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1.
J Oncol Pharm Pract ; : 10781552241235573, 2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38404003

RESUMEN

INTRODUCTION: Drug-drug interactions (DDIs) pose a significant threat to patients with cancer, resulting in several adverse events in an oncology setting. Our study aims to identify potential DDIs in inpatient oncology wards, assess their severity, and provide recommendations to avoid these interactions. MATERIALS AND METHODS: This prospective study was conducted in 79 hospitalized cancer patients over a period of 9 months (from August 2021 to May 2022) at the Amrita Institute of Medical Sciences, Kochi receiving at least two oncological or non-oncological drugs for 5 days. RESULTS: Significant differences were found in drug count (61.6% vs. 38.4%), hospitalization duration (63.1% vs. 36.9%), and medications for comorbidities (63% vs. 37%) between patients with and without DDIs (p < 0.001, <0.001, and 0.01, respectively). The study identified 321 DDIs, with 14 (4.4%) X interactions, 93 (30%) D interactions, 161 (50%) C interactions, and 53 (15.6%) B interactions. Severity-wise, 76 (23.7%) were major, 190 (59.1%) were moderate, and 55 (17.2%) were minor. CONCLUSION: Our study showed that drug count, medications for comorbidities, and hospitalization duration significantly increase the risk of DDIs in hospitalized oncology patients. Around 96.4% of recommendations for potential interactions were accepted and implemented, highlighting the huge opportunities and requirements for improvement, implementation, and management of drug interactions in oncology settings.

2.
J Hand Surg Am ; 46(9): 812.e1-812.e5, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33487489

RESUMEN

PURPOSE: The purpose of the study was to evaluate the utility of the levator scapulae motor nerve (LSN) as a donor nerve for brachial plexus nerve transfer. We hypothesized that the LSN could be transferred to the suprascapular nerve (SSN) or long thoracic nerve (LTN) with a reliable tension-free coaptation and appropriate donor-to-recipient axon count ratio. METHODS: Twelve brachial plexus dissections were performed on 6 adult cadavers, bilaterally. We identified the LSN, spinal accessory nerve (SAN), SSN, and LTN. Each nerve was prepared for transfer and nerve redundancies were calculated. Cross-sections of each nerve were examined histologically, and axons counted. We transferred the LSN to target first the SSN and then the LTN, in a tension-free coaptation. For reference, we transferred the distal SAN to target the SSN and LTN and compared transfer parameters. RESULTS: Three cadavers demonstrated 2 LSN branches supplying the levator scapulae. The axon count ratio of donor-to-recipient nerve was 1:4.0 (LSN:SSN) and 1:2.1 (LSN:LTN) for a single LSN branch and 1:3.0 (LSN:SSN) and 1:1.6 (LSN:LTN) when 2 LSN branches were available. Comparatively, the axon count ratio of donor-to-recipient nerve was 1:2.5 and 1:1.3 for the SAN to the SSN and the LTN, respectively. The mean redundancy from the LSN to the SSN and the LTN was 1.7 cm (SD, 3.1 cm) and 2.9 cm (SD, 2.8 cm), and the redundancy from the SAN to the SSN and the LTN was 4.5 (SD, 0.7 cm) and 0.75 cm (SD, 1.0 cm). CONCLUSIONS: These data support the use of the LSN as a potential donor for direct nerve transfer to the SSN and LTN, given its adequate redundancy and size match. CLINICAL RELEVANCE: The LSN should be considered as an alternative nerve donor source for brachial plexus reconstruction, especially in 5-level injuries with scarce donor nerves. If used in lieu of the SAN during primary nerve reconstruction, trapezius tendon transfer for improved external rotation would be enabled.


Asunto(s)
Neuropatías del Plexo Braquial , Plexo Braquial , Transferencia de Nervios , Músculos Superficiales de la Espalda , Nervio Accesorio/cirugía , Adulto , Plexo Braquial/cirugía , Neuropatías del Plexo Braquial/cirugía , Cadáver , Humanos
3.
J Hand Surg Am ; 46(1): 43-53, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32868098

