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1.
J Neurosurg Spine ; : 1-7, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39178468

RESUMEN

OBJECTIVE: Advances in surface architecture and technology have made interbody fusion devices more bioactive, with the hope of facilitating the fusion process more successfully. The advent of these increasingly bioactive implants may reduce reliance on more expensive biologics that have previously been used to achieve high fusion rates. METHODS: A retrospective review of prospectively collected data (August 2018-December 2019) was conducted of consecutively performed anterior lumbar interbody fusions in which an acid-etched, nanosurface-modulated, titanium interbody device packed only with corticocancellous allograft chips and local blood was used. Minimum follow-up was 1 year, and inclusion required available imaging and outcome metrics preoperatively and at 1 year. Fusion and subsidence were assessed via CT scans and/or dynamic radiographs. Health-related quality-of-life measures (Oswestry Disability Index [ODI], visual analog scale [VAS] back/leg) were collected pre- and postoperatively. RESULTS: In total, 55 patients met inclusion criteria (1 year of follow-up, available imaging, and outcome metrics). A total of 69 lumbar levels were treated in these 55 patients. The mean age was 67 ± 12.1 years, with 47% female patients. Roughly one-third (35%) had previous spine surgery, and approximately one-tenth (9.1%) had prior spinal fusion. A total of 20.6% were treated at multiple levels (mean levels per patient 1.2, minimum 1, maximum 3). The mean preoperative patient-reported outcomes were as follows: ODI 39.71 ± 18.15, VAS back 6.49 ± 2.19, and VAS leg 5.41 ± 2.71. One year after surgery, the mean improvements in patient-reported outcomes (vs preoperative scores) were as follows: ODI -22.9 ± 13.08 (p < 0.001), VAS back -3.75 ± 2.03 (p < 0.001), VAS leg -3.73 ± 2.32 (p < 0.001). All levels achieved fusion at 1 year postoperatively based on CT scans (65/69 levels) or dynamic radiographs (4/69 levels, change in score < 5% on flexion-extension radiographs). Four of the 65 levels were assigned to the grade 3 category according to a CT-based grading system, meaning cranial and caudal endplate bone apposition to the implant on both surfaces with no clear intervertebral bone connection through or around the implant. Sixty-one of 65 were found to have contiguous intervertebral bone bridging and thus were assigned to grade 1 (n = 54) or grade 2 (n = 7). Low-grade graft subsidence (Marchi grade 0 or I) occurred in 9 levels (13.0%) and high-grade subsidence (Marchi grade II or III) in 4 levels (5.8%). No patients required reoperation at the level of anterior lumbar interbody fusion and no radiographic or clinical evidence of pedicle screw loosening or failure was observed. CONCLUSIONS: The combination of advances in materials science and surface technology as demonstrated with a nanotechnology titanium cage resulted in the ability to obtain lumbar interbody fusion with allograft chips and local blood alone. Achieving high fusion rates with low-cost biologics/allograft provides for an attractive pathway toward reducing the cost of reconstructive spine care, and a potential incremental benefit for healthcare economics.

2.
Clin Spine Surg ; 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39206970

RESUMEN

STUDY DESIGN: Retrospective review. OBJECTIVE: We sought to characterize complications associated with anterior column release (ACR). SUMMARY OF BACKGROUND DATA: Correction of positive sagittal imbalance was traditionally completed with anterior column grafts or posterior osteotomies. ACR is a minimally invasive technique for addressing sagittal plane deformity by restoring lumbar lordosis. METHODS: We conducted a retrospective review of consecutive patients who underwent ACR in a prospectively kept database at a tertiary care academic center from January 2012 to December 2018. The prespecified complications were hardware failure (rod fracture, hardware loosening, or screw fracture), proximal junctional kyphosis, ipsilateral thigh numbness, ipsilateral femoral nerve weakness, arterial injury requiring blood transfusion, bowel injury, and abdominal pseudohernia. RESULTS: Thirty-eight patients were identified. Thirty-five patients had ACR at L3-4, 1 had ACR at L4-5, and 1 patient had ACR at L2-3 and L3-4. Eighteen patients (47.4%) had one of the prespecified complications (10 patients had multiple). Ten patients developed hardware failure (26.3%); 8 patients (21.1%) had rod fracture, 4 (10.5%) had screw fracture, and 1 (2.6%) had screw loosening. At discharge, rates of ipsilateral thigh numbness (37.8%) and hip flexor (37.8%)/quadriceps weakness (29.7%) were the highest. At follow-up, 6 patients (16.2%) had ipsilateral anterolateral thigh numbness, 5 (13.5%) suffered from ipsilateral hip flexion weakness, and 3 patients (5.4%) from ipsilateral quadriceps weakness. Arterial injury occurred in 1 patient (2.7%). Abdominal pseudohernia occurred in 1 patient (2.7%). There were no bowel injuries observed. CONCLUSIONS: ACR is associated with a higher than initially anticipated risk of neurological complications, hardware failure, and proximal junctional kyphosis.

