Quantifying nanoscopic alterations associated with mitochondrial dysfunction using three-dimensional single-molecule localization microscopy.

Mitochondrial morphology provides unique insights into their integrity and function. Among fluorescence microscopy techniques, 3D super-resolution microscopy uniquely enables the analysis of mitochondrial morphological features individually. However, there is a lack of tools to extract morphological parameters from super-resolution images of mitochondria. We report a quantitative method to extract mitochondrial morphological metrics, including volume, aspect ratio, and local protein density, from 3D single-molecule localization microscopy images, with single-mitochondrion sensitivity. We validated our approach using simulated ground-truth SMLM images of mitochondria. We further tested our morphological analysis on mitochondria that have been altered functionally and morphologically in controlled manners. This work sets the stage to quantitatively analyze mitochondrial morphological alterations associated with disease progression on an individual basis.

Outcomes of venous thromboembolism in patients with inherited thrombophilia treated with direct oral anticoagulants: insights from the RIETE registry.

While direct oral anticoagulants (DOACs) are frequently used to treat venous thromboembolism (VTE), the outcomes of patients with inherited thrombophilia (IT) receiving DOACs for VTE remain understudied. We used data from the international RIETE registry to compare the rates of VTE recurrences, major bleeding, and mortality during anticoagulant treatment in VTE patients with and without IT, grouped by the use of DOACs or standard anticoagulant therapy. Among 103,818 enrolled patients, 21,089 (20.3%) were tested for IT, of whom 8422 (39.9%) tested positive: Protein C deficiency 294, Protein S deficiency 726, Antithrombin deficiency 240, Factor V Leiden 2248, Prothrombin gene mutation 1434, combined IT 3480. Overall, 14,189 RIETE patients (6.2% with IT) received DOACs, and 89,629 standard anticoagulation (8.4% with IT), mostly with heparins followed by vitamin K antagonists. Proportions of patients receiving DOACs did not differ between IT-positive and IT-negative patients. Rates of VTE recurrence on anticoagulant treatment were highest in patients with AT deficiency (P < 0.01). Rates of on-treatment major bleeding and all-cause mortality were lowest among patients with Factor V Leiden (FVL) or PT G20210A mutations, compared with patients who tested negative. Patients with IT who received DOACs had lower rates of major bleeding than those receiving standard anticoagulation. Excluding FVL and Protein S deficiency, patients with IT had lower rates of VTE recurrence with DOACs than with standard anticoagulation. DOACs are equally safe and effective in VTE patients with IT, with lower bleeding rates than those on standard anticoagulation.

Multiscale imaging of corneal endothelium damage and Rho-kinase inhibitor application in mouse models of acute ocular hypertension.

We developed a multiscale optical imaging workflow, integrating and correlating visible-light optical coherence tomography, confocal laser scanning microscopy, and single-molecule localization microscopy to investigate mouse cornea damage from the in-vivo tissue level to the nanoscopic single-molecule level. We used electron microscopy to validate the imaged nanoscopic structures. We imaged wild-type mice and mice with acute ocular hypertension and examined the effects of Rho-kinase inhibitor application. We defined four types of intercellular tight junction structures as healthy, compact, partially-distorted, and fully-distorted types by labeling the zonula occludens-1 protein in the corneal endothelial cell layer. We correlated the statistics of the four types of tight junction structures with cornea thickness and intraocular pressure. We found that the population of fully-distorted tight junctions correlated well with the level of corneal edema, and applying Rho-kinase inhibitor reduced the population of fully-distorted tight junctions under acute ocular hypertension. Together, these data point to the utility of multiscale optical imaging in revealing fundamental biology relevant to disease and therapeutics.

Prevention of Venous Thromboembolism in Medical Patients with Thrombocytopenia or with Platelet Dysfunction: The Last 10 Years.