RESUMEN

PURPOSE: Wide variability in the recovery of patients affected by neuralgic amyotrophy (NA) is recognized, with up to 30% experiencing residual motor deficits. Using magnetic resonance imaging and ultrasound (US), we identified hourglass constrictions (HGCs) in all affected nerves of patients with chronic motor paralysis from NA. We hypothesized that chronic NA patients undergoing microsurgical epineurolysis and perineurolysis of constrictions would experience greater recovery compared with patients managed nonsurgically. METHODS: We treated 24 patients with chronic motor palsy from NA and HGCs identified on magnetic resonance imaging and US either with microsurgical epineurolysis and perineurolysis of HGCs (11 of 24) or nonsurgically (13 of 24). Muscle strength (both groups) and electrodiagnostic testing (EDX) (operative group) was performed before and after surgery. Preoperative EDX confirmed muscle denervation in the distribution of affected nerve(s). All patients met criteria for microneurolysis: 12 months without improvement since onset or failure of clinical and EDX improvement after 6 months documented by 3 successive examinations, each at least 6 weeks apart. RESULTS: Mean time from onset to surgery was 12.5 ± 4.0 months. Average time to most recent post-onset follow-up occurred at 27.3 months (range, 18-42 months; 15 nerves). Average time to latest follow-up among nonsurgical patients was 33.6 months (range, 18-108 months; 16 nerves). Constrictions involved individual fascicular groups (FCs) of the median nerve and the suprascapular, axillary and radial nerves proper (HGCs). Nine of 11 operative patients experienced clinical recovery compared with 3 of 13 nonsurgical patients. EMG revealed significant motor unit recovery from axonal regeneration in the operative group. CONCLUSIONS: Microsurgical epineurolysis and perineurolysis of FCs and HGCs was associated with significantly improved clinical and nerve regeneration at an average follow-up of 14.8 months compared with nonsurgical management. We recommend microneurolysis of HGCs and FCs as a treatment option for patients with chronic NA who have failed to improve with nonsurgical treatment. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.


Asunto(s)
Neuritis del Plexo Braquial , Neuritis del Plexo Braquial/terapia , Constricción , Humanos , Imagen por Resonancia Magnética , Nervio Mediano , Ultrasonografía
4.
Chembiochem ; 18(20): 2069-2078, 2017 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-28783875

RESUMEN

Ferrostatin-1 (Fer-1) is a lipophilic antioxidant that effectively blocks ferroptosis, a distinct non-apoptotic form of cell death caused by lipid peroxidation. During many infections, both pathogens and host cells are subjected to oxidative stress, but the occurrence of ferroptosis had not been investigated. We examined ferroptosis in macrophages infected with the pathogenic yeast Histoplasma capsulatum. Unexpectedly, Fer-1 not only reduced the death of macrophages infected in vitro, but inhibited the growth of H. capsulatum and related species Paracoccidioides lutzii and Blastomyces dermatitidis at concentrations under 10 µm. Other antioxidant ferroptosis inhibitors, including liproxstatin-1, did not prevent fungal growth or reduce macrophage death. Structural analysis revealed a potential similarity of Fer-1 to inhibitors of fungal sterol synthesis, and ergosterol content of H. capsulatum decreased more than twofold after incubation with Fer-1. Strikingly, additional Fer-1 analogues with slight differences from Fer-1 had limited impact on fungal growth. In conclusion, the ferroptosis inhibitor Fer-1 has unexpected antifungal potency distinct from its antiferroptotic activity.


Asunto(s)
Antifúngicos/química , Antifúngicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Ciclohexilaminas/química , Ciclohexilaminas/farmacología , Interacciones Hidrofóbicas e Hidrofílicas , Fenilendiaminas/química , Fenilendiaminas/farmacología , Histoplasma/efectos de los fármacos , Relación Estructura-Actividad
5.
Antimicrob Agents Chemother ; 60(3): 1438-49, 2015 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-26666917

RESUMEN

In a search for new antifungal compounds, we screened a library of 4,454 chemicals for toxicity against the human fungal pathogen Aspergillus fumigatus. We identified sr7575, a molecule that inhibits growth of the evolutionary distant fungi A. fumigatus, Cryptococcus neoformans, Candida albicans, and Saccharomyces cerevisiae but lacks acute toxicity for mammalian cells. To gain insight into the mode of inhibition, sr7575 was screened against 4,885 S. cerevisiae mutants from the systematic collection of haploid deletion strains and 977 barcoded haploid DAmP (decreased abundance by mRNA perturbation) strains in which the function of essential genes was perturbed by the introduction of a drug resistance cassette downstream of the coding sequence region. Comparisons with previously published chemogenomic screens revealed that the set of mutants conferring sensitivity to sr7575 was strikingly narrow, affecting components of the endoplasmic reticulum-associated protein degradation (ERAD) stress response and the ER membrane protein complex (EMC). ERAD-deficient mutants were hypersensitive to sr7575 in both S. cerevisiae and A. fumigatus, indicating a conserved mechanism of growth inhibition between yeast and filamentous fungi. Although the unfolded protein response (UPR) is linked to ERAD regulation, sr7575 did not trigger the UPR in A. fumigatus and UPR mutants showed no enhanced sensitivity to the compound. The data from this chemogenomic analysis demonstrate that sr7575 exerts its antifungal activity by disrupting ER protein quality control in a manner that requires ERAD intervention but bypasses the need for the canonical UPR. ER protein quality control is thus a specific vulnerability of fungal organisms that might be exploited for antifungal drug development.


