Round Structures Research Articles

Design and Generation of Self-Assembling Peptide Virus-like Particles with Intrinsic GPCR Inhibitory Activity.

Synthetic analogs of the second transmembrane domain (TM) containing a portion of the extracellular loop 1 of G-protein-coupled receptors (GPCR) can serve as biased antagonists of the corresponding receptor. Analogs with negative charges added to the extracellular end self-assemble into round structures. Addition of polyethylene glycol chains of defined length to the C-terminus of the peptides prevents super aggregation and results in highly uniform particles that can fuse with cell membranes spontaneously. Added PEG chains slow down cell fusion, while attachment of receptor ligands to the surface of particles results in receptor-mediated membrane fusion and cell-selective delivery. Critical assembly concentration of TM peptide particles is in the nanomolar range and thus requires nontraditional methods of determination. In this chapter, we outline sequence selection and design of self-assembling GPCR antagonists, methods of the preparation of the nanoparticles, and biophysical methods of particle characterization. The protocols allow for straightforward rational design, generation, and characterization of self-assembling GPCR antagonists for a variety of applications.

Abstract 332: Nanofibrillar cellulose hydrogel as 3D culture matrix towards the development of tumor models

Abstract Introduction. Physiologically relevant and robust in vitro cell models are needed for cancer model development, as well as standard cell-based drug screening assays. These models and assays may require the use of well-established cancer cell-lines or primary patient-derived cells. It is well known that three-dimensional (3D) cell culture provides a more in vivo -like environment for cells compared to traditional 2D monolayer culture. GrowDex®, a nanofibrillar cellulose (NFC) hydrogel, derived from the Birch tree, has been shown to reproducibly support the culture of many different cell types in 3D. Many animal derived hydrogels contain growth factors, other biological signaling molecules and unknown amounts of different ECM proteins, and have also suffered from variation between lots. The tunable stiffness, shear thinning properties and room-temperature stability, enable GrowDex to be used in a multitude of applications with a wide variety of different cell types and tissues. Additionally, cellulase enzyme (GrowDase™) treatment allows the recovery of cells or multicellular structures without impact to cell viability, phenotype or function. Methods and Results. Cancer cells derived from either solid tumor (e.g. osteosarcoma or breast cancer) or liquid biopsies (e.g. pleural or ascites effusion) require different culturing conditions. Studies have shown that GrowDex provides a suitable inert matrix where anchorage dependent and independent cancer cells can be cultured for short- or long-term studies, without observing uncontrolled matrix induced effects. Cells were seen to form round well-defined spheroids or multicellular structures. Additionally, co-cultures of cancer cells with fibroblasts provided a more physiologically relevant environment for the investigation of cell-cell effects on microtissue formation. When cells were seeded with different cell ratios, microtissues showed different morphologies and sizes. GrowDex has also been used successfully for the culture and characterization of an intensively pigmented cell line derived from a highly aggressive NRAS mutated cutaneous melanoma. Cultured cells maintained their natural in vivo behavior and morphology, as well as increasing the deep brown pigmentation staining. In addition, GrowDex has been shown to be an optimum matrix for use with patient derived cancer (PDC) cells cultured for use in drug screening tests for personalized medicine. Differences in drug responses with the PDC cells in 2D and 3D conditions were observed. Conclusions. GrowDex is highly biocompatible with over150 cell types including human cancer cells and primary tumor tissue. The hydrogel is animal-free, ready-to-use with shear-thinning properties making it easy to handle and automate providing a well-defined 3D environment for drug screening and cell-based disease model development assays. Citation Format: Jonathan Sheard. Nanofibrillar cellulose hydrogel as 3D culture matrix towards the development of tumor models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 332.

