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1.
Med Phys ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39241224

RESUMEN

BACKGROUND: Radiotherapy of the prostate and the pelvic lymph nodes (LN) is a part of the standard of care treatment for high-risk prostate cancer. The independent translational and rotational (i.e., six-degrees-of-freedom, [6DoF]) motion of the prostate and LN target during and between fractions can perturb the dose distribution. However, no standard dose reconstruction method accounting for differential 6DoF target motion is available. PURPOSE: We present a framework for monitoring motion-induced dose perturbations for two independently moving target volumes in 6DoF. The framework was used to determine the dose perturbation for the prostate and the LN target caused by differential 6DoF motion for a cohort of high-risk prostate cancer patients. As a potential first step toward real-time dose-guided high-risk prostate radiotherapy, we furthermore investigated if the dose reconstruction was fast enough for real-time application for both targets. METHODS: Twenty high-risk prostate cancer patients were treated with 3-arc volumetric modulated arc therapy (VMAT). Kilovoltage intrafraction monitoring (KIM) with triggered kilovoltage (kV) images acquired every 3 throughout 7-10 fractions per patient was used for retrospective 6DoF intrafraction prostate motion estimation. The 6DoF interfraction LN motion was determined from a pelvic bone match between the planning CT and a post-treatment cone beam CT (CBCT). Using the retrospectively extracted motion, real-time 6DoF motion-including dose reconstruction was simulated using the in-house developed software DoseTracker. A data stream with the 6DoF target positions and linac parameters was broadcasted at a 3-Hz frequency to DoseTracker. In a continuous loop, DoseTracker calculated the target dose increments including the specified motion and, for comparison, without motion. The motion-induced change in D99.5% for the prostate CTV (ΔD99.5%) and in D98% for the LN CTV (ΔD98%) was calculated using the final cumulative dose of each fraction and averaged over all imaged fractions. The real-time reconstructed dose distribution of DoseTracker was benchmarked against a clinical treatment planning system (TPS) and it was investigated whether the calculation speed was fast enough to keep up with the incoming data stream. RESULTS: Translational motion was largest in cranio-caudal (CC) direction (prostate: [-5.9, +8.4] mm; LN: [-9.9; +11.0] mm) and anterior-posterior (AP) direction (prostate:[-5.6; +6.9] mm; LN: [-9.6; +11.0] mm). The pitch was the largest rotation (prostate: [-22.5; +25.2] deg; LN: [-3.9; +5.5] deg). The prostate CTV ΔD99.5% was [-16.2; +2.5]% for single fractions and [-3.0; +1.7]% when averaged over all imaged fractions. The LN CTV ΔD98% was [-19.8; +1.2]% for single fractions and [-3.1; +0.9]% after averaging. Mean (Standard deviation) absolute dose errors in DoseTracker of 107.8% (Std: 1.9%) for the prostate and 105.5% (Std:1.4%) for the LN were corrected during dose reconstruction by automatically calculated normalization factors. It resulted in accurate calculation of the motion-induced dose errors with relative differences between DoseTracker and TPS dose calculations of -0.1% (Std: 0.5%) (prostate CTV ΔD99.5%) and -0.2% (Std: 0.5%) (LN CTV ΔD98%). The DoseTracker calculation was fast enough to keep up with the incoming inputs for all but two out of 107 184 dose calculations. CONCLUSION: Using the developed framework for dose perturbation monitoring, we found that the differential 6DoF target motion caused substantial dose perturbation for individual fractions, which largely averaged out after several fractions. The framework was shown to provide reliable dose calculations and a sufficiently high-dose reconstruction speed to be applicable in real-time.