Asunto(s)
Antifúngicos/farmacología , Antifúngicos/toxicidad , Aspergillus fumigatus/efectos de los fármacos , Degradación Asociada con el Retículo Endoplásmico/efectos de los fármacos , Animales , Aspergillus fumigatus/genética , Candida albicans/efectos de los fármacos , Cryptococcus neoformans/efectos de los fármacos , Evaluación Preclínica de Medicamentos/métodos , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Degradación Asociada con el Retículo Endoplásmico/genética , Células HeLa/efectos de los fármacos , Humanos , Ratones Endogámicos , Pruebas de Sensibilidad Microbiana , Mutación , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética , Bibliotecas de Moléculas Pequeñas/farmacología , Respuesta de Proteína Desplegada/efectos de los fármacos
7.
BMC Genomics ; 15: 159, 2014 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-24568630

RESUMEN

BACKGROUND: The unfolded protein response (UPR) is a network of intracellular signaling pathways that supports the ability of the secretory pathway to maintain a balance between the load of proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the ER lumen. Current evidence indicates that several pathogenic fungi rely heavily on this pathway for virulence, but there is limited understanding of the mechanisms involved. The best known functional output of the UPR is transcriptional upregulation of mRNAs involved in ER homeostasis. However, this does not take into account mechanisms of translational regulation that involve differential loading of ribosomes onto mRNAs. In this study, a global analysis of transcript-specific translational regulation was performed in the pathogenic mold Aspergillus fumigatus to determine the nature and scope of the translational response to ER stress. RESULTS: ER stress was induced by treating the fungus with dithiothreitol, tunicamycin, or a thermal up-shift. The mRNAs were then fractionated on the basis of ribosome occupancy into an under-translated pool (U) and a well-translated pool (W). The mRNAs were used to interrogate microarrays and the ratio of the hybridization signal (W/U) was used as an indicator of the relative translational efficiency of a mRNA under each condition. The largest category of translationally upregulated mRNAs during ER stress encoded proteins involved in translation. Components of the ergosterol and GPI anchor biosynthetic pathways also showed increased polysome association, suggesting an important role for translational regulation in membrane and cell wall homeostasis. ER stress induced limited remodeling of the secretory pathway translatome. However, a select group of transcription factors was translationally upregulated, providing a link to subsequent modification of the transcriptome. Finally, we provide evidence that one component of the ER stress translatome is a novel mRNA isoform from the yvc1 gene that is induced by ER stress in a UPR-dependent manner. CONCLUSIONS: Together, these findings define a core set of mRNAs subject to translational control during the adaptive response to acute ER stress in A. fumigatus and reveal a remarkable breadth of functions that are needed to resolve ER stress in this organism.


Asunto(s)
Aspergillus fumigatus/genética , Aspergillus fumigatus/metabolismo , Estrés del Retículo Endoplásmico , Polirribosomas/metabolismo , Biosíntesis de Proteínas , Adaptación Biológica , Membrana Celular/metabolismo , Pared Celular/metabolismo , Análisis por Conglomerados , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Calor , Isoformas de ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reproducibilidad de los Resultados , Vías Secretoras , Transcripción Genética , Respuesta de Proteína Desplegada
8.
Eukaryot Cell ; 12(4): 512-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23355008

RESUMEN

Proteins that are destined for release outside the eukaryotic cell, insertion into the plasma membrane, or delivery to intracellular organelles are processed and folded in the endoplasmic reticulum (ER). An imbalance between the level of nascent proteins entering the ER and the organelle's ability to manage that load results in the accumulation of unfolded proteins. Terminally unfolded proteins are disposed of by ER-associated degradation (ERAD), a pathway that transports the aberrant proteins across the ER membrane into the cytosol for proteasomal degradation. The ERAD pathway was targeted in the mold pathogen Aspergillus fumigatus by deleting the hrdA gene, encoding the A. fumigatus ortholog of Hrd1, the E3 ubiquitin ligase previously shown to contribute to ERAD in other species. Loss of HrdA was associated with impaired degradation of a folding-defective ERAD substrate, CPY*, as well as activation of the unfolded-protein response (UPR). The ΔhrdA mutant showed resistance to voriconazole and reduced thermotolerance but was otherwise unaffected by a variety of environmental stressors. A double-deletion mutant deficient in both HrdA and another component of the same ERAD complex, DerA, was defective in secretion and showed hypersensitivity to ER, thermal, and cell wall stress. However, the ΔhrdA ΔderA mutant remained virulent in mouse and insect infection models. These data demonstrate that HrdA and DerA support complementary ERAD functions that promote survival under conditions of ER stress but are dispensable for virulence in the host environment.


