Fluorescence Methods to Measure Pexophagy.

We outline our approach for studying the selective autophagy of peroxisomes (pexophagy), using fluorescence microscopy in tissue cell culture models. Ratiometric reporters, which specifically localize to peroxisomes, allow a quantitative assessment of pexophagy in fixed and live cells, as well as whole organisms. We discuss chemical and physiological inducers of pexophagy and any overlap with the induction of mitophagy.

Contrast-Enhanced Ultrasound as a Diagnostic Procedure in Renal Diseases: A Case Report.

Standard ultrasound (US) finds wide use in renal diseases as a screening procedure, but it is not always able to characterize lesions, especially in differential diagnosis between benign and malignant lesions. In contrast, contrast-enhanced ultrasonography (CEUS) is appropriate in differentiating between solid and cystic lesions as well as between tumors and pseudotumors. We show the case of a nephropathic patient who showed a complex, large, growing renal mass, characterized through a CEUS. This seventy-five-year-old diabetic heart patient showed a 6 cm-complex and plurisected cyst on ultrasound of left kidney. Laboratory data showed the presence of stage IIIb chronic renal failure with GFR 30 ml/min, creatinine 2.33 mg/dl, azotemia 88 mg/dl. The patient performed abdominal CT without contrast medium, showing at the level of the left upper pole, a roundish formation with the dimensions of approximately 70x53x50 mm. At the semiannual checkup, the nephrology examination showed a slight rise in creatinine and, therefore, after six months, it was decided to perform a CT scan without contrast medium again. CT showed a slight increase in the size of the mass located at the left kidney (74x56x57 mm). Given the increased size of the left mass, albeit modest, a CEUS was performed to reach a diriment diagnosis. CEUS concluded for complex cystic formation with presence of intraluminal solid-corpuscular material, with thrombotic-hemorrhagic etiology, in progressive phase of organization, classifiable as Bosniak type II cyst. CEUS in the kidneys is a cost-effective and valuable imaging technique; it is accurate in the characterization of indeterminate lesions and complex cysts.

Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera.

The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28 days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.

Segregation of pathways leading to pexophagy.

Peroxisomes are organelles with key roles in metabolism including long-chain fatty acid production. Their metabolic functions overlap and interconnect with those of mitochondria, with which they share an overlapping but distinct proteome. Both organelles are degraded by selective autophagy processes termed pexophagy and mitophagy. Although mitophagy has received intense attention, the pathways linked to pexophagy and associated tools are less well developed. We have identified the neddylation inhibitor MLN4924 as a potent activator of pexophagy and show that this is mediated by the HIF1α-dependent up-regulation of BNIP3L/NIX, a known adaptor for mitophagy. We show that this pathway is distinct from pexophagy induced by the USP30 deubiquitylase inhibitor CMPD-39, for which we identify the adaptor NBR1 as a central player. Our work suggests a level of complexity to the regulation of peroxisome turnover that includes the capacity to coordinate with mitophagy, via NIX, which acts as a rheostat for both processes.

Epidemiology of Treponema pallidum and HIV co-infections in the Italian blood donor population: 2009-2021.

BACKGROUND: In recent years, co-infection from HIV and Treponema pallidum has become more common. Early detection of the co-infection allows us to implement therapeutic strategies to control the evolution of the disease and to contain its transmission in the general population. The donor population is the target of choice for the detection of early-stage infections. This study aims to evaluate the trend of HIV/T. pallidum positivity in the Italian blood donor population, defining the type of donor most involved. MATERIALS AND METHODS: A retrospective analysis of consecutive blood donors' records, covering the period between January 2009 and December 2021, was conducted using the database of the National Blood Information System. The data extracted were the results of of confirmed positivity notifications for T. pallidum and sociodemographic variables of blood donors. The effect of age, female gender, donor category, year, and Italian origin on the probability of HIV/T. pallidum co-infection were estimated using a logistic regression model. RESULTS: In the period of observation, we found 79 subjects with HIV/T. pallidum dual co-infection, 3 with HIV/HCV/T. pallidum triple co-infections, and 2 with HIV/HBV/T. pallidum triple co-infections. Seventy-one out of 84 co-infections (89%) were among first-time tested donors, reporting sexual behaviors at risk. The results of the logistic regression show that age, female gender and regular donor status were not associated with HIV/T. pallidum co-infection. DISCUSSION: The transfusion network can provide a valid contribution to containing the spread of HIV and T. pallidum infections, raising the awareness of donors, and promptly referring the donor with confirmed positivity to the reference specialist.

Chagas Disease and Transfusion Risk in Italy: The Results of a National Survey.

