Molecular MR Imaging of Renal Fibrogenesis in Mice.

BACKGROUND: In most CKDs, lysyl oxidase oxidation of collagen forms allysine side chains, which then form stable crosslinks. We hypothesized that MRI with the allysine-targeted probe Gd-oxyamine (OA) could be used to measure this process and noninvasively detect renal fibrosis. METHODS: Two mouse models were used: hereditary nephritis in Col4a3-deficient mice (Alport model) and a glomerulonephritis model, nephrotoxic nephritis (NTN). MRI measured the difference in kidney relaxation rate, ΔR1, after intravenous Gd-OA administration. Renal tissue was collected for biochemical and histological analysis. RESULTS: ΔR1 was increased in the renal cortex of NTN mice and in both the cortex and the medulla of Alport mice. Ex vivo tissue analyses showed increased collagen and Gd-OA levels in fibrotic renal tissues and a high correlation between tissue collagen and ΔR1. CONCLUSIONS: Magnetic resonance imaging using Gd-OA is potentially a valuable tool for detecting and staging renal fibrogenesis.

Urgent Juxtarenal Aortic Aneurysm Repair With Modified Off-the-shelf Endograft to Preserve Intercostal Arteries and Branch Incorporation by Transfemoral Access.

PURPOSE: To demonstrate the feasibility of the modification to preserve intercostal arteries of the t-Branch Endograft (Cook Medical, Bloomington, IN) in an urgent setting, associated with a less invasive approach for branch incorporation from percutaneous femoral access with steerable sheaths. TECHNIQUE: A 73-year-old female patient presented at our institution with intense abdominal pain. Angiotomography showed a 50-mm juxtarenal aortic aneurysm, with no signs of rupture. Urgent endovascular repair was indicated due to abdominal symptom with an off-the-shelf multi-branched endograft. To limit descending thoracic aortic coverage, we performed t-Branch modification to preserve intercostal arteries and minimize the risk of spinal cord injury, associated with a percutaneous transfemoral approach and branch incorporation with steerable sheaths to avoid the risks associated with a superior axillary or brachial access. Control angiotomography showed adequate aneurysm sac exclusion with patency of all four visceral vessels. CONCLUSION: t-Branch-modified endograft to limit aortic coverage is an alternative option in urgent cases to diminish the risk of spinal cord injury, and association of steerable sheaths with branch incorporation is leading complex aortic repairs to an even less invasive procedure. CLINICAL IMPACT: This paper highlights the possibility of performing complex endovascular aortic repair in an urgent setting with modification of an off-the-shelf multi branched endograft limiting intercostal arteries coverage, thereby diminishing the risk of spinal cord ischemia. This technical innovation provides an alternative for clinicians when treating large, rapidly expanding, or symptomatic juxtarenal, pararenal, paravisceral or type 4 thoracoabdominal aortic aneurysms that could not wait for a custom-made device and do not need extensive thoracic aortic coverage that an off-the-shelf device provides. In summary, expand the possibilities of an endovascular repair of complex aortic aneurysms.

Physicochemical properties of ultrasmall colloidal silver nanoparticles: an experimental and computational approach.

Silver nanoparticles (AgNPs) exhibit very interesting properties that have been employed in several kinds of applications spanning from antibacterial activity to plasmon-polaritons generation. Nanoparticle size strongly influences these applications. However, the characterization of ultrasmall AgNPs (particle diameter < 10 nm) encompassing different aspects such as average size, polydispersion, shape (anisotropy), concentration, and density remains a challenging task. To address these challenges, we combined TEM measurements with a computational framework based on Mie-Gans theory. This allowed us to describe the aforementioned AgNP features accurately. The synthesis of AgNPs in an aqueous medium involved the use of silver nitrate as a chemical precursor and sodium borohydride as a reducing agent, with polyvinylpyrrolidone acting as a stabilizing agent. Our outcomes showed that increasing the concentration of the precursor and reducing agent with a fixed 1 : 2 molar ratio tends to yield ultrasmall AgNPs with low to moderate polydispersion, a nearly spherical shape (low anisotropy), concentration in the nanomolar range and density close to silver bulk. Also, we established an analytical expression that correlates the extinction molar absorptivity to AgNP size considering the nanoparticle shape. Notably, the computational framework proved to be highly effective in extracting crucial information about the AgNPs from UV-vis spectroscopy data. In conclusion, our study sheds light on the unique properties of ultrasmall AgNPs and presents a comprehensive approach for properly characterizing these nanoparticles, paving the way for further advancements in their applications.

