Mosquitoes integrate visual and acoustic cues to mediate conspecific interactions in swarms.

Male mosquitoes form aerial aggregations, known as swarms, to attract females and maximize their chances of finding a mate. Within these swarms, individuals must be able to recognize potential mates and navigate the social environment to successfully intercept a mating partner. Prior research has almost exclusively focused on the role of acoustic cues in mediating the male mosquito's ability to recognize and pursue females. However, the role of other sensory modalities in this behavior has not been explored. Moreover, how males avoid collisions with one another in the swarm while pursuing females remains poorly understood. In this study, we combined free-flight and tethered-flight simulator experiments to demonstrate that swarming Anopheles coluzzii mosquitoes integrate visual and acoustic information to track conspecifics and avoid collisions. Our tethered experiments revealed that acoustic stimuli gated mosquito steering responses to visual objects simulating nearby mosquitoes, especially in males that exhibited a strong response toward visual objects in the presence of female flight tones. Additionally, we observed that visual cues alone could trigger changes in mosquitoes' wingbeat amplitude and frequency. These findings were corroborated by our free-flight experiments, which revealed that Anopheles coluzzii modulate their thrust-based flight responses to nearby conspecifics in a similar manner to tethered animals, potentially allowing for collision avoidance within swarms. Together, these results demonstrate that both males and females integrate multiple sensory inputs to mediate swarming behavior, and for males, the change in flight kinematics in response to multimodal cues might allow them to simultaneously track females while avoiding collisions.

No sexual pheromones in Anopheles mosquitoes?

Swarming behavior is the cornerstone of the anopheline mating system. At dusk, males congregate in monospecific swarms in which females come to find a mate once in their lives. Although many Anopheles species coexist in sympatry, hybrids are infrequent, suggesting the existence of strong premating reproductive barriers. Chemical cues, particularly pheromones, often play a crucial role in bringing sexes together in a species-specific manner among insects. While the existence of sexual pheromones in Anopheles species has been postulated, only a few studies developed experimental designs to investigate their presence. Here, we discuss the contrasting and debatable findings regarding both long-range and contact sex pheromones in the context of swarm ecology in Anopheles species.

Identification of Semiochemical Candidates Involved in Glossina Palpalis Gambiensis Larviposition Site Selection and Behavioural Responses of Adult Gravid Females.

Tsetse flies (Diptera: Glossinidae) are the cyclical vectors of human and animal trypanosomes. This viviparous insect develops and produces a single larva at 10-day intervals deposited in specific sites. In some species aggregation of larvae has been shown and seems to be mediated by both physical factors and volatile semiochemicals of larval origin. In this context, this study aims to identify chemicals emitted during the pupariation process in Glossina palpalis gambiensis. Volatile Organic Compounds (VOCs) emitted by larvae were identified using static headspace solid-phase microextraction and gas-chromatography mass-spectrometry (GC-MS) analysis. Electrophysiology and behavioural assays were performed on gravid females to confirm VOCs behavioural activity and attractiveness. GC-MS results revealed ten chemicals emitted during the pupariation process of G. p. gambiensis larvae. Among these chemicals, gravid females were shown to detect nine of them during coupled gas chromatography - electroantennographic detection tests. Behavioural assays highlighted two compounds were as attractive as pupae and one compound and a blend of four compounds were more attractive than pupae. Although the larval origin of some of them needs to be confirmed as they may also likely produced by micro-organisms, these compounds induced significant behavioural responses in the laboratory. Further experiments have to explore the biological activity and competitiveness of these compounds in the field. This work opens interesting opportunities for behavioural manipulation and control of tsetse flies.

Predictive role of hepatic venous pressure gradient in bleeding events among patients with cirrhosis undergoing orthotopic liver transplantation.