BACKGROUND: Universal serological screening in endemic areas is essential for preventing Chagas disease transmission by transfusions, while in non-endemic areas, screening is provided only to donors exposed to the infection risk. In this respect, in order to ensure high and uniform standards of quality and safety of blood components, the Italian National Blood Centre conducted a survey to detect information on management of donors at risk of Chagas disease and on the current transfusion risk. METHODS: The National Blood Centre conducted a survey on preventive measures for Chagas disease in the years 2020-2021. RESULTS: Survey results are broadly representative of the national situation; out of 24,269 tested donors, only 15 donors were confirmed positive (0.4 out of 100,000 donors). This rate is lower than the number of positive donors (72/100,000) for transfusion transmissible infections (HIV, HBV, HCV, and T. pallidum) in the same period. Furthermore, the number of T. cruzi positive blood donors is lower than the T. cruzi positive subjects in the general population. CONCLUSIONS: In Italy, T. cruzi infection transfusion risk may be considered still very low, and this is confirmed by the absence of documented transfusion transmission.

Benchmarking a highly selective USP30 inhibitor for enhancement of mitophagy and pexophagy.

The deubiquitylase USP30 is an actionable target considered for treatment of conditions associated with defects in the PINK1-PRKN pathway leading to mitophagy. We provide a detailed cell biological characterization of a benzosulphonamide molecule, compound 39, that has previously been reported to inhibit USP30 in an in vitro enzymatic assay. The current compound offers increased selectivity over previously described inhibitors. It enhances mitophagy and generates a signature response for USP30 inhibition after mitochondrial depolarization. This includes enhancement of TOMM20 and SYNJ2BP ubiquitylation and phosphoubiquitin accumulation, alongside increased mitophagy. In dopaminergic neurons, generated from Parkinson disease patients carrying loss of function PRKN mutations, compound 39 could significantly restore mitophagy to a level approaching control values. USP30 is located on both mitochondria and peroxisomes and has also been linked to the PINK1-independent pexophagy pathway. Using a fluorescence reporter of pexophagy expressed in U2OS cells, we observe increased pexophagy upon application of compound 39 that recapitulates the previously described effect for USP30 depletion. This provides the first pharmacological intervention with a synthetic molecule to enhance peroxisome turnover.

Single centre experience on Acquired Haemophilia A patients: Diagnosis, clinical management and analysis of factors predictive of response and outcome.

BACKGROUND: Acquired Haemophilia A (AHA) patients show a high response rate to immunosuppressive therapy (IST) but few information about predictors of response and outcome are reported. AIMS: We describe a large single-centre AHA cohort, investigating prognostic variables for the 'best response' (BR), time to BR (TTBR) and overall survival (OS). METHODS: A total of 61 patients were included, collecting data from clinical charts. RESULTS: A progressive increase in diagnoses, from 1978 to 2019, was observed. Fifty/56 patients (89%) underwent haemostatic therapy (rFVIIa 46%, aPCC 34%) with no significant differences in the response (rFVIIa 92.3% vs aPCC 100%) and no thromboembolic events. Sixty/61 patients underwent first-line IST with an initial response rate of 58.4%. The 12-months OS was 85%, the bleeding associated mortality rate 3% (2/61). The response rates at last observation were: CR 64%, PR 8%. We evaluated the influence of age, gender, associated conditions, IST, haemoglobin levels, FVIII:C, inhibitor titre on BR, TTBR and OS: post-partum AHA achieved the BR after a longer time than AHA related to other aetiologies or idiopathic (p = .05); in univariate analysis female sex (p = .03) and the achievement of BR (p = .001) had a positive impact on the OS while AHA secondary to neoplasms showed a shorter survival (p = .04); only the BR achievement remained significant in multivariate analysis (p = .02). CONCLUSIONS: Our data on response and survival confirmed those from the main registries. Post-partum AHA and BR achievement were significantly associated to a longer TTBR and a longer OS, respectively. Other predictors of outcome deserve to be explored in prospective studies.

Von Willebrand factor with increased binding capacity is associated with reduced platelet aggregation but enhanced agglutination in COVID-19 patients: another COVID-19 paradox?

Patients with Coronavirus-associated disease-2019 (COVID-19) display alterations of the hemostatic system and the presence of a prothrombotic status frequently leading to vascular complications. However, the impact of COVID-19 on platelet activity, aggregation and agglutination still needs to be clarified. We measured total levels of von Willebrand factor (vWF) and vWF binding to the platelet glycoprotein (Gp) complex (GPIb-IX-V), in a cohort of COVID-19 patients admitted to the intensive care unit of our Institution. Moreover, we evaluated platelet aggregation in response to agonists (ADP, collagen, arachidonic acid) and platelet agglutination in response to ristocetin. We found that levels of vWF antigen and the active form of vWF binding to platelets (vWF:RCo), were markedly increased in these patients. These results were associated with higher agglutination rates induced by ristocetin, thereby indirectly indicating an increased capability of vWF to bind to platelets. Conversely, we found that platelet aggregation in response to both ADP and collagen was lower in COVID-19 patients compared to healthy volunteers. This study shows that COVID-19 is associated with increased vWF-induced platelet agglutination but reduced platelet responsivity to aggregation stimuli. Our findings have translational relevance since platelet adhesion to vWF may represent a marker to predict possible complications and better delineate therapeutic strategies in COVID-19 patients.