Current guideline recommendations for primary prophylaxis of venous thromboembolism (VTE) are based on randomized clinical trials that usually exclude subjects at a potentially high risk of bleeding complications. For this reason, no specific guideline is available for thromboprophylaxis in hospitalized patients with thrombocytopenia and/or platelet dysfunction. However, except in patients with absolute contraindications to anticoagulant drugs, antithrombotic prophylaxis should always be considered, for example, in hospitalized cancer patients with thrombocytopenia, especially in those with multiple VTE risk factors. Low platelet number, platelet dysfunction, and clotting abnormalities are also very common in patients with liver cirrhosis, but these patients have a high incidence of portal venous thrombosis, implying that cirrhotic coagulopathy does not fully protect against thrombosis. These patients may benefit from antithrombotic prophylaxis during hospitalization. Patients hospitalized for COVID-19 need prophylaxis, but frequently experience thrombocytopenia or coagulopathy. In patients with antiphospholipid antibodies, a high thrombotic risk is usually present, even in the presence of thrombocytopenia. VTE prophylaxis in high-risk conditions is thus suggested in these patients. At variance with severe thrombocytopenia (< 50,000/mm3), mild/moderate thrombocytopenia (≥ 50,000/mm3) should not interfere with VTE prevention decisions. In patients with severe thrombocytopenia, pharmacological prophylaxis should be considered on an individual basis. Aspirin is not as effective as heparins in lowering the risk of VTE. Studies in patients with ischemic stroke demonstrated that thromboprophylaxis with heparins is safe in these patients also during antiplatelet treatment. The use of direct oral anticoagulants in the prophylaxis of VTE in internal medicine patients has been recently evaluated, but no specific recommendation exists for patients with thrombocytopenia. The need for VTE prophylaxis in patients on chronic treatment with antiplatelet agents should be evaluated after assessing the individual risk of bleeding complications. Finally, the selection of patients who require post-discharge pharmacological prophylaxis remains debated. New molecules currently under development (such as the inhibitors of factor XI) may contribute to improve the risk/benefit ratio of VTE primary prevention in this setting of patients.

Nucleoporin downregulation modulates progenitor differentiation independent of nuclear pore numbers.

Nucleoporins (NUPs) comprise nuclear pore complexes, gateways for nucleocytoplasmic transport. As primary human keratinocytes switch from the progenitor state towards differentiation, most NUPs are strongly downregulated, with NUP93 being the most downregulated NUP in this process. To determine if this NUP downregulation is accompanied by a reduction in nuclear pore numbers, we leveraged Stochastic Optical Reconstruction Microscopy. No significant changes in nuclear pore numbers were detected using three independent NUP antibodies; however, NUP reduction in other subcellular compartments such as the cytoplasm was identified. To investigate how NUP reduction influences keratinocyte differentiation, we knocked down NUP93 in keratinocytes in the progenitor-state culture condition. NUP93 knockdown diminished keratinocytes' clonogenicity and epidermal regenerative capacity, without drastically affecting nuclear pore numbers or permeability. Using transcriptome profiling, we identified that NUP93 knockdown induces differentiation genes related to both mechanical and immune barrier functions, including the activation of known NF-κB target genes. Consistently, keratinocytes with NUP93 knockdown exhibited increased nuclear localization of the NF-κB p65/p50 transcription factors, and increased NF-κB reporter activity. Taken together, these findings highlight the gene regulatory roles contributed by differential NUP expression levels in keratinocyte differentiation, independent of nuclear pore numbers.

Effects of anti-Xa activity monitoring on the outcome of high-risk pregnancies treated with a prophylactic dose of low-molecular-weight heparin.

OBJECTIVE: To evaluate if anti-Xa level monitoring and dose adjustment in women using a prophylactic dose of enoxaparin can decrease placenta-mediated pregnancy complications. METHODS: This retrospective observational cohort study included pregnant women receiving enoxaparin prophylaxis, who were followed at the Thrombosis and Hemostasis Outpatient clinic between 2010 and 2017. The dose was adjusted according to enoxaparin anti-Xa levels in the study group or the weight of individuals in the control group. RESULTS: Of 585 women surveyed, 110 met the inclusion criteria; 63 of them were included in the study group and 47 in the control group. Mean starting dose was 46 versus 43 mg (p = .25), mean final dose was 52 mg versus 45 mg (p = .03) and dose adjustment was required in 37% versus 11% (p = .002) in the study and control groups, respectively. Twenty-eight percent of anti-Xa measurements in the second trimester were beneath the prophylactic threshold, compared to 11% and 16% in the first and third trimesters, respectively (p = .02). Labors ended with live birth in 91% versus 94% of cases (p = .5), 85% versus 68% of pregnancies were term (p = .05), 11% versus 23% of newborns were low birth weight (p = .1) and placenta-mediated pregnancy complications were documented in 9% versus 19%, (p = .17) in the study group relative to controls, respectively. CONCLUSIONS: The most prominent decrease in anti-Xa levels was observed in the second trimester. Monitored women had significantly more term deliveries and demonstrated a trend toward higher birth weight and fewer placenta-mediated pregnancy complications. Larger studies are needed to confirm improved pregnancy outcome in monitored women.