Background & Aims: Major bleeding events during orthotopic liver transplantation (OLT) are associated with poor outcomes. The proportion of this risk related to portal hypertension is unclear. Hepatic venous pressure gradient (HVPG) is the gold standard for estimating portal hypertension. The aim of this study was to analyze the ability of HVPG to predict intraoperative major bleeding events during OLT in patients with cirrhosis. Methods: We retrospectively analyzed a prospective database including all patients with cirrhosis who underwent OLT between 2010 and 2020 and had liver and right heart catheterizations as part of their pre-transplant assessment. The primary endpoint was the occurrence of an intraoperative major bleeding event. Results: The 468 included patients had a median HVPG of 17 mmHg [interquartile range, 13-22] and a median MELD on the day of OLT of 16 [11-24]. Intraoperative red blood cell transfusion was required in 72% of the patients (median 2 units transfused), with a median blood loss of 1,000 ml [575-1,500]. Major intraoperative bleeding occurred in 156 patients (33%) and was associated with HVPG, preoperative hemoglobin level, severity of cirrhosis at the time of OLT (MELD score, ascites, encephalopathy), hemostasis impairment (thrombocytopenia, lower fibrinogen levels), and complications of cirrhosis (sepsis, acute-on-chronic liver failure). By multivariable regression analysis with backward elimination, HVPG, preoperative hemoglobin level, MELD score, and tranexamic acid infusion were associated with the primary endpoint. Three categories of patients were identified according to HVPG: low-risk (HVPG <16 mmHg), high-risk (HVGP ≥16 mmHg), and very high-risk (HVPG ≥20 mmHg). Conclusions: HVPG predicted major bleeding events in patients with cirrhosis undergoing OLT. Including HVPG as part of pre-transplant assessment might enable better anticipation of the intraoperative course. Impact and implications: Major bleeding events during orthotopic liver transplantation (OLT) are associated with poor outcomes but the proportion of this risk related to portal hypertension is unclear. Our work shows that hepatic venous pressure gradient (HVPG), the gold standard for estimating portal hypertension, is a strong predictor of major bleeding events and blood loss volume in patients with cirrhosis undergoing OLT. Three groups of patients can be identified according to their risk of major bleeding events: low-risk patients with HVPG <16 mmHg, high-risk patients with HVPG ≥16 mmHg, and very high-risk patients with HVPG ≥20 mmHg. HVPG could be systematically included in the pre-transplant assessment to anticipate intraoperative course and tailor patient management.

Multisensory integration in Anopheles mosquito swarms: The role of visual and acoustic information in mate tracking and collision avoidance.

Male mosquitoes form aerial aggregations, known as swarms, to attract females and maximize their chances of finding a mate. Within these swarms, individuals must be able to recognize potential mates and navigate the dynamic social environment to successfully intercept a mating partner. Prior research has almost exclusively focused on the role of acoustic cues in mediating the male mosquito's ability to recognize and pursue flying females. However, the role of other sensory modalities in this behavior has not been explored. Moreover, how males avoid collisions with one another in the dense swarm while pursuing females remains poorly understood. In this study, we combined free-flight and tethered flight simulator experiments to demonstrate that swarming Anopheles coluzzii mosquitoes integrate visual and acoustic information to track conspecifics and avoid collisions. Our tethered experiments revealed that acoustic stimuli gated mosquito steering responses to visual objects simulating nearby mosquitoes, especially in males that exhibited attraction to visual objects in the presence of female flight tones. Additionally, we observed that visual cues alone could trigger changes in mosquitoes' wingbeat amplitude and frequency. These findings were corroborated by our free-flight experiments, which revealed that mosquitoes modulate their flight responses to nearby conspecifics in a similar manner to tethered animals, allowing for collision avoidance within swarms. Together, these results demonstrate that both males and females integrate multiple sensory inputs to mediate swarming behavior, and for males, the change in flight kinematics in response to multimodal cues allows them to simultaneously track females while avoiding collisions.

Autoimmune hepatitis recurrence after liver transplantation: "Les jeux sont faits".

Autoimmune hepatitis (AIH) may recur after liver transplantation (LT). The aims of this study were to evaluate the incidence and risk factors for recurrent autoimmune hepatitis (rAIH). A multicenter retrospective French nationwide study, including all patients aged ≥16 transplanted for AIH, with at least 1 liver biopsy 1 year after LT, was conducted between 1985 and 2018. Risk factors for rAIH were identified using a multivariate Cox regression model. Three hundred and forty-four patients were included (78.8% women) with a median age at LT of 43.6 years. Seventy-six patients (22.1%) developed recurrence in a median time of 53.6 months (IQR, 14.1-93.2). Actuarial risk for developing rAIH was 41.3% 20 years after LT. In multivariate analysis, the strongest risk factor for rAIH was cytomegalovirus D+/R- mismatch status (HR=2.0; 95% CI: 1.1-3.6; p =0.03), followed by associated autoimmune condition. Twenty-one patients (27.6% of rAIH patients) developed liver graft cirrhosis after rAIH. Independent risk factors for these severe forms of rAIH were young age at LT, IgG levels >20.7 g/L, and LT in the context of (sub)fulminant hepatitis. Immunosuppression, especially long-term maintenance of corticosteroid therapy, was not significantly associated with rAIH. Recurrence of AIH after LT is frequent and may lead to graft loss. Recurrence is more frequent in young patients with active disease at the time of LT, yet systematic corticosteroid therapy does not prevent it.

Osteoporosis and Fragility Fractures in Patients With Cirrhosis Evaluated for Liver Transplantation: Identification of High-Risk Patients Based on Computed Tomography at Evaluation.