Effects of tungsten and cobalt concentration on microstructure and anticorrosive property of cobalt-tungsten alloys

The replacement of chrome coatings for materials that maintain the same properties has become the Co-W alloy relevant. In this context, we proposed to evaluate the effects of the Co and W concentration in the electrolytic bath on the faradaic efficiency, morphology, and anticorrosive property of the Co-W alloy. The diffractograms indicated a tendency to amorphization when the W concentration increased from 0.1 to 0.3 M, and the faradaic efficiency achieved values close to 70%. Alloy surfaces demonstrated a homogeneous composition according to the energy-dispersive X-ray mapping. The increase of Co and W concentration promoted the formation of rounded structures and reduced the space between the microcracks. Moreover, the high concentration of these promoted greater corrosion resistance with a corrosion current density of 1.83 µA cm−2.

Ultrastructural, Cytochemical, and Comparative Genomic Evidence of Peroxisomes in Three Genera of Pathogenic Free-Living Amoebae, Including the First Morphological Data for the Presence of This Organelle in Heteroloboseans.

Peroxisomes perform various metabolic processes that are primarily related to the elimination of reactive oxygen species and oxidative lipid metabolism. These organelles are present in all major eukaryotic lineages, nevertheless, information regarding the presence of peroxisomes in opportunistic parasitic protozoa is scarce and in many cases it is still unknown whether these organisms have peroxisomes at all. Here, we performed ultrastructural, cytochemical, and bioinformatic studies to investigate the presence of peroxisomes in three genera of free-living amoebae from two different taxonomic groups that are known to cause fatal infections in humans. By transmission electron microscopy, round structures with a granular content limited by a single membrane were observed in Acanthamoeba castellanii, Acanthamoeba griffini, Acanthamoeba polyphaga, Acanthamoeba royreba, Balamuthia mandrillaris (Amoebozoa), and Naegleria fowleri (Heterolobosea). Further confirmation for the presence of peroxisomes was obtained by treating trophozoites in situ with diaminobenzidine and hydrogen peroxide, which showed positive reaction products for the presence of catalase. We then performed comparative genomic analyses to identify predicted peroxin homologues in these organisms. Our results demonstrate that a complete set of peroxins—which are essential for peroxisome biogenesis, proliferation, and protein import—are present in all of these amoebae. Likewise, our in silico analyses allowed us to identify a complete set of peroxins in Naegleria lovaniensis and three novel peroxin homologues in Naegleria gruberi. Thus, our results indicate that peroxisomes are present in these three genera of free-living amoebae and that they have a similar peroxin complement despite belonging to different evolutionary lineages.

Microvesicles derived from squamous cell carcinoma induce cell death, autophagy, and invasion of benign myoepithelial cells.

There has been great interest recently in the mechanisms of cell-to-cell communication through microvesicles (MV). These structures are produced by many different cell types and can modulate cellular activity by induction of epigenetic alterations. These vesicles may promote tumor mass increase either by stimulating cell proliferation via growth factors or by inhibiting apoptosis, which reinforces the role of such vesicles as important modulators of tumor progression. The present in vitro study aimed to characterize MV derived from malignant neoplastic epithelial cell cultures (EP) and their effect on the expression of apoptosis/autophagy and invasion related genes of benign myoepithelial (Myo) cell cultures. The results revealed round structures with a mean size of 153.6 (±0.2) nm, with typical MV morphology. CD63 quantification indicated that EP cell culture at 70%-80% confluence secreted 3.088×108 MV/mL. Overall, Myo exposed to MVs derived from EP showed both up- and downregulation of tumorigenesis promoting genes. MVs from EP cells promoted cell death of Myo cells and positively modulate BAX, SURVIVIN, LC3B, MMP-2, and MMP-9 expression. Furthermore, an increasing of MMP-2 and MMP-9 secretion by Myo was observed after MV exposure. These findings suggest that MVs from EP modulate autophagy of Myo cells, which may, in part, explain the disappearance of these cells in in situ areas of invasive carcinoma ex-pleomorphic adenoma. Additionally, the overexpression of MMPs contributes to the development of an invasive phenotype of Myo cells, which could favor the dissolution of the basement membrane during tumorigenesis process.

Evaluation of emulsified silicone oil with spectral domain-optical coherence tomography and fluorescein angiography.

