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1.
Radiol Case Rep ; 19(7): 2603-2607, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38645963

RESUMO

Extramedullary plasmacytoma (EMP) is an uncommon tumor marked by the monoclonal growth of plasma cells without the characteristics of multiple myeloma. EMP represents 3% of all plasma cell tumors. An 89-year-old male patient with hypertension was admitted to our tertiary care hospital with uncontrolled unilateral epistaxis. After a year and a half of recurring epistaxis, the patient's bleeding became more frequent and could no longer be controlled with nasal packing. Angiofibroma was suspected as the initial differential diagnosis, and angiofibroma embolization was performed. The patient experienced difficulty swallowing and slurred speech and was diagnosed with an ischemic stroke. However, antiplatelet and tranexamic acid medications were contraindicated due to bleeding risks. The patient underwent functional endoscopic sinus surgery, and unexpectedly, histology results revealed a plasmacytoma. After surgery, the patient remained stable and was discharged for further management.

2.
bioRxiv ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38464309

RESUMO

Distinct, seemingly independent, cellular pathways affecting intracellular machineries or extracellular matrix (ECM) deposition and organization, have been implicated in aneurysm formation. One of the key genes associated with the pathology in both humans and mice is Lysyl oxidase (LOX), a secreted ECM-modifying enzyme, highly expressed in medial vascular smooth muscle cells. To dissect the mechanisms leading to aneurysm development, we conditionally deleted Lox in smooth muscle cells. We find that cytoskeletal organization is lost following Lox deletion. Cell culture assays and in vivo analyses demonstrate a cell-autonomous role for LOX affecting myosin light chain phosphorylation and cytoskeletal assembly resulting in irregular smooth muscle contraction. These results not only highlight new intracellular roles for LOX, but notably they link between multiple processes leading to aneurysm formation suggesting LOX coordinates ECM development, cytoskeletal organization and cell contraction required for media development and function.

3.
Radiol Case Rep ; 19(3): 1136-1140, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38259714

RESUMO

In this case report, a 33-year-old male with a history of smoking presented with recurrent palpitations and chest discomfort. Holter monitoring revealed atrial flutter, and imaging showed a giant left atrial appendage aneurysm. Due to the risk of arrhythmias and thromboembolic events, surgical resection was performed successfully. This case underscores the importance of considering uncommon structural cardiac abnormalities in the evaluation of arrhythmia symptoms in young patients.

4.
Cureus ; 15(11): e48287, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38058337

RESUMO

Sarcoidosis is an idiopathic multisystem disorder associated with hilar lymphadenopathy and noncaseating granulomas that can affect any organ. Ocular involvement is less common; however, sarcoidosis is a known cause of uveitis, dry eye, and conjunctival nodules. We report a case of a 36-year-old male with an occupational history of dust exposure presenting to the ophthalmology clinic with bilateral painless upper eyelid swelling of one-week duration. The diagnosis of sarcoidosis was suspected based on clinical examination, laboratory analysis, and imaging showing mediastinal lymphadenopathy, further confirmed by pathologic examination showing noncaseating granulomas with the presence of some asteroid and Schaumann bodies. A treatment plan consisting of prednisone, folic acid, and azathioprine was effective for the patient, though azathioprine was eventually changed to methotrexate due to an allergic reaction. The patient is on a maintenance dose of methotrexate and is asymptomatic after a year of careful management and follow-up. This case emphasizes the significance of considering sarcoidosis as a differential diagnosis in patients presenting with bilateral dacryoadenitis.

5.
Adv Mater ; 35(51): e2304654, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37753928

RESUMO

Monoclonal antibodies (mAbs) hold promise in treating Parkinson's disease (PD), although poor delivery to the brain hinders their therapeutic application. In the current study, it is demonstrated that brain-targeted liposomes (BTL) enhance the delivery of mAbs across the blood-brain-barrier (BBB) and into neurons, thereby allowing the intracellular and extracellular treatment of the PD brain. BTL are decorated with transferrin to improve brain targeting through overexpressed transferrin-receptors on the BBB during PD. BTL are loaded with SynO4, a mAb that inhibits alpha-synuclein (AS) aggregation, a pathological hallmark of PD. It is shown that 100-nm BTL cross human BBB models intact and are taken up by primary neurons. Within neurons, SynO4 is released from the nanoparticles and bound to its target, thereby reducing AS aggregation, and enhancing neuronal viability. In vivo, intravenous BTL administration results in a sevenfold increase in mAbs in brain cells, decreasing AS aggregation and neuroinflammation. Treatment with BTL also improve behavioral motor function and learning ability in mice, with a favorable safety profile. Accordingly, targeted nanotechnologies offer a valuable platform for drug delivery to treat brain neurodegeneration.


Assuntos
Doença de Parkinson , Animais , Humanos , Camundongos , alfa-Sinucleína/metabolismo , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Sintomas Comportamentais , Encéfalo/metabolismo , Lipossomos/metabolismo , Doença de Parkinson/tratamento farmacológico , Transferrinas
6.
Cureus ; 15(7): e42079, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37602130

RESUMO

We present a case of a 57-year-old male patient with a history of prolonged intensive care unit (ICU) stay for coronavirus disease 2019 (COVID-19) who developed fungal spondylodiscitis, a rare complication. The patient initially presented complaining of respiratory symptoms and was subsequently treated with tocilizumab, remdesivir, enoxaparin, and dexamethasone. Following ICU discharge, he experienced recurrent infections, including extended-spectrum beta-lactamase Klebsiella urinary tract infection. Two months later, he developed back pain; magnetic resonance imaging (MRI) revealed inflammatory spondylodiscitis. Despite empirical antibiotic therapy, his condition did not improve, and a bone biopsy confirmed Candida albicans infection. Antifungal treatment with fluconazole and anidulafungin resulted in a significant clinical improvement. The patient achieved complete recovery after six months of therapy. This case highlights the rare occurrence of fungal spondylodiscitis in COVID-19 patients with a history of ICU stay and emphasizes the importance of early recognition and appropriate management to mitigate potential complications.

