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Recent innovations in image guidance, treatment delivery, and adaptive radiotherapy (RT) have created a new paradigm for planning target volume (PTV) margin design for patients with prostate cancer. We performed a review of the recent literature on PTV margin selection and design for intact prostate RT, excluding post-operative RT, brachytherapy, and proton therapy. Our review describes the increased focus on prostate and seminal vesicles as heterogenous deforming structures with further emergence of intra-prostatic GTV boost and concurrent pelvic lymph node treatment. To capture recent innovations, we highlight the evolution in cone beam CT guidance, and increasing use of MRI for improved target delineation and image registration and supporting online adaptive RT. Moreover, we summarize new and evolving image-guidance treatment platforms as well as recent reports of novel immobilization strategies and motion tracking. Our report also captures recent implementations of artificial intelligence to support image guidance and adaptive RT. To characterize the clinical impact of PTV margin changes via model-based risk estimates and clinical trials, we highlight recent high impact reports. Our report focusses on topics in the context of PTV margins but also showcase studies attempting to move beyond the PTV margin recipes with robust optimization and probabilistic planning approaches. Although guidelines exist for target margins conventional using CT-based image guidance, further validation is required to understand the optimal margins for online adaptation either alone or combined with real-time motion compensation to minimize systematic and random uncertainties in the treatment of patients with prostate cancer.
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Braquiterapia , Neoplasias da Próstata , Masculino , Humanos , Inteligência Artificial , Tomografia Computadorizada de Feixe Cônico , LinfonodosRESUMO
A growing body of evidence has demonstrated a relationship between the microbiome, adiposity, and cancer development. The microbiome is emerging as an important factor in metabolic disease and cancer pathogenesis. This review aimed to highlight the role of the microbiome in obesity and its association with cancer, with a particular focus on breast cancer. This review discusses how microbiota dysbiosis may contribute to obesity and obesity-related diseases, which are linked to breast cancer. It also explores the potential of the gut microbiome to influence systemic immunity, leading to carcinogenesis via the modulation of immune function. This review underscores the potential use of the microbiome profile as a diagnostic tool and treatment target, with strategies including probiotics, fecal microbiota transplantation, and dietary interventions. However, this emphasizes the need for more research to fully understand the complex relationship between the microbiome, metabolic disorders, and breast cancer. Future studies should focus on elucidating the mechanisms underlying the impact of the microbiome on breast cancer and exploring the potential of the microbiota profile as a biomarker and treatment target.
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Sphingolipids have key functions in membrane structure and cellular signaling. Ceramide is the central molecule of the sphingolipid metabolism and is generated by ceramide synthases (CerS) in the de novo pathway. Despite their critical function, mechanisms regulating CerS remain largely unknown. Using an unbiased proteomics approach, we find that the small heat shock protein 27 (Hsp27) interacts specifically with CerS1 but not other CerS. Functionally, our data show that Hsp27 acts as an endogenous inhibitor of CerS1. Wild-type Hsp27, but not a mutant deficient in CerS1 binding, inhibits CerS1 activity. Additionally, silencing of Hsp27 enhances CerS1-generated ceramide accumulation in cells. Moreover, phosphorylation of Hsp27 modulates Hsp27-CerS1 interaction and CerS1 activity in acute stress-response conditions. Biologically, we show that Hsp27 knockdown impedes mitochondrial function and induces lethal mitophagy in a CerS1-dependent manner. Overall, we identify an important mode of CerS1 regulation and CerS1-mediated mitophagy through protein-protein interaction with Hsp27.
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Ceramidas , Proteínas de Choque Térmico HSP27 , Ceramidas/metabolismo , Proteínas de Choque Térmico HSP27/genética , Mitocôndrias/metabolismo , Mitofagia , Esfingolipídeos/metabolismo , HumanosRESUMO
Technologies are transforming the understanding of adipose tissue as a complex and dynamic tissue that plays a critical role in energy homoeostasis and metabolic health. This mini-review provides a brief overview of the potential impact of novel technologies in biomedical research and aims to identify areas where these technologies can make the most significant contribution to adipose tissue research. It discusses the impact of cutting-edge technologies such as single-cell sequencing, multi-omics analyses, spatial transcriptomics, live imaging, 3D tissue engineering, microbiome analysis, in vivo imaging, and artificial intelligence/machine learning. As these technologies continue to evolve, we can expect them to play an increasingly important role in advancing our understanding of adipose tissue and improving the treatment of related diseases.