3.
Biomedicines ; 12(8)2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39200102

RESUMEN

AIM: Hyperglycemia damages mitochondria and downregulates transcription of mtDNA-encoded genes and the long noncoding RNA LncCytB, causing mitochondrial genomic instability. The genes encoded by mtDNA are transcribed as large polycistronic transcripts, and the 5' ends of precursor tRNAs are processed by mitochondrial-targeted ribonuclease P (MRPPs). Our aim was to investigate the role of MRPP1 in the downregulation of LncCytB in diabetic retinopathy. METHODS: Using human retinal endothelial cells incubated in 20 mM D-glucose for 96 h, the gene expression and mitochondrial localization (immunofluorescence) of MRPP1 and the interaction between MRPP1 and LncCytB (determined by RNA-FISH and RNA immunoprecipitation) were quantified. The results were confirmed in retinal microvessels from streptozotocin-induced diabetic mice and from human donors with documented diabetic retinopathy. RESULTS: Compared to normal glucose, high glucose decreased mRNA and mitochondrial localization of MRPP1 and its interaction with LncCytB. While MRPP1 overexpression prevented glucose-induced decrease in MRPP1-LncCytB interaction, LncCytB expression and mitochondrial damage (reduction in protective nucleoids in mtDNA), MRPP1-siRNA further worsened them. Similar results were obtained from retinal microvessels from diabetic mice and from human donors with diabetic retinopathy. CONCLUSIONS: Downregulation of MRPP1 in diabetes suppresses LncCytB transcription, resulting in mitochondrial functional and genomic instability, ultimately leading to the development of diabetic retinopathy. Thus, preventing MRPP1 downregulation has the potential to inhibit retinopathy and prevent the fear of vision loss in diabetic patients.

4.
J Biol Chem ; 300(8): 107561, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39002674

RESUMEN

Protein phosphatase 1D (PPM1D, Wip1) is induced by the tumor suppressor p53 during DNA damage response signaling and acts as an oncoprotein in several human cancers. Although PPM1D is a potential therapeutic target, insights into its atomic structure were challenging due to flexible regions unique to this family member. Here, we report the first crystal structure of the PPM1D catalytic domain to 1.8 Å resolution. The structure reveals the active site with two Mg2+ ions bound, similar to other structures. The flap subdomain and B-loop, which are crucial for substrate recognition and catalysis, were also resolved, with the flap forming two short helices and three short ß-strands that are followed by an irregular loop. Unexpectedly, a nitrogen-oxygen-sulfur bridge was identified in the catalytic domain. Molecular dynamics simulations and kinetic studies provided further mechanistic insights into the regulation of PPM1D catalytic activity. In particular, the kinetic experiments demonstrated a magnesium concentration-dependent lag in PPM1D attaining steady-state velocity, a feature of hysteretic enzymes that show slow transitions compared with catalytic turnover. All combined, these results advance the understanding of PPM1D function and will support the development of PPM1D-targeted therapeutics.


Asunto(s)
Dominio Catalítico , Proteína Fosfatasa 2C , Proteína Fosfatasa 2C/metabolismo , Proteína Fosfatasa 2C/química , Proteína Fosfatasa 2C/genética , Humanos , Cristalografía por Rayos X , Magnesio/metabolismo , Magnesio/química , Simulación de Dinámica Molecular , Cinética , Fosfoproteínas Fosfatasas/química , Fosfoproteínas Fosfatasas/metabolismo , Fosfoproteínas Fosfatasas/genética
5.
Mitochondrion ; 78: 101925, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38944370