2.
J Cardiothorac Surg ; 19(1): 490, 2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39180091

RESUMEN

BACKGROUND: Surgical aortic valve replacement (SAVR) is an established therapy for severe calcific aortic stenosis. Enhanced recovery after cardiac surgery (ERACS) protocols have been shown to improve outcomes for elective cardiac procedures. The COVID-19 pandemic prompted early extubation post-elective surgeries to preserve critical care resources. AIM OF THIS STUDY: To investigate the effects of extubating patients within 6 h post-elective SAVR on hospital and ICU length of stay, mortality rates, ICU readmissions, and postoperative pneumonia. STUDY DESIGN AND METHODS: The retrospective analysis at the University Hospital Aachen, Germany, includes data from 2017 to 2022 and compares a total of 73 elective SAVR patients. Among these, 23 patients were extubated within 6 h (EXT group), while 50 patients remained intubated for over 6 h (INT group). RESULTS: The INT group experienced longer postoperative ventilation, needed more vasopressor support, had a higher incidence of postoperative pneumonia, and longer ICU length of stay. No significant differences were noted in overall hospital length of stay, mortality, or ICU readmission rates between the groups. CONCLUSION: This study demonstrates that early extubation in high-risk, multimorbid surgical aortic valve replacement patients is safe, and is associated with a reduction of pneumonia rates, and with shorter ICU and hospital length of stays, reinforcing the benefits of ERACS protocols, especially critical during the COVID-19 pandemic to optimize intensive care use.


Asunto(s)
Extubación Traqueal , COVID-19 , Procedimientos Quirúrgicos Electivos , Implantación de Prótesis de Válvulas Cardíacas , Tiempo de Internación , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Masculino , Femenino , Estudios Retrospectivos , Anciano , Implantación de Prótesis de Válvulas Cardíacas/métodos , Tiempo de Internación/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Estenosis de la Válvula Aórtica/cirugía , Anciano de 80 o más Años , Válvula Aórtica/cirugía , Persona de Mediana Edad , Alemania/epidemiología , SARS-CoV-2 , Pandemias
3.
J Clin Med ; 13(13)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38999326

RESUMEN

Background: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a critical intervention for patients with severe lung failure, especially acute respiratory distress syndrome (ARDS). The weaning process from ECMO relies largely on expert opinion due to a lack of evidence-based guidelines. The ventilatory ratio (VR), which correlates with dead space and mortality in ARDS, is calculated as [minute ventilation (mL/min) x arterial pCO2 (mmHg)]/[predicted body weight × 100 × 37.5]. Objectives: The aim of this study was to determine whether the VR alone can serve as a reliable predictor of safe or unsafe liberation from VV-ECMO in critically ill patients. Methods: A multicenter retrospective analysis was conducted, involving ARDS patients undergoing VV-ECMO weaning at Massachusetts General Hospital (January 2016 - December 2020) and at the University Hospital Aachen (January 2012-December 2021). Safe liberation was defined as no need for ECMO recannulation within 48 h after decannulation. Clinical parameters were obtained for both centers at the same time point: 30 min after the start of the SGOT (sweep gas off trial). Results: Of the patients studied, 83.3% (70/84) were successfully weaned from VV-ECMO. The VR emerged as a significant predictor of unsafe liberation (OR per unit increase: 0.38; CI: 0.17-0.81; p = 0.01). Patients who could not be safely liberated had longer ICU and hospital stays, with a trend towards higher mortality (38% vs. 13%; p = 0.05). Conclusions: The VR may be a valuable predictor for safe liberation from VV-ECMO in ARDS patients, with higher VR values associated with an elevated risk of unsuccessful weaning and adverse clinical outcomes.

5.
Methods Appl Fluoresc ; 12(2)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38428020

RESUMEN

We here report the formation of a turbid-gel phase in acrylic cuvettes upon exposure to pure Dimethyl Sulfoxide (DMSO) at room temperature. The observed phenomenon occurred over a 10 h to 14 h incubation in the presence of environmental oxygen. After the turbid gel was removed from the cuvette, it became a white solid exhibiting unique emission behavior. The formation of the turbid-gel phase was accelerated upon exposure to UV 295 LED pulses of light from 6 h to 8 h. Surprisingly, subsequent exposure of the white solid to a few microliters of pure DMSO and vortexing resulted in its transformation into a transparent gel state in just a few minutes, eventually acquiring transparent and liquid properties. Additionally, the white-solid phase can load other molecules, such as Resveratrol and Quercetin, leading to shifts in the respective emission spectra compared with the same molecule in liquid and pure DMSO. These novel findings highlight the interaction between UV photons, oxygen, DMSO and Acrylic, and potentially distort fluorescence spectroscopy experiments.