To report emulsified particles and related complications after removal of silicone oil (SO) by spectral domain-optical coherence tomography (SD-OCT) and fluorescein angiography (FA). A prospective, single-center investigation was performed using SD-OCT, FA and flare cell photometry measurements to evaluate in a cohort of eyes with emulsified silicone particles after removal of long-term SO tamponade. Nineteen eyes of the 19 patients with emulsified silicone particles detected in ophthalmoscopic exam were included in the study: 13 (68%) were male, and 6 (31.6%) were female, and their mean age was 52.75 ± 16.06years. Preoperative diagnoses were rhegmatogenous retinal detachment in all eyes. The mean duration of the silicone oil's presence in the eye was found as 12.63 ± 4.87 (7-26) months. SD-OCT examination postoperatively showed small, round and hyper-reflective structures compatible with emulsified silicone particles on preretinal surface in 7 (36.8%) eyes, intraretinally in 6 (31.6%) eyes and in the vitreous in 12 (63%) eyes. FA imaging demonstrated pearl-like hyper-fluorescence at early and late phases on the large blood vessels in 9 (47.4%) eyes. Late phase hyper-fluorescence due to leakage on the macula was observed in 17 (89.5%) eyes. Diffuse peripheral leakage and hyper-fluorescence was detected in 11 (57.9%) eyes. Flare levels were higher in eyes with emulsified SO compared to unaffected fellow eyes (p < 0.05). Emulsified silicone particles that remain in the eye may lead to retinal complications and inflammation in addition to their known complications such as keratopathy and glaucoma. The particles that lead to inflammation and presence of inflammation may be examined by imaging methods such as SD-OCT and FA. Removing the SO before emulsification would be suitable for avoiding such complications.

Multiparametric imaging reveals that mitochondria-rich intercalated cells in the kidney collecting duct have a very high glycolytic capacity.

Alpha intercalated cells (αICs) in the kidney collecting duct (CD) belong to a family of mitochondria rich cells (MRCs) and have a crucial role in acidifying the urine via apical V-ATPase pumps. The nature of metabolism in αICs and its relationship to transport was not well-understood. Here, using multiphoton live cell imaging in mouse kidney tissue, FIB-SEM, and other complementary techniques, we provide new insights into mitochondrial structure and function in αICs. We show that αIC mitochondria have a rounded structure and are not located in close proximity to V-ATPase containing vesicles. They display a bright NAD(P)H fluorescence signal and low uptake of voltage-dependent dyes, but are energized by a pH gradient. However, expression of complex V (ATP synthase) is relatively low in αICs, even when stimulated by metabolic acidosis. In contrast, anaerobic glycolytic capacity is surprisingly high, and sufficient to maintain intracellular calcium homeostasis in the presence of complete aerobic inhibition. Moreover, glycolysis is essential for V-ATPase-mediated proton pumping. Key findings were replicated in narrow/clear cells in the epididymis, also part of the MRC family. In summary, using a range of cutting-edge techniques to investigate αIC metabolism in situ, we have discovered that these mitochondria dense cells have a high glycolytic capacity.

Novel 2-amino-4-aryl-6-pyridopyrimidines and N-alkyl derivatives: Synthesis, characterization and investigation of anticancer, antibacterial activities and DNA/BSA binding affinities.

A series of new 2-amino-4-aryl-6-pyridopyrimidines, and their N-alkyl bromide derivatives were designed and synthesized by employing methyl substituted azachalcones. These novel compounds were evaluated and compared to the well-known chemotherapeutics in terms of their anti-cancer and anti-microbial functions, and their DNA/protein binding affinities. In order for the cell proliferation, cytotoxicity and microdilution features to be observed, various cancer cell lines (Hep3B, A549, HeLa, C6, HT29, MCF7) were treated with 2-amino-4-aryl-6-pyridopyrimidines (1-9) and their N-alkyl bromide derivatives (2a-c, 3a-c,5a-c,6a-c, 8a-c, 9a-c). Studies on the cells revealed that both pyrimidines and their alkyl derivatives (i) have a high anti-proliferative and anti-microbial activities, (ii) cause cell rounding, cytoplasmic blebs, and anomalous globular structure, and (iii) strongly bound to DNA/BSA macromolecules. Especially the length of the alkyl chain of the N-alkyl bromides has an increasing effect on the antiproliferative, antibacterial and cytotoxic functions, also DNA/protein binding affinity. Those results indicate the novel compounds to be promising antiproliferative agents, and their anti-cancer potential makes them candidates to be used for cancer therapy.