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Tecido Adiposo , Inteligência Artificial , Perfilação da Expressão Gênica , Homeostase , MultiômicaRESUMO
PURPOSE OF REVIEW: Artificial intelligence (AI) is a transformative technology that has the potential to improve and augment the clinical workflow in supportive and palliative care (SPC). The objective of this study was to provide an overview of the recent studies applying AI to SPC in cancer patients. RECENT FINDINGS: Between 2020 and 2022, 29 relevant studies were identified and categorized into two applications: predictive modeling and text screening. Predictive modeling uses machine learning and/or deep learning algorithms to make predictions regarding clinical outcomes. Most studies focused on predicting short-term mortality risk or survival within 6 months, while others used models to predict complications in patients receiving treatment and forecast the need for SPC services. Text screening typically uses natural language processing (NLP) to identify specific keywords, phrases, or documents from patient notes. Various applications of NLP were found, including the classification of symptom severity, identifying patients without documentation related to advance care planning, and monitoring online support group chat data. SUMMARY: This literature review indicates that AI tools can be used to support SPC clinicians in decision-making and reduce manual workload, leading to potentially improved care and outcomes for cancer patients. Emerging data from prospective studies supports the clinical benefit of these tools; however, more rigorous clinical validation is required before AI is routinely adopted in the SPC clinical workflow.
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Inteligência Artificial , Neoplasias , Humanos , Cuidados Paliativos , Estudos Prospectivos , AlgoritmosRESUMO
Women have a higher risk of having an ischemic stroke and increased cognitive decline after stroke as compared to men. The female sex hormone 17ß-estradiol (E2) is a potent neuro- and cognitive-protective agent. Periodic E2 or estrogen receptor subtype-beta (ER-ß) agonist pre-treatments every 48 h before an ischemic episode ameliorated ischemic brain damage in young ovariectomized or reproductively senescent (RS) aged female rats. The current study aims to investigate the efficacy of post-stroke ER-ß agonist treatments in reducing ischemic brain damage and cognitive deficits in RS female rats. Retired breeder (9-10 months) Sprague-Dawley female rats were considered RS after remaining in constant diestrus phase for more than a month. The RS rats were exposed to transient middle cerebral artery occlusion (tMCAO) for 90 min and treated with either ER-ß agonist (beta 2, 3-bis(4-hydroxyphenyl) propionitrile; DPN; 1 mg/kg; s.c.) or DMSO vehicle at 4.5 h after induction of tMCAO. Subsequently, rats were treated with either ER-ß agonist or DMSO vehicle every 48 h for ten injections. Forty-eight hours after the last treatment, animals were tested for contextual fear conditioning to measure post-stroke cognitive outcome. Neurobehavioral testing, infarct volume quantification, and hippocampal neuronal survival were employed to determine severity of stroke. Periodic post-stroke ER-ß agonist treatment reduced infarct volume, improved recovery of cognitive capacity by increasing freezing in contextual fear conditioning, and decreased hippocampal neuronal death in RS female rats. These data suggest that periodic post-stroke ER-ß agonist treatment to reduce stroke severity and improve post-stroke cognitive outcome in menopausal women has potential for future clinical investigation.
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Receptores de Estrogênio , Acidente Vascular Cerebral , Ratos , Feminino , Animais , Ratos Sprague-Dawley , Receptor beta de Estrogênio , Dimetil Sulfóxido , Estrogênios/farmacologia , Estradiol/farmacologia , Estradiol/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Cognição , Infarto/tratamento farmacológico , Receptor alfa de Estrogênio/agonistasRESUMO
Incidents of strokes are increased in young women relative to young men, suggesting that oral contraceptive (OC) use is one of the causes of stroke among young women. Long-term exposures to the varying combinations of estrogen and progestogen found in OCs affect blood clotting, lipid and lipoprotein metabolism, endothelial function, and de novo synthesis of neurosteroids, especially brain-derived 17ß-estradiol. The latter is essential for neuroprotection, memory, sexual differentiation, synaptic transmission, and behavior. Deleterious effects of OCs may be exacerbated due to comorbidities like polycystic ovary syndrome, sickle cell anemia, COVID-19, exposures to endocrine disrupting chemicals, and conventional or electronic cigarette smoking. The goal of the current review is to revisit the available literature regarding the impact of OC use on stroke, to explain possible underlying mechanisms, and to identify gaps in our understanding to promote future research to reduce and cure stroke in OC users.