6.
bioRxiv ; 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38106154

RESUMEN

Generating animal models for individual patients within clinically-useful timeframes holds great potential toward enabling personalized medicine approaches for genetic epilepsies. The ability to rapidly incorporate patient-specific genomic variants into model animals recapitulating elements of the patient's clinical manifestations would enable applications ranging from validation and characterization of pathogenic variants to personalized models for tailoring pharmacotherapy to individual patients. Here, we demonstrate generation of an animal model of an individual epilepsy patient with an ultra-rare variant of the NMDA receptor subunit GRIN2A, without the need for germline transmission and breeding. Using in utero prime editing in the brain of wild-type mice, our approach yielded high in vivo editing precision and induced frequent, spontaneous seizures which mirrored specific elements of the patient's clinical presentation. Leveraging the speed and versatility of this approach, we introduce PegAssist, a generalizable workflow to generate bedside-to-bench animal models of individual patients within weeks. The capability to produce individualized animal models rapidly and cost-effectively will reduce barriers to access for precision medicine, and will accelerate drug development by offering versatile in vivo platforms to identify compounds with efficacy against rare neurological conditions.

7.
J Clin Med ; 12(6)2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36983341

RESUMEN

Purpose: Several suture techniques have been described in the past for direct ACL repair with poor healing capacity and a high re-rupture rate. Therefore, we investigated a refixation technique for acute primary proximal ACL repair. The purpose of this study is to compare the biomechanical properties of different suture configurations using a knotless anchor. Methods: In this study, 35 fresh-frozen porcine knees underwent proximal ACL refixation. First, in 10 porcine femora, the biomechanical properties of the knotless anchor, without the ligament attached, were tested. Then, three different suture configurations were evaluated to reattach the remaining ACL. Using a material testing machine, the structural properties were evaluated for cyclic loading followed by loading to failure. Results: The ultimate failure load of the knotless anchor was 198, 76 N ± 23, 4 N significantly higher than all of the tested ACL suture configurations. Comparing the different configurations, the modified Kessler-Bunnell suture showed significant superior ultimate failure load, with 81, 2 N ± 15, 6 N compared to the twofold and single sutures (50, 5 N ± 14 N and 37, 5 ± 3, 8 N). In cyclic loading, there was no significant difference noted for the different configurations in terms of stiffness and elongation. Conclusions: The results of this in vitro study show that when performing ACL suture using a knotless anchor, a modified Kessler-Bunnell suture provides superior biomechanical properties than a single and a twofold suture. Within this construct, no failure at the bone-anchor interface was seen. Clinical relevance: Since primary suture repair techniques of ACL tears have been abandoned because of inconsistent results, ACL reconstruction remains the gold standard of treating ACL tears. However, with the latest improvements in surgical techniques, instrumentation, hardware and imaging, primary ACL suture repair might be a treatment option for a select group of patients. By establishing an arthroscopic technique in which proximal ACL avulsion can be reattached, the original ACL can be preserved by using a knotless anchor and a threefold suture configuration. Nevertheless, this technique provides an inferior ultimate failure load compared to graft techniques, so a careful rehabilitation program must be followed if using this technique in vivo.

8.
Nat Neurosci ; 25(12): 1664-1674, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36357811

RESUMEN

How an established behavior is retained and consistently produced by a nervous system in constant flux remains a mystery. One possible solution to ensure long-term stability in motor output is to fix the activity patterns of single neurons in the relevant circuits. Alternatively, activity in single cells could drift over time provided that the population dynamics are constrained to produce the same behavior. To arbitrate between these possibilities, we recorded single-unit activity in motor cortex and striatum continuously for several weeks as rats performed stereotyped motor behaviors-both learned and innate. We found long-term stability in single neuron activity patterns across both brain regions. A small amount of drift in neural activity, observed over weeks of recording, could be explained by concomitant changes in task-irrelevant aspects of the behavior. These results suggest that long-term stable behaviors are generated by single neuron activity patterns that are themselves highly stable.


