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1.
Cancer Discov ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38959428

RESUMO

Immunotherapies have shown great promise in pleural mesothelioma (PM), yet most patients still do not achieve significant clinical response, highlighting the importance of improving understanding of the tumor microenvironment (TME). Here, we utilized high-throughput, single-cell RNA-sequencing to de novo identify 54 expression programs and construct a comprehensive cellular catalogue of the PM TME. We found four cancer-intrinsic programs associated with poor disease outcome and a novel fetal-like, endothelial cell population that likely responds to VEGF signaling and promotes angiogenesis. Throughout cellular compartments, we observe substantial difference in the TME associated with a cancer-intrinsic sarcomatoid signature, including enrichment in fetal-like endothelial cells, CXCL9+ macrophages, cytotoxic, exhausted, and regulatory T cells, which we validated using imaging and bulk deconvolution analyses on independent cohorts. Finally, we show, both computationally and experimentally, that NKG2A-HLA-E interaction between NK and tumor cells represents an important new therapeutic axis in PM, especially for epithelioid cases.

3.
Clin Radiol ; 79(1): 1-9, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37867078

RESUMO

Since the first few cases of pneumonia attributed to infection with the highly contagious novel coronavirus 2 (SARs-CoV-2) were detected in Wuhan, China, in December 2019, imaging has proven an invaluable diagnostic tool throughout the resulting global pandemic. This review describes the imaging features of severe pulmonary disease caused by SARs-CoV-2, named COVID-19 by the World Health Organization (WHO), particularly focussing on computed tomography (CT). CT plays an important role in understanding the pathology behind the progression of disease, as well as helping to identify the potential complications of COVID-19 pneumonia and recognising possible alternative or concurrent diagnoses. This review also focusses on follow-up imaging of survivors of COVID-19, which continues to contribute substantially to our understanding of the longer-term pulmonary changes in patients who have survived severe COVID-19 pneumonia.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico por imagem , SARS-CoV-2 , Seguimentos , Pulmão/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , China
5.
Appl Radiat Isot ; 198: 110841, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37224692

RESUMO

While modern nuclear decay data can provide many details of a given nuclides ß-decay modes (branching ratios, decay heating etc.), knowledge of the emitted ß-energy spectrum is often not included. This limitation hampers the use of decay data in some analysis, such as ß-spectrometry of irradiated material, prediction of ß-decay Bremsstrahlung or antineutrino, ν̄, detection. To address this deficiency, and for increased ease of ß-spectrometry studies of complex samples, a library of ß, ν and Bremsstrahlung-spectra, called BNBSL (Beta-Neutrino-Bremsstrahlung spectra library), has been produced. It has been found that the content compares favourably with experimental data and methodologies for its application to complex nuclear inventories have been developed. BNBSL contains spectra for over 1500 nuclides, which is hoped will benefit applied nuclear, radiation and materials science studies.


Assuntos
Radioatividade , Análise Espectral
6.
J Clin Oncol ; 41(21): 3712-3723, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37192435

RESUMO

PURPOSE: Compared with people living without HIV (PWOH), people living with HIV (PWH) and cancer have traditionally been excluded from immune checkpoint inhibitor (ICI) trials. Furthermore, there is a paucity of real-world data on the use of ICIs in PWH and cancer. METHODS: This retrospective study included PWH treated with anti-PD-1- or anti-PD-L1-based therapies for advanced cancers. Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Objective response rates (ORRs) were measured per RECIST 1.1 or other tumor-specific criteria, whenever feasible. Restricted mean survival time (RMST) was used to compare OS and PFS between matched PWH and PWOH with metastatic NSCLC (mNSCLC). RESULTS: Among 390 PWH, median age was 58 years, 85% (n = 331) were males, 36% (n = 138) were Black; 70% (n = 274) received anti-PD-1/anti-PD-L1 monotherapy. Most common cancers were NSCLC (28%, n = 111), hepatocellular carcinoma ([HCC]; 11%, n = 44), and head and neck squamous cell carcinoma (HNSCC; 10%, n = 39). Seventy percent (152/216) had CD4+ T cell counts ≥200 cells/µL, and 94% (179/190) had HIV viral load <400 copies/mL. Twenty percent (79/390) had any grade immune-related adverse events (irAEs) and 7.7% (30/390) had grade ≥3 irAEs. ORRs were 69% (nonmelanoma skin cancer), 31% (NSCLC), 16% (HCC), and 11% (HNSCC). In the matched mNSCLC cohort (61 PWH v 110 PWOH), 20% (12/61) PWH and 22% (24/110) PWOH had irAEs. Adjusted 42-month RMST difference was -0.06 months (95% CI, -5.49 to 5.37; P = .98) for PFS and 2.23 months (95% CI, -4.02 to 8.48; P = .48) for OS. CONCLUSION: Among PWH, ICIs demonstrated differential activity across cancer types with no excess toxicity. Safety and activity of ICIs were similar between matched cohorts of PWH and PWOH with mNSCLC.