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COVID-19 , Sistemas Eletrônicos de Liberação de Nicotina , Acidente Vascular Cerebral , Masculino , Feminino , Humanos , Anticoncepcionais Orais/farmacologia , Amigos , Acidente Vascular Cerebral/etiologiaRESUMO
Xenoestrogens, foreign synthetic chemicals mimicking estrogens, are lurking in our surroundings. Climate change may alter their toxicity and bioavailability. Since xenoestrogens have extremely high lipid solubility and are structurally similar to natural endogenous estrogens, they can bind to estrogen receptors (ERs) -alpha (ER-α) and -beta (ER-ß). Scientific evidence accumulated over the past decades have suggested that natural 17ß-estradiol (E2; a potent estrogen), via activation of its receptors, plays a pivotal role in regulation of brain development, differentiation, metabolism, synaptic plasticity, neuroprotection, cognition, anxiety, body temperature, feeding and sexual behavior. In the brain, ER-ß is predominantly expressed in the various regions, including cerebral cortex and hippocampus, that have been shown to play a key role in cognition. Therefore, disturbances in function of ER-ß mediated E2 signaling by xenoestrogens can lead to deleterious effects that potentiate a variety of neurological diseases starting from prenatal to post-menopause in women. The goal of this review is to identify the possible neurological effects of xenoestrogens that can alter estrogen receptor-mediated signaling in the brain during different stages of the female lifespan.
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Encéfalo/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Exposição Ambiental/efeitos adversos , Doenças do Sistema Nervoso/induzido quimicamente , Receptores de Estrogênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Feminino , Humanos , Doenças do Sistema Nervoso/metabolismoRESUMO
Pheochromocytoma (PCC) is a rare catecholamine-secreting tumor that arises from chromaffin cells of the adrenal medulla which are derived from the neural crest. This report illustrates a 51-year-old Caucasian male with a history of hypertension diagnosed two years ago who presented to the hospital due to acute onset of right testicular pain of 3-day duration. Laboratory results and imaging revealed a presumptive diagnosis of PCC. The patient had undergone robot-assisted laparoscopic right adrenalectomy 14 days after being diagnosed with PCC due to perioperative management with phenoxybenzamine. The final pathology report revealed a PCC. At follow-up two weeks after discharge, the patient reported complete resolution of his testicular pain.
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Korsakoff syndrome is a neuropsychiatric condition frequently seen as a progression of Wernicke's encephalopathy and is often associated with long-term alcohol abuse. It is characterized by further cognitive impairments, such as indiscriminate anterograde and retrograde amnesia, in addition to executive function deficits. As the syndrome is a result of severe thiamine deficiency, its management primarily focuses on nutritional replenishment and electrolyte maintenance. In recent years, a few published reports have detailed the off-label use of Food and Drug Administration (FDA) approved drugs for Alzheimer's in an attempt to treat neurocognitive deficits associated with Korsakoff patients. In this particular case, we note subjective improvement in cognition after initiating memantine, an N-Methyl-d-aspartate (NMDA) receptor antagonist.
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This report describes a patient who developed intraprocedural vascular stasis immediately following elective endovascular coil emboliation. Urgent antiplatelet treatment with the GpIIb/IIIa agent tirofiban was used. It was infused intra-arterially during the procedure, followed by a fixed rate intravenous continuous infusion, and successfully restored normal circulation. There were no reports of further bleeding or haemodynamic compromise during the hospital stay. The patient's condition returned to baseline and he was discharged the following day with no neurological deficits.
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Procedimentos Endovasculares , Aneurisma Intracraniano/cirurgia , Complicações Intraoperatórias/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Tromboembolia/tratamento farmacológico , Tirofibana/uso terapêutico , Artéria Vertebral/cirurgia , Idoso , Cerebelo/irrigação sanguínea , Angiografia Cerebral , Humanos , Injeções Intra-Arteriais , Masculino , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidoresRESUMO
Retinopathy of prematurity (ROP) is a leading cause of childhood blindness that occurs due to incomplete development of retinal blood vessels in preterm infants. Glaucoma is an ocular comorbidity in some patients with ROP, and it may be associated with immature anterior chamber development, ROP itself, or the treatment for ROP. There have been a few reports of narrow-angle glaucoma after laser treatment for ROP. In this case report, we describe the course of a female infant born at 24 weeks and 5 days of gestational age with treatment-requiring ROP treated with laser photocoagulation who subsequently developed very elevated intraocular pressure and shallow anterior chambers without pupillary block. The patient required bilateral ab externo trabeculotomy for elevated intraocular pressure, which normalized after the procedure. The patient has remained stable at the last follow-up at 51 weeks postmenstrual age. Differing from previous glaucoma presentations in this setting, we illustrate a case of elevated intraocular pressure and anterior chamber narrowing after laser therapy without pupillary block or synechiae. The possible multifactorial etiology of glaucoma in this patient, including incomplete angle development, ischemia, and laser treatment, highlight the need for glaucoma screening in patients with ROP, both in the short and long term.