Size-Dependent Photobleaching Mechanism and Kinetics Induced by Nanosecond Laser Pulses in Colloidal Semiconductor Quantum Dots.

An experimental-theoretical approach is proposed to investigate the size-dependent photobleaching of colloidal semiconductor quantum dots (QDs) excited by a nanosecond pulsed laser. In the experimental background, the ground-state absorption and photoluminescence (PL) spectra of chemically prepared QDs are monitored over an excitation time at distinct laser irradiances. The magnitude of photobleaching in the QD solution is quantified by the decay rate of the PL signal as a function of the excitation time and the laser power. A theoretical spectroscopy model is then used to estimate the particle size distribution (PSD) in colloidal solution from the absorption data generated at different laser powers. The resulting evolution of the PSD of the QD ensemble under irradiation is analyzed in terms of classical crystallization theories dealing with the formation, growth, and dissolution of colloidal particles in a supersaturated medium. The QD response to laser irradiation is also interpreted by a simple mechanical model that correlates the photoinduced hydrostatic strain at the solid/liquid interface and the predicted variation of the mean particle size. The reported experimental and theoretical methods are used to completely elucidate the basic physico-chemical processes responsible for the laser-induced photobleaching kinetics of glutathione-capped CdTe aqueous QDs with very small mean sizes. For this purpose, we synthesized a series of colloidal QD samples with mean particle diameters ranging from 1.95 to 2.68 nm. Our results indicate that a faster photobleaching rate occurs in QD samples with smaller sizes in which particle dissolution under laser irradiation is predominant. On the other hand, the photobleaching rate becomes slower in samples with larger dot sizes, possibly due to the formation of core/shell structures in solution via thermal degradation of thiol ligands either during the chemical synthesis or as a consequence of the subsequent interaction with the excitation laser.

Multi-Branched Thoracoabdominal Endovascular Aortic Repair With Branch Access Through a Left Thoracotomy and Descending Thoracic Aortic Conduit: A Novel and Effective Alternative Access.

PURPOSE: To demonstrate an alternative access to perform directional branch catheterization during complex endovascular aortic repair. TECHNIQUE: Urgent endovascular aortic repair was indicated to treat a symptomatic post dissection thoracoabdominal aneurysm with large infrarenal dilatation with an off-the-shelf t-Branch endograft (Cook Medical, Bloomington, IN, USA). Traditional proximal arterial accesses were not suitable due to a previous aortic arch endograft. A novel approach was performed through a left postero-lateral thoracotomy, isolation of the descending thoracic aorta and anastomosed a polyester graft conduit to allow sheaths passage to the thoracoabdominal aorta with subsequently directional branch catheterization. CONCLUSION: The descending thoracic aortic conduit technique is an effective alternative for directional branch catheterization and should be considered whenever traditional proximal arterial accesses are not suitable and other endografts configurations not considered due to anatomic limitations.

Size-dependent photoinduced transparency in colloidal CdTe quantum dots in the strong confinement regime: an inverse linear relationship.

Nanomaterials have been investigated as saturable absorbers for ultrafast lasers because of their large photoinduced transparency related to ground-state bleaching. However, the quantum dot size effect on the photoinduced transparency in the strong confinement regime has not been explored due to the challenge of accurately measuring the ground state and the excited-state absorption cross-sections. At the same time, these optical properties are essential to calculate several chemical and physical quantities at the nanoscale. In this context, we have employed the photoluminescence saturation method to determine the ground-state absorption cross-section and the femtosecond open-aperture Z-scan technique to investigate the size-dependent ground-state bleaching of glutathione-capped CdTe QDs synthesized in an aqueous medium. The results were modeled using rate equations within the three-energy levels approach. Our results pointed out that the photoinduced transparency rate at the 1S3/2(h) → 1S(e) transition peak presents an inverse linear relationship with the QD diameter (from 2.2 nm up to 3 nm). Otherwise, the larger QDs have a higher ground-state cross-section, which is directly proportional to the ground-state bleaching. To explain this apparent contradiction, we calculate the effective absorption coefficient αeff = σ/V (σ is the absorption cross section and V is the QD volume) for the QDs and observed that the smaller QDs have a higher absorption from the ground to the first excited state, corroborating our results. Finally, our results showed that the saturable absorption effect in CdTe-QDs is slightly higher than that obtained for graphene and other 2D materials and smaller than the black phosphorus in the visible region.