INTRODUCTION: Osteoporosis in candidates for liver transplantation (LT) is often underdiagnosed despite the important consequences of morbidity. METHODS: We included 376 patients with cirrhosis evaluated for LT with available computed tomography (CT) scans. Prevalent vertebral fractures (VFs) were identified on CT reconstructions, and bone density was assessed by measuring CT attenuation of the L1 vertebra (L1-CT). RESULTS: We identified 139 VFs in 55 patients (14.6%). Logistic regression models showed that low L1-CT was the only independent determinant of VF. DISCUSSION: In patients with cirrhosis evaluated for LT, CT scans identified persons with severe osteoporosis without additional costs.

Legionnaires Disease in Solid Organ Transplant Recipients: A Decade-Long Nationwide Study in France.

BACKGROUND: Legionnaires disease (LD) is a rare, life-threatening opportunistic bacterial infection that poses a significant risk to patients with impaired cell-mediated immunity such as solid organ transplant recipients. However, the epidemiologic features, clinical presentation, and outcomes of LD in this population are poorly described. RESEARCH QUESTION: What are the clinical manifestations, radiologic presentation, risk factors for severity, treatment, and outcome of LD in solid organ transplant recipients? STUDY DESIGN AND METHODS: In this 10-year multicenter retrospective cohort study in France, where LD notification is mandatory, patients were identified by hospital discharge databases. Diagnosis of LD relied on positive culture findings from any respiratory sample, positive urinary antigen test (UAT) results, positive specific serologic findings, or a combination thereof. Severe LD was defined as admission to the ICU. RESULTS: One hundred one patients from 51 transplantation centers were eligible; 64 patients (63.4%) were kidney transplant recipients. Median time between transplantation and LD was 5.6 years (interquartile range, 1.5-12 years). UAT results were positive in 92% of patients (89/97). Among 31 patients with positive culture findings in respiratory samples, Legionella pneumophila serogroup 1 was identified in 90%. Chest CT imaging showed alveolar consolidation in 98% of patients (54 of 57), ground-glass opacity in 63% of patients (36 of 57), macronodules in 21% of patients (12 of 57), and cavitation in 8.8% of patients (5 of 57). Fifty-seven patients (56%) were hospitalized in the ICU. In multivariate analysis, severe LD was associated with negative UAT findings at presentation (P = .047), lymphopenia (P = .014), respiratory symptoms (P = .010), and pleural effusion (P = .039). The 30-day and 12-month mortality rates were 8% (8 of 101) and 20% (19 of 97), respectively. In multivariate analysis, diabetes mellitus was the only factor associated with 12-month mortality (hazard ratio, 3.2; 95% OR, 1.19-8.64; P = .022). INTERPRETATION: LD is a late and severe complication occurring in solid organ transplant recipients that may present as pulmonary nodules on which diabetes impacts its long-term prognosis.

Herpes Simplex Virus Hepatitis in Patients Requiring Intensive Care Unit Admission: A Retrospective, Multicenter, Observational Study.

The clinical features and short-term prognosis of patients admitted to the intensive care unit for herpes hepatitis are lacking. Of 33 patients admitted between 2006 and 2022, 22 were immunocompromised, 4 were pregnant women, and 23 died. Sixteen patients developed a hemophagocytic syndrome. Acyclovir was initiated a median (interquartile range) of 1 (0-3) day after admission.

Novel prognostic biomarkers in decompensated cirrhosis: a systematic review and meta-analysis.

BACKGROUND: Patients with decompensated cirrhosis experience high mortality rates. Current prognostic scores, including the model for end-stage liver disease (MELD), may underperform in settings other than in those they were initially developed. Novel biomarkers have been proposed to improve prognostication accuracy and even to predict development of complications. METHODS: We performed a systematic review and meta-analysis on novel urine and blood biomarkers and their ability to predict 90-day mortality in patients with decompensated cirrhosis. Secondary outcomes included 28-day and 1-year mortality, and development of acute-on-chronic liver failure, acute kidney injury and other complications. To overcome differences in units, temporal changes in assays and reporting heterogeneity, we used the ratio of means (RoM) as measure of association for assessing strength in predicting outcomes. An RoM>1 implies that the mean biomarker level is higher in those that develop the outcome than in those that do not. RESULTS: Of 6629 unique references, 103 were included, reporting on 29 different biomarkers, with a total of 31 362 biomarker patients. Most studies were prospective cohorts of hospitalised patients (median Child-Pugh-Turcotte score of 9 and MELD score of 18). The pooled 90-day mortality rate was 0.27 (95% CI 0.24 to 0.29). The RoM for predicting 90-day mortality was highest for interleukin 6 (IL-6) (2.56, 95% CI 2.39 to 2.74), followed by urinary neutrophil gelatinase-associated lipocalin (uNGAL) (2.42, 95% CI 2.20 to 2.66) and copeptin (2.33, 95% CI 2.17 to 2.50). These RoMs were all higher than for MELD (1.44, 95% CI 1.42 to 1.46). CONCLUSION: Novel biomarkers, including IL-6, uNGAL and copeptin, can probably improve prognostication of patients with decompensated cirrhosis compared with MELD alone.