences.

PURPOSE: To assess whether two-point Dixon (TPD) MRI, true fast imaging with steady-state free precession (TRUFI) MRI and non-contrast-enhanced CT (NECT) can accurately measure muscle fat fraction (FF) in the autochthonous back muscles (AM) and the psoas muscle (PM) compared to multi-point Dixon (MPD) MRI. METHOD: 29 oncological patients who received MRI including MPD, TPD and NECT imaging in a period of three months were analyzed retrospectively. A sub-cohort of 16 patients additionally underwent TRUFI MRI and were included in a sub-analysis. Region of interest (ROI) measurements for each muscle compartment of the AM and PM were conducted by two examiners. Additionally, the Goutallier classification was used to quantify the amount of fatty infiltration of each muscle. Intermodality correlations were assessed with the Pearson correlation coefficient (r), and interreader and intrareader agreements with the intraclass correlation coefficient (ICC). RESULTS: Good intermodality correlations were found for NECT (r = 0.969), TPD (r = 0.942) and TRUFI (r = 0.904, all P < 0.001) when assessing FF in the AM and slightly lower in the PM. Interreader agreement showed good correlations and low median deviations (1.1 - 4.1 %, depending on the modality). The Goutallier classification of the AM showed good separation between grades with substantial interreader agreement (κ = 0.627, P < 0.001). CONCLUSIONS: ROI measurements of the AM in NECT, TPD and TRUFI highly correlate with muscle FF measurements in MPD MRI and may be used to assess sarcopenia in oncological patients.

A Polymorphism of Bactericidal/Permeability-Increasing Protein Affects Its Neutralization Efficiency towards Lipopolysaccharide.

Gram-negative sepsis driven by lipopolysaccharide (LPS) has detrimental outcomes, especially in neonates. The neutrophil-derived bactericidal/permeability-increasing protein (BPI) potently neutralizes LPS. Interestingly, polymorphism of the BPI gene at position 645 (rs4358188) corresponds to a favorable survival rate of these patients in the presence of at least one allele 645 A as opposed to 645 G. When we exploited the existing X-ray crystal structure, the corresponding amino acid at position 216 was revealed as surface exposed and proximal to the lipid-binding pocket in the N-terminal domain of BPI. Our further analysis predicted a shift in surface electrostatics by a positively charged lysine (BPI216K) exchanging a negatively charged glutamic acid (BPI216E). To investigate differences in interaction with LPS, we expressed both BPI variants recombinantly. The amino acid exchange neither affected affinity towards LPS nor altered bactericidal activity. However, when stimulating human peripheral blood mononuclear cells, BPI216K exhibited a superior LPS-neutralizing capacity (IC50 12.0 ± 2.5 pM) as compared to BPI216E (IC50 152.9 ± 113.4 pM, p = 0.0081) in respect to IL-6 secretion. In conclusion, we provide a functional correlate to a favorable outcome of sepsis in the presence of BPI216K.

Expressed prognostic biomarkers for primary prostate cancer independent of multifocality and transcriptome heterogeneity.

The majority of prostate cancer patients are diagnosed with multiple primary malignant foci. The distinct foci are exceptionally heterogeneous with regard to DNA mutations, but whether this is recapitulated at the transcriptome level remains unknown. In this study, inter- and intrafocal heterogeneity has been assessed by whole-transcriptome sequencing of 87 tissue samples from 23 patients with localized prostate cancer treated with radical prostatectomy. From each patient, multiple samples were taken from one or more malignant foci, in addition to one sample from benign prostate tissue. Transcriptomic profiles of different malignant foci from the same patient showed a similar level of heterogeneity as tumors from different patients. This applies to expression of genes, fusion genes, and somatic mutations. Within-patient pair-wise analyses identified expression patterns linked to ETS status and extraprostatic extension. A set of 62 genes were found with low intrapatient heterogeneity and high interpatient heterogeneity, retaining stable expression profiles across foci within the same patient. Among these, 16 genes are associated with biochemical recurrence in a separately published study and are therefore nominated as biomarkers with prognostic value regardless of which malignant focus is sampled. In conclusion, an extensive heterogeneity in multifocal prostate cancer is confirmed at the gene expression level. Diagnostic biomarkers were identified for ETS positive samples and samples from extraprostatic extensions. Finally, prognostic biomarkers independent of multifocal heterogeneity were found.