Quantum Statistical Complexity Measure as a Signaling of Correlation Transitions.

We introduce a quantum version for the statistical complexity measure, in the context of quantum information theory, and use it as a signaling function of quantum order-disorder transitions. We discuss the possibility for such transitions to characterize interesting physical phenomena, as quantum phase transitions, or abrupt variations in correlation distributions. We apply our measure on two exactly solvable Hamiltonian models: the 1D-Quantum Ising Model (in the single-particle reduced state), and on Heisenberg XXZ spin-1/2 chain (in the two-particle reduced state). We analyze its behavior across quantum phase transitions for finite system sizes, as well as in the thermodynamic limit by using Bethe Ansatz technique.

Stent Graft Modification to Preserve Intercostal Arteries Using Thoracoabdominal Off-the-Shelf Multibranched (t-Branch) Endograft.

Purpose: To demonstrate an off-the-shelf multibranched (t-Branch) modification to allow intercostal arteries preservation during juxtarenal, pararenal, paravisceral, and extent IV thoracoabdominal aortic aneurysm repair. Technique: The t-Branch is an off-the-shelf device not customized for specific patient anatomy and may be offered for urgent endovascular repair for patients with complex aortic aneurysms. However, a concern when treating patients who do not aneurysms extending above the celiac axis is that the more proximal extension which is required with this device may render patients at high risk for spinal cord injury. We report a novel technique with t-Branch modification performing a 180° fabric back windows at the first 2 sealing stents that allow perfusion to the intercostal arteries. Conclusion: T-Branch-PIA (preserving intercostal arteries) modification limits intercostal arteries coverage while optimizing proximal seal zone in juxtarenal, pararenal, paravisceral, and extent IV thoracoabdominal aneurysms, thereby may decrease the risk of spinal cord injury.

68Ga-NODAGA-Indole: An Allysine-Reactive Positron Emission Tomography Probe for Molecular Imaging of Pulmonary Fibrogenesis.

Oxidized collagen, wherein lysine residues are converted to the aldehyde allysine, is a universal feature of fibrogenesis, i.e. actively progressive fibrosis. Here we report the small molecule, allysine-binding positron emission tomography probe, 68Ga-NODAGA-indole, that can noninvasively detect and quantify pulmonary fibrogenesis. We demonstrate that the uptake of 68Ga-NODAGA-indole in actively fibrotic lungs is 7-fold higher than in control groups and that uptake is linearly correlated ( R2 = 0.98) with the concentration of lung allysine.

Hybrid surgery in excision of a Shamblin II glomus tumor.

Glomus tumors are rare benign neoplasms originating from paraganglionic cells of the neural crest developing in the adventitious layer of the vessel. They are nonencapsulated and highly vascularized. A 64-year-old female patient was identified with a hypervascularized glomus tumor measuring 5 cm, posterior to the left carotid bifurcation and contralateral carotid occlusion. We performed preoperative embolization via endovascular access followed by direct percutaneous puncture, guided by angiography, to fill the remaining area. After embolization, surgical excision of the tumor was performed with reduced bleeding and it was easier to find the cleavage planes to adjacent structures. At late follow-up, the patient is free from tumor recurrence. The tumor was classified as Shamblin II, measuring 4 to 6 cm with moderate arterial insertion. Through this double approach we observed a relative reduction in intraoperative bleeding and improved identification of the cleavage plane, facilitating excision and avoiding surgical clamping.

Advanced Technical Considerations for Implanting the t-Branch Off-the-Shelf Multibranched Stent-Graft to Treat Thoracoabdominal Aneurysms.