RESUMEN

In diabetic retinopathy, mitochondrial DNA (mtDNA) is damaged and mtDNA-encoded genes and long noncoding RNA cytochrome B (LncCytB) are downregulated. LncRNAs lack an open reading frame, but they can regulate gene expression by associating with DNA/RNA/protein. Double stranded mtDNA has promoters on both heavy (HSP) and light (LSP) strands with binding sites for mitochondrial transcription factor A (TFAM) between them. The aim was to investigate the role of LncCytB in mtDNA transcription in diabetic retinopathy. Using human retinal endothelial cells incubated in high glucose, the effect of regulation of LncCytB on TFAM binding at mtDNA promoters was investigated by Chromatin immunoprecipitation, and binding of LncCytB at TFAM by RNA immunoprecipitation and RNA fluorescence in situ hybridization. High glucose decreased TFAM binding at both HSP and LSP, and binding of LncCytB at TFAM. While LncCytB overexpression ameliorated decrease in TFAM binding and transcription of genes encoded by both H- and L- strands, LncCytB-siRNA further downregulated them. Maintenance of mitochondrial homeostasis by overexpressing mitochondrial superoxide dismutase or Sirtuin-1 protected diabetes-induced decrease in TFAM binding at mtDNA and LncCytB binding at TFAM, and mtDNA transcription. Similar results were obtained from mouse retinal microvessels from streptozotocin-induced diabetic mice. Thus, LncCytB facilitates recruitment of TFAM at HSP and LSP, and its downregulation in diabetes compromises the binding, resulting in the downregulation of polypeptides encoded by mtDNA. Regulation of LncCytB, in addition to protecting mitochondrial genomic stability, should also help in maintaining the transcription of mtDNA encoded genes and electron transport chain integrity in diabetic retinopathy.


Asunto(s)
ADN Mitocondrial , Retinopatía Diabética , ARN Largo no Codificante , Transcripción Genética , Retinopatía Diabética/genética , Retinopatía Diabética/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Animales , Humanos , Ratones , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Células Endoteliales/metabolismo , Glucosa/metabolismo , Citocromos b/genética , Citocromos b/metabolismo , Regulación de la Expresión Génica , Sirtuina 1/metabolismo , Sirtuina 1/genética , Inmunoprecipitación de Cromatina , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo
6.
Comput Biol Med ; 177: 108646, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38824788

RESUMEN

Improved data sharing between healthcare providers can lead to a higher probability of accurate diagnosis, more effective treatments, and enhanced capabilities of healthcare organizations. One critical area of focus is brain tumor segmentation, a complex task due to the heterogeneous appearance, irregular shape, and variable location of tumors. Accurate segmentation is essential for proper diagnosis and effective treatment planning, yet current techniques often fall short due to these complexities. However, the sensitive nature of health data often prohibits its sharing. Moreover, the healthcare industry faces significant issues, including preserving the privacy of the model and instilling trust in the model. This paper proposes a framework to address these privacy and trust issues by introducing a mechanism for training the global model using federated learning and sharing the encrypted learned parameters via a permissioned blockchain. The blockchain-federated learning algorithm we designed aggregates gradients in the permissioned blockchain to decentralize the global model, while the introduced masking approach retains the privacy of the model parameters. Unlike traditional raw data sharing, this approach enables hospitals or medical research centers to contribute to a globally learned model, thereby enhancing the performance of the central model for all participating medical entities. As a result, the global model can learn about several specific diseases and benefit each contributor with new disease diagnosis tasks, leading to improved treatment options. The proposed algorithm ensures the quality of model data when aggregating the local model, using an asynchronous federated learning procedure to evaluate the shared model's quality. The experimental results demonstrate the efficacy of the proposed scheme for the critical and challenging task of brain tumor segmentation. Specifically, our method achieved a 1.99% improvement in Dice similarity coefficient for enhancing tumors and a 19.08% reduction in Hausdorff distance for whole tumors compared to the baseline methods, highlighting the significant advancement in segmentation performance and reliability.


Asunto(s)
Algoritmos , Neoplasias Encefálicas , Humanos , Neoplasias Encefálicas/diagnóstico por imagen , Cadena de Bloques , Aprendizaje Automático , Privacidad , Imagen por Resonancia Magnética/métodos
7.
Neuro Oncol ; 26(9): 1545-1556, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-38770775

RESUMEN

Drug delivery to the central nervous system (CNS) has been a major challenge for CNS tumors due to the impermeability of the blood-brain barrier (BBB). There has been a multitude of techniques aimed at overcoming the BBB obstacle aimed at utilizing natural transport mechanisms or bypassing the BBB which we review here. Another approach that has generated recent interest in the recently published literature is to use new technologies (Laser Interstitial Thermal Therapy, LITT; or Low-Intensity Focused Ultrasound, LIFU) to temporarily increase BBB permeability. This review overviews the advantages, disadvantages, and major advances of each method. LIFU has been a major area of research to allow for chemotherapeutics to cross the BBB which has a particular emphasis in this review. While most of the advances remain in animal studies, there are an increasing number of translational clinical trials that will have results in the next few years.