Assuntos
Carcinoma Hepatocelular , Carcinoma Pulmonar de Células não Pequenas , Infecções por HIV , Neoplasias de Cabeça e Pescoço , Neoplasias Hepáticas , Neoplasias Pulmonares , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Inibidores de Checkpoint Imunológico/efeitos adversos , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Infecções por HIV/tratamento farmacológico
7.
Transl Vis Sci Technol ; 12(3): 8, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36917118

RESUMO

Purpose: A reference atlas of optic nerve (ON) retinal ganglion cell (RGC) axons could facilitate studies of neuro-ophthalmic diseases by detecting subtle RGC axonal changes. Here we construct an RGC axonal atlas for normotensive eyes in Brown Norway rats, widely used in glaucoma research, and also develop/evaluate several novel metrics of axonal damage in hypertensive eyes. Methods: Light micrographs of entire ON cross-sections from hypertensive and normotensive eyes were processed through a deep learning-based algorithm, AxoNet2.0, to determine axonal morphological properties and were semiquantitatively scored using the Morrison grading scale (MGS) to provide a damage score independent of AxoNet2.0 outcomes. To construct atlases, ONs were conformally mapped onto an ON "template," and axonal morphometric data was computed for each region. We also developed damage metrics based on myelin morphometry. Results: In normotensive eyes, average axon density was ∼0.3 axons/µm2 (i.e., ∼80,000 axons in an ON). We measured axoplasm diameter, eccentricity, cross-sectional area, and myelin g-ratio and thickness. Most morphological parameters exhibited a wide range of coefficients of variation (CoV); however, myelin thickness CoV was only ∼2% in normotensive eyes. In hypertensive eyes, increased myelin thickness correlated strongly with MGS (P < 0.0001). Conclusions: We present the first comprehensive normative RGC axon morphometric atlas for Brown Norway rat eyes. We suggest objective, repeatable damage metrics based on RGC axon myelin thickness for hypertensive eyes. Translational Relevance: These tools can evaluate regional changes in RGCs and overall levels of damage in glaucoma studies using Brown Norway rats.


Assuntos
Glaucoma , Doenças do Nervo Óptico , Ratos , Animais , Células Ganglionares da Retina , Nervo Óptico , Axônios , Doenças do Nervo Óptico/diagnóstico , Ratos Endogâmicos BN
8.
Transl Vis Sci Technol ; 12(3): 9, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36917117

RESUMO

Purpose: Assessment of glaucomatous damage in animal models is facilitated by rapid and accurate quantification of retinal ganglion cell (RGC) axonal loss and morphologic change. However, manual assessment is extremely time- and labor-intensive. Here, we developed AxoNet 2.0, an automated deep learning (DL) tool that (i) counts normal-appearing RGC axons and (ii) quantifies their morphometry from light micrographs. Methods: A DL algorithm was trained to segment the axoplasm and myelin sheath of normal-appearing axons using manually-annotated rat optic nerve (ON) cross-sectional micrographs. Performance was quantified by various metrics (e.g., soft-Dice coefficient between predicted and ground-truth segmentations). We also quantified axon counts, axon density, and axon size distributions between hypertensive and control eyes and compared to literature reports. Results: AxoNet 2.0 performed very well when compared to manual annotations of rat ON (R2 = 0.92 for automated vs. manual counts, soft-Dice coefficient = 0.81 ± 0.02, mean absolute percentage error in axonal morphometric outcomes < 15%). AxoNet 2.0 also showed promise for generalization, performing well on other animal models (R2 = 0.97 between automated versus manual counts for mice and 0.98 for non-human primates). As expected, the algorithm detected decreased in axon density in hypertensive rat eyes (P ≪ 0.001) with preferential loss of large axons (P < 0.001). Conclusions: AxoNet 2.0 provides a fast and nonsubjective tool to quantify both RGC axon counts and morphological features, thus assisting with assessing axonal damage in animal models of glaucomatous optic neuropathy. Translational Relevance: This deep learning approach will increase rigor of basic science studies designed to investigate RGC axon protection and regeneration.


