Development, feeding, and sex shape the relative quantity of the nutritional obligatory symbiont Wolbachia in bed bugs.

The common bed bug, Cimex lectularius, is a hemipteran insect that feeds only on blood, and whose bites cause public health issues. Due to globalization and resistance to insecticides, this pest has undergone a significant and global resurgence in recent decades. Blood is an unbalanced diet, lacking notably sufficient B vitamins. Like all strict hematophagous arthropods, bed bugs host a nutritional symbiont supplying B vitamins. In C. lectularius, this nutritional symbiont is the intracellular bacterium Wolbachia (wCle). It is located in specific symbiotic organs, the bacteriomes, as well as in ovaries. Experimental depletion of wCle has been shown to result in longer nymphal development and lower fecundity. These phenotypes were rescued by B vitamin supplementation. Understanding the interaction between wCle and the bed bug may help to develop new pest control methods targeting the disruption of this symbiotic interaction. The objective of this work was thus to quantify accurately the density of wCle over the life cycle of the host and to describe potential associated morphological changes in the bacteriome. We also sought to determine the impact of sex, feeding status, and aging on the bacterial population dynamics. We showed that the relative quantity of wCle continuously increases during bed bug development, while the relative size of the bacteriome remains stable. We also showed that adult females harbor more wCle than males and that wCle relative quantity decreases slightly in adults with age, except in weekly-fed males. These results are discussed in the context of bed bug ecology and will help to define critical points of the symbiotic interaction during the bed bug life cycle.

Pancreatic neuroendocrine tumors in French VHL mutation carriers: a multicentric retrospective study.

BACKGROUND: Von Hippel-Lindau disease (VHL) is a rare autosomal dominant hereditary cancer-predisposition syndrome caused by germline pathogenic variants (PV) in VHL gene. It is associated with a high penetrance of benign and malignant vascular tumors in multiples organs, including pancreatic neuroendocrine tumors (PanNETs), whose long-term natural history is ill-known. METHODS: Patients with both documented germline PV in VHL gene and PanNETs included in the French PREDIR database between 1995 and 2022 were included. Primary endpoint was the proportion of patients with PanNET-related metastases and secondary endpoint was overall survival (OS). Genotype/phenotype correlations were studied. RESULTS: We included 121 patients with 259 PanNETs. Median age at diagnosis was 38 years. Median follow-up was 89.5 months. PanNET surgical resection was performed in 51 patients. Overall, 29 patients (24%) had metastases (5 synchronous, 10 metachronous), with a higher risk in case of larger PanNET size (p=0.0089; best threshold 28 mm) and grade 2 PanNET (p=0.048), and a pejorative prognostic impact (p=0.043). Patients with PV in VHL exon 1 had larger PanNETs (p=0.018), more often metastatic disease (48% vs 11.5%; p < 0.001) and a trend toward shorter OS (p=0.16). CONCLUSION: The risk of metastases associated to VHL-related PanNETs remains low (24%) but increases with tumor size >28 mm, higher grade and in case of PV located VHL exon 1. These data might help improving the management of these patients, who should be referred to an expert center.

Trifluridine/tipiracil + oxaliplatin ± nivolumab vs FOLFOX ± nivolumab in HER2 negative advanced oesogastric adenocarcinoma: The PRODIGE73-UCGI40-LOGICAN trial.

BACKGROUND: Trifluridine/tipiracil (FTD/TPI) is approved in third-line treatment of patients with advanced/metastatic gastric and gastroesophageal junction adenocarcinomas (aGA/GEJA). The association of oxaliplatin with FTD/TPI is promising and the combination of FTD/TPI + oxaliplatin + nivolumab has shown a predictable and manageable safety profile. AIMS: The aim is to evaluate the efficacy and safety of FTD/TPI plus oxaliplatin with or without nivolumab in patients, with HER2 negative aGA/GEJA, unfit for triplet chemotherapy (TFOX/mFLOT regimen), in the first-line metastatic setting in comparison with the standard of care FOLFOX with or without nivolumab. METHODS: This study is a prospective randomised, open label, comparative, multicentre, phase II trial designed to include 118 patients. The primary objective is to evaluate the superiority of FTD/TPI plus oxaliplatin with or without nivolumab over FOLFOX regimen with or without nivolumab in terms of PFS in a population of patients non candidate for triplet chemotherapy. Nivolumab will be used for patients whose tumour express PD-L1 with a CPS score ≥5. DISCUSSION: PRODIGE73-UCGI40-LOGICAN study will provide efficacy and safety data on the association of FTD/TPI plus oxaliplatin with or without nivolumab versus FOLFOX regimen with or without nivolumab in first-line palliative setting, in patients with aGA/GEJA (NCT05476796).