Asunto(s)
Corteza Motora , Animales , Ratas , Corteza Motora/fisiología , Neuronas/fisiología
9.
Biochim Biophys Acta Biomembr ; 1864(12): 184048, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36115495

RESUMEN

We used the Langmuir monolayers technique to study the surface properties of melittin toxin mixed with either liquid-condensed DSPC or liquid-expanded POPC phospholipids. Pure melittin peptide forms stable insoluble monolayers at the air-water interface without interacting with Thioflavin T (Th-T), a sensitive probe to detect protein amyloid formation. When melittin peptide is mixed with DSPC lipid at 50 % of peptide area proportion at the surface, we observed the formation of fibril-like structures detected by Brewster angle microscopy (BAM), but they were not observable with POPC. The nano-structures in the melittin-DSPC mixtures became Th-T positive labeling when the arrangement was observed with fluorescence microscopy. In this condition, Th-T undergoes an unexpected shift in the typical emission wavelength of this amyloid marker when a 2D fluorescence analysis is conducted. Even when reflectivity analysis of BAM imaging evidenced that these structures would correspond to the DSPC lipid component of the mixture, the interpretation of ATR-FTIR and Th-T data suggested that both components were involved in a new lipid-peptide rearrangement. These nano-fibril arrangements were also evidenced by scanning electron and atomic force microscopy when the films were transferred to a mica support. The fibril formation was not detected when melittin was mixed with the liquid-expanded POPC lipid. We postulated that DSPC lipids can dynamically trigger the process of amyloid-like nano-arrangement formation at the interface. This process is favored by the relative peptide content, the quality of the interfacial environment, and the physical state of the lipid at the surface.


Asunto(s)
Meliteno , Fosfolípidos , Microscopía de Fuerza Atómica , Propiedades de Superficie , Agua/química
11.
Protein Sci ; 31(5): e4305, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35481649

RESUMEN

Actin histidine Nτ -methylation by histidine methyltransferase SETD3 plays an important role in human biology and diseases. Here, we report integrated synthetic, biocatalytic, biostructural, and computational analyses on human SETD3-catalyzed methylation of actin peptides possessing histidine and its structurally and chemically diverse mimics. Our enzyme assays supported by biostructural analyses demonstrate that SETD3 has a broader substrate scope beyond histidine, including N-nucleophiles on the aromatic and aliphatic side chains. Quantum mechanical/molecular mechanical molecular dynamics and free-energy simulations provide insight into binding geometries and the free energy barrier for the enzymatic methyl transfer to histidine mimics, further supporting experimental data that histidine is the superior SETD3 substrate over its analogs. This work demonstrates that human SETD3 has a potential to catalyze efficient methylation of several histidine mimics, overall providing mechanistic, biocatalytic, and functional insight into actin histidine methylation by SETD3.


Asunto(s)
Actinas , Metiltransferasas , Actinas/química , Actinas/metabolismo , Histidina/química , Histona Metiltransferasas/química , Histona Metiltransferasas/metabolismo , Humanos , Metilación , Metiltransferasas/metabolismo
12.
Sci Adv ; 8(8): eabk0231, 2022 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-35213216

RESUMEN

The acquisition and execution of motor skills are mediated by a distributed motor network, spanning cortical and subcortical brain areas. The sensorimotor striatum is an important cog in this network, yet the roles of its two main inputs, from motor cortex and thalamus, remain largely unknown. To address this, we silenced the inputs in rats trained on a task that results in highly stereotyped and idiosyncratic movement patterns. While striatal-projecting motor cortex neurons were critical for learning these skills, silencing this pathway after learning had no effect on performance. In contrast, silencing striatal-projecting thalamus neurons disrupted the execution of the learned skills, causing rats to revert to species-typical pressing behaviors and preventing them from relearning the task. These results show distinct roles for motor cortex and thalamus in the learning and execution of motor skills and suggest that their interaction in the striatum underlies experience-dependent changes in subcortical motor circuits.