Asunto(s)
Barrera Hematoencefálica , Sistemas de Liberación de Medicamentos , Barrera Hematoencefálica/metabolismo , Humanos , Sistemas de Liberación de Medicamentos/métodos , Animales , Consenso , Neoplasias Encefálicas/terapia , Antineoplásicos/uso terapéutico
8.
J Neurol Surg B Skull Base ; 85(2): 156-160, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38449584

RESUMEN

Objective We aim to describe a novel positioning technique using a specific surgical table to achieve the optimal angle during percutaneous glycerol rhizotomy (PGR) for trigeminal neuralgia (TN). Design This is a descriptive and photographic analysis of successful cases for future implementation. Setting This study was conducted at a single-institution, academic center. Participants The participants were adult patients with TN who underwent PGR and provided consent for publication. Main Outcome Measures Primary outcomes of this study were TN symptomatic relief and surgical complications. Results The use of a beach chair sliding headboard surgical table for PGR is plausible and ensures precise and immobile head flexion for 1 hour postglycerol injection. There were no intraoperative or postoperative complications. All patients achieved successful reduction of TN symptoms. Conclusions Utilizing this new method of intraoperative navigation with a unique surgical table in the upright position, surgeons may achieve precise head adjustments post-PGR. Head flexion has been postulated as a means of ensuring glycerol containment in Meckel's cave. This method can help standardize this procedure for future systematic studies on the importance of head positioning post-PGR.

9.
Cureus ; 16(1): e51750, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38318550

RESUMEN

Arachnoid cysts are abnormal intradural collections of cerebrospinal fluid. For posterior fossa arachnoid cysts (PFACs), symptoms vary greatly, often relating to cranial nerve impingement and/or hydrocephalus. Literature on long-term symptomatic and radiographic follow-up of PFACs is lacking. This case study describes a 32-year-old man who presented with headaches and left-sided hearing loss and was found to have a large left-sided cerebellopontine angle arachnoid cyst with syrinx and ventriculomegaly. After PFAC fenestration and excision, his headaches resolved and his hearing markedly improved. At the one-year postoperative evaluation, symptom improvement persisted, and MRI demonstrated a stable decreased cyst and near-complete resolution of his syrinx.

10.
Eur Spine J ; 33(2): 590-598, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38224408

RESUMEN

PURPOSE: Three-column osteotomies (TCOs) and minimally invasive techniques such as anterior column realignment (ACR) are powerful tools used to restore lumbar lordosis and sagittal alignment. We aimed to appraise the differences in construct and global spinal stability between TCOs and ACRs in long constructs. METHODS: We identified consecutive patients who underwent a long construct lumbar or thoracolumbar fusion between January 2016 and November 2021. "Long construct" was any construct where the uppermost instrumented vertebra (UIV) was L2 or higher and the lowermost instrumented vertebra (LIV) was in the sacrum or ileum. RESULTS: We identified 69 patients; 14 (20.3%) developed PJK throughout follow-up (mean 838 days). Female patients were less likely to suffer PJK (p = 0.009). TCO was more associated with open (versus minimally invasive) screw/rod placement, greater number of levels, higher UIV, greater rate of instrumentation to the ilium, and posterior (versus anterior) L5-S1 interbody placement versus the ACR cohort (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.005, respectively). Patients who developed PJK were more likely to have undergone ACR (12 (32.4%) versus 2 (6.3%, p = 0.007)). The TCO cohort had better improvement of lumbar lordosis despite similar preoperative measurements (ACR: 16.8 ± 3.78°, TCO: 23.0 ± 5.02°, p = 0.046). Pelvic incidence-lumbar lordosis mismatch had greater improvement after TCO (ACR: 14.8 ± 4.02°, TCO: 21.5 ± 5.10°, p = 0.042). By multivariate analysis, ACR increased odds of PJK by 6.1-times (95% confidence interval: 1.20-31.2, p = 0.29). CONCLUSION: In patients with long constructs who undergo ACR or TCO, we experienced a 20% rate of PJK. TCO decreased PJK 6.1-times compared to ACR. TCO demonstrated greater improvement of some spinopelvic parameters.