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Hyperammonemia is a metabolic abnormality characterized by elevated levels of ammonia in the blood. This case report illustrates a 72-year-old Caucasian female with a history of prior gastric bypass surgery done 15 years ago, who was admitted multiple times for acute encephalopathy over the course of a few months. The patient was found to have a gastro-gastric fistula seen on a CT scan of the abdomen, which was the culprit of her acute encephalopathy. The patient underwent fistula closure via esophagogastroduodenoscopy.
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Closed reduction and percutaneous pinning is the treatment of choice for displaced pediatric phalangeal neck fractures. Multiple techniques have been described to address challenges in managing these unstable fractures. We describe our technique of closed reduction and percutaneous pinning, which avoids the physis and increases the wire insertion accuracy, minimizing the number of attempts and wire passes made at percutaneous pinning.
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Fixação Intramedular de Fraturas , Fraturas Ósseas , Fios Ortopédicos , Criança , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , HumanosRESUMO
PURPOSE: To report an atypical case of vitreoretinal lymphoma, secondary to non-central nervous system (non-CNS) systemic lymphoma, masquerading as an infectious retinitis. OBSERVATIONS: A 76-year-old female with a history of cecal diffuse large B-cell lymphoma with two prior occurrences of posterior segment ocular involvement presented with a complaint of blurry vision in the right eye. Exam findings were significant for large areas of retinal whitening and retinal hemorrhages in the absence of choroidal lesions or significant vitritis. The clinical suspicion of an infectious retinitis, was supported by a presumptive immunosuppressive state secondary to her recent treatment (within 1 month) with both intravitreal and systemic rituximab plus high-dose methotrexate. Aggressive treatment with intravitreal and systemic antivirals and antibiotics was initiated. However, polymerase chain reaction (PCR) testing of aqueous fluid was negative for cytomegalovirus (CMV), herpes simplex virus, herpes zoster virus and toxoplasma, and her condition continued to worsen, so suspicion was raised for a masquerading recurrent malignancy. She was treated empirically with serial intravitreal injections of methotrexate and showed dramatic clinical improvement. A subsequent relapse occurred that responded rapidly to intravitreal methotrexate in the absence of antiviral/antibiotics. CONCLUSION: It is important for clinicians to be aware of atypical presentations of vitreoretinal lymphoma. This case emphasizes the fact that secondary ocular lymphoma after systemic lymphoma can have a vitreoretinal presentation rather than the more common choroidal involvement. Furthermore, it shows that recurrences of this disease in the same patient can have very different manifestations, including an appearance indistinguishable from a viral retinitis.
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Subacute sclerosing panencephalitis (SSPE) is a slowly progressive degenerative disorder caused by measles virus. It is characterised by typical clinical and electrophysiological features in the form of slow myoclonic jerks, with progressive cognitive impairment, visual symptoms, and periodic complexes on EEG, with raised titres of anti-measles antibodies in CSF and serum. Atypical presentations of SSPE have been reported including brainstem involvement, ADEM-like presentation, acute encephalitis, and cerebellar ataxia. Presentation with predominant extrapyramidal features is uncommon. We describe a case of SSPE presenting with extensive rigidity with highly elevated CPK values, mimicking neuroleptic malignant syndrome (NMS) which was most probably due to central dopaminergic blockade induced by the disease process. To our knowledge, this is the first case of SSPE presenting with a NMS-like syndrome.