Assuntos
Aprendizado Profundo , Glaucoma , Ratos , Camundongos , Animais , Células Ganglionares da Retina/fisiologia , Estudos Transversais , Modelos Animais de Doenças , Axônios/fisiologia , Glaucoma/diagnóstico
9.
WMJ ; 122(1): 44-47, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36940121

RESUMO

BACKGROUND: We wanted to assess whether a regional approach to bed management and staffing could improve financial sustainability without reducing services in rural communities. METHODS: Regional approaches to patient placement, hospital throughput, and staffing were coupled with enhanced services at 1 hub hospital and 4 critical access hospitals. RESULTS: We improved the use of patient beds in the 4 critical access hospitals, increased hub hospital capacity, and improved the health system's financial performance while maintaining or enhancing services at the critical access hospitals. DISCUSSION: Sustainability of critical access hospitals can be attained without a decrease in services for rural patients and communities. One way to achieve this result is to invest in and enhance care at the rural site.


Assuntos
Acessibilidade aos Serviços de Saúde , Hospitais Rurais , Humanos
10.
BMJ Mil Health ; 169(1): 23-26, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33461982

RESUMO

INTRODUCTION: Thirty four per cent of women use hormonal contraceptives in the UK and the contraceptive pill is the most common method. There are no comparable data in the UK Armed Forces, but servicewomen are often required to complete physically arduous job roles in combat zones and may be more likely to take contraceptives to control or stop menstrual bleeding than the general population. We explored the prevalence of hormonal contraceptive prescriptions in the UK Armed Forces. METHODS: The study used defence medical records (Defence Medical Information Capability Programme) to identify hormonal contraceptive prescriptions for all serving regular UK servicewomen (n=15 738) as of 1 September 2017. RESULTS: Thirty one per cent of servicewomen (Royal Navy, 28%; British Army, 30%; Royal Air Force, 34%) had a current prescription for a hormonal contraceptive. Non-officer ranks were more likely to have a prescription for a hormonal contraceptive (32%) than officers (27%) (p<0.01). The contraceptive pill was more commonly prescribed (68%) than long-acting reversible contraceptive methods (32%) (contraceptive injection, 11%; contraceptive implant, 11%; intrauterine device, 10%). CONCLUSION: Prescription data suggest that the prevalence of hormonal contraceptive use in UK servicewomen is comparable with the general UK population. These findings suggest that military service does not influence prevalence or choice of hormonal contraceptives.


Assuntos
Anticoncepcionais , Militares , Humanos , Feminino , Anticoncepção/métodos , Prescrições , Reino Unido
11.
Clin Toxicol (Phila) ; 60(10): 1094-1098, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35943421

RESUMO

OBJECTIVE: Synthetic cannabinoid receptor agonists (SCRA) are commonly encountered new psychoactive substances. Here we report the recent detection of ADB-BUTINACA in samples from patients attending United Kingdom emergency departments with toxicity after suspected drug misuse and describe the associated clinical features. METHODS: Consenting adults (≥16 y) presenting to participating hospitals with toxicity after suspected drug misuse have been included in the Identification Of Novel psychoActive substances (IONA) study since March 2015. Demographic and clinical features are recorded and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry. RESULTS: By December 2021, analytical data were available for 1279 IONA participants and ADB-BUTINACA was detected in at least one sample from 10 (9 males, age range 16-51 median 45 years), all presenting since February 2021. Smoking 'spice' was reported by four patients, two had ingested edible "cannabis" gums and four reported heroin use (2 intravenous, 1 smoked, 1 route not known). Co-use of pregabalin (oral) and crack cocaine (smoked) were also reported. In 3 cases ADB-BUTINACA was the only substance detected, while in seven other substances of misuse were also detected including other SCRA, opioids, benzodiazepines cocaine and pregabalin. Clinical features reported in these 2 groups respectively included reduced level of consciousness (3/3, 6/7), agitation (0/3, 4/7), tachycardia (0/3, 3/7), seizures (1/3, 1/7), hallucinations (1/3, 1/7), hypotension (1/3, 1/7). Metabolic acidosis (1/3, 0/7) and respiratory acidosis (1/3, 0/7), All 10 patients recovered with supportive care, including intubation and ventilation for one case. The median length of hospital stay was 19 h (range 2.6-131 h). CONCLUSIONS: ADB-BUTINACA has recently emerged as a drug of misuse in England. Clinical features of toxicity are consistent with those of other SCRA and include reduced level of consciousness, respiratory and/or metabolic acidosis, seizures, confusion and hallucinations.