Asunto(s)
Aspergillus fumigatus/genética , Aspergillus fumigatus/patogenicidad , Farmacorresistencia Fúngica/efectos de los fármacos , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Ubiquitina-Proteína Ligasas/genética , Animales , Antifúngicos/farmacología , Aspergilosis/microbiología , Aspergilosis/mortalidad , Aspergillus fumigatus/efectos de los fármacos , Aspergillus fumigatus/metabolismo , Citosol/efectos de los fármacos , Farmacorresistencia Fúngica/genética , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/genética , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/genética , Degradación Asociada con el Retículo Endoplásmico/efectos de los fármacos , Degradación Asociada con el Retículo Endoplásmico/genética , Proteínas Fúngicas/metabolismo , Eliminación de Gen , Ratones , Complejo de la Endopetidasa Proteasomal/metabolismo , Pliegue de Proteína , Pirimidinas/farmacología , Análisis de Supervivencia , Triazoles/farmacología , Ubiquitina-Proteína Ligasas/metabolismo , Virulencia , Voriconazol
9.
Chemosphere ; 351: 141220, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38224749

RESUMEN

Hydrogen (H2) generation by electrochemical water splitting is a key technique for sustainable energy applications. Two-dimensional (2D) transition-metal dichalcogenide (MoS2) and silver phosphate (Ag3PO4) possess excellent electrochemical hydrogen evolution reaction (HER) properties when they are combined together as a composite rather than individuals. Reports examining the HER activity by using Ag3PO4, especially, in combination with the 2D layered MoS2 are limited in literature. The weight fraction of MoS2 in Ag3PO4 is optimized for 1, 3, and 5 wt%. The Ag3PO4/1 wt % MoS2 combination exhibits enhanced HER activity with least overpotential of 235 mV among the other samples in the acidic medium. The synergistic effect of optimal nano-scale 2D layered MoS2 structure and Ag3PO4 is essential for creating higher electrochemical active surface area of 217 mF/cm2, and hence this leads to faster reaction kinetics in the HER. This work suggests the advantages of Ag3PO4/1 wt % MoS2 heterogeneous composite catalyst for electrochemical analysis and HER indicating lower resistivity and low Tafel slope value (179 mV/dec) among the prepared catalysts making it a promising candidate for its use in practical energy applications.


Asunto(s)
Molibdeno , Nanoestructuras , Humanos , Hidrógeno , Cinética , Física
10.
Nat Commun ; 15(1): 5194, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890271

RESUMEN

Resistance to clinical malaria takes years to develop even in hyperendemic regions and sterilizing immunity has rarely been observed. To evaluate the maturation of the host response against controlled repeat exposures to P. falciparum (Pf) NF54 strain-infected mosquitoes, we systematically monitored malaria-naïve participants through an initial exposure to uninfected mosquitoes and 4 subsequent homologous exposures to Pf-infected mosquitoes over 21 months (n = 8 males) (ClinicalTrials.gov# NCT03014258). The primary outcome was to determine whether protective immunity against parasite infection develops following repeat CHMI and the secondary outcomes were to track the clinical signs and symptoms of malaria and anti-Pf antibody development following repeat CHMI. After two exposures, time to blood stage patency increases significantly and the number of reported symptoms decreases indicating the development of clinical tolerance. The time to patency correlates positively with both anti-Pf circumsporozoite protein (CSP) IgG and CD8 + CD69+ effector memory T cell levels consistent with partial pre-erythrocytic immunity. IFNγ levels decrease significantly during the participants' second exposure to high blood stage parasitemia and could contribute to the decrease in symptoms. In contrast, CD4-CD8 + T cells expressing CXCR5 and the inhibitory receptor, PD-1, increase significantly after subsequent Pf exposures, possibly dampening the memory response and interfering with the generation of robust sterilizing immunity.