The respective and dependent effects of scattering and bone matrix absorption on ultrasound attenuation in cortical bone.

Cortical bone is characterized by a dense solid matrix permeated by fluid-filled pores. Ultrasound scattering has potential for the non-invasive evaluation of changes in bone porosity. However, there is an incomplete understanding of the impact of ultrasonic absorption in the solid matrix on ultrasound scattering. In this study, maps were derived from scanning acoustic microscopy images of human femur cross-sections. Finite-difference time domain ultrasound scatter simulations were conducted on these maps. Pore density, diameter distribution of the pores, and nominal absorption values in the solid and fluid matrices were controlled. Ultrasound pulses with a central frequency of 8.2 MHz were propagated, both in through-transmission and backscattering configurations. From these data, the scattering, bone matrix absorption, and attenuation extinction lengths were calculated. The results demonstrated that as absorption in the solid matrix was varied, the scattering, absorption, and attenuation extinction lengths were significantly impacted. It was shown that for lower values of absorption in the solid matrix (less than 2 dB mm-1), attenuation due to scattering dominates, whereas at higher values of absorption (more than 2 dB mm-1), attenuation due to absorption dominates. This will impact how ultrasound attenuation and scattering parameters can be used to extract quantitative information on bone microstructure.

Lung Quantitative Ultrasound to Stage and Monitor Interstitial Lung Diseases.

Chronic interstitial lung diseases (ILDs) require frequent point-of-care monitoring. X-ray-based methods lack resolution and are ionizing. Chest computerized tomographic (CT) scans are expensive and provide more radiation. Conventional ultrasound can detect severe lung damage via vertical artifacts (B-lines). However, this information is not quantitative, and the appearance of B-lines is operator- and system-dependent. Here we demonstrate novel ultrasound-based biomarkers to assess severity of ILDs. Lung alveoli scatter ultrasound waves, leading to a complex acoustic signature, which is affected by changes in alveolar density due to ILDs. We exploit ultrasound scattering in the lung and combine Quantitative Ultrasound (QUS) parameters, to develop ultrasound-based biomarkers that significantly correlate to the severity of pulmonary fibrosis and edema in rodent lungs. These innovative QUS biomarkers will be very significant for monitoring severity of chronic ILDs and response to treatment, especially in this new era of miniaturized and highly portable ultrasound devices.

High-Performance PMN-PT Single-Crystal-Based 1-3 Composite Transducer Integrated with a Biopsy Needle.

To address the need for high-resolution imaging in lung nodule detection and overcome the limitations of the shallow imaging depth associated with high-frequency ultrasound and the complex structure of lung tissue, we successfully integrated 50 MHz ultrasound transducers with 18-gauge biopsy needles. Featuring a miniaturized size of 0.6 × 0.5 × 0.5 mm3, the 50 MHz micromachined 1-3 composite transducer was tested to perform mechanical scanning of a nodule within a lung-tissue-mimicking phantom in vitro. The high-frequency transducer demonstrated the ability to achieve imaging with an axial resolution of 30 µm for measuring nodule edges. Moreover, the integrated biopsy needle prototype exhibited high accuracy (1.74% discrepancy) in estimating nodule area compared to actual dimensions in vitro. These results underscore the promising potential of biopsy-needle-integrated transducers in enhancing the accuracy of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) for clinical applications.

Deep dive into the chronic toxicity of tyre particle mixtures and their leachates.