TEOS and Na2SiO3 as silica sources: study of synthesis and characterization of hollow silica nanospheres as nano thermal insulation materials

Hollow structured material (HSM) consisting of monodisperse hollow silica nanospheres (HSN) shows a promising potential for construction insulation due to its affordable cost and simple process. Yet the studies of high-yield and low-energy for the synthetic of HSN are still insufficient. This research reported the comparison of morphology and performance of synthesize HSN utilizing TEOS and Na2SiO3 as silica source. The average yield of Na2SiO3-based samples can reach 93.75%, which is about 10 times higher that of TEOS-based samples. Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) results revealed that the shell morphology of TEOS-based samples was raspberry-like or smooth structure, while the shell of the Na2SiO3-based samples was round honeycomb-like structure. Hot Disk thermal constant analyzer results demonstrated that the thermal conductivity of the Na2SiO3-based samples was lower than that of the TEOS-based samples with similar inner-diameter and shell thickness. Thereafter, the influence mechanism of the morphology on thermal insulation performance was also investigated. The prepared HSN as filler significantly enhanced the thermal insulation of acrylic coating. This research confirms that the synthesis route with Na2SiO3 was a greener method which can solve the low yield and high energy consumption caused using TEOS as a silica source. Excellent thermal insulation properties indicate HSN will have a broad application prospect in heat-insulating and energy-saving construction.

Nephrology Fellows' and Program Directors' Perceptions of Hospital Rounds in the United States.

Hospital rounds are a traditional vehicle for patient-care delivery and experiential learning for trainees. We aimed to characterize practices and perceptions of rounds in United States nephrology training programs. We conducted a national survey of United States nephrology fellows and program directors. Fellows received the survey after completing the 2019 National Board of Medical Examiners Nephrology In-Training Exam. Program directors received the survey at the American Society of Nephrology's 2019 Nephrology Training Program Directors' Retreat. Surveys assessed the structure and perceptions of rounds, focusing on workload, workflow, value for patient care, and fellows' clinical skill-building. Directors were queried about their expectations for fellow prerounds and efficiency of rounds. Responses were quantified by proportions. Fellow and program director response rates were 73% (n=621) and 70% (n=55). Most fellows (74%) report a patient census of >15, arrive at the hospital before 7:00 am (59%), and complete progress notes after 5:00 pm (46%). Among several rounding activities, fellows most valued bedside discussions for building their clinical skills (34%), but only 30% examine all patients with the attending at the bedside. Most directors (71%) expect fellows to both examine patients and collect data before attending-rounds. A majority (78%) of directors commonly complete their documentation after 5:00 pm, and for 36%, after 8:00 pm. Like fellows, directors most value bedside discussion for development of fellows' clinical skills (44%). Lack of preparedness for the rigors of nephrology fellowship was the most-cited barrier to efficient rounds (31%). Hospital rounds in United States nephrology training programs are characterized by high patient volumes, early-morning starts, and late-evening clinical documentation. Fellows use a variety of prerounding styles and examine patients at the beside with their attendings at different frequencies. This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_03_17_CJN.10190819.mp3.