Asunto(s)
Malaria Falciparum , Plasmodium falciparum , Proteínas Protozoarias , Humanos , Malaria Falciparum/inmunología , Malaria Falciparum/parasitología , Malaria Falciparum/sangre , Plasmodium falciparum/inmunología , Masculino , Proteínas Protozoarias/inmunología , Animales , Adulto , Anticuerpos Antiprotozoarios/inmunología , Anticuerpos Antiprotozoarios/sangre , Interferón gamma/metabolismo , Interferón gamma/inmunología , Femenino , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Adulto Joven , Linfocitos T CD8-positivos/inmunología , Mosquitos Vectores/parasitología , Mosquitos Vectores/inmunología , Anopheles/parasitología
11.
J Thorac Oncol ; 19(1): 94-105, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37595684

RESUMEN

INTRODUCTION: With global adoption of computed tomography (CT) lung cancer screening, there is increasing interest to use artificial intelligence (AI) deep learning methods to improve the clinical management process. To enable AI research using an open-source, cloud-based, globally distributed, screening CT imaging data set and computational environment that are compliant with the most stringent international privacy regulations that also protect the intellectual properties of researchers, the International Association for the Study of Lung Cancer sponsored development of the Early Lung Imaging Confederation (ELIC) resource in 2018. The objective of this report is to describe the updated capabilities of ELIC and illustrate how this resource can be used for clinically relevant AI research. METHODS: In this second phase of the initiative, metadata and screening CT scans from two time points were collected from 100 screening participants in seven countries. An automated deep learning AI lung segmentation algorithm, automated quantitative emphysema metrics, and a quantitative lung nodule volume measurement algorithm were run on these scans. RESULTS: A total of 1394 CTs were collected from 697 participants. The LAV950 quantitative emphysema metric was found to be potentially useful in distinguishing lung cancer from benign cases using a combined slice thickness more than or equal to 2.5 mm. Lung nodule volume change measurements had better sensitivity and specificity for classifying malignant from benign lung nodules when applied to solid lung nodules from high-quality CT scans. CONCLUSIONS: These initial experiments revealed that ELIC can support deep learning AI and quantitative imaging analyses on diverse and globally distributed cloud-based data sets.


Asunto(s)
Aprendizaje Profundo , Enfisema , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patología , Inteligencia Artificial , Detección Precoz del Cáncer , Pulmón/patología , Enfisema/patología
12.
PLoS Pathog ; 7(10): e1002330, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22028661

RESUMEN

Endoplasmic reticulum (ER) stress is a condition in which the protein folding capacity of the ER becomes overwhelmed by an increased demand for secretion or by exposure to compounds that disrupt ER homeostasis. In yeast and other fungi, the accumulation of unfolded proteins is detected by the ER-transmembrane sensor IreA/Ire1, which responds by cleaving an intron from the downstream cytoplasmic mRNA HacA/Hac1, allowing for the translation of a transcription factor that coordinates a series of adaptive responses that are collectively known as the unfolded protein response (UPR). Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus. Gene expression profiling revealed that A. fumigatus IreA signals predominantly through the canonical IreA-HacA pathway under conditions of severe ER stress. However, in the absence of ER stress IreA controls dual signaling circuits that are both HacA-dependent and HacA-independent. We found that a ΔireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a ΔhacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. In support of this conclusion, we found that the ΔireA mutant had more severe defects in the expression of multiple virulence-related traits relative to ΔhacA, including reduced thermotolerance, decreased nutritional versatility, impaired growth under hypoxia, altered cell wall and membrane composition, and increased susceptibility to azole antifungals. In addition, full or partial virulence could be restored to the ΔireA mutant by complementation with either the induced form of the hacA mRNA, hacA(i), or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireA(Δ10). Together, these findings demonstrate that IreA has both HacA-dependent and HacA-independent functions that contribute to the expression of traits that are essential for virulence in A. fumigatus.


Asunto(s)
Aspergillus fumigatus/patogenicidad , Retículo Endoplásmico/metabolismo , Proteínas Reguladoras del Hierro/metabolismo , Proteínas Represoras/metabolismo , Respuesta de Proteína Desplegada/fisiología , Animales , Animales no Consanguíneos , Aspergillus fumigatus/genética , Aspergillus fumigatus/metabolismo , Modelos Animales de Enfermedad , Retículo Endoplásmico/genética , Femenino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Genes Fúngicos , Humanos , Proteínas Reguladoras del Hierro/genética , Pulmón/microbiología , Pulmón/patología , Glicoproteínas de Membrana , Ratones , Mutación , ARN Mensajero/metabolismo , Proteínas Represoras/genética , Virulencia/genética
13.
J Appl Clin Med Phys ; 14(1): 4066, 2013 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-23318394