Asunto(s)
Cifosis , Lordosis , Anomalías Musculoesqueléticas , Animales , Humanos , Femenino , Lordosis/diagnóstico por imagen , Lordosis/cirugía , Sacro , Tornillos Óseos , Osteotomía
11.
Mol Neurobiol ; 61(1): 188-199, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37596436

RESUMEN

Retinopathy fails to halt even after diabetic patients in poor glycemic control try to institute tight glycemic control, suggesting a "metabolic memory" phenomenon, and the experimental models have demonstrated that mitochondria continue to be damaged/dysfunctional, fueling into the vicious cycle of free radicals. Our aim was to investigate the role of removal of the damaged mitochondria in the metabolic memory. Using human retinal endothelial cells (HRECs), incubated in 20 mM D-glucose for 4 days, followed by 5 mM D-glucose for 4 additional days, mitochondrial turnover, formation of mitophagosome, and mitophagy flux were evaluated. Mitophagy was confirmed in a rat model of metabolic memory where the rats were kept in poor glycemic control (blood glucose ~ 400 mg/dl) for 3 months soon after induction of streptozotocin-induced diabetes, followed by 3 additional months of good control (BG < 150 mg/dl). Reversal of high glucose by normal glucose had no effect on mitochondrial turnover and mitophagosome formation, and mitophagy flux remained compromised. Similarly, 3 months of good glycemic control in rats, which had followed 3 months of poor glycemic control, had no effect on mitophagy flux. Thus, poor turnover/removal of the damaged mitochondria, initiated during poor glycemic control, does not benefit from the termination of hyperglycemic insult, and the damaged mitochondria continue to produce free radicals, suggesting the importance of mitophagy in the metabolic memory phenomenon associated with the continued progression of diabetic retinopathy.


Asunto(s)
Diabetes Mellitus Experimental , Retinopatía Diabética , Hiperglucemia , Humanos , Ratas , Animales , Retinopatía Diabética/metabolismo , Células Endoteliales/metabolismo , Ratas Wistar , Mitocondrias/metabolismo , Hiperglucemia/complicaciones , Hiperglucemia/metabolismo , Glucosa/metabolismo , Diabetes Mellitus Experimental/metabolismo , Radicales Libres/metabolismo , Radicales Libres/farmacología
12.
Pediatr Neurosurg ; 58(5): 281-289, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37531944

RESUMEN

BACKGROUND: Spinal tumors are rare pathology in the pediatric population. The tumors can be classified as extradural, intradural extramedullary, or intramedullary. Any of the spinal tumors can eventually lead to spinal deformity. The progressive spinal deformity can be part of the initial presentation or evolve on long follow-up, even years after the initial intervention and treatment. SUMMARY: Management of spinal deformity associated with spinal tumors in children is not well defined. Patients with progressive symptoms and even neurological deficits need correction for their deformity when diagnosed. Patients that do not have pain or related neurological deficits should be evaluated for the severity of their deformity and followed long-term. Special consideration is needed for young patients who need multilevel surgery or have deformity at presentation. KEY MESSAGES: When considering the need for instrumentation and fusion, the surgeon should consider the age of the patient, expected future growth of the spine, neurologic status, extent of initial deformity, and the number of vertebral levels involved by tumor. Providers should also consider how surgery may fix or prevent deformity, especially when instrumentation can affect imaging at follow-up.


Asunto(s)
Neoplasias de la Médula Espinal , Fusión Vertebral , Neoplasias de la Columna Vertebral , Humanos , Niño , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Neoplasias de la Columna Vertebral/cirugía , Resultado del Tratamiento , Columna Vertebral , Neoplasias de la Médula Espinal/diagnóstico por imagen , Neoplasias de la Médula Espinal/cirugía , Laminectomía/métodos , Fusión Vertebral/métodos , Estudios Retrospectivos
13.
Antioxid Redox Signal ; 39(13-15): 817-828, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37464864

RESUMEN

Aims: Mitochondrial dysfunction is closely associated with the development of diabetic complications. In diabetic retinopathy, electron transport chain is compromised and mitochondrial DNA (mtDNA) is damaged, downregulating transcription of mtDNA-encoded cytochrome B (CYTB) and its antisense long noncoding RNA, long noncoding RNA cytochrome B (LncCytB). Our goal was to investigate the role of LncCytB in the regulation of CYTB and mitochondrial function in diabetic retinopathy. Methods: Using human retinal endothelial cells, genetically manipulated for LncCytB (overexpression or silencing), the effect of high glucose (20 mM d-glucose) on LncCytB-CYTB interactions (by chromatin isolation by RNA purification), CYTB gene expression (by real-time quantitative polymerase chain reaction), complex III activity, mitochondrial free radicals, and oxygen consumption rate (OCR, by Seahorse XF analyzer) was investigated. Key results were confirmed in the retinal microvessels from streptozotocin-induced diabetic mice. Results: High glucose decreased LncCytB-CYTB interactions, and while LncCytB overexpression ameliorated glucose-induced decrease in CYTB gene transcripts, complex III activity and OCR and increase in mitochondrial reactive oxygen species, LncCytB-siRNA further attenuated CYTB gene transcription, complex III activity, and OCR. Similar decrease in LncCytB-CYTB interactions and CYTB transcription was observed in diabetic mice. Furthermore, maintenance of mitochondrial homeostasis by overexpressing superoxide dismutase or sirtuin 1 in mice ameliorated diabetes-induced decrease in LncCytB-CYTB interactions and CYTB gene transcripts, and also improved complex III activity and mitochondrial respiration. Innovation and Conclusion: LncCytB downregulation in hyperglycemic milieu downregulates CYTB transcription, which inhibits complex III activity and compromises mitochondrial stability and OCR. Thus, preventing LncCytB downregulation in diabetes has potential of inhibiting the development of diabetic retinopathy, possibly via maintaining mitochondrial respiration. Antioxid. Redox Signal. 39, 817-828.