PURPOSE: To demonstrate different techniques and device modifications that can expand the anatomic suitability of the off-the-shelf multibranched t-Branch for treatment of thoracoabdominal aortic aneurysm. TECHNIQUE: The t-Branch device is not customized for specific patient anatomy, and the most frequent limitations to its use are an inadequate sealing zone and renal artery anatomy. Experience with this device has prompted the development of several techniques that can be employed to maximize the suitability of this stent-graft. Advice is offered on modification of the device to minimize the risk of paraplegia or better match patient anatomy. Maneuvers are explained to ease delivery through tortuous anatomy or existing stent-grafts, catheterize visceral target vessels, select a bridging stent, reduce ischemia time in the limbs, and alter the configuration of the branches. CONCLUSION: Employing adjunctive maneuvers can increase the anatomic suitability of the t-Branch; in our experience, these techniques have increased the applicability to more than 80% of all elective and urgent thoracoabdominal aortic aneurysm cases.

"Snare-Ride": A Bailout Technique to Catheterize Target Vessels With Unfriendly Anatomy in Branched Endovascular Aortic Repair.

PURPOSE: To describe a novel endovascular bailout technique for successful completion of target vessel stenting during branched stent-graft repair of thoracoabdominal aortic aneurysms (TAAA) after encountering difficulties with standard catheterization techniques. TECHNIQUE: Technical difficulties when using fenestrated and branched grafts should be expected, especially in difficult anatomy or when an off-the-shelf device (eg, standard 4-branch device) is used that does not perfectly "match" the anatomy. The "snare-ride technique" facilitates antegrade transaxillary side branch catheterization and stent placement during TAAA branched grafting using a snare via a transfemoral approach. The branch of the graft is catheterized from an axillary access. The respective target vessel is then catheterized via a femoral access. An Indy snare is advanced over the transfemoral wire and positioned near the entrance of the target vessel. The transaxillary wire inside the branch of the graft is then advanced, snared, and pushed inside the target vessel with the snare. The procedure is thereafter continued with antegrade bridging of the target vessel in routine fashion. CONCLUSION: The snare-ride technique can be a useful maneuver to catheterize target vessels with difficult anatomy in TAAA branched stent-graft repair. Early experience shows safety and feasibility.

Evaluation of antitumor activity and cardiac toxicity of a bone-targeted ph-sensitive liposomal formulation in a bone metastasis tumor model in mice.

Chemotherapy for bone tumors is a major challenge because of the inability of therapeutics to penetrate dense bone mineral. We hypothesize that a nanostructured formulation with high affinity for bone could deliver drug to the tumor while minimizing off-target toxicity. Here, we evaluated the efficacy and toxicity of a novel bone-targeted, pH-sensitive liposomal formulation containing doxorubicin in an animal model of bone metastasis. Biodistribution studies with the liposome showed good uptake in tumor, but low accumulation of doxorubicin in the heart. Mice treated with the bone-targeted liposome formulation showed a 70% reduction in tumor volume, compared to 35% reduction for free doxorubicin at the same dose. Both cardiac toxicity and overall mortality were significantly lower for animals treated with the bone-targeted liposomes compared to free drug. Bone-targeted, pH-sensitive, doxorubicin containing liposomes represent a promising approach to selectively delivering doxorubicin to bone tumors while minimizing cardiac toxicity.

Molecular Magnetic Resonance Imaging of Lung Fibrogenesis with an Oxyamine-Based Probe.

Fibrogenesis is the active production of extracellular matrix in response to tissue injury. In many chronic diseases persistent fibrogenesis results in the accumulation of scar tissue, which can lead to organ failure and death. However, no non-invasive technique exists to assess this key biological process. All tissue fibrogenesis results in the formation of allysine, which enables collagen cross-linking and leads to tissue stiffening and scar formation. We report herein a novel allysine-binding gadolinium chelate (GdOA), that can non-invasively detect and quantify the extent of fibrogenesis using magnetic resonance imaging (MRI). We demonstrate that GdOA signal enhancement correlates with the extent of the disease and is sensitive to a therapeutic response.