Particles from the tread of vehicle tyres are a global pollutant, which are emitted into the environment at an approximate rate of 1.4 kg.year-1 for an average passenger-car. In this study, popular tyre brands were used to generate a tyre tread microparticle mixture. The chronic toxicity of both particles and chemical leachates were compared on a planktonic test species (Daphnia magna). Over 21 days of exposure, pristine tyre tread microparticles were more toxic (LC50 60 mg.L-1) than chemical lechates alone (LC50 542 mg.L-1). Microparticles and leachates showed distinct effects on reproduction and morphological development at environmentally relevant concentrations, with dose-dependent uptake of particles visible in the digestive tract. Chemical characterization of leachates revealed a metal predominance of zinc, titanium, and strontium. Of the numerous organic chemicals present, at least 54 were shared across all 5 tyre brands, with many classified to be very toxic. Our results provide a critically needed information on the toxicity of tyre tread particles and the associated chemicals that leach from them to inform future mitigation measures. We conclude that tyre particles are hazardous pollutants of particular concern that are close to or possibly above chronic environmental safety limits in some locations.

Differences in regulation mechanisms of glutamine synthetases from methanogenic archaea unveiled by structural investigations.

Glutamine synthetases (GS) catalyze the ATP-dependent ammonium assimilation, the initial step of nitrogen acquisition that must be under tight control to fit cellular needs. While their catalytic mechanisms and regulations are well-characterized in bacteria and eukaryotes, only limited knowledge exists in archaea. Here, we solved two archaeal GS structures and unveiled unexpected differences in their regulatory mechanisms. GS from Methanothermococcus thermolithotrophicus is inactive in its resting state and switched on by 2-oxoglutarate, a sensor of cellular nitrogen deficiency. The enzyme activation overlays remarkably well with the reported cellular concentration for 2-oxoglutarate. Its binding to an allosteric pocket reconfigures the active site through long-range conformational changes. The homolog from Methermicoccus shengliensis does not harbor the 2-oxoglutarate binding motif and, consequently, is 2-oxoglutarate insensitive. Instead, it is directly feedback-inhibited through glutamine recognition by the catalytic Asp50'-loop, a mechanism common to bacterial homologs, but absent in M. thermolithotrophicus due to residue substitution. Analyses of residue conservation in archaeal GS suggest that both regulations are widespread and not mutually exclusive. While the effectors and their binding sites are surprisingly different, the molecular mechanisms underlying their mode of action on GS activity operate on the same molecular determinants in the active site.

Discontinuation of Drug Treatment in Cushing's Disease Not Cured by Pituitary Surgery.

OBJECTIVE: When transsphenoidal surgery (TSS) does not cure Cushing's disease (CD), 4 treatments are available: drug treatment (DT), second TSS (2nd TSS), bilateral adrenalectomy (BA), and pituitary radiotherapy (PR). DT is attractive but supposes long-term continuation, which we aimed to evaluate. DESIGN AND METHODS: Retrospective study, in a center prioritizing 2nd TSS, of 36 patients, including 19 with TSS failure and 17 with recurrence, out of 119 patients with CD treated by a first TSS, average follow-up 6.1 years (95% confidence interval 5.27-6.91). Control was defined as normalization of urinary free cortisol (UFC) and final treatment (FT) as the treatment allowing control at last follow-up. We also analyzed discontinuation rates of DT in published CD prospective clinical trials. RESULTS: Control was achieved in 33/36 patients (92%). DT was initiated in 29/36 patients (81%), allowing at least 1 normal UFC in 23/29 patients (79%) but was discontinued before last follow-up in 18/29 patients (62%). DT was FT in 11/29 patients (38%), all treated with cortisol synthesis inhibitors. Second TSS was FT in 8/16 (50%), BA in 14/14 (100%), and PR in 0/5. In published trials, discontinuation of DT was 11% to 51% at 1 year and 32% to 74% before 5 years. CONCLUSION: DT allowed at least 1 normal UFC in 23/29 patients (79%) but obtained long-term control in only 11/29 (38%), as discontinuation rate was high, although similar to published data. Interestingly, a successful 2nd TSS was the cause for discontinuing efficient and well-tolerated DT in 5 patients. Further studies will show whether different strategies with cortisol synthesis inhibitors may allow for a lower discontinuation rate in patients not candidates for a 2nd TSS so that BA may be avoided in these patients.

Lymphoma In Patients With Inflammatory Bowel Disease: A Multicenter Collaborative Study Between Getaid And Lysa.