Asunto(s)
Diabetes Mellitus Experimental , Retinopatía Diabética , Genoma Mitocondrial , ARN Largo no Codificante , Ratones , Humanos , Animales , Retinopatía Diabética/genética , Retinopatía Diabética/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Citocromos b/genética , Citocromos b/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Células Endoteliales/metabolismo , Complejo III de Transporte de Electrones/genética , Complejo III de Transporte de Electrones/metabolismo , ADN Mitocondrial/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , Glucosa/metabolismo
14.
Front Endocrinol (Lausanne) ; 14: 1160155, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37415667

RESUMEN

Introduction: Mitochondrial dynamic plays a major role in their quality control, and the damaged mitochondrial components are removed by autophagy. In diabetic retinopathy, mitochondrial fusion enzyme, mitofusin 2 (Mfn2), is downregulated and mitochondrial dynamic is disturbed resulting in depolarized and dysfunctional mitochondria. Our aim was to investigate the mechanism of inhibition of Mfn2, and its role in the removal of the damaged mitochondria, in diabetic retinopathy. Methods: Using human retinal endothelial cells, effect of high glucose (20mM) on the GTPase activity of Mfn2 and its acetylation were determined. Role of Mfn2 in the removal of the damaged mitochondria was confirmed by regulating its acetylation, or by Mfn2 overexpression, on autophagosomes- autolysosomes formation and the mitophagy flux. Results: High glucose inhibited GTPase activity and increased acetylation of Mfn2. Inhibition of acetylation, or Mfn2 overexpression, attenuated decrease in GTPase activity and mitochondrial fragmentation, and increased the removal of the damaged mitochondria. Similar phenomenon was observed in diabetic mice; overexpression of sirtuin 1 (a deacetylase) ameliorated diabetes-induced inhibition of retinal Mfn2 and facilitated the removal of the damaged mitochondria. Conclusions: Acetylation of Mfn2 has dual roles in mitochondrial homeostasis in diabetic retinopathy, it inhibits GTPase activity of Mfn2 and increases mitochondrial fragmentation, and also impairs removal of the damaged mitochondria. Thus, protecting Mfn2 activity should maintain mitochondrial homeostasis and inhibit the development/progression of diabetic retinopathy.


Asunto(s)
Diabetes Mellitus Experimental , Retinopatía Diabética , Ratones , Humanos , Animales , Retinopatía Diabética/metabolismo , Dinámicas Mitocondriales , Diabetes Mellitus Experimental/metabolismo , Células Endoteliales/metabolismo , Mitocondrias , GTP Fosfohidrolasas/metabolismo , Glucosa/metabolismo
15.
Global Spine J ; 13(7): 2001-2006, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35012363

RESUMEN

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: Spinal fusion, specifically constructs connected to pelvic bones, has been consistently reported as a predisposing factor to sacroiliac joint (SIJ) pain. The aim of this study is to compare SIJ outcomes in patients with constructs to the pelvis following instrumentation vs instrumentation plus fusion of the SIJ. METHODS: Data of study subjects was extracted from a prospectively maintained database as well as retrospectively collected from records at a tertiary academic medical center in the United States between 2018 and 2020. RESULTS: A cohort of 103 patients was divided into 2 groups: 65 in Group 1 [S2AI screw without fusion device] and 38 in Group 2 [S2AI screw with fusion device]. None of the patients in Group 2 developed postoperative SIJ pain compared to 44.6% in Group 1. Sacroiliac joint fusion occurred in all Group 2 but none of Group 1 patients. The postoperative Visual Analogue Scale (VAS) for lower extremity (LE) pain (.8 vs .5; P = .03) and postoperative Oswestry Disability Index (ODI) (18.7 vs 14.2; P < .01) were significantly higher in Group 1. The rate of distal junctional break, failure, and/or kyphosis (DJBFK) and time to DJBFK were not significantly different between the two groups, and the rate of DJBFK did not change in the presence of multiple covariates. CONCLUSION: The SIJs carry the heavy load of long lumbosacral fusion constructs extending to the pelvis. Simultaneous SIJ instrumentation and fusion decreases the risk of disability, prevents the development of postoperative SIJ pain, and may also protect the S2AI screw from loosening and failure.