RESUMEN

Quantitative validation of deformable image registration (DIR) algorithms is extremely difficult because of the complexity involved in constructing a deformable phantom that can duplicate various clinical scenarios. The purpose of this study is to describe a framework to test the accuracy of DIR based on computational modeling and evaluating using inverse consistency and other methods. Three clinically relevant organ deformations were created in prostate (distended rectum and rectal gas), head and neck (large neck flexion), and lung (inhale and exhale lung volumes with variable contrast enhancement) study sets. DIR was performed using both B-spline and diffeomorphic demons algorithms in the forward and inverse direction. A compositive accumulation of forward and inverse deformation vector fields was done to quantify the inverse consistency error (ICE). The anatomical correspondence of tumor and organs at risk was quantified by comparing the original RT structures with those obtained after DIR. Further, the physical characteristics of the deformation field, namely the Jacobian and harmonic energy, were computed to quantify the preservation of image topology and regularity of spatial transformation obtained in DIR. The ICE was comparable in prostate case but the B-spline algorithm had significantly better anatomical correspondence for rectum and prostate than diffeomorphic demons algorithm. The ICE was 6.5 mm for demons algorithm for head and neck case when compared to 0.7 mm for B-spline. Since the induced neck flexion was large, the average Dice similarity coefficient between both algorithms was only 0.87, 0.52, 0.81, and 0.67 for tumor, cord, parotids, and mandible, respectively. The B-spline algorithm accurately estimated deformations between images with variable contrast in our lung study, while diffeomorphic demons algorithm led to gross errors on structures affected by contrast variation. The proposed framework offers the application of known deformations on any image datasets, to evaluate the overall accuracy and limitations of a DIR algorithm used in radiation oncology. The evaluation based on anatomical correspondence, physical characteristics of deformation field, and image characteristics can facilitate DIR verification with the ultimate goal of implementing adaptive radiotherapy. The suitability of application of a particular evaluation metric in validating DIR is dependent on the clinical deformation observed.


Asunto(s)
Neoplasias/diagnóstico por imagen , Neoplasias/radioterapia , Reconocimiento de Normas Patrones Automatizadas/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radioterapia Guiada por Imagen/métodos , Técnica de Sustracción , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Humanos , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
14.
Biomolecules ; 13(5)2023 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-37238689

RESUMEN

D-serine is an important signalling molecule, which activates N-methyl D-aspartate receptors (NMDARs) in conjunction with its fellow co-agonist, the neurotransmitter glutamate. Despite its involvement in plasticity and memory related to excitatory synapses, its cellular source and sink remain a question. We hypothesise that astrocytes, a type of glial cell that surrounds synapses, are likely candidates to control the extracellular concentration of D-Serine by removing it from the synaptic space. Using in situ patch clamp recordings and pharmacological manipulation of astrocytes in the CA1 region of the mouse hippocampal brain slices, we investigated the transport of D-serine across the plasma membrane. We observed the D-serine-induced transport-associated currents upon puff-application of 10 mM D-serine on astrocytes. Further, O-benzyl-L-serine and trans-4-hydroxy-proline, known substrate inhibitors of the alanine serine cysteine transporters (ASCT), reduced D-serine uptake. These results indicate that ASCT is a central mediator of astrocytic D-serine transport and plays a role in regulating its synaptic concentration by sequestration into astrocytes. Similar results were observed in astrocytes of the somatosensory cortex and Bergmann glia in the cerebellum, indicative of a general mechanism expressed across a range of brain areas. This removal of synaptic D-serine and its subsequent metabolic degradation are expected to reduce its extracellular availability, influencing NMDAR activation and NMDAR-dependent synaptic plasticity.


Asunto(s)
Astrocitos , Potenciación a Largo Plazo , Ratones , Animales , Potenciación a Largo Plazo/fisiología , Astrocitos/metabolismo , Sinapsis/metabolismo , Hipocampo/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Serina/metabolismo , Encéfalo/metabolismo
15.
Quant Imaging Med Surg ; 13(9): 6193-6204, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37711774

RESUMEN

Background: A calibration phantom-based method has been developed for predicting small lung nodule volume measurement bias and precision that is specific to a particular computed tomography (CT) scanner and acquisition protocol. Methods: The approach involves CT scanning a simple reference object with a specific acquisition protocol, analyzing the scan to estimate the fundamental imaging properties of the CT acquisition system, generating numerous simulated images of a target geometry using the fundamental imaging properties, measuring the simulated images with a standard nodule volume segmentation algorithm, and calculating bias and precision performance statistics from the resulting volume measurements. We evaluated the ability of this approach to predict volume measurement bias and precision of Teflon spheres (diameters =4.76, 6.36, and 7.94 mm) placed within an anthropomorphic chest phantom when using 3M Scotch Magic™ tape as the reference object. CT scanning of the spheres was performed with 0.625, 1.25, and 2.5 mm slice thickness and spacing. Results: The study demonstrated good agreement between predicted volumetric performance and observed volume measurement performance for both volumetric measurement bias and precision. The predicted and observed volume mean for all slice thicknesses was found to be 28% and 13% lower on average than the manufactured sphere volume, respectively. When restricted to 0.625 and 1.25 mm slice thickness scans, which are recommended for small lung nodule volume measurement, we found that the difference between predicted and observed volume coefficient of variation was less than 1.0 %. The approach also showed a resilience to varying CT image acquisition protocols, a critical capability when deploying in a real-world clinical setting. Conclusions: This is the first report of a calibration phantom-based method's ability to predict both small lung nodule volume measurement bias and precision. Volume measurement bias and precision for small lung nodules can be predicted using simple low-cost reference objects to estimate fundamental CT image characteristics and modeling and simulation techniques. The approach demonstrates an improved method for predicting task specific, clinically relevant measurement performance using advanced and fully automated image analysis techniques and low-cost reference objects.