Multiscale imaging of corneal endothelium damage and effects of Rho Kinase inhibitor application in mouse models of acute ocular hypertension.

We developed a multiscale optical imaging workflow, integrating and correlating visible-light optical coherence tomography, confocal laser scanning microscopy, and single-molecule localization microscopy to investigate the mouse cornea damages from the in-vivo tissue level to the nanoscopic single-molecule level. We used electron microscopy to validate the imaged nanoscopic structures. We imaged wild-type mice and mice with acute ocular hypertension and examined the effects of Rho Kinase inhibitor application. We defined four types of intercellular tight junction structures as healthy, compact, partially-distorted, and fully-distorted types by labeling the Zonula occludens-1 protein in the corneal endothelial cell layer. We correlated the statistics of the four types of tight junction structures with cornea thickness and intraocular pressure. We found that the population of fully-distorted tight junctions correlated well with the level of cornea edema, and applying Rho Kinase inhibitor reduced the population of fully-distorted tight junctions under acute ocular hypertension.

Assessment-based management of placenta-mediated pregnancy complications: Pragmatism until a precision medicine approach evolves.

The management of pregnant women with thrombophilia and a history of gestational vascular complications remains debatable. Treatment of the latter is often based on clinical outcome rather than disease mechanism. While the use of venous thromboembolism prophylaxis in pregnancy is recommended for those at increased risk, the ability of anticoagulant and/or antiplatelet agents to lower the risk of placenta-mediated complications in this clinical setting remains controversial. The available guidelines are inconsistent in some situations, which reflects the limited evidence base. This review critically discusses risk assessment models (RAMs) and management strategies of women with thrombophilia and pregnancy complications, using clinical vignettes. RAMs, taking into account obstetric and thrombotic history as well as thrombophilia status, could drive a precision medicine approach, based on disease mechanism, and guide individual therapeutic interventions in high-risk clinical settings.

Associations of maternal and placental extracellular vesicle miRNA with preeclampsia.

Introduction: Gestational vascular complications (GVCs), including gestational hypertension and preeclampsia, are leading causes of maternal morbidity and mortality. Elevated levels of extracellular vesicles (EVs), in GVC have been linked to vascular injury. This study aims to characterize placental and circulating EV miRNA in GVCs, and explores the involvement of EV-miRNA in GVC, and whether they may be used to distinguish between placental and maternal pathologies. Methods: Blood samples were obtained from 15 non-pregnant (NP), 18 healthy-pregnant (HP), and 23 women with GVC during the third trimester. Placental sections were obtained after caesarian section. Platelet-poor-plasma (PPP) and EV pellets were characterized: EV size/concentration, protein content and miRNA expression were measured by nanoparticle tracking analysis, western blot, nano-string technology and RT-PCR. The effects of EVs on trophoblasts and EC miRNA expression were evaluated. Results: Higher EVs concentrations were observed in HP-PPP and GVC-PPP (p < 0.0001) compared to the NP-PPP. The concentration of large EVs (>100 nm) was higher in PPP and EV pellets of HP and GVC compared to the NP group. EV pellets of pregnant women demonstrated lower expression of exosomal markers CD63/CD81 compared to NP-EVs. GVC-EVs expressed more human placental lactogen (hPL) hormone than HP-EVs, reflecting their placental origin. Screening of miRNAs in EV pellets and in PPP identified certain miRNAs that were highly expressed only in EVs pellets of the HP (13%) and GVC groups (15%), but not in the NP group. Differences were detected in the expression of hsa-miR-16-5p, hsa-miR-210, and hsa-miR-29b-3p. The expression of hsa-miR-16-5p and hsa-miR-210 was low in EV pellets obtained from NP, higher in HP-EVs, and significantly lower in GVC-EVs. Except for hsa-miR-29b-3p, which was upregulated in GVC, no significant differences were found in the levels of other miRNAs in placental sections. Exposure to GVC-EVs resulted in higher expression of hsa-miR-29b-3p compared to cells exposed to HP-EVs in villous trophoblasts, but not in EC. Conclusion: Expression of hsa-miR-16-5p and hsa-miR-210 reflects maternal pathophysiological status, while hsa-miR-29b-3p reflects placental status. These findings suggest that EV-miRNA are involved in GVC, and that they may be used to distinguish between pathologies of placental and maternal origins in preeclampsia.