Existing fluid responsiveness studies using the mini-fluid challenge may be misleading: Methodological considerations and simulations.

BACKGROUND: The mini-fluid challenge (MFC) is a clinical concept of predicting fluid responsiveness by rapidly infusing a small amount of intravenous fluids, typically 100 ml, and systematically assessing its haemodynamic effect. The MFC method is meant to predict if a patient will respond to a subsequent, larger fluid challenge, typically another 400 ml, with a significant increase in stroke volume. METHODS: We critically evaluated the general methodology of MFC studies, with statistical considerations, secondary analysis of an existing study and simulations. RESULTS: Secondary analysis of an existing study showed that the MFC could predict the total fluid response (MFC + 400 ml) with an area under the receiver operator characteristic curve (AUROC) of 0.92, but that the prediction was worse than random for the response to the remaining 400 ml (AUROC = 0.33). In a null simulation with no response to both the MFC and the subsequent fluid challenge, the commonly used analysis could predict fluid responsiveness with an AUROC of 0.73. CONCLUSION: Many existing MFC studies are likely overestimating the classification accuracy of the MFC. This should be considered before adopting the MFC into clinical practice. A better study design includes a second, independent measurement of stroke volume after the MFC. This measurement serves as reference for the response to the subsequent fluid challenge.

Changes in arterial blood pressure characteristics following an extrasystolic beat or a fast 50 ml fluid challenge do not predict fluid responsiveness during cardiac surgery.

Prediction of fluid responsiveness is essential in perioperative goal directed therapy, but dynamic tests of fluid responsiveness are not applicable during open-chest surgery. We hypothesised that two methods could predict fluid responsiveness during cardiac surgery based on their ability to alter preload and thereby induce changes in arterial blood pressure characteristics: (1) the change caused by extrasystolic beats and (2) the change caused by a fast infusion of 50 ml crystalloid (micro-fluid challenge). Arterial blood pressure and electrocardiogram waveforms were collected during surgical preparation of the left internal mammary artery in patients undergoing coronary artery bypass surgery. Patients received a fluid challenge (5 ml/kg ideal body weight). The first 50 ml were infused in 10 s and comprised the micro-fluid challenge. Predictor variables were defined as post-ectopic beat changes (compared with sinus beats preceding ectopy) in arterial blood pressure characteristics, such as pulse pressure and systolic pressure, or micro-fluid challenge induced changes in the same blood pressure characteristics. Patients were considered fluid responsive if stroke volume index increased by 15% or more after the full fluid challenge. Diagnostic accuracy was calculated by the area under the receiver operating characteristics curve (AUC). Fifty-six patients were included for statistical analysis. Thirty-one had extrasystoles. The maximal AUC was found for the extrasystolic change in pulse pressure and was 0.70 (CI [0.35 to 1.00]). The micro-fluid challenge method generally produced lower AUC point estimates. Extrasystoles did not predict fluid responsiveness with convincing accuracy in patients undergoing cardiac surgery and changes in arterial waveform indices following a micro-fluid challenge could not predict fluid responsiveness. Given a low number of fluid responders and inherently reduced statistical power, our data does not support firm conclusions about the utility of the extrasystolic method. CLINICAL TRIAL REGISTRATION: Unique identifier: NCT02903316. https://clinicaltrials.gov/ct2/show/NCT02903316?cond=NCT02903316&rank=1 .

Identifying extracellular vesicle populations from single cells.