USP30 sets a trigger threshold for PINK1-PARKIN amplification of mitochondrial ubiquitylation.

The mitochondrial deubiquitylase USP30 negatively regulates the selective autophagy of damaged mitochondria. We present the characterisation of an N-cyano pyrrolidine compound, FT3967385, with high selectivity for USP30. We demonstrate that ubiquitylation of TOM20, a component of the outer mitochondrial membrane import machinery, represents a robust biomarker for both USP30 loss and inhibition. A proteomics analysis, on a SHSY5Y neuroblastoma cell line model, directly compares the effects of genetic loss of USP30 with chemical inhibition. We have thereby identified a subset of ubiquitylation events consequent to mitochondrial depolarisation that are USP30 sensitive. Within responsive elements of the ubiquitylome, several components of the outer mitochondrial membrane transport (TOM) complex are prominent. Thus, our data support a model whereby USP30 can regulate the availability of ubiquitin at the specific site of mitochondrial PINK1 accumulation following membrane depolarisation. USP30 deubiquitylation of TOM complex components dampens the trigger for the Parkin-dependent amplification of mitochondrial ubiquitylation leading to mitophagy. Accordingly, PINK1 generation of phospho-Ser65 ubiquitin proceeds more rapidly in cells either lacking USP30 or subject to USP30 inhibition.

Camera Calibration with Weighted Direct Linear Transformation and Anisotropic Uncertainties of Image Control Points.

Camera calibration is a crucial step for computer vision in many applications. For example, adequate calibration is required in infrared thermography inside gas turbines for blade temperature measurements, for associating each pixel with the corresponding point on the blade 3D model. The blade has to be used as the calibration frame, but it is always only partially visible, and thus, there are few control points. We propose and test a method that exploits the anisotropic uncertainty of the control points and improves the calibration in conditions where the number of control points is limited. Assuming a bivariate Gaussian 2D distribution of the position error of each control point, we set uncertainty areas of control points' position, which are ellipses (with specific axis lengths and rotations) within which the control points are supposed to be. We use these ellipses to set a weight matrix to be used in a weighted Direct Linear Transformation (wDLT). We present the mathematical formalism for this modified calibration algorithm, and we apply it to calibrate a camera from a picture of a well known object in different situations, comparing its performance to the standard DLT method, showing that the wDLT algorithm provides a more robust and precise solution. We finally discuss the quantitative improvements of the algorithm by varying the modules of random deviations in control points' positions and with partial occlusion of the object.

A Linear Approach to Optimize an EMG-Driven Neuromusculoskeletal Model for Movement Intention Detection in Myo-Control: A Case Study on Shoulder and Elbow Joints.

The growing interest of the industry production in wearable robots for assistance and rehabilitation purposes opens the challenge for developing intuitive and natural control strategies. Myoelectric control, or myo-control, which consists in decoding the human motor intent from muscular activity and its mapping into control outputs, represents a natural way to establish an intimate human-machine connection. In this field, model based myo-control schemes (e.g., EMG-driven neuromusculoskeletal models, NMS) represent a valid solution for estimating the moments of the human joints. However, a model optimization is needed to adjust the model's parameters to a specific subject and most of the optimization approaches presented in literature consider complex NMS models that are unsuitable for being used in a control paradigm since they suffer from long-lasting setup and optimization phases. In this work we present a minimal NMS model for predicting the elbow and shoulder torques and we compare two optimization approaches: a linear optimization method (LO) and a non-linear method based on a genetic algorithm (GA). The LO optimizes only one parameter per muscle, whereas the GA-based approach performs a deep customization of the muscle model, adjusting 12 parameters per muscle. EMG and force data have been collected from 7 healthy subjects performing a set of exercises with an arm exoskeleton. Although both optimization methods substantially improved the performance of the raw model, the findings of the study suggest that the LO might be beneficial with respect to GA as the latter is much more computationally heavy and leads to minimal improvements with respect to the former. From the comparison between the two considered joints, it emerged also that the more accurate the NMS model is, the more effective a complex optimization procedure could be. Overall, the two optimized NMS models were able to predict the shoulder and elbow moments with a low error, thus demonstrating the potentiality for being used in an admittance-based myo-control scheme. Thanks to the low computational cost and to the short setup phase required for wearing and calibrating the system, obtained results are promising for being introduced in industrial or rehabilitation real time scenarios.

Fiber-Optic Liquid Level Sensing by Temperature Profiling with an FBG Array.

We describe a fiber-optic system to measure the liquid level inside a container. The technique is based on the extraction of the temperature profile of the fiber by using a fiber Bragg grating (FBG) array. When the temperatures of the liquid and the gas are different, the liquid level can be estimated. We present a physical model of the system and the experimental results and we compare different algorithms to extract the liquid level from the temperature profile. We also show how air convection influences the temperature profile and the level of estimation accuracy. We finally show dynamic response measurements which are used to obtain the response time of the sensor. Turbomachinery monitoring is proposed as one possible application of the device.