13.
Radiother Oncol ; 171: 62-68, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35033604

RESUMEN

INTRODUCTION: In vivo dosimetry (IVD) can be used for source tracking (ST), i.e., estimating source positions, during brachytherapy. The aim of this study was to exploit IVD-based ST to perform 3D dose reconstruction for high-dose-rate prostate brachytherapy and to evaluate the robustness of the treatments against observed geometric variations. MATERIALS AND METHODS: Twenty-three fractions of high-dose-rate prostate brachytherapy were analysed. The treatment planning was based on MRI. Time-resolved IVD was performed using a fibre-coupled scintillator. ST was retrospectively performed using the IVD measurements. The ST identified 2D positional shifts of each treatment catheter and thereby inferred updated source positions. For each fraction, the dose was recalculated based on the source-tracked catheter positions and compared with the original plan dose using differences in dose volume histogram indices. RESULTS: Of 352 treatment catheters, 344 had shifts of less than 5 mm. Shifts between 5 and 10 mm were observed for 3 catheters, and shifts greater than 10 mm for 2 catheters. The ST failed for 3 catheters. The maximum relative difference in clinical target volume (prostate + 3 mm isotropic margin) D90% was 5%. In one fraction, the bladder D2cm3 dose increased by 18% (1.4 Gy) due to a single source position being inside the bladder rather than nearby as planned. The max increase in urethra dose was 1.5 Gy (15%). CONCLUSION: IVD-based 3D dose reconstruction for high-dose-rate prostate brachytherapy is feasible. The dosimetric impact of the observed catheter shifts was limited. Dose reconstruction can therefore aid in determining the dosimetric impact of geometric variations and errors in brachytherapy.


Asunto(s)
Braquiterapia , Dosimetría in Vivo , Neoplasias de la Próstata , Catéteres , Humanos , Masculino , Próstata , Neoplasias de la Próstata/radioterapia , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Estudios Retrospectivos
14.
Lasers Surg Med ; 54(2): 256-267, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34350599

RESUMEN

BACKGROUND AND OBJECTIVES: Carbon monoxide (CO) inhalation is the leading cause of poison-related deaths in the United States. CO binds to hemoglobin (Hb), displaces oxygen, and reduces oxygen delivery to tissues. The optimal treatment for CO poisoning in patients with normal lung function is the administration of hyperbaric oxygen (HBO). However, hyperbaric chambers are only available in medical centers with specialized equipment, resulting in delayed therapy. Visible light dissociates CO from Hb with minimal effect on oxygen binding. In a previous study, we combined a membrane oxygenator with phototherapy at 623 nm to produce a "mini" photo-ECMO (extracorporeal membrane oxygenation) device, which improved CO elimination and survival in CO-poisoned rats. The objective of this study was to develop a larger photo-ECMO device ("maxi" photo-ECMO) and to test its ability to remove CO from a porcine model of CO poisoning. STUDY DESIGN/MATERIALS AND METHODS: The "maxi" photo-ECMO device and the photo-ECMO system (six maxi photo-ECMO devices assembled in parallel), were tested in an in vitro circuit of CO poisoning. To assess the ability of the photo-ECMO device and the photo-ECMO system to remove CO from CO-poisoned blood in vitro, the half-life of COHb (COHb-t1/2 ), as well as the percent COHb reduction in a single blood pass through the device, were assessed. In the in vivo studies, we assessed the COHb-t1/2 in a CO-poisoned pig under three conditions: (1) While the pig breathed 100% oxygen through the endotracheal tube; (2) while the pig was connected to the photo-ECMO system with no light exposure; and (3) while the pig was connected to the photo-ECMO system, which was exposed to red light. RESULTS: The photo-ECMO device was able to fully oxygenate the blood after a single pass through the device. Compared to ventilation with 100% oxygen alone, illumination with red light together with 100% oxygen was twice as efficient in removing CO from blood. Changes in gas flow rates did not alter CO elimination in one pass through the device. Increases in irradiance up to 214 mW/cm2 were associated with an increased rate of CO elimination. The photo-ECMO device was effective over a range of blood flow rates and with higher blood flow rates, more CO was eliminated. A photo-ECMO system composed of six photo-ECMO devices removed CO faster from CO-poisoned blood than a single photo-ECMO device. In a CO-poisoned pig, the photo-ECMO system increased the rate of CO elimination without significantly increasing the animal's body temperature or causing hemodynamic instability. CONCLUSION: In this study, we developed a photo-ECMO system and demonstrated its ability to remove CO from CO-poisoned 45-kg pigs. Technical modifications of the photo-ECMO system, including the development of a compact, portable device, will permit treatment of patients with CO poisoning at the scene of their poisoning, during transit to a local emergency room, and in hospitals that lack HBO facilities.