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Sarampo/diagnóstico por imagem , Síndrome Maligna Neuroléptica/diagnóstico por imagem , Panencefalite Esclerosante Subaguda/diagnóstico por imagem , Adulto , Diagnóstico Diferencial , Progressão da Doença , Eletroencefalografia , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética , Masculino , Sarampo/complicações , Sarampo/fisiopatologia , Sarampo/virologia , Vírus do Sarampo/isolamento & purificação , Síndrome Maligna Neuroléptica/complicações , Síndrome Maligna Neuroléptica/fisiopatologia , Síndrome Maligna Neuroléptica/virologia , Panencefalite Esclerosante Subaguda/complicações , Panencefalite Esclerosante Subaguda/fisiopatologia , Panencefalite Esclerosante Subaguda/virologiaRESUMO
BACKGROUND: Piper nigrum (PN) is well known for its cytotoxic and pharmacological benefits. However, there is minimal documented evidence about its cytotoxic efficacy against colorectal carcinoma. We therefore sought to procure a precisely quantitative and qualitative result, pertaining the efficacy of an ethanolic extract of PN (EEPN) against colorectal carcinoma. MATERIALS AND METHODS: EEPN was prepared by subjecting dried PN seeds to gradient ethanol fractionation. The total phenol content (TPC), antioxidant activity (AOA), and anti-inflammatory activity (AIA) were determined using Folin-Ciocalteu assay, ferric reducing ability of plasma and 2, 2-diphenyl-1-picrylhydrazyl methods, and human red blood cells membrane stabilizing assay, respectively. Colorectal carcinoma cell lines (HCT-116, HCT-15, and HT-29) were procured from National Centre for Cell Science, Pune, and were cultured in Dulbecco's modified eagle media supplemented with 10% fetal bovine serum and 1 mM L-glutamine. Cells were seeded into a 96-well plate, followed by treatment with increasing concentrations of EEPN. The cytotoxic efficacy was evaluated based on percentage inhibition of cells, using sulforhodamine-B assay. The IC-50 values were calculated using Prism software (Prism from GraphPad software, Inc. CA, USA). RESULTS: Biochemical analysis revealed that 50% EEPN exhibited higher TPC, AOA, and AIA when compared to 70% and 100% EEPN at any given concentration (P = 0.041). Cytotoxic analysis revealed a dose-dependent response with maximum cellular inhibition at TPC of 6 and 3 µg/ml, using 50% EEPN. However, 50% inhibition of cellular growth using 50% EEPN was seen with TPC of 3.2, 2.9, and 1.9 µg/ml at 24, 48, and 72 h, respectively, in HCT-15 cells. Hence, time- and dose-dependent increase in the cytotoxic efficacy of 50% EEPN against colorectal carcinoma cell lines were noted (P < 0.001). CONCLUSION: Given the significantly positive correlations exhibited between the biochemical and the cytotoxic properties evaluated in our study, we hereby conclude PN as a novel therapeutic spice for the treatment of colorectal carcinoma.
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BACKGROUND AND PURPOSE: In recent trials, acute ischemic stroke (AIS) from large artery occlusion (LAO) was resistant to intravenous thrombolysis and adjunctive stent retriever thrombectomy (SRT) was associated with better perfusion and outcomes. Despite benefit, 39-68% of patients had poor outcomes. Thrombectomy in AIS with LAO within 3â h is performed secondary to intravenous thrombolysis, which may be associated with delay. The purpose of our study is to evaluate the safety, feasibility, recanalization rate, and outcome of primary SRT within 3â h without intravenous thrombolysis in AIS from LAO. METHODS: Based on an institutionally approved protocol, stroke patients with LAO within 3â h were offered primary SRT as an alternative to intravenous recombinant tissue plasminogen activator. Consecutive patients who underwent primary SRT for LAO within 3â h from 2012 to 2014 were enrolled. Outcomes were measured using the modified Rankin Scale (mRS). RESULTS: 18 patients with LAO of mean age 62.83±15.32â years and median NIH Stroke Scale (NIHSS) score 16 (10-23) chose primary SRT after giving informed consent. Near complete (TICI 2b in 1 patient) or complete (TICI 3 in 17 patients) recanalization was observed in all patients. Time to recanalization from symptom onset and groin puncture was 188.5±82.7 and 64.61±40.14â min, respectively. NIHSS scores immediately after thrombectomy, at 24â h and 30â days were 4 (0-12), 1 (0-12), and 0 (0-4), respectively. Asymptomatic perfusion-related hemorrhage developed in four patients (22%). 90-day outcomes were mRS 0 in 50%, mRS 1 in 44.4%, and mRS 2 in 5.6%. CONCLUSIONS: Our study demonstrates that primary SRT in AIS from LAO is safe and feasible and is associated with complete recanalization and good outcome. Further study is required.