BACKGROUND: IBD is associated with an increased risk of developing lymphoma. Although recent data clarifies lymphoma epidemiology in IBD patients, clinical and pathological characteristics of lymphoma occurring in IBD remain ill-known. METHODS: Patients with IBD and lymphoma were retrospectively identified in the framework of a national collaborative study including the Groupe d'Étude Thérapeutique des Affections Inflammatoires du Tube Digestif (GETAID) and the Lymphoma Study Association (LYSA). We characterized clinical and prognostic features for the 3 most frequent lymphoma subtypes occurring in IBD. We performed a multicentric case-control study. Controls (lymphoma de novo) were matched (5:1) to cases on gender, age at diagnosis, lymphoma subtype, year of diagnosis, IPI/FLIPI indexes. Overall survival (OS) and progression free survival were compared between cases and controls. RESULTS: 133 IBD patients with lymphoma were included (males = 62.4 %, median age at lymphoma diagnosis = 49 years in males ; 42 in females). Most had Crohn's disease (73.7 %) and were exposed to thiopurines (59.4 %). The most frequent lymphoma subtypes were diffuse large B cell lymphoma (DLBCL, 45.1 %), Hodgkin lymphoma (HL, 18.8 %), and follicular lymphoma (FL, 10.5 %). When matched with 365 controls, prognosis was improved in IBD patients with DLBCL compared to controls (p = 0.0064, hazard ratio = 0.36) or similar (HL and FL). CONCLUSION: Lymphomas occurring in IBD patients do not seem to have a worse outcome than in patients without IBD. Due to the scarcity of this situation, those patients should be managed in expert centers.

[Ukrainian war and its consequences Module "Mother and Child" of the Swiss Humanitarian Aid in Moldova]. / La guerre en Ukraine et ses conséquences. Le module « Mère-Enfant ¼ de l'aide humanitaire suisse en Moldavie.

As a result of the Ukraine conflict, more than 6.3 million refugees had to flee to neighbouring countries, among them the Republic of Moldova (RoM), triggering a social and humanitarian crisis. From our assessment of the general health situation and upon request of the RoM Ministry of Health, Swiss Humanitarian Aid module "mother and child" has been deployed to refugee transit centres to deliver primary health care of mothers and children. Due to the specific refugee population consisting mainly of mothers and children, the module showed to be very beneficial, extremely flexible and was highly appreciated. Simultaneously, strategic hospitals were revisited for contingency planning, but also in view of logistical support. We organized a "train the trainer" course together with the National Centre of pre-hospital assistance.

En raison du conflit en Ukraine, plus de 6,3 millions de réfugiés ont dû fuir vers les pays voisins, dont la Moldavie, déclenchant une crise sociale et humanitaire. Sur la base de notre évaluation et à la demande du ministère de la Santé de Moldavie, le module « Mère-Enfant ¼ de l'Aide humanitaire suisse a été déployé dans les centres de transit pour réfugiés afin de fournir des soins de santé primaires aux mères et aux enfants. La population spécifique de réfugiés étant composée principalement de mères et d'enfants, le module s'est avéré très bénéfique, flexible et très apprécié. Dans le même temps, les hôpitaux stratégiques ont été revisités pour la planification d'urgence, mais aussi pour le soutien logistique. Nous avons organisé des « formations des formateurs ¼ en collaboration avec le Centre national d'assistance préhospitalière.

Probability of sporadic lymphangioleiomyomatosis in women presenting with spontaneous pneumothorax.