Assuntos
Agonistas de Receptores de Canabinoides , Cocaína Crack , Adulto , Masculino , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Heroína , Pregabalina , Serviço Hospitalar de Emergência , Inglaterra/epidemiologia , Alucinações , Benzodiazepinas , Convulsões
12.
Vision (Basel) ; 6(3)2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35893761

RESUMO

We tested if the misapplication of perceptual constancy mechanisms might explain the perceived misalignment of the oblique lines in the Poggendorff illusion. Specifically, whether these mechanisms might treat the rectangle in the middle portion of the Poggendorff stimulus as an occluder in front of one long line appearing on either side, causing an apparent decrease in the rectangle's width and an apparent increase in the misalignment of the oblique lines. The study aimed to examine these possibilities by examining the effects of adding pictorial depth cues. In experiments 1 and 2, we presented a central rectangle composed of either large or small bricks to determine if this manipulation would change the perceived alignment of the oblique lines and the perceived width of the central rectangle, respectively. The experiments demonstrated no changes that would support a misapplication of perceptual constancy in driving the illusion, despite some evidence of perceptual size rescaling of the central rectangle. In experiment 3, we presented Poggendorff stimuli in front and at the back of a corridor background rich in texture and linear perspective depth cues to determine if adding these cues would affect the Poggendorff illusion. The central rectangle was physically large and small when presented in front and at the back of the corridor, respectively. The strength of the Poggendorff illusion varied as a function of the physical size of the central rectangle, and, contrary to our predictions, the addition of pictorial depth cues in both the central rectangle and the background decreased rather than increased the strength of the illusion. The implications of these results with regards to different theories are discussed. It could be the case that the illusion depends on both low-level and cognitive mechanisms and that deleterious effects occur on the former when the latter ascribes more certainty to the oblique lines being the same line receding into the distance.

13.
Transl Vis Sci Technol ; 11(5): 7, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35536721

RESUMO

Purpose: Scleral stiffening may protect against glaucomatous retinal ganglion cell (RGC) loss or dysfunction associated with ocular hypertension. Here, we assess the potential neuroprotective effects of two treatments designed to stiffen either the entire posterior sclera or only the sclera adjacent to the peripapillary sclera in an experimental model of glaucoma. Methods: Rat sclerae were stiffened in vivo using either genipin (crosslinking the entire posterior sclera) or a regionally selective photosensitizer, methylene blue (stiffening only the juxtaperipapillary region surrounding the optic nerve). Ocular hypertension was induced using magnetic microbeads delivered to the anterior chamber. Morphological and functional outcomes, including optic nerve axon count and appearance, retinal thickness measured by optical coherence tomography, optomotor response, and electroretinography traces, were assessed. Results: Both local (juxtaperipapillary) and global (whole posterior) scleral stiffening treatments were successful at increasing scleral stiffness, but neither provided demonstrable neuroprotection in hypertensive eyes as assessed by RGC axon counts and appearance, optomotor response, or electroretinography. There was a weak indication that scleral crosslinking protected against retinal thinning as assessed by optical coherence tomography. Conclusions: Scleral stiffening was not demonstrated to be neuroprotective in ocular hypertensive rats. We hypothesize that the absence of benefit may in part be due to RGC loss associated with the scleral stiffening agents themselves (mild in the case of genipin, and moderate in the case of methylene blue), negating any potential benefit of scleral stiffening. Translational Relevance: The development of scleral stiffening as a neuroprotective treatment will require the identification of better tolerated stiffening protocols and further preclinical testing.


Assuntos
Glaucoma , Esclera , Animais , Pressão Intraocular , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Neuroproteção , Ratos
14.
JTO Clin Res Rep ; 3(1): 100260, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35005653

RESUMO

Osimertinib is the standard of care for the first-line treatment of EGFR-mutated NSCLC. We report a case of a 52-year-old woman who developed life-threatening myopathy because of treatment with osimertinib. Limited instances of myositis have been previously reported in the literature; however, none have resulted in life-threatening oropharyngeal and respiratory muscle weakness as seen in this case. Care should be taken in administering osimertinib concurrently with other medications metabolized by the CYP3A4 system, and ongoing work to identify patients at risk for severe reactions is necessary. The use of routine creatinine phosphokinase monitoring should be considered as part of oncologic management.