Spectroscopic single-molecule localization microscopy: applications and prospective.

Single-molecule localization microscopy (SMLM) breaks the optical diffraction limit by numerically localizing sparse fluorescence emitters to achieve super-resolution imaging. Spectroscopic SMLM or sSMLM further allows simultaneous spectroscopy and super-resolution imaging of fluorescence molecules. Hence, sSMLM can extract spectral features with single-molecule sensitivity, higher precision, and higher multiplexity than traditional multicolor microscopy modalities. These new capabilities enabled advanced multiplexed and functional cellular imaging applications. While sSMLM suffers from reduced spatial precision compared to conventional SMLM due to splitting photons to form spatial and spectral images, several methods have been reported to mitigate these weaknesses through innovative optical design and image processing techniques. This review summarizes the recent progress in sSMLM, its applications, and our perspective on future work.

Developmental Outcomes Following Abusive Head Trauma in Infancy: A Systematic Review.

OBJECTIVE: A systematic review of the literature was conducted to identify measures used to evaluate developmental outcomes after abusive head trauma (AHT), as well as describe outcomes among those with AHT, and explore factors and interventions influencing such outcomes. DESIGN: This systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The protocol is in PROSPERO, registration number CRD42020179592. On April 17, 2020, OVID Medline, Embase, OVID PsycINFO, Web of Science, CINAHL, Cochrane Library, and Google Scholar were searched (since inception). Inclusion criteria included original, peer-reviewed study data; AHT exposure; infants younger than 24 months at time of AHT; and evaluation of developmental outcomes. Reviewers independently evaluated studies for inclusion and assessed risk of bias using the Effective Public Health Practice Project quality assessment tool for quantitative studies. A descriptive synthesis approach was utilized as variability of study designs, follow-up periods, and outcome assessment tools precluded a meta-analytic approach. RESULTS: Fifty-nine studies were included; 115 assessment tools were used to evaluate developmental outcomes; and 42 studies examined factors influencing outcomes. Two studies evaluated interventions. Five percent of studies ( n = 3) were rated low risk of bias. CONCLUSIONS: Notable variation was observed in terms of case ascertainment criteria. Developmental outcomes after AHT have been assessed in a manner that limits understanding of how AHT impacts development, as well as the efficacy of interventions intended to improve outcomes. Researchers and clinicians are encouraged to adopt consistent diagnostic and assessment approaches.

Risk factors for recurrence and major bleeding in patients with cancer-associated venous thromboembolism.

Risks of recurrence and treatment-emergent bleeding are high in patients with cancer-associated venous thromboembolism (VTE) but factors associated with these risks remain substantially undefined. The aim of this analysis in patients with cancer-associated VTE included in the Caravaggio study was to identify risk factors for recurrent VTE and major bleeding. Variables potentially predictive for recurrent VTE or major bleeding were evaluated in a Cox proportional hazard multivariable analysis with backward variable selection. Recurrent VTE occurred in 78 patients (6.8%) and major bleeding in 45 (3.9%). Independent risk factors for recurrent VTE were deep vein thrombosis (DVT) as index event (Hazard ratio (HR) 1.84, 95% CI 1.17-2.88), ECOG status of 1 or more (HR 1.95, 95% CI 1.11-3.43), pancreatic or hepatobiliary cancer site (HR 2.20, 95% CI 1.19-4.06), concomitant anti-cancer treatment (HR 1.98, 95% CI 1.03-3.81) and creatinine clearance (HR 1.10, 95% CI 1.00-1.20 for every 10 ml/min absolute increase). Independent risk factors for major bleeding were ECOG status of 2 (HR 2.31, 95% CI 1.24-4.29), genitourinary cancer site (HR 2.72, 95% CI 1.28-5.77), upper gastrointestinal cancer site (HR 3.17, 95% CI 1.22-8.23), and non-resected luminal gastrointestinal cancer (HR 2.77, 95% CI 1.38-5.56). This analysis of the Caravaggio study in patients with cancer-associated VTE who were on standardized anticoagulant treatment identified five independent predictors for recurrent VTE and four independent predictors of treatment-emergent major bleeding. Considering these risks could help clinicians to optimize the anticoagulant treatment in patients with cancer-associated VTE.