7.
Cureus ; 15(5): e38400, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37265888

RESUMO

Vasoplegic syndrome is a type of distributive shock characterized by mean arterial pressure of less than 65 mmHg, with normal to high cardiac output and often refractory to fluid resuscitation, high doses of intravenous vasopressors, and inotropes. It is usually observed after cardiac and solid organ transplantation surgeries. Here, we report a 56-year-old female patient who presented with a profound vasoplegia manifesting as lethargy and confusion in the setting of amlodipine toxicity. This case of severe vasoplegia was refractory to all conditional lines of medical management reported in the literature. The mainstay treatment modalities for vasoplegia include volume resuscitation, catecholamines, vasopressin, angiotensin II, and possibly methylene blue in unresponsive cases. Our patient was given hydroxocobalamin in favor of methylene blue, given the history of serotonin reuptake inhibitors use, which would have caused a life-threatening serotonin syndrome. Hydroxycobolamine resulted in a dramatic clinical recovery, suggesting its potentially significant role in refractory vasoplegia.

8.
Nat Commun ; 12(1): 4873, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381027

RESUMO

Refractory high-entropy alloys (RHEAs) are designed for high elevated-temperature strength, with both edge and screw dislocations playing an important role for plastic deformation. However, they can also display a significant energetic driving force for chemical short-range ordering (SRO). Here, we investigate mechanisms underlying the mobilities of screw and edge dislocations in the body-centered cubic MoNbTaW RHEA over a wide temperature range using extensive molecular dynamics simulations based on a highly-accurate machine-learning interatomic potential. Further, we specifically evaluate how these mechanisms are affected by the presence of SRO. The mobility of edge dislocations is found to be enhanced by the presence of SRO, whereas the rate of double-kink nucleation in the motion of screw dislocations is reduced, although this influence of SRO appears to be attenuated at increasing temperature. Independent of the presence of SRO, a cross-slip locking mechanism is observed for the motion of screws, which provides for extra strengthening for refractory high-entropy alloy system.

9.
Science ; 372(6543): 729-733, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33986178

RESUMO

Despite persistent and extensive observations of crystals with chiral shapes, the mechanisms underlying their formation are not well understood. Although past studies suggest that chiral shapes can form because of crystallization in the presence of chiral additives, or because of an intrinsic tendency that stems from the crystal structure, there are many cases in which these explanations are not suitable or have not been tested. Here, an investigation of model tellurium nanocrystals provides insights into the chain of chirality transfer between crystal structure and shape. We show that this transfer is mediated by screw dislocations, and shape chirality is not an outcome of the chiral crystal structure or ligands.

10.
Nat Mater ; 20(4): 468-472, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33020612

RESUMO

It has been known for decades that the application of pulsed direct current can significantly enhance the formability of metals. However, the detailed mechanisms of this effect have been difficult to separate from simple Joule heating. Here, we study the electroplastic deformation of Ti-Al (7 at.% Al), an alloy that is uniquely suited for uncoupling this behaviour because, contrary to most metals, it has inherently lower ductility at higher temperature. We find that during mechanical deformation, electropulsing enhances cross-slip, producing a wavy dislocation morphology, and enhances twinning, which is similar to what occurs during cryogenic deformation. As a consequence, dislocations are prevented from localizing into planar slip bands that would lead to the early failure of the alloy under tension. Our results demonstrate that this macroscopic electroplastic behaviour originates from defect-level microstructural reconfiguration that cannot be rationalized by simple Joule heating.

11.
Carbohydr Polym ; 130: 227-32, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26076621

RESUMO

Polyester-cotton (PECO) blends are widely used in the textile industry because they combine the softness of cotton and the strength and durability of polyester. Unfortunately, both fiber types share the disadvantage of being flammable. The layer-by-layer coating technique was used to deposit a highly effective flame retardant (melamine polyphosphate) from water onto polyester-cotton fabric. Soluble melamine and sodium hexametaphosphate form this water-insoluble flame retardant during the coating procedure. This unique nanocoating imparts self-extinguishing properties to PECO with only 12% relative coating weight. Vertical flame testing, pyrolysis combustion flow calorimetry (PCFC), thermogravimetric analysis (TGA), and scanning electron microscopy were used to evaluate the quality of the coating as well as its flame retardant performance. A combination of both condensed and gas-phase activity appears to be the reason for this effective flame retardancy. Degradation pathways of both cotton and polyester are affected by the applied coating, as shown by PCFC and TGA. Use of environmentally benign and non-toxic chemicals, and the ease of layer-by-layer deposition, making this coating an industrially feasible alternative to render polyester-cotton fabric self-extinguishing.


Assuntos
Quitosana/química , Retardadores de Chama/síntese química , Gossypium/química , Nanoestruturas/química , Poliésteres/química , Polifosfatos/química , Triazinas/química , Água/química , Calorimetria , Materiais Revestidos Biocompatíveis/química , Microscopia Eletrônica de Varredura , Têxteis
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