16.
Mol Microbiol ; 79(4): 1045-62, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21210869

RESUMEN

The genome of Aspergillus fumigatus encodes two isoforms of the catalytic subunit of the cAMP-dependent Protein Kinase (PKA). Although deletion of the class I isoform, pkaC1, leads to an attenuation of virulence, the function of the class II subunit, PkaC2, was previously uninvestigated. In this report, we demonstrate that both isoforms act in concert to support various physiologic processes that promote the virulence of this pathogen. Whereas pkaC1 and pkaC2 single-deletion mutants display wild-type conidial germination, a double-deletion mutant is delayed in germination in response to environmental nutrients. Furthermore, PkaC1 and PkaC2 interact to positively regulate flux through the carbohydrate catabolic pathway and, consequently, the ΔpkaC1ΔpkaC2 mutant is unable to grow on low glucose concentrations. Importantly, the reduced germinative capacity and inability to utilize glucose observed for the ΔpkaC1ΔpkaC2 strain correlated with an inability of the mutant to establish infection in a murine model. Conversely, overexpression of pkaC2 both promotes the in vitro growth on glucose, and restores the fungal burden and mortality associated with the ΔpkaC1 to that of the wild-type organism. Taken together, these data demonstrate the functional capacity of pkaC2 and emphasize the importance of PKA-mediated metabolic control in the pathogenic potential of A. fumigatus.


Asunto(s)
Aspergillus fumigatus/genética , Metabolismo de los Hidratos de Carbono , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas Fúngicas/metabolismo , Esporas Fúngicas/crecimiento & desarrollo , Secuencia de Aminoácidos , Animales , Aspergillus fumigatus/enzimología , Aspergillus fumigatus/crecimiento & desarrollo , Aspergillus fumigatus/patogenicidad , Proteínas Quinasas Dependientes de AMP Cíclico/genética , Femenino , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Genoma Fúngico , Glucosa/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Ratones , Mitocondrias/metabolismo , Datos de Secuencia Molecular , ARN de Hongos/genética , Eliminación de Secuencia , Esporas Fúngicas/genética , Virulencia
17.
J Am Soc Nephrol ; 22(12): 2187-92, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22021713

RESUMEN

T cells and endothelin (ET-1) both contribute to angiotensin II (AngII)-dependent hypertension. To determine whether ET-1, via the ET(A) receptor, facilitates T cell infiltration in the kidney during AngII-dependent hypertension, we measured T cell infiltration in response to four different treatments: saline, AngII infusion, AngII infusion with an ET(A) receptor antagonist, or AngII infusion with triple-antihypertensive therapy. After 14 days, AngII increased both BP and the numbers of CD3(+) and proliferating cells in the kidney. Mice treated concomitantly with the ET(A) receptor antagonist had lower BP and fewer CD3(+) and proliferating cells in the renal cortex. Mice treated with triple therapy had similar reductions in BP but no change in renal cortical CD3(+) cells compared with kidneys from AngII-infused hypertensive mice. In the outer medulla, both the ET(A) receptor antagonist and triple therapy reduced the number of CD3(+) cells and macrophages. Taken together, these data suggest that ET(A) receptor activation in AngII-mediated hypertension increases CD3(+) cells and proliferation in the renal cortex independent of changes in BP, but changes in the number of inflammatory cells in the renal medulla are BP dependent.


Asunto(s)
Angiotensina II/farmacología , Riñón/citología , Receptor de Endotelina A/fisiología , Linfocitos T/efectos de los fármacos , Linfocitos T/fisiología , Animales , Hipertensión/etiología , Masculino , Ratones , Ratones Endogámicos C57BL
18.
HSS J ; 18(1): 78-82, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35087336