Thrombosis in Pregnant Women with Hemolytic Anemia.

Hemolytic anemias are a group of uncommon disorders affecting both genders, frequently occurring at the reproductive age. While a link between hemolysis and hypercoagulability has been suggested based on the elucidation of certain involved pathophysiological mechanisms, the extent of thrombotic risk in pregnant women with hemolytic anemia remains debatable. Due to the paucity of pregnancy-related data, risk assessment of gestations in women with hemolytic anemia is complicated. This review will highlight the latest advances in the diagnosis and management of these challenging disorders in pregnancy.

Thrombosis in Pregnant Women with Hematological Malignancies: A Case-Based Review.

Cancer and pregnancy induce a procoagulant environment which may lead to maternal and fetal complications, such as venous thromboembolism, fetal growth restriction, and fetal loss. The incidence of hematological malignancies diagnosed during pregnancy is rising, and thrombotic events in such malignancies are not rare. Management of thrombosis during pregnancy poses a therapeutic challenge, that is further exacerbated by the impact of cancer. The available data on managing pregnant women with hematological malignancies are limited to those with myeloproliferative neoplasms, mainly essential thrombocythemia, and, to a lesser extent, polycythemia vera. Low-dose aspirin is recommended throughout pregnancy, and considering treatment with low-molecular-weight heparin and interferon formulations is advised for high-risk patients. Currently, guidelines for handling thrombotic events in pregnant women with lymphoma or leukemia are lacking, and their management is based on data extrapolated from retrospective studies, and guidelines for prevention and treatment of cancer-associated thrombosis. The present case-based review will focus on the complex issue of thrombotic risk in pregnant women with hematological malignancies, specifically myeloproliferative neoplasms, lymphomas, and leukemias.

Monolithic dual-wedge prism-based spectroscopic single-molecule localization microscopy.

By manipulating the spectral dispersion of detected photons, spectroscopic single-molecule localization microscopy (sSMLM) permits concurrent high-throughput single-molecular spectroscopic analysis and imaging. Despite its promising potential, using discrete optical components and managing the delicate balance between spectral dispersion and spatial localization compromise its performance, including non-uniform spectral dispersion, high transmission loss of grating, high optical alignment demands, and reduced precision. We designed a dual-wedge prism (DWP)-based monolithic imaging spectrometer to overcome these challenges. We optimized the DWP for spectrally dispersing focused beam without deviation and with minimal wavefront error. We integrated all components into a compact assembly, minimizing total transmission loss and significantly reducing optical alignment requirements. We show the feasibility of DWP using ray-tracing and numerical simulations. We validated our numerical simulations by experimentally imaging individual nanospheres and confirmed that DWP-sSMLM achieved much improved spatial and spectral precisions of grating-based sSMLM. We also demonstrated DWP-sSMLM in 3D multi-color imaging of cells.

Thrombotic complications in patients with cancer: Advances in pathogenesis, prevention, and treatment-A report from ICTHIC 2021.

Venous thromboembolism (VTE) is a common complication in cancer patients, resulting in deep vein thrombosis (DVT) or pulmonary embolism (PE), and is responsible for high morbidity and mortality. This article discusses evidence and future perspectives on pathogenesis and prevention and treatment of thrombotic complications in patients with cancer. In April 2021, international basic researchers and clinicians met for the virtual edition of the 10th International Conference on Thrombosis & Hemostasis Issues in Cancer. Pathogenic mechanisms, markers and scores for risk assessment, diagnosis and therapy issues, current prophylaxis recommendations, and special settings, such as palliative care, pediatrics, and COVID-19 patients were discussed. Emerging areas of interest in cancer associated VTE are the role of immunotherapy, platelet activation markers, genetic alterations and real-world systems-based approaches to prevention and treatment.