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Although radiotherapy continues to evolve as a mainstay of the oncological armamentarium, research and innovation in radiotherapy in low-income and middle-income countries (LMICs) faces challenges. This third Series paper examines the current state of LMIC radiotherapy research and provides new data from a 2022 survey undertaken by the International Atomic Energy Agency and new data on funding. In the context of LMIC-related challenges and impediments, we explore several developments and advances-such as deep phenotyping, real-time targeting, and artificial intelligence-to flag specific opportunities with applicability and relevance for resource-constrained settings. Given the pressing nature of cancer in LMICs, we also highlight some best practices and address the broader need to develop the research workforce of the future. This Series paper thereby serves as a resource for radiation professionals.
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Países em Desenvolvimento , Neoplasias , Radioterapia (Especialidade) , Humanos , Países em Desenvolvimento/economia , Neoplasias/radioterapia , Radioterapia (Especialidade)/economia , Pesquisa Biomédica/economia , Radioterapia/economia , PobrezaRESUMO
Based on the current state of science, the use of animals remains essential in bringing safe and effective medicines to patients. Respect for laboratory animal welfare and the application of 3Rs principles (the replacement, reduction, and refinement of animal use in research) are a priority throughout the pharmaceutical industry. Given the rapid pace of development, technological progress, and the emergence of new-approach methodologies (NAMs) in the field of biomedical research, maintaining a leading position in scientific advancements with a focus on the principles of replace, reduce, and refine (3Rs) can be quite challenging. To effectively address these challenges and sustain a prominent position in the scientific community, organizations can derive significant advantages from establishing an internal 3Rs advisory group (3Rs AG). The primary objective of a 3Rs AG is to stay at the forefront of the knowledge of best practices related to the 3Rs principles in the industry. This group plays a crucial role in fostering innovation and facilitating the seamless integration and implementation of 3Rs principles into a company's policies and procedures. The thoughtful reduction in and replacement of animal studies and the refinement of study designs and practices, enabled by a 3Rs AG, can minimize animal use as well as guide resources and positively impact study and data quality. This article provides guidance on how to establish a successful and impactful 3Rs AG.
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Herpes simplex virus 1 (HSV-1) commandeers the host cell proteasome at several steps of its replication cycle, including entry. Here we demonstrate that HSV-2, pseudorabies virus (PRV), and bovine herpesvirus 1 (BoHV-1) entry are blocked by bortezomib, a proteasome inhibitor that is an FDA-approved cancer drug. Proteasome-dependent entry of HSV-1 is thought to be ubiquitin-independent. To interrogate further the proteasomal mechanism of entry, we determined the involvement of the ubiquitin-like molecule NEDD8 and the neddylation cascade in alphaherpesvirus entry and infection. MLN4924 is a small-molecule inhibitor of neddylation that binds directly to the NEDD8-activating enzyme. Cell treatment with MLN4924 inhibited plaque formation and infectivity by HSV-1, PRV, and BoHV-1 at noncytotoxic concentrations. Thus, the neddylation pathway is broadly important for alphaherpesvirus infection. However, the neddylation inhibitor had little effect on entry of the veterinary viruses but had a significant inhibitory effect on entry of HSV-1 and HSV-2 into seven different cell types. Washout experiments indicated that MLN4924's effect on viral entry was reversible. A time-of-addition assay suggested that the drug was acting on an early step in the entry process. Small interfering RNA (siRNA) knockdown of NEDD8 significantly inhibited HSV entry. In probing the neddylation-dependent step in entry, we found that MLN4924 dramatically blocked endocytic uptake of HSV from the plasma membrane by >90%. In contrast, the rate of HSV entry into cells that support direct fusion of HSV with the cell surface was unaffected by MLN4924. Interestingly, proteasome activity was less important for the endocytic internalization of HSV from the cell surface. The results suggest that the NEDD8 cascade is critical for the internalization step of HSV entry. IMPORTANCE Alphaherpesviruses are ubiquitous pathogens of humans and veterinary species that cause lifelong latent infections and significant morbidity and mortality. Host cell neddylation is important for cell homeostasis and for the infection of many viruses, including HSV-1, HSV-2, PRV, and BoHV-1. Inhibition of neddylation by a pharmacologic inhibitor or siRNA blocked HSV infection at the entry step. Specifically, the NEDD8 pathway was critically important for HSV-1 internalization from the cell surface by an endocytosis mechanism. The results expand our limited understanding of cellular processes that mediate HSV internalization. To our knowledge, this is the first demonstration of a function for the neddylation cascade in virus entry.