16.
Reprod Fertil Dev ; 33(4): 279-290, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33573715

RESUMO

The myometrium goes through physiological, cellular and molecular alterations during gestation that necessitate effective cellular proteostasis. Inducible heat shock protein A1A (HSPA1A) is a member of the 70-kDa heat shock protein A (HSPA) family, which acts as a chaperone to regulate proteostasis; however, HSPA1A also participates as a cytokine in inflammatory regulation, leading to its designation as a chaperokine. This study examined the spatiotemporal expression of HSPA1A protein in the rat myometrium throughout gestation and assessed whether it is secreted as cargo of myometrial cell-derived extracellular vesicles (EVs). Immunoblot analysis demonstrated that HSPA1A expression was markedly elevated during late pregnancy and labour and increased by uterine distension. Myometrial HSPA1A expression insitu increased in myocytes of longitudinal and circular muscle layers from Day 19 through to postpartum, specifically in the cytoplasm and nuclei of myocytes from both muscle layers, but frequently detectable just outside myocyte membranes. Scanning electron microscopy examination of samples isolated from hTERT-HM cell-conditioned culture medium, using EV isolation spin columns, confirmed the presence of EVs. EV lysates contained HSPA8, HSPA1A and the EV markers apoptosis-linked gene 2-interacting protein X (Alix), the tetraspanin cluster of differentiation 63 (CD63), tumour susceptibility gene 101 (TSG101) and HSP90, but not the endoplasmic reticulum protein calnexin. These results indicate that HSPA1A may act as a chaperokine in the myometrium during pregnancy.


Assuntos
Vesículas Extracelulares/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Miócitos de Músculo Liso/metabolismo , Miométrio/metabolismo , Contração Uterina , Animais , Linhagem Celular , Vesículas Extracelulares/ultraestrutura , Feminino , Idade Gestacional , Proteínas de Choque Térmico HSP70/genética , Humanos , Miócitos de Músculo Liso/ultraestrutura , Miométrio/ultraestrutura , Gravidez , Proteostase , Ratos Sprague-Dawley , Regulação para Cima
17.
Exp Eye Res ; 202: 108354, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33171192

RESUMO

Most animal models of glaucoma rely on induction of ocular hypertension (OHT), yet such models can suffer from high IOPs leading to undesirable retinal ischemia. Thus, animals with IOPs exceeding a threshold (e.g. > 60 mmHg) are often excluded from studies. However, due to the intermittent nature of IOP measurements, this approach may fail to detect ischemia. Conversely, it may also inappropriately eliminate animals with IOP spikes that do not induce ischemic damage. It is known that acute ischemia selectively impairs inner retinal function, which results in a reduced b-wave amplitude. Here, we explore the potential of using electroretinography (ERG) to detect ischemic damage in OHT eyes. 74 Brown Norway rats received a unilateral injection of magnetic microbeads to induce OHT, while contralateral eyes served as controls. IOP was measured every 2-3 days for 14 days after microbead injection. Retinal function was evaluated using dark-adapted bright flash ERG (2.1 log cd•s/m2) prior to, and at 7 and 14 days after, injection. We investigated two criteria for excluding animals: (IOP Criterion) a single IOP measurement > 60 mmHg; or (ERG Criterion) a b-wave amplitude below the 99.5% confidence interval for naïve eyes. 49 of 74 rats passed both criteria, 7 of 74 failed both, and 18 passed one criterion but not the other. We suggest that ERG testing can detect unwelcome ischemic damage in animal models of OHT. Since brief IOP spikes do not necessarily lead to ischemic retinal damage, and because extended periods of elevated IOP can be missed, such ERG-based criteria may provide more objective and robust exclusion criteria in future glaucoma studies.


Assuntos
Adaptação à Escuridão/fisiologia , Glaucoma/fisiopatologia , Pressão Intraocular/fisiologia , Isquemia/fisiopatologia , Células Ganglionares da Retina/patologia , Animais , Modelos Animais de Doenças , Eletrorretinografia , Glaucoma/complicações , Glaucoma/diagnóstico , Isquemia/diagnóstico , Isquemia/etiologia , Masculino , Ratos , Ratos Endogâmicos BN
18.
Sci Rep ; 10(1): 17695, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077765