Extracellular vesicles (EVs) are constantly secreted from both eukaryotic and prokaryotic cells. EVs, including those referred to as exosomes, may have an impact on cell signaling and an incidence in diseased cells. In this manuscript, a platform to capture, quantify, and phenotypically classify the EVs secreted from single cells is introduced. Microfluidic chambers of about 300 pL are employed to trap and isolate individual cells. The EVs secreted within these chambers are then captured by surface-immobilized monoclonal antibodies (mAbs), irrespective of their intracellular origin. Immunostaining against both plasma membrane and cytosolic proteins was combined with highly sensitive, multicolor total internal reflection fluorescence microscopy to characterize the immobilized vesicles. The data analysis of high-resolution images allowed the assignment of each detected EV to one of 15 unique populations and demonstrated the presence of highly heterogeneous phenotypes even at the single-cell level. The analysis also revealed that each mAb isolates phenotypically different EVs and that more vesicles were effectively immobilized when CD63 was targeted instead of CD81. Finally, we demonstrate how a heterogeneous suppression in the secreted vesicles is obtained when the enzyme neutral sphingomyelinase is inhibited.

Loss of response to anti-TNFα agents depends on treatment duration in patients with inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is often managed with anti-tumour necrosis factor-α therapy (anti-TNFα), but treatment efficacy is compromised by high annual rates of loss of response (13%-21% per patient-year). AIMS: To assess whether the incidence of loss of response decreases with longer treatment duration METHODS: This was a multicentre, retrospective cohort study of patients with ulcerative colitis (UC) or Crohn's disease (CD) who received anti-TNFα for at least 4 months between 2011 and 2019. We studied the incidence of loss of response as a function of treatment duration, employing parametric survival modelling. Predictors of loss of response were identified by Cox regression analysis. Secondary outcomes included overall anti-TNFα discontinuation and dose escalation. RESULTS: We included 844 anti-TNFα treatment episodes in 708 individuals. Loss of response occurred in 211 (25.0%) episodes, with anti-drug antibodies detected in 66 (31.3%). During the first year, the incidence of loss of response was three-fold higher than after four years of treatment (17.2% vs 4.8% per patient-year, P < 0.001). The incidence of anti-TNFα discontinuation (28.6% vs 14.0% per patient-year, P < 0.001) and dose escalations (38.0% vs 6.8% per patient-year, P < 0.001) also decreased significantly from the first year to after four years, respectively. Predictors of loss of response included UC (vs CD, adjusted hazard ratio [aHR] 1.53, 95% CI 1.10-2.15) and, among patients with CD, stricturing or penetrating disease (aHR 1.68, 95% CI 1.15-2.46) and male sex (aHR 0.55, 95% CI 0.38-0.78). Immunomodulators were protective against loss of response with anti-drug antibodies (aHR 0.42, 95% CI 0.24-0.74). CONCLUSIONS: Patients with sustained benefit to anti-TNFα after 2 years are at low risk of subsequent loss of response.

The heart arrhythmia-linked D130G calmodulin mutation causes premature inhibitory autophosphorylation of CaMKII.

The Ca2+/calmodulin (CaM)-dependent kinase II (CaMKII) is well known for transmitting Ca2+-signals, which leads to a multitude of physiological responses. Its functionality is believed to involve CaMKII holoenzyme dynamics where trans-autophosphorylation of the crucial phosphorylation site, T286 occurs. Phosphorylation of this site does not occur when stimulated exclusively with the arrhythmia associated D130G mutant form of CaM in vitro. Here, we present evidence that the loss-of-CaMKII function correlates with premature phosphorylation of its inhibitory phosphosite T306 in CaMKIIα and T307 in CaMKIIδ as this site was up to 20-fold more phosphorylated in the presence of D130G CaM compared to wildtype CaM. Indeed, changing this phosphosite to a non-phosphorylatable alanine reversed the inhibitory effect of D130G both in vitro and in live cell experiments. In addition, several phosphosites with so far undescribed functions directing the Ca2+-sensitivity of the CaMKII sensor were also affected by the presence of the D130G mutation implicating a role of several additional autophosphosites (besides T286 and T306/T307) so far not known to regulate CaMKII Ca2+ sensitivity. Furthermore, we show that introducing a D130G mutation in the CALM2 gene of the P19CL6 pluripotent mouse embryonic carcinoma cell line using CRISPR/Cas9 decreased the spontaneous beat frequency compared to wildtype cells when differentiated into cardiomyocytes supporting an alteration of cardiomyocyte physiology caused by this point mutation. In conclusion, our observations shed for the first time light on how the D130G CaM mutation interferes with the function of CaMKII and how it affects the beating frequency of cardiomyocyte-like cells.