Ursolic acid incorporation does not prevent the formation of a non-lamellar phase in pH-sensitive and long-circulating liposomes.

Ursolic acid (UA) is a triterpene found in different plant species that has been shown to possess significant antitumor activity. However, UA presents a low water solubility, which limits its biological applications. In this context, our research group has proposed the incorporation of UA in long-circulating and pH-sensitive liposomes (SpHL-UA).These liposomes, composed of dioleylphosphatidylethanolamine (DOPE), cholesteryl hemisuccinate (CHEMS), and distearoylphosphatidylethanolamine-polyethylene glycol2000 (DSPE-PEG2000), were shown to be very promising carriers for UA. Considering that the release of UA from SpHL-UA and its antitumor activity depend upon the occurrence of the lamellar to non-lamellar phase transition of DOPE, in the present work, the interactions of UA with the components of the liposomes were evaluated, aiming to clarify their role in the structural organization of DOPE. The study was carried out by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) under low hydration conditions. DSC studies revealed that DOPE phase transition temperatures did not shift significantly upon UA addition. On the other hand, in SAXS studies, a different pattern of DOPE phase organization was observed in the presence of UA, with the occurrence of the cubic phase Im3m at 20 °C and the cubic phase Pn3m at 60 °C. These findings suggest that UA interacts with the lipids and changes their self-assembly. However, these interactions between the lipids and UA were unable to eliminate the lamellar to non-lamellar phase transition, which is essential for the cytoplasmic delivery of UA molecules from SpHL-UA.

Probing the cw-Laser-Induced Fluorescence Enhancement in CsPbBr3 Nanocrystal Thin Films: An Interplay between Photo and Thermal Activation.

Perovskite nanocrystals hold significant promise for a wide range of applications, including solar cells, LEDs, photocatalysts, humidity and temperature sensors, memory devices, and low-cost photodetectors. Such technological potential stems from their exceptional quantum efficiency and charge carrier conduction capability. Nevertheless, the underlying mechanisms of photoexcitation, such as phase segregation, annealing, and ionic diffusion, remain insufficiently understood. In this context, we harnessed hyperspectral fluorescence microspectroscopy to advance our comprehension of fluorescence enhancement triggered by UV continuous-wave (cw) laser irradiation of CsPbBr3 colloidal nanocrystal thin films. Initially, we explored the kinetics of fluorescence enhancement and observed that its efficiency (φph) correlates with the laser power (P), following the relationship φph = 7.7⟨P⟩0.47±0.02. Subsequently, we estimated the local temperature induced by the laser, utilizing the finite-difference method framework, and calculated the activation energy (Ea) required for fluorescence enhancement to occur. Our findings revealed a very low activation energy, Ea ∼ 9 kJ/mol. Moreover, we mapped the fluorescence photoenhancement by spatial scanning and real-time static mode to determine its microscale length. Below a laser power of 60 µW, the photothermal diffusion length exhibited nearly constant values of approximately (22 ± 5) µm, while a significant increase was observed at higher laser power levels. These results were ascribed to the formation of nanocrystal superclusters within the film, which involves the interparticle spacing reduction, creating the so-called quantum dot solid configuration along with laser-induced annealing for higher laser powers.

Effect of body position and external ankle load on the pendulum test in adults.

BACKGROUND: The pendulum test is commonly used to measure passive stiffness about the knee in healthy and clinical populations. While most studies used an upright position, some studies explored different body positions, particularly with children. Additionally, including external ankle load increases the passive motion of the lower leg in children with Down syndrome. Does combining body position and ankle loading affect joint kinematics and muscle activity of the knee extensors during the pendulum test? METHODS: Twenty young adults participated in this study. Three body positions were included: 90-dgree upright, 45-degree incline, and 0-degree supine. Three load conditions were tested: no load (0%), and ankle loads equal to 3% and 6% of the subject's body mass. This resulted in a total of 9 conditions. Five trials were collected for each condition. RESULTS: The upright position elicited a greater number of leg swings and a longer duration of the first knee flexion, while the incline position produced a higher relaxation index. Both ankle load conditions (3% and 6%) increased the magnitude of the first flexion excursion and relaxation index, and the 6% condition produced greater kinematic variables than the 3% load condition. Neither body position nor ankle load elicited muscle activity of the quadriceps. CONCLUSIONS: Body position and external ankle load can affect the kinematics of leg swing during the pendulum test in healthy young adults. Particularly, ankle loads may increase passive motion about the knee. However, we wonder whether small differences across body positions would be clinically relevant.