RESUMEN

Background: Assessing the extent and specific location of brachial plexus injuries can be difficult given the variety of mechanisms of injury and anatomic complexity of the plexus. We developed a program to accurately assess the location of a patient's neurologic injury based on electromyographic data. Purpose: We sought to test our hypothesis that the location of traumatic brachial plexopathies could be accurately assessed with a novel program that processed electromyogram (EMG) and mechanism of injury data. Methods: This retrospective diagnostic cohort study was carried out with a novel diagnostic algorithm developed with the Python programming language. The program accepts user input of muscles demonstrating decreased motor unit recruitment, positive sharp waves, or fibrillation potentials. The testing data set was derived from a registry of brachial plexus injuries treated at our center. The primary outcome was the percent concordance of the algorithm's diagnosis with the surgical diagnosis. Results: Ninety-five cases met the inclusion criteria. Median time from injury onset to EMG examination was 4 months; median time from EMG examination to surgery was 1.2 months. The program diagnosis matched the surgical diagnosis in 92 out of 95 (97%) of cases, including cases with multilevel injuries and additional peripheral nerve injuries. Conclusion: This program accurately localized brachial plexopathies in nearly all cases, including those involving polytrauma or complex patterns of injury. This algorithm may be valuable as an aid to complete electrodiagnostic examinations, a diagnostic adjunct when planning treatment of severe plexus palsies, or an educational tool.

19.
Med Mycol ; 49 Suppl 1: S101-6, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20608779

RESUMEN

The ability of Aspergillus fumigatus to establish and maintain an infection requires a continuous supply of nutrients to fuel energy production and growth. Like other filamentous fungi, A. fumigatus acquires nutrients by absorption, a mode of nutrition that depends upon the secretion of extracellular hydrolases to degrade the complex organic polymers in host tissues into reduced forms of carbon and nitrogen. If the folding capacity of the endoplasmic reticulum (ER) is exceeded during periods of high secretory activity, a signaling pathway known as the unfolded protein response (UPR) is activated to relieve the stress on the ER. Current evidence indicates that A. fumigatus relies upon this pathway to sustain the high rate of protease secretion needed to grow optimally in mammalian tissue. In addition, the UPR strengthens the ability of the secretory system to deliver cell wall and membrane components to the hyphal apex, which promotes the invasive growth of the expanding hyphae and protects the fungus from damage caused by antifungal drugs. The important contribution of UPR-dependent functions to the pathogenesis of invasive aspergillosis and antifungal susceptibility suggests that components of this pathway could be promising new targets for antifungal therapy.


Asunto(s)
Antifúngicos/farmacología , Aspergilosis/microbiología , Aspergillus fumigatus/fisiología , Retículo Endoplásmico/fisiología , Respuesta de Proteína Desplegada/fisiología , Animales , Antifúngicos/uso terapéutico , Aspergilosis/tratamiento farmacológico , Aspergillus fumigatus/efectos de los fármacos , Aspergillus fumigatus/patogenicidad , Pared Celular/fisiología , Farmacorresistencia Fúngica , Retículo Endoplásmico/metabolismo , Hifa/fisiología , Pliegue de Proteína , Transducción de Señal/fisiología , Virulencia/fisiología
20.
Recent Pat Biotechnol ; 15(4): 266-285, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34602042

RESUMEN

BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS), also known as progeria of childhood or progeria is a rare, rapid, autosomal dominant genetic disorder characterized by premature aging which occurs shortly after birth. HGPS occurs as a result of de novo point mutation in the gene recognized as LMNA gene that encodes two proteins, Lamin A protein and Lamin C protein which are the structural components of the nuclear envelope. Mutations in the gene trigger abnormal splicing and induce internal deletion of 50 amino acids leading to the development of a truncated form of Lamin A protein known as Progerin. Progerin generation can be considered the crucial step in HGPS since the protein is highly toxic to human cells, permanently farnesylated, and exhibits variation in several biochemical and structural properties within the individual. HGPS also produces complications such as skin alterations, growth failure, atherosclerosis, hair and fat loss, and bone and joint diseases. We have also revised all relevant patents relating to Hutchinson-Gilford progeria syndrome and its therapy in the current article. METHODS: The goal of the present review article is to provide information about Hutchinson- Gilford progeria syndrome (HGPS) and the use of CRISPR/Cas technology as a promising treatment approach in the treatment of the disease. The review also discusses about different pharmacological and non-pharmacological methods of treatment currently used for HGPS. RESULTS: The main limitation associated with progeria is the lack of a definitive cure. The existing treatment modality provides only symptomatic relief. Therefore, it is high time to develop a therapeutic method that hastens premature aging in such patients. CONCLUSION: CRISPR/Cas technology is a novel gene-editing tool that allows genome editing at specific loci and is found to be a promising therapeutic approach for the treatment of genetic disorders such as HGPS where dominant-negative mutations take place.


Asunto(s)
Progeria , Sistemas CRISPR-Cas , Terapia Genética , Humanos , Patentes como Asunto , Progeria/genética , Tecnología
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