16.
Diabetes ; 72(4): 520-531, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36563021

RESUMEN

Mitochondria experience genomic and functional instability in diabetes, and mitochondrial dysfunction has a critical role in the development of diabetic retinopathy. Diabetes also alters expressions of many long noncoding RNAs (LncRNAs), the RNAs with >200 nucleotides and no open reading frame. LncRNAs are mainly encoded by the nuclear genome, but mtDNA also encodes three LncRNAs. Our goal was to investigate the effect of hyperglycemia on mtDNA-encoded LncRNA cytochrome B (LncCytB) in mtDNA stability in diabetic retinopathy. Retinal endothelial cells, transfected with LncCytB-overexpressing plasmids or siRNA, incubated in 5 mmol/L d-glucose (normal glucose [NG]) or 20 mmol/L d-glucose (high glucose [HG]) for 4 days, were analyzed for LncCytB expression by strand-specific PCR and its mitochondrial localization by RNA fluorescence in situ hybridization. Damage-sensitive mtDNA regions were examined by micrococcal nuclease (MNase) digestion sequencing and LncCytB occupancy at mtDNA by chromatin isolation by RNA purification. Protective nucleoids in mtDNA were analyzed by SYBR Green-MitoTracker Red staining and confirmed in isolated mitochondria by flow cytometry. Compared with NG, HG downregulated LncCytB by >50% but had no significant effect on the other mtDNA-encoded LncRNAs. mtDNA packaging was impaired, MNase sensitivity was increased, and LncCytB occupancy at mtDNA was decreased. While LncCytB overexpression ameliorated mtDNA damage and decrease in nucleoids and copy numbers, LncCytB-siRNA exacerbated damage and further reduced nucleoids. Retinal microvessels from streptozotocin-induced diabetic mice and human donors with diabetic retinopathy presented a similar decrease in LncCytB and mtDNA nucleoids. Thus, LncCytB has a major role in maintaining mitochondrial genomic stability, and its downregulation in the hyperglycemic milieu contributes to increased vulnerability of mtDNA to damage.


Asunto(s)
Diabetes Mellitus Experimental , Retinopatía Diabética , Genoma Mitocondrial , ARN Largo no Codificante , Ratones , Humanos , Animales , Retinopatía Diabética/genética , Retinopatía Diabética/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Diabetes Mellitus Experimental/metabolismo , Células Endoteliales/metabolismo , Hibridación Fluorescente in Situ , Mitocondrias/genética , Mitocondrias/metabolismo , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Glucosa/metabolismo
17.
Comput Med Imaging Graph ; 102: 102139, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36395604

RESUMEN

Medical healthcare centers are envisioned as a promising paradigm to handle the massive volume of data for COVID-19 patients using artificial intelligence (AI). Traditionally, AI techniques require centralized data collection and training models within a single organization. This practice can be considered a weakness as it leads to several privacy and security concerns related to raw data communication. To overcome this weakness and secure raw data communication, we propose a blockchain-based federated learning framework that provides a solution for collaborative data training. The proposed framework enables the coordination of multiple hospitals to train and share encrypted federated models while preserving data privacy. Blockchain ledger technology provides decentralization of federated learning models without relying on a central server. Moreover, the proposed homomorphic encryption scheme encrypts and decrypts the gradients of the model to preserve privacy. More precisely, the proposed framework: (i) train the local model by a novel capsule network for segmentation and classification of COVID-19 images, (ii) furthermore, we use the homomorphic encryption scheme to secure the local model that encrypts and decrypts the gradients, (iii) finally, the model is shared over a decentralized platform through the proposed blockchain-based federated learning algorithm. The integration of blockchain and federated learning leads to a new paradigm for medical image data sharing over the decentralized network. To validate our proposed model, we conducted comprehensive experiments and the results demonstrate the superior performance of the proposed scheme.