Neuropsychiatric symptoms as a prodromal factor in Alzheimer's type neurodegenerative disease: a scoping review.

Objective: Identifying neuropsychiatric symptoms (NPS) can aid in the early detection of Alzheimer's disease (AD); however, there is still a need for a greater consensus. This review aims to delineate the predominant NPS, compile a comprehensive list of the most commonly employed NPS assessment tools, and corroborate the principal findings regarding the link between NPS and neuropsychological assessment and neurobiological substrates. Methods: To conduct this scoping review, we followed the Preferred Reporting Items for Systematic Reviews guidelines and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). We searched for relevant articles published between 2017 and 2023 in MEDLINE, PsycINFO, PubMed, Web of Science, and Cochrane Library. Results: Of the 61 eligible articles, depression, anxiety, and apathy were the main NPSs. The Neuropsychiatric Inventory Questionnaire and Neuropsychiatric Inventory were the primary assessment tools used to evaluate NPS. Correlations between NPS severity and neurobiological markers were considered clinically significant. Furthermore, clinical procedures prioritized the use of global cognitive screening tools, assessments of executive functions, and functionality evaluations. Conclusion: Standardization of procedures is necessary because of the diversity of methods. The data show that NPS can predict the etiology, severity, form, and type of disease progression, serving as a precursor sign of AD. The results of the most common cognitive screening tools and NPS instruments provided an interesting overview of future clinical approaches.

Hospital Dermatology: analysis of dermatological consultations in a tertiary teaching hospital.

BACKGROUND: In hospital settings, dermatology can offer substantial clinical support for the diagnosis and management of skin conditions, reducing morbidity and mortality. Thus, the study aimed to analyze the profile of referrals and consultations performed by the Dermatology Service of the Santa Casa de Misericordia de Porto Alegre, from August 2018 to January 2020. METHODS: This study is descriptive, quantitative, and retrospective, conducted through data collection and review of medical records and referrals. The variables included were clinical data of referrals, in-patients profiles, dermatological diagnoses, complementary exams, therapeutic conduct, and recommended follow-ups. RESULTS: A total of 1020 referrals were analyzed, which resulted in 641 consultations (328 men, 313 women). The most prevalent skin disease groups were 'Dermatitis and Eczema' (33.1%) and 'Other infectious skin diseases (21.8%), while the most frequent ICD-10 were 'Drug eruptions - L27' (9.9%) and 'Other and unspecified dermatitis - L30' (6.6%). Corticoids were the most recommended treatments (27.7%), followed by antifungals (13.1%). 'Consultation Discharge' (44%) and 'Outpatient' Dermatology follow-up (27%) were the most frequent causes for ending consultation. STUDY LIMITATIONS: Among the study limitations, the authors highlight its retrospective nature, with data analysis based on referrals and medical records, which may present inaccurate or incomplete information. In addition to this, the study may demonstrate a certain degree of subjectivity due to the review and interpretation process conducted by the researchers. However, the definition of objective criteria based on previous studies attenuates such possible bias. Furthermore, considering that the Dermatology teams are composed of a preceptor dermatologist and residents, the established diagnoses were not submitted to third-party verification, except in the cases of skin biopsies and cultures. Thus, the professional's experience and skills may have influenced the dermatological diagnoses. CONCLUSIONS: These findings underlie the importance of Dermatology in hospital assistance, contributing to the management of a wide range of skin conditions.

Evaluation of the SEVERITY of FACIAL and GENERAL TRAUMA in child and adolescent victims of traffic accidents.

•Evaluation of the FISS and TRISS SpO2 to obtain greater rigor in a standardized epidemiological profile of injury severity.•More accurate determination of trauma severity in child and adolescent victims of traffic accidents for improved urgency and emergency care.•Relation between the scales allows for better decisions on patient hospitalization, adequate treatment and the prevention of irreversible injuries.