Asunto(s)
Intoxicación por Monóxido de Carbono , Venenos , Animales , Monóxido de Carbono , Intoxicación por Monóxido de Carbono/terapia , Carboxihemoglobina/metabolismo , Humanos , Fototerapia/métodos , Ratas , Porcinos
15.
Lasers Surg Med ; 54(3): 426-432, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34658052

RESUMEN

BACKGROUND AND OBJECTIVES: Carbon monoxide (CO) poisoning is responsible for nearly 50,000 emergency department visits and 1200 deaths per year. Compared to oxygen, CO has a 250-fold higher affinity for hemoglobin (Hb), resulting in the displacement of oxygen from Hb and impaired oxygen delivery to tissues. Optimal treatment of CO-poisoned patients involves the administration of hyperbaric 100% oxygen to remove CO from Hb and to restore oxygen delivery. However, hyperbaric chambers are not widely available and this treatment requires transporting a CO-poisoned patient to a specialized center, which can result in delayed treatment. Visible light is known to dissociate CO from carboxyhemoglobin (COHb). In a previous study, we showed that a system composed of six photo-extracorporeal membrane oxygenation (ECMO) devices efficiently removes CO from a large animal with CO poisoning. In this study, we tested the hypothesis that the application of hyperbaric oxygen to the photo-ECMO device would further increase the rate of CO elimination. STUDY DESIGN/MATERIAL AND METHODS: We developed a hyperbaric photo-ECMO device and assessed the ability of the device to remove CO from CO-poisoned human blood. We combined four devices into a "hyperbaric photo-ECMO system" and compared its ability to remove CO to our previously described photo-ECMO system, which was composed of six devices ventilated with normobaric oxygen. RESULTS: Under normobaric conditions, an increase in oxygen concentration from 21% to 100% significantly increased CO elimination from CO-poisoned blood after a single pass through the device. Increased oxygen pressure within the photo-ECMO device was associated with higher exiting blood PO2 levels and increased CO elimination. The system of four hyperbaric photo-ECMO devices removed CO from 1 L of CO-poisoned blood as quickly as the original, normobaric photo-ECMO system composed of six devices. CONCLUSION: This study demonstrates the feasibility and efficacy of using a hyperbaric photo-ECMO system to increase the rate of CO elimination from CO-poisoned blood. This technology could provide a simple portable emergency device and facilitate immediate treatment of CO-poisoned patients at or near the site of injury.


Asunto(s)
Intoxicación por Monóxido de Carbono , Monóxido de Carbono , Animales , Intoxicación por Monóxido de Carbono/complicaciones , Intoxicación por Monóxido de Carbono/terapia , Carboxihemoglobina , Hemoglobinas , Humanos , Oxígeno , Fototerapia/métodos
16.
Haematologica ; 107(2): 478-488, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34320783