Lung adenocarcinoma as a cause of spontaneous pneumothorax in a cat

A 15-year-old indoor/outdoor female, neutered, domestic European short haired cat was presented to our clinic with a history of neck-elongation and wheezing during inspiration/expiration. The first signs of respiratory disease occurred two weeks before the clinical presentation. After taking of clinical history, clinical examination and basic laboratory tests (complete blood count, blood smear, snap Feline Immunodeficiency Virus / Feline Leukemia Virus Combo test), a lung x-ray was performed showing the presence of left lung atelectasis and pneumothorax. The primary causes of lung atelectasis were not determined. Given that the general condition of the cat was very bad, she was put in an oxygen cage, thoracocentesis was performed, but the animal?s condition did not improve, and 24 hours after clinical presentation, the cat died. Autopsy revealed the presence of a tumor mass on the caudal lobe of the right lung, tumor formation in the area of trachea bifurcation and changes in the liver in the form of four round structures of different sizes. Histopathologically, the existence of primary undifferentiated lung adenocarcinoma with metastases on the liver and trachea was determined.

Meet-in-the-Middle Attacks and Structural Analysis of Round-Reduced PRINCE

NXP Semiconductors and its academic partners challenged the cryptographic community with finding practical attacks on the block cipher they designed, PRINCE. Instead of trying to attack as many rounds as possible using attacks which are usually impractical despite being faster than brute force, the challenge invites cryptographers to find practical attacks and encourages them to actually implement them. In this paper, we present new attacks on round-reduced PRINCE including the ones which won the challenge in the 4-, 6- and 8-round categories—the highest for which winners were identified. Our first attacks rely on a meet-in-the-middle approach and break up to ten rounds of the cipher. We also describe heuristic methods we used to find practical SAT-based and differential attacks. Finally, we also present an analysis of the cycle structure of the internal rounds of PRINCE leading both to a low complexity distinguisher for 4-round PRINCE-core and an alternative representation of the cipher valid in particular contexts and which highlights, in these cases, a poor diffusion.

Research progress of outer retinal tabulation

The outer retinal tubular structure (ORT) indicates a round or oval-shaped structure with a highly reflective border and a relatively low reflective lumen on spectrum-domain coherence tomography. ORTs are located in the outer nuclear layer accompanied by disruption and curling of the external limiting membrane and retinal pigment epithelial atrophy. Histopathological researches have revealed that ORTs are some kind of remodeling of the outer retina especially photoreceptors under pathological conditions, representing an advanced damage to the outer retina and a common final pathway of various retinal degenerative diseases. ORTs are common in neovascular age-related macular degeneration. They show some similarities in morphology with inter retinal fluid or cystoid edema on spectrum-domain coherence tomography, but they are not an indication for neovascular activity and retreatment. Their response to anti-vascular endothelial growth factor is poor, and the visual prognosis is not optimistic. Therefore, raising awareness of ORTs is very important for guiding clinical treatment and judging prognosis. (Chin J Ophthalmol, 2020, 56: 149-154).

Design and optimisation for a piezoelectric frame to harvest energy from structure vibrations

ABSTRACT Energy harvesting from low amplitude vibrating sources is a challenging problem. To overcome this problem, there is a requirement to design and optimise a harvester device to amplify the vibration to access a considerable amount of harvested energy. In this paper, a new diamond frame design for piezoelectric energy harvesting is purposed and compared with a single frame conventional design of piezoelectric harvesters to amplify the vibration amplitude to harvest more energy. Also, a linear optimisation function is obtained to optimise the frame shape which means with different values of input displacement to the device, an optimum angle of frame is obtained. To show the versatility of the novel design, it is used in both flat and round structures. Based on the results with the new design in a flat and round structure, 35% and 70% improvement in energy harvesting are obtained, respectively.

Mixed methods quality evaluation of structured interprofessional medical ward rounds.