RESUMO

Nucleophosmin is commonly both over-expressed and mutated in acute myeloid leukemia (AML). NPM1 mutations are always heterozygous. In addition, NPM1 has a number of different splice variants with the major variant encoded by exons 1-9 and 11-12 (NPM1.1). Further variants include NPM1.2 which lacks exons 8 and 10 and NPM1.3 which comprises exons 1-10 (and so lacks the region of sequence mutated in AML). In this study we quantified the expression of these three variants in 108 AML patient samples with and without NPM1 mutations and also assessed the level of expression from the wild-type and mutant alleles in variants NPM1.1 and NPM1.2. The results show that NPM1.1 is the most commonly expressed variant, however transcripts from wild-type and mutated alleles do not occur at equal levels, with a significant bias toward the mutated allele. Considering the involvement of mutant nucleophosmin in the progression and maintenance of AML, a bias towards mutated transcripts could have a significant impact on disease maintenance.


Assuntos
Alelos , Leucemia Mieloide Aguda/genética , Mutação , Proteínas Nucleares/genética , Transcrição Gênica , Humanos , Nucleofosmina
19.
Transl Vis Sci Technol ; 9(10): 8, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32974080

RESUMO

Purpose: Genipin has been proposed as a possible neuroprotective therapy in myopia and glaucoma. Here, we aim to determine the effects of prolonged genipin-induced scleral stiffening on visual function. Methods: Eyes from Brown Norway rats were treated in vivo with either a single 15 mM genipin retrobulbar injection or sham retrobulbar injection and were compared to naïve eyes. Intraocular pressure, optomotor response, and electroretinograms were repeatedly measured over 4 weeks following retrobulbar injections to determine visual and retinal function. At 4 weeks, we quantified retinal ganglion cell axon counts. Finally, molecular changes in gene and protein expression were analyzed via real-time polymerase chain reaction (RT-PCR) and proteomics. Results: Retrobulbar injection of genipin did not affect intraocular pressure (IOP) or retinal function, nor have a sustained impact on visual function. Although genipin-treated eyes had a small decrease in retinal ganglion cell axon counts compared to contralateral sham-treated eyes (-8,558 ± 18,646; mean ± SD), this was not statistically significant (P = 0.206, n = 9). Last, we did not observe any changes in gene or protein expression due to genipin treatment. Conclusions: Posterior scleral stiffening with a single retrobulbar injection of 15 mM genipin causes no sustained deficits in visual or retinal function or at the molecular level in the retina and sclera. Retinal ganglion cell axon morphology appeared normal. Translational Significance: These results support future in vivo studies to determine the efficacy of genipin-induced posterior scleral stiffening to help treat ocular diseases, like myopia and glaucoma.


Assuntos
Glaucoma , Esclera , Animais , Iridoides/farmacologia , Ratos , Retina
20.
Biomech Model Mechanobiol ; 19(6): 2195-2212, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32361821

RESUMO

It is widely accepted that biomechanics plays an important role in glaucoma pathophysiology, but the mechanisms involved are largely unknown. Rats are a common animal model of glaucoma, and finite element models are being developed to provide much-needed insight into the biomechanical environment of the posterior rat eye. However, material properties of rat ocular tissues, including the sclera, are currently unknown. Since the sclera plays a major role in posterior ocular biomechanics, our goal was to use inverse finite element modeling to extract rat scleral material properties. We first used digital image correlation to measure scleral surface displacement during whole-globe inflation testing. We modeled the sclera as a nonlinear material with embedded collagen fibers and then fit modeled displacements to experimental data using a differential evolution algorithm. Subject-specific models were constructed in which 3 parameters described the stiffness of the ground substance and collagen fibers in the posterior eye, and 16 parameters defined the primary orientation and alignment of fibers within eight scleral sub-regions. We successfully extracted scleral material properties for eight rat eyes. Model displacements recreated general patterns of the experimental displacements but did not always match local patterns. The fiber directions and fiber concentration parameters were highly variable, but on average, fibers were aligned circumferentially and were more aligned in the peripapillary sclera than in the peripheral sclera. The material properties determined here will be used to inform future finite element models of the rat posterior eye with the goal of elucidating the role of biomechanics in glaucoma pathophysiology.


Assuntos
Esclera/diagnóstico por imagem , Esclera/fisiopatologia , Tomografia de Coerência Óptica/métodos , Algoritmos , Animais , Anisotropia , Fenômenos Biomecânicos , Modelos Animais de Doenças , Módulo de Elasticidade , Matriz Extracelular , Análise de Elementos Finitos , Glaucoma/fisiopatologia , Processamento de Imagem Assistida por Computador , Pressão Intraocular , Masculino , Ratos
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