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Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/cirurgia , Trombectomia/métodos , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/uso terapêutico , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Stents , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/prevenção & controle , Trombectomia/normas , Fatores de Tempo , Tempo para o Tratamento/normas , Resultado do TratamentoRESUMO
PURPOSE: To evaluate the foveal microstructure using high-density (24-line) radial scans and their correlation with visual recovery following macular hole surgery. DESIGN: Retrospective, consecutive, interventional case series. METHODS: Forty-five eyes of 43 patients with ≥6 months follow-up following surgery were analyzed. Preoperative predictive measures evaluated included basal hole and minimum linear diameters. Outcome measures included best-corrected visual acuity (BCVA), postoperative foveal lucency horizontal and vertical size, external limiting membrane, and ellipsoid zone defect. RESULTS: Mean basal hole diameter was 642 ± 330 µm and minimum linear diameter was 277 ± 161 µm. BCVA (logMAR) improved from 0.67 ± 0.23 to 0.31 ± 0.16 at 12 months (P < .001). Foveal lucency horizontal and vertical sizes (µm) improved from 97 ± 81 and 33 ± 18 at 1 month to 26 ± 33 and 19 ± 18, respectively (P < .05) at 12 months. External limiting membrane recovered in all cases at 1 month. Mean ellipsoid zone defect (µm) reduced from 136 ± 164 at 1 month to 32 ± 33 at 12 months (P < .05). Preoperative basal hole diameter correlated with horizontal foveal lucency size at all time points (P < .05). Horizontal foveal lucency size at 1 month correlated (P < .05) with BCVA at 6 and 12 months. Basal hole diameter ≥700 µm (71% sensitivity and 70% specificity) and minimum linear diameter ≥330 µm (71% sensitivity and 70% specificity) were predictive of foveal lucency development. Cataract surgery did not influence foveal lucency resolution and no holes reopened. CONCLUSION: Using radial scans, 71% of eyes demonstrated a foveal lucency at 1 month, whose size correlated with visual recovery. Preoperative basal hole diameter was predictive of foveal lucency development and size.
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Fóvea Central/patologia , Perfurações Retinianas/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Vitrectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Perfurações Retinianas/fisiopatologia , Perfurações Retinianas/cirurgia , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: A promising cancer vaccine involves the fusion of tumor cells with dendritic cells (DCs). As such, a broad spectrum of both known and unidentified tumor antigens is presented to the immune system in the context of the potent immunostimulatory capacity of DCs. Murine studies have demonstrated the efficacy of fusion immunotherapy. However the clinical impact of DC/tumor fusion vaccines has been limited, suggesting that the immunosuppresive milieu found in patients with malignancies may blunt the efficacy of cancer vaccination. Thus, novel strategies to enhance fusion vaccine efficacy are needed. Regulatory T cells (Tregs) are known to suppress anti-tumor immunity, and depletion or functional inactivation of these cells improves immunotherapy in both animal models and clinical trials. In this study, we sought to investigate whether functional inactivation of CD4+CD25+FoxP3+ Treg with anti-CD25 monoclonal antibody (mAb) PC61 prior to DC/tumor vaccination would significantly improve immunotherapy in the murine B16 melanoma model. METHODS: Treg blockade was achieved with systemic PC61 administration. This blockage was done in conjunction with DC/tumor fusion vaccine administration to treat established melanoma pulmonary metastases. Enumeration of these metastases was performed and compared between experimental groups using Wilcoxon Rank Sum Test. IFN-gamma ELISPOT assay was performed on splenocytes from treated mice. RESULTS: We demonstrate that treatment of mice with established disease using mAb PC61 and DC/tumor fusion significantly reduced counts of pulmonary metastases compared to treatment with PC61 alone (p=0.002) or treatment with control antibody plus fusion vaccine (p=0.0397). Furthermore, IFN-gamma ELISPOT analyses reveal that the increase in cancer immunity was mediated by anti-tumor specific CD4+ T-helper cells, without concomitant induction of CD8+ cytotoxic T cells. Lastly, our data provide proof of principle that combination treatment with mAb PC61 and systemic IL-12 can lower the dose of IL-12 necessary to obtain maximal therapeutic efficacy. CONCLUSIONS: To our knowledge, this is the first report investigating the effects of anti-CD25 mAb administration on DC/tumor-fusion vaccine efficacy in a murine melanoma model, and our results may aide the design of future clinical trials with enhanced therapeutic impact.