Asunto(s)
Cadena de Bloques , COVID-19 , Humanos , Privacidad , Inteligencia Artificial , Algoritmos
18.
Eur J Med Chem ; 243: 114763, 2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36179402

RESUMEN

The wild-type p53 induced phosphatase 1 (Wip1), a member of the serine/threonine-specific PP2C family, is overexpressed in numerous human cancers. Wip1 dephosphorylates p53 as well as several kinases (such as p38 MAPK, ATM, Chk1, and Chk2) in the DNA damage response pathway that are responsible for maintaining genomic stability and preventing oncogenic transformation. As a result, Wip1 is an attractive target for synthetic inhibitors that could be further developed into therapeutics to treat some cancers. In this study, we report a series of alkyl-substituted N-methylaryl-N'-aryl-4-aminobenzamides and their inhibitory activity of the Wip1 phosphatase. A straightforward synthetic route was developed to synthesize the target compounds from commercially available starting materials. Three different portions (R1, R2, R3) of the core scaffold were extensively modified to examine structure-activity relationships. This study revealed interesting trends about a new molecular scaffold to inhibit Wip1.


Asunto(s)
Fosfoproteínas Fosfatasas , Proteína p53 Supresora de Tumor , Humanos , Proteína Fosfatasa 2C/genética , Proteína Fosfatasa 2C/metabolismo , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Serina-Treonina Quinasas , Daño del ADN , Fosforilación
19.
Environ Sci Pollut Res Int ; 29(48): 72445-72460, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35655014

RESUMEN

Induction furnace dust (IFD) is a waste product of the alloy-making process whose disposal by landfill process becomes unsafe due to the presence of heavy metals in high concentrations. It further reduces the fertility of soil and pollutes the air making it harmful for human health. However, efforts can be made to utilize this dust in construction material as it has the same oxides (silica, aluminium oxide, and magnesium oxide) as found in cement, bricks, fine aggregates, coarse aggregates, etc. This study is aimed at the utilization of pre-treated induction furnace dust with Aspergillus niger fungus to replace cement for the construction of concrete structures through Taguchi design of experiments (DOE). The purpose of Aspergillus niger fungus is to reduce the heavy metal concentration from IFD to prevent the surroundings from getting toxic. The optimization of operating parameters such as dust replacement (5%, 10%, and 15%), curing days (7, 14, and 28 days), and cell count of fungus (104, 106, and 108 CFU/ml of distilled water) is done using Multi-objective Genetic Algorithm (G.A.) for effective compressive strength and water absorption capacity of cubes. The best results have been found in the case of IFD treated with Aspergillus niger fungus having dust replacement, curing time, and cell count of 14.96%, 28 days, and 9.22 × 107 CFU/ml of distilled water respectively for concrete production.


Asunto(s)
Aspergillus niger , Polvo , Aleaciones , Óxido de Aluminio , Humanos , Óxido de Magnesio , Óxidos , Dióxido de Silicio , Suelo , Residuos , Agua
20.
Sci Rep ; 12(1): 10419, 2022 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-35729184

RESUMEN

The fragile X mental retardation (FMR1) gene contains an expansion-prone CGG repeat within its 5' UTR. Alleles with 55-200 repeats are known as premutation (PM) alleles and confer risk for one or more of the FMR1 premutation (PM) disorders that include Fragile X-associated Tremor/Ataxia Syndrome (FXTAS), Fragile X-associated Primary Ovarian Insufficiency (FXPOI), and Fragile X-Associated Neuropsychiatric Disorders (FXAND). PM alleles expand on intergenerational transmission, with the children of PM mothers being at risk of inheriting alleles with > 200 CGG repeats (full mutation FM) alleles) and thus developing Fragile X Syndrome (FXS). PM alleles can be somatically unstable. This can lead to individuals being mosaic for multiple size alleles. Here, we describe a detailed evaluation of somatic mosaicism in a large cohort of female PM carriers and show that 94% display some evidence of somatic instability with the presence of a series of expanded alleles that differ from the next allele by a single repeat unit. Using two different metrics for instability that we have developed, we show that, as with intergenerational instability, there is a direct relationship between the extent of somatic expansion and the number of CGG repeats in the originally inherited allele and an inverse relationship with the number of AGG interruptions. Expansions are progressive as evidenced by a positive correlation with age and by examination of blood samples from the same individual taken at different time points. Our data also suggests the existence of other genetic or environmental factors that affect the extent of somatic expansion. Importantly, the analysis of candidate single nucleotide polymorphisms (SNPs) suggests that two DNA repair factors, FAN1 and MSH3, may be modifiers of somatic expansion risk in the PM population as observed in other repeat expansion disorders.


Asunto(s)
Síndrome del Cromosoma X Frágil , Discapacidad Intelectual , Regiones no Traducidas 5' , Alelos , Ataxia , Niño , Femenino , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/metabolismo , Síndrome del Cromosoma X Frágil/genética , Humanos , Discapacidad Intelectual/genética , Mutación , Transactivadores/genética , Temblor , Expansión de Repetición de Trinucleótido
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