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Herpes Simples , Herpesvirus Humano 1 , Herpesvirus Suídeo 1 , Animais , Humanos , RNA Interferente Pequeno , Inibidores de Proteassoma , Bortezomib , Complexo de Endopeptidases do Proteassoma , Linhagem Celular , Herpesvirus Humano 1/fisiologia , Herpesvirus Suídeo 1/fisiologia , UbiquitinasRESUMO
Viruses confiscate cellular components of the ubiquitin-proteasome system (UPS) to facilitate many aspects of the infectious cycle. The 26S proteasome is an ATP-dependent, multisubunit proteolytic machine present in all eukaryotic cells. The proteasome executes the controlled degradation of functional proteins, as well as the hydrolysis of aberrantly folded polypeptides. There is growing evidence for the role of the UPS in viral entry. The UPS assists in several steps of the initiation of infection, including endosomal escape of the entering virion, intracellular transport of incoming nucleocapsids and uncoating of the viral genome. Inhibitors of proteasome activity, including MG132, epoxomicin, lactacystin and bortezomib have been integral to developments in this area. Here, we review the mechanistic details of UPS involvement in the entry process of viruses from a multitude of families. The possibility of proteasome inhibitors as therapeutic antiviral agents is highlighted.
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Interações entre Hospedeiro e Microrganismos , Complexo de Endopeptidases do Proteassoma/fisiologia , Inibidores de Proteassoma/farmacologia , Ubiquitina/fisiologia , Internalização do Vírus , Fenômenos Fisiológicos Virais , Vírus/efeitos dos fármacos , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Animais , Antivirais/farmacologia , Bortezomib/farmacologia , Humanos , Leupeptinas/farmacologia , Nucleocapsídeo/metabolismo , Oligopeptídeos/farmacologia , Proteólise , Vírion/metabolismoRESUMO
PURPOSE: Spray drying plays an important role in the pharmaceutical industry for product development of sensitive bio-pharmaceutical formulations. Process design, implementation and optimisation require in-depth knowledge of process-product interactions. Here, an integrated approach for the rapid, early-stage spray drying process development of trehalose and glucagon on lab-scale is presented. METHODS: Single droplet drying experiments were used to investigate the particle formation process. Process implementation was supported using in-line process analytical technology within a data acquisition framework recording temperature, humidity, pressure and feed rate. During process implementation, off-line product characterisation provided additional information on key product properties related to residual moisture, solid state structure, particle size/morphology and peptide fibrillation/degradation. RESULTS: A psychrometric process model allowed the identification of feasible operating conditions for spray drying trehalose, achieving high yields of up to 84.67%, and significantly reduced levels of residual moisture and particle agglomeration compared to product obtained during non-optimal drying. The process was further translated to produce powders of glucagon and glucagon-trehalose formulations with yields of >83.24%. Extensive peptide aggregation or degradation was not observed. CONCLUSIONS: The presented data-driven process development concept can be applied to address future isolation problems on lab-scale and facilitate a systematic implementation of spray drying for the manufacturing of sensitive bio-pharmaceutical formulations.
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Excipientes/química , Glucagon/isolamento & purificação , Tecnologia Farmacêutica , Trealose/química , Estabilidade de Medicamentos , Liofilização , Pós , Agregados Proteicos , Estabilidade Proteica , Tecnologia Farmacêutica/instrumentaçãoRESUMO
INTRODUCTION: Retroperitoneal sarcoma (RPS) is a rare malignancy, and curative resection is considered the main therapy. Use of chemotherapy and/or radiation in addition to surgery (multimodality therapy) is controversial. OBJECTIVE: To determine treatment factors that influence overall survival in RPS. METHODS: This retrospective Institutional Review Board-approved study identified patients with RPS treated at a single institution between 2000 and 2017. Patient, tumor, and treatment modalities were collected. Prism (v.8.2.1) was used to calculate Kaplan-Meier survival curves. RESULTS: There were 695 patients with sarcoma between 2000 and 2017, and 61 adults had RPS. The mean age was 59 (range 31-86) years, with 57.4% females (n = 35). Patients were 68.9% Caucasian (n = 42), 21.3% Hispanic (n = 13), 8.2% black (n = 5), and 1.6% Asian (n = 1). There were 4 patients who had neoadjuvant therapy (chemotherapy, n = 3; radiation, n = 2) and 17 who had adjuvant therapy (chemotherapy, n = 6; radiation, n = 14). There was no significant difference in survival between the groups who received multimodality therapy compared to surgery alone. There was a significant improvement in the median overall survival for patients who underwent one or multiple surgeries (P < .05). CONCLUSIONS: These institutional data suggest that treatment factors associated with overall survival included multiple resections. Use of multimodality therapy was low and did not influence overall survival in patients with RPS compared to surgery alone.