RESUMEN

Hepcidin regulates iron homeostasis by controlling the level of ferroportin, the only membrane channel that facilitates export of iron from within cells. Binding of hepcidin to ferroportin induces the ubiquitination of ferroportin at multiple lysine residues and subsequently causes the internalization and degradation of the ligand-channel complex within lysosomes. The objective of this study was to identify components of the ubiquitin system that are involved in ferroportin degradation. A HepG2 cell line, which inducibly expresses ferroportingreen fluorescent protein (FPN-GFP), was established to test the ability of small interfering (siRNA) directed against components of the ubiquitin system to prevent BMP6- and exogenous hepcidin-induced ferroportin degradation. Of the 88 siRNA directed against components of the ubiquitin pathway that were tested, siRNA-mediated depletion of the alternative E1 enzyme UBA6 as well as the adaptor protein NDFIP1 prevented BMP6- and hepcidin-induced degradation of ferroportin in vitro. A third component of the ubiquitin pathway, ARIH1, indirectly inhibited ferroportin degradation by impairing BMP6-mediated induction of hepcidin. In mice, the AAV-mediated silencing of Ndfip1 in the murine liver increased the level of hepatic ferroportin and increased circulating iron. The results suggest that the E1 enzyme UBA6 and the adaptor protein NDFIP1 are involved in iron homeostasis by regulating the degradation of ferroportin. These specific components of the ubiquitin system may be promising targets for the treatment of iron-related diseases, including iron overload and anemia of inflammation.


Asunto(s)
Proteínas de Transporte de Catión , Sobrecarga de Hierro , Proteínas de la Membrana , Enzimas Activadoras de Ubiquitina , Animales , Proteínas Portadoras/genética , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Hepcidinas/genética , Hepcidinas/metabolismo , Humanos , Hierro/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Proteolisis , Enzimas Activadoras de Ubiquitina/genética , Enzimas Activadoras de Ubiquitina/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación
17.
Int J Mol Sci ; 22(19)2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34639197

RESUMEN

TRPV1 mediates pain occurring during sickling episodes in sickle cell disease (SCD). We examined if hemin, a porphyrin released during intravascular hemolysis modulates TRPV1. Calcium imaging and patch clamp were employed to examine effects of hemin on mouse dorsal root ganglion (DRG) neurons and HEK293t cells expressing TRPV1 and TRPA1. Hemin induced a concentration-dependent calcium influx in DRG neurons which was abolished by the unspecific TRP-channel inhibitor ruthenium red. The selective TRPV1-inhibitor BCTC or genetic deletion of TRPV1 only marginally impaired hemin-induced calcium influx in DRG neurons. While hTRPV1 expressed in HEK293 cells mediated a hemin-induced calcium influx which was blocked by BCTC, patch clamp recordings only showed potentiated proton- and heat-evoked currents. This effect was abolished by the PKC-inhibitor chelerythrine chloride and in protein kinase C (PKC)-insensitive TRPV1-mutants. Hemin-induced calcium influx through TRPV1 was only partly PKC-sensitive, but it was abolished by the reducing agent dithiothreitol (DTT). In contrast, hemin-induced potentiation of inward currents was not reduced by DTT. Hemin also induced a redox-dependent calcium influx, but not inward currents on hTRPA1. Our data suggest that hemin induces a PKC-mediated sensitization of TRPV1. However, it also acts as a photosensitizer when exposed to UVA-light used for calcium imaging. The resulting activation of redox-sensitive ion channels such as TRPV1 and TRPA1 may be an in vitro artifact with limited physiological relevance.


Asunto(s)
Ganglios Espinales/metabolismo , Hemina/farmacología , Neuronas/metabolismo , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/fisiología , Animales , Calcio/metabolismo , Ganglios Espinales/efectos de los fármacos , Células HEK293 , Humanos , Técnicas In Vitro , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/efectos de los fármacos , Canal Catiónico TRPA1/efectos de los fármacos , Canal Catiónico TRPA1/genética , Canales Catiónicos TRPV/efectos de los fármacos , Canales Catiónicos TRPV/genética
18.
Animals (Basel) ; 11(9)2021 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-34573483