BACKGROUND: Sporadic lymphangioleiomyomatosis (S-LAM) is a rare low-grade neoplasm of young women characterized by multiple pulmonary cysts leading to progressive dyspnea and recurrent spontaneous pneumothorax (SP). The diagnosis of S-LAM may be delayed by several years. To reduce this delay, chest computed tomography (CT) screening has been proposed to uncover cystic lung disease in women presenting with SP. However, the probability to discover S-LAM in this population has not been determined precisely. The aim of this study was to calculate the probability of finding S-LAM in women presenting with (a) SP, and (b) apparent primary SP (PSP) as first manifestation of S-LAM. METHODS: Calculations were made by applying the Bayes theorem to published epidemiological data on S-LAM, SP and PSP. Each term of the Bayes equation was determined by meta-analysis, and included: (1) the prevalence of S-LAM in the general female population, (2) the incidence rate of SP and PSP in the general female population, and (3) the incidence rate of SP and apparent PSP in women with S-LAM. RESULTS: The prevalence of S-LAM in the general female population was 3.03 per million (95% confidence interval 2.48, 3.62). The incidence rate of SP in the general female population was 9.54 (8.15, 11.17) per 100,000 person-years (p-y). The incidence rate of SP in women with S-LAM was 0.13 (0.08, 0.20). By combining these data in the Bayes theorem, the probability of finding S-LAM in women presenting with SP was 0.0036 (0.0025, 0.0051). For PSP, the incidence rate in the general female population was 2.70 (1.95, 3.74) per 100,000 p-y. The incidence rate of apparent PSP in women with S-LAM was 0.041 (0.030, 0.055). With the Bayes theorem, the probability of finding S-LAM in women presenting with apparent PSP as first disease manifestation was 0.0030 (0.0020, 0.0046). The number of CT scans to perform in women to find one case of S-LAM was 279 for SP and 331 for PSP. CONCLUSION: The probability of discovering S-LAM at chest CT in women presenting with apparent PSP as first disease manifestation was low (0.3%). Recommending chest CT screening in this population should be reconsidered.

Population transcriptogenomics highlights impaired metabolism and small population sizes in tree frogs living in the Chernobyl Exclusion Zone.

BACKGROUND: Individual functional modifications shape the ability of wildlife populations to cope with anthropogenic environmental changes. But instead of adaptive response, human-altered environments can generate a succession of deleterious functional changes leading to the extinction of the population. To study how persistent anthropogenic changes impacted local species' population status, we characterised population structure, genetic diversity and individual response of gene expression in the tree frog Hyla orientalis along a gradient of radioactive contamination around the Chernobyl nuclear power plant. RESULTS: We detected lower effective population size in populations most exposed to ionizing radiation in the Chernobyl Exclusion Zone that is not compensated by migrations from surrounding areas. We also highlighted a decreased body condition of frogs living in the most contaminated area, a distinctive transcriptomics signature and stop-gained mutations in genes involved in energy metabolism. While the association with dose will remain correlational until further experiments, a body of evidence suggests the direct or indirect involvement of radiation exposure in these changes. CONCLUSIONS: Despite ongoing migration and lower total dose rates absorbed than at the time of the accident, our results demonstrate that Hyla orientalis specimens living in the Chernobyl Exclusion Zone are still undergoing deleterious changes, emphasizing the long-term impacts of the nuclear disaster.

Ultrasound Characterization of Cortical Bone Using Shannon Entropy.

OBJECTIVE: Ultrasound backscattered signals encompass information on the microstructure of heterogeneous media such as cortical bone, in which pores act as scatterers and result in the scattering and multiple scattering of ultrasound waves. The objective of this study was to investigate whether Shannon entropy can be exploited to characterize cortical porosity. METHODS: In the study described here, to demonstrate proof of concept, Shannon entropy was used as a quantitative ultrasound parameter to experimentally evaluate microstructural changes in samples with controlled scatterer concentrations made of a highly absorbing polydimethylsiloxane matrix (PDMS). Similar assessment was then performed using numerical simulations on cortical bone structures with varying average pore diameter (Ct.Po.Dm.), density (Ct.Po.Dn.) and porosity (Ct.Po.). RESULTS: The results suggest that an increase in pore diameter and porosity lead to an increase in entropy, indicating increased levels of randomness in the signals as a result of increased scattering. The entropy-versus-scatterer volume fraction in PDMS samples indicates an initial increasing trend that slows down as the scatterer concentration increases. High levels of attenuation cause the signal amplitudes and corresponding entropy values to decrease drastically. The same trend is observed when porosity of the bone samples is increased above 15%. CONCLUSION: Sensitivity of entropy to microstructural changes in highly scattering and absorbing media can potentially be exploited to diagnose and monitor osteoporosis.

Perioperative Cetuximab with Cisplatin and 5-Fluorouracil in Esogastric Adenocarcinoma: A Phase II Study.