Standardised structure and content of interdisciplinary medical ward rounds can promote patient safety and patient-centred teamwork. To evaluate interdisciplinary ward rounds using a Structured Interdisciplinary Bedside Rounding (SIBR) intervention. The study involved multi-method, repeat measures with a non-equivalent control group. Non-participant observations were collected at: 1 and 6 months, on an intervention ward that introduced SIBR; and a control ward that continued traditional rounds. Focus group and survey data were also collected on the intervention ward. Participants were clinicians (medicine, nursing and allied health) working in two general medicine wards at a tertiary hospital in Melbourne, Australia. Seventy-eight patient rounds were observed at Time 1, and 239 at Time 2. The SIBR ward rounds had all clinician disciplines represented, whereas allied health and nurses were present for less than 20% of non-SIBR rounds. Interdisciplinary participation and frequency of desired clinician behaviours increased, and variability in duration of time per patient decreased, on the SIBR rounds. Longitudinal data reflected decreased performance of some SIBR behaviours in the intervention ward, while some desired behaviours increased in the control ward. Qualitative survey and focus group data indicated many positive views, but fit with broader ward routines impacted SIBR implementation. The overall recommendation by staff was that SIBR should continue. The results provide insights into the adoption of SIBR behaviours and illustrated diffusion of behaviours across wards. Highlighting successes and identifying barriers can help meet challenges for ongoing improvement.

Hemmule: A Novel Structure with the Properties of the Stem Cell Niche.

Stem cells are nurtured and regulated by a specialized microenvironment known as stem cell niche. While the functions of the niches are well defined, their structure and location remain unclear. We have identified, in rat bone marrow, the seat of hematopoietic stem cells—extensively vascularized node-like compartments that fit the requirements for stem cell niche and that we called hemmules. Hemmules are round or oval structures of about one millimeter in diameter that are surrounded by a fine capsule, have afferent and efferent vessels, are filled with the extracellular matrix and mesenchymal, hematopoietic, endothelial stem cells, and contain cells of the megakaryocyte family, which are known for homeostatic quiescence and contribution to the bone marrow environment. We propose that hemmules are the long sought hematopoietic stem cell niches and that they are prototypical of stem cell niches in other organs.

Tumefactive perivascular space demonstrated with post-contrast time-of-flight MR angiography

The cerebral perivascular spaces are interstitial fluid-filled anatomic structures surrounding the perforating arteries. They appear as small, round or curvilinear structures on magnetic resonance (MR) imaging. Occasionally, these structures may become very large and cause mass effect. In this case, they may imitate malignant processes and are referred to as tumefactive perivascular spaces. In this study, we present a case of tumefactive perivascular space demonstrated with post-contrast time-of-flight (TOF) MR angiography. To our knowledge, there have been no previous clear demonstrations of the perforating artery in tumefactive perivascular space with contrast-enhanced TOF MR angiography. The purpose of this study was to describe advanced imaging findings in this unusual condition.

Eruptive vellus hair cyst: Unveiling the diagnostic features

Eruptive vellus hair cyst (EVHC) is a rare developmental abnormality of the vellus hair follicles presenting in children and adolescents as multiple, asymptomatic papules over the chest, axillae, and buttocks. Clinically, it can easily be misdiagnosed as comedonal acne, keratosis pilaris, steatocystoma multiplex, syringomas, milia, lichen nitidus, perforating folliculitis, and molluscum contagiosum. Here, we report a 4-year-old girl who was being treated as a case of steroid-induced folliculitis and was later diagnosed with EVHC based on dermoscopic features and confirmed by histopathological examination. Dermoscopy of EVHC shows the presence of homogenous blue areas, round or oval yellowish structures, with occasional erythematous halos and cystic openings in the epidermis. We report this case to emphasize the role of dermoscopy in early diagnosis of eruptive vellus hair cyst which is a rare condition and can be missed easily. Dermoscopy, being a non-invasive and painless diagnostic tool, can prove to be a useful, particularly in children for differentiating EVHC from its mimickers, thus avoiding the need for biopsy.

Corneal side effects induced by EGFR-inhibitor antibody-drug conjugate ABT-414 in patients with recurrent glioblastoma: a prospective clinical and confocal microscopy study.