RESUMEN

South American camelids (SAC) are being more and more presented at the veterinary Clinics in Germany. A bad nutritional condition, which can be easily categorized using a body condition score (BCS) of the animals, is often not noticed by the owners. Further anaemia is also often only detected in an advanced stage in SAC. Clinical detection of anaemia can be performed by assessing the FAMACHA©-score (FS), that is adapted from small ruminants. So far, there is only little information available about BCS and FS in SAC. In this study, both clinical scores were assessed in alpacas and llamas presented at the veterinary clinic and compared with the haematological parameters from the animals. The data were extracted retrospectively from the animals' medical records and compared statistically. More than half of the alpacas (60%) and llamas (70%) had a BCS < 3, while 12% of the alpacas and 21% of the llamas had a FS > 2. A decreased BCS was associated with a decrease in haematocrit, haemoglobin, lymphocytes, and eosinophils, as well as an increase in FS and neutrophils. BCS and FS should be assessed regularly in SAC to detect emaciation and anaemia in time.

19.
Nitric Oxide ; 116: 7-13, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34400339

RESUMEN

BACKGROUND: Inhaled nitric oxide (NO) is a selective pulmonary vasodilator. In-vitro studies report that NO donors can inhibit replication of SARS-CoV-2. This multicenter study evaluated the feasibility and effects of high-dose inhaled NO in non-intubated spontaneously breathing patients with Coronavirus disease-2019 (COVID-19). METHODS: This is an interventional study to determine whether NO at 160 parts-per-million (ppm) inhaled for 30 min twice daily might be beneficial and safe in non-intubated COVID-19 patients. RESULTS: Twenty-nine COVID-19 patients received a total of 217 intermittent inhaled NO treatments for 30 min at 160 ppm between March and June 2020. Breathing NO acutely decreased the respiratory rate of tachypneic patients and improved oxygenation in hypoxemic patients. The maximum level of nitrogen dioxide delivered was 1.5 ppm. The maximum level of methemoglobin (MetHb) during the treatments was 4.7%. MetHb decreased in all patients 5 min after discontinuing NO administration. No adverse events during treatment, such as hypoxemia, hypotension, or acute kidney injury during hospitalization occurred. In our NO treated patients, one patient of 29 underwent intubation and mechanical ventilation, and none died. The median hospital length of stay was 6 days [interquartile range 4-8]. No discharged patients required hospital readmission nor developed COVID-19 related long-term sequelae within 28 days of follow-up. CONCLUSIONS: In spontaneous breathing patients with COVID-19, the administration of inhaled NO at 160 ppm for 30 min twice daily promptly improved the respiratory rate of tachypneic patients and systemic oxygenation of hypoxemic patients. No adverse events were observed. None of the subjects was readmitted or had long-term COVID-19 sequelae.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , Hospitalización , Óxido Nítrico/administración & dosificación , Neumonía Viral/tratamiento farmacológico , Respiración/efectos de los fármacos , Administración por Inhalación , COVID-19/complicaciones , COVID-19/virología , Relación Dosis-Respuesta a Droga , Humanos , Óxido Nítrico/farmacología , Óxido Nítrico/uso terapéutico , Neumonía Viral/complicaciones
20.
Nat Neurosci ; 24(9): 1256-1269, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34267392

RESUMEN

The basal ganglia are known to influence action selection and modulation of movement vigor, but whether and how they contribute to specifying the kinematics of learned motor skills is not understood. Here, we probe this question by recording and manipulating basal ganglia activity in rats trained to generate complex task-specific movement patterns with rich kinematic structure. We find that the sensorimotor arm of the basal ganglia circuit is crucial for generating the detailed movement patterns underlying the acquired motor skills. Furthermore, the neural representations in the striatum, and the control function they subserve, do not depend on inputs from the motor cortex. Taken together, these results extend our understanding of the basal ganglia by showing that they can specify and control the fine-grained details of learned motor skills through their interactions with lower-level motor circuits.


Asunto(s)
Ganglios Basales/fisiología , Destreza Motora/fisiología , Animales , Fenómenos Biomecánicos/fisiología , Femenino , Aprendizaje/fisiología , Ratas , Ratas Long-Evans
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