PURPOSE: While perioperative chemotherapy provides a survival benefit over surgery alone in gastric and gastroesophageal junction (G/GEJ) adenocarcinomas, the results need to be improved. This study aimed to evaluate the efficacy and safety of perioperative cetuximab combined with 5-fluorouracil and cisplatin. PATIENTS AND METHODS: Patients received six cycles of cetuximab, cisplatin, and simplified LV5FU2 before and after surgery. The primary objective was a combined evaluation of the tumor objective response (TOR), assessed by computed tomography, and the absence of major toxicities resulting in discontinuation of neoadjuvant chemotherapy (NCT) (45% and 90%, respectively). RESULTS: From 2011 to 2013, 65 patients were enrolled. From 64 patients evaluable for the primary endpoint, 19 (29.7%) had a morphological TOR and 61 (95.3%) did not stop NCT prematurely due to major toxicity. Sixty patients (92.3%) underwent resection. Sixteen patients (/56 available, 28.5%) had histological responses (Mandard tumor regression grade ≤3). After a median follow-up of 44.5 months, median disease-free and overall survival were 24.4 [95% CI: 16.4-39.4] and 40.3 months [95% CI: 27.5-NA], respectively. CONCLUSION: Adding cetuximab to the NCT regimen in operable G/GEJ adenocarcinomas is safe, but did not show enough efficacy in the present study to meet the primary endpoint (NCT01360086).

Atezolizumab plus bevacizumab in advanced hepatocellular carcinoma after treatment failure with multikinase inhibitors.

BACKGROUND AND AIMS: Data on the effectiveness of atezolizumab plus bevacizumab (atezo-bev) after failure of multikinase inhibitor (MKI) therapy in patients with advanced hepatocellular carcinoma are scarce. METHODS: This retrospective multicentre study included all consecutive patients treated with atezo-bev after failing one or more MKI treatments in the setting of an early access program. The primary endpoint was the objective response rate (ORR) by investigator assessment (using Response Evaluation Criteria in Solid Tumors v1.1). Overall survival (OS) and progression-free survival (PFS) were assessed using the Kaplan‒Meier method. RESULTS: Fifty patients were included in this analysis. Atezo-bev was started between April 2020 and November 2021 (median follow-up, 18.21 months). The investigator-assessed ORR was 14% (95% CI 5.37-22.63%), with 7 patients displaying a tumour response, and the disease control rate was 56% (95% CI 51.21-60.8%). After starting atezo-bev, the median OS was 17.1 months (95% CI 10.58-22.01), and the median PFS was 7.99 months (95% CI 4.78-10.50). Treatment-related adverse events led to treatment discontinuation in 7 patients. CONCLUSIONS: Atezo-bev every three weeks showed clinical benefit for a proportion of patients previously treated with one or multiple lines of MKIs.

Evolution of the proportion of colistin-resistant isolates in animal clinical Escherichia coli over time - A hierarchical mixture model approach.

Colistin resistance has been the subject of much attention since mcr genes encoding plasmid-mediated colistin resistance description in 2015. To date, surveillance data about resistance levels encountered in food-producing animals are scarce. In France, the Resapath dataset, consisting in a large collection of disk diffusion antibiogram results transmitted by a network of laboratories. It offers a unique opportunity to study the evolution of resistance towards colistin over the past 15 years in Escherichia coli isolated from diseased food-producing animals. This study used a Bayesian hierarchical Gaussian mixture model to estimate the resistant proportions from those data. This non-classical approach deals with the colistin-specific problem of overlapping distributions of diameters measured for susceptible and resistant isolates that makes the definition of epidemiological cut-off very hard. This model also considers the variability observed between the measurements performed by different laboratories. Proportion of resistant isolates has been calculated for several food-producing animals and most encountered diseases. From those estimations, a marked evolution of the proportions of resistant isolates is noticeable, for swine suffering from digestive disorders. In this group, an increase over the 2006-2011 period from 0.1% [ 0.0%, 1.2%] in 2006-28.6% [25.1%, 32.3%] in 2011 was followed by a decrease to reach 3.6% [2.3%;5.3%] in 2018. For isolates related to digestive disorders in calves, percentages increased and reached 7% in 2009 then decreased as for swine. In contrast, for poultry productions, estimated proportions and credibility intervals were constantly very close to zero.