Background:The aim of this study was to prospectively analyse, for the first time worldwide by in vivo clinical confocal microscopy (CCM), corneal side effects secondary to the use of epidermal growth factor receptor (EGFR) inhibitor depatuxizumab mafodotin (ABT-414) in a cohort of patients affected by EGFR-amplified recurrent glioblastoma.Methods:Each enrolled patient underwent full ophthalmologic examination including in vivo CCM of the cornea. Each patient was examined at baseline and every 2 weeks during treatment as long as patient conditions allowed it.Results:A total of 10 patients were consecutively enrolled. Median follow-up was 5 months. No Common Terminology Criteria for Adverse Events Version 4.0 grade 4 toxicity was documented. Two (20%) grade 3 toxicities were documented at week 8. CCM examination detected in all eyes multiple and diffuse hyperreflective white round spots in the corneal basal epithelial layers (100%), progressive subbasal nerve plexus layer fibres fragmentation followed by full disappearance (100%) and appearance of round cystic structures in the corneal epithelium (100%). All CCM documented side effects reached the peak of prevalence and severity after a median of 3 infusions. After treatment discontinuation, the reversibility of corneal side effects was documented at CCM after a median of 4 weeks.Conclusion:ABT-414 toxicity is not only directed to the corneal epithelium, but also to corneal nerves. Side effects are detectable in all treated patients and CCM documents early corneal epithelium and subbasal nerve plexus toxicity, with subsequent progressive restoration after treatment discontinuation. Ocular side effects due to ABT-414 can be manageable.

P1257 Additional value of echocardiography in critical patient: a quick and effective tool to improve diagnosis and treatment

Abstract A 72 year-old woman with Hashimoto thyroiditis in replacement therapy and no known CV risk factors was admitted to the emergency department because of worsening asthenia, nausea, vomiting and fever unresponsive to antibiotic therapy. Two weeks before the admission, she had a syncopal episode preceded by intense chest pain for which she hadn’t seek medical help. At admission, the patient was unconscious and hemodynamically unstable with signs of shock (BP 80/50 mmHg, HR 120 bpm, lactate 6.11 mmol/L). She was promptly intubated and mechanically ventilated, and fluids and vasopressor treatment was administered. Lab tests showed moderate anaemia (haemoglobin 8.3 mg/dl), mild neutrophilia, elevated inflammatory markers (C-reactive protein 87 mg/dl) and troponin I (679 ng/L). An ECG showed sinus tachycardia and inferior Q waves. A thoraco-abdominal CT excluded pulmonary embolism and showed a suspect acute cholecystitis, suggesting a septic shock. However, a focused transthoracic echocardiogram in the emergency room showed a dilated and non-collapsing inferior vena cava, a severe mitral regurgitation and a very large rounded structure suggestive of left ventricle (LV) aneurysm/pseudoaneurysm, but it was inconclusive due to the poor acoustic window of the patient. The review of CT images also did not allow to make a clear diagnosis of LV aneurysm vs pseudoaneurysm. The patient was transferred in the ICU for further investigation; inotropes, vasopressors, blood transfusion and antibiotics were administered. A complete transthoracic echocardiogram (TTE) was performed to clarify the diagnosis between septic and cardiogenic shock. TTE revealed a large aneurysm (55x40 mm) of the inferior interventricular septum and inferior basal and mid LV segments, with a ventricular septal defect (VSD) with left-right shunt, a severe ischaemic mitral regurgitation and a severely dilated and dysfunctional right ventricle. Due to the suboptimal quality of TTE, an urgent transoesophageal examination (TEE) was done which revealed mobile masses attached on the tricuspid and the aortic valves suggestive of vegetations and confirmed the VSD at the level of a large inferoseptal LV aneurysm and severe ischaemic mitral regurgitation with no signs of papillary muscle or chordal rupture (Figure). Coronary angiography was performed, showing proximal occlusion of right coronary artery (likely embolic) with initial collateral circulation. Blood cultures were positive. The patient underwent cardiac surgery, which confirmed the diagnosis of endocarditis associated with VSD and LV aneurysm. The postoperative course was complicated by multiple organ dysfunction syndrome and death after 19 days of intensive care. Learning point in challenging cases with unclear diagnosis of septic versus cardiogenic shock, both TTE and TOE play a pivotal role showing a series of findings that can help clarifying the diagnosis and guide patient treatment in emergency settings. Abstract P1257 Figure