Study of Modifications Induced by Continued Direct Oral Anticoagulant Therapy during Atrial Fibrillation Ablation Procedures on Standard Hemostasis Parameters.

BACKGROUND: Unfractionated heparin (UFH) is used as an anticoagulant during the atrial fibrillation (AF) ablation procedure to prevent the occurrence of thromboembolic events. Guidelines recommend an activated clotting time (ACT) greater than 300 s (s) based on studies of patients treated with vitamin K antagonist (VKA) for their AF. However, direct oral anticoagulants (DOACs) have supplanted VKAs in AF and are now used as first-line therapy. It is recommended not to interrupt them during the procedure, which could interfere with the ACT measures. OBJECTIVE: To assess the real-life relationship between ACT, DOAC concentrations, and UFH anti-Xa activity in patients treated by uninterrupted DOAC therapy. METHODS: We conducted a single-center retrospective study. We analyzed consecutive patients with AF who underwent catheter ablation under DOAC therapy. RESULTS: In total, 40 patients were included, including 15 (37.5%), 20 (50.0%), and 5 (12.5%) on rivaroxaban, apixaban, and dabigatran, respectively. Baseline ACT was significantly lower in the apixaban group. ACT was linearly correlated with the residual concentration of apixaban and dabigatran but not with rivaroxaban. After UFH injection, ACT was linearly correlated with the anti-Xa activity, regardless of DOAC. Patients in the apixaban group received a higher total dose of UFH during the procedure to achieve a target ACT > 300 s, which resulted in significantly higher anti-Xa activity during the procedure. CONCLUSION: Our results raise the question of optimal management of intra-procedural heparin therapy and highlight the limitations of the ACT test, particularly in patients on apixaban.

Numerical and experimental evaluation of low-intensity transcranial focused ultrasound wave propagation using human skulls for brain neuromodulation.

BACKGROUND: Low-intensity transcranial focused ultrasound (tFUS) has gained considerable attention as a promising noninvasive neuromodulatory technique for human brains. However, the complex morphology of the skull hinders scholars from precisely predicting the acoustic energy transmitted and the region of the brain impacted during the sonication. This is due to the fact that different ultrasound frequencies and skull morphology variations greatly affect wave propagation through the skull. PURPOSE: Although the acoustic properties of human skull have been studied for tFUS applications, such as tumor ablation using a multielement phased array, there is no consensus about how to choose a single-element focused ultrasound (FUS) transducer with a suitable frequency for neuromodulation. There are interests in exploring the magnitude and dimension of tFUS beam through human parietal bone for modulating specific brain lobes. Herein, we aim to investigate the wave propagation of tFUS on human skulls to understand and address the concerns above. METHODS: Both experimental measurements and numerical modeling were conducted to investigate the transmission efficiency and beam pattern of tFUS on five human skulls (C3 and C4 regions) using single-element FUS transducers with six different frequencies (150-1500 kHz). The degassed skull was placed in a water tank, and a calibrated hydrophone was utilized to measure acoustic pressure past it. The cranial computed tomography scan data of each skull were obtained to derive a high-resolution acoustic model (grid point spacing: 0.25 mm) in simulations. Meanwhile, we modified the power-law exponent of acoustic attenuation coefficient to validate numerical modeling and enabled it to be served as a prediction tool, based on the experimental measurements. RESULTS: The transmission efficiency and -6 dB beamwidth were evaluated and compared for various frequencies. An exponential decrease in transmission efficiency and a logarithmic decrease of -6 dB beamwidth with an increase in ultrasound frequency were observed. It is found that a >750 kHz ultrasound leads to a relatively lower tFUS transmission efficiency (<5%), whereas a <350 kHz ultrasound contributes to a relatively broader beamwidth (>5 mm). Based on these observations, we further analyzed the dependence of tFUS wave propagation on FUS transducer aperture size. CONCLUSIONS: We successfully studied tFUS wave propagation through human skulls at different frequencies experimentally and numerically. The findings have important implications to predict tFUS wave propagation for ultrasound neuromodulation in clinical applications, and guide researchers to develop advanced ultrasound transducers as neural interfaces.