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Neoplasias Retroperitoneais/mortalidade , Neoplasias Retroperitoneais/cirurgia , Sarcoma/mortalidade , Sarcoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de SobrevidaRESUMO
PURPOSE: To assess the impact of longitudinal telehealth training in stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) for clinicians in Latin America. MATERIALS AND METHODS: Professionals from two Peruvian centers received an initial SBRT/SRS on-site training course and subsequently received follow-up telehealth training (interventional group) or not (negative control arm). Twelve live video conference sessions were scheduled. Surveys pre- and post-curriculum measured participants' confidence in seven practical domains of SBRT/SRS, based on Likert scales of 1-5, and post-curriculum surveys assessed educators' experiences. RESULTS: Sixty-one participants were registered, with an average of 24 attendees per session. Pre- and post- surveys were completed by 22 participants. For interventional and negative-control groups, mean changes in Likert scale were satisfactory for the former and remained unmodified for the latter. CONCLUSIONS: Conducting telehealth educational programs via virtual classroom sessions could be a reliable method to augment training for SBRT and SRS.
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Radiocirurgia , Telemedicina , Humanos , América Latina , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: Palliative radiation therapy (pRT) is often used to improve quality of life for pediatric patients. Though palliative doses are generally lower than those for cure, pRT may still introduce undesirable effects. The decision to pursue additional therapy for a child may be challenging and depends on parents' knowledge and expectations. The goal of this study was to explore parental perceptions of pRT. METHODS: Twenty-eight children referred for pRT were enrolled in our prospective study. Parents were counseled regarding the indication and expected outcomes. They then completed a series of questionnaires to assess their understanding of pRT, side effects that their child experienced, and how the outcomes compared to their expectations. RESULTS: The majority of parents listed pain relief and addressing new disease as the main indication for pRT. When asked about expectations, the majority chose improvement in quality of life and prolongation of their child's life. Interestingly, 32% of parents expected pRT to cure their child's disease. Most patients undergoing pRT did not experience any adverse symptoms. The outcomes of pRT in the majority of cases exceeded parental expectations. CONCLUSION: Improved quality of life with pRT sometimes blurs the distinction between palliation and cure. We found that most parents understand the aim to improve quality of life, although a proportion of parents perceived pRT as a cure to their child's disease. Despite this, the majority of parents reported that the outcome of the pRT course exceeded their expectations. We postulate that parents derive comfort from pursuing active treatment.
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Tomada de Decisões , Neoplasias/radioterapia , Cuidados Paliativos , Pais/psicologia , Qualidade de Vida , Radioterapia/métodos , Adolescente , Criança , Feminino , Seguimentos , Humanos , Masculino , Neoplasias/patologia , Estudos Prospectivos , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Avian species host diverse communities of microorganisms which have important roles in the life of birds, including increased metabolism, protection from disease, and immune system development. Along with high human populations and a diversity of human uses of coastal zones, anthropogenic food sources are becoming increasingly available to some species, including gulls. Anthropogenic associations increase the likelihood of encountering foreign or pathogenic bacteria. Diseases in birds caused by bacteria are a substantial source of avian mortality; therefore, it is essential to characterize the microbiome of seabirds. Here, we determined both core and environmentally derived microbial communities of breeding western gulls (Larus occidentalis) from six colonies in California and Oregon. Using DNA extracted from bacterial swabs of the bill, cloaca, and feet of gulls, 16S rRNA gene sequencing was performed targeting the V4 region. We identified a total of 8542 operational taxonomic units (OTUs) from 75 gulls. Sixty-eight OTUs were identified in gulls from all six colonies with the greatest representation from phyla's of Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. Overall, microbial richness based on Chao's Abundance-based Coverage Estimator (ACE) index was similar for all colonies (mean = 2347 OTUs) with the smallest coastal colonies having the highest richness (mean = 2626 OTUs) and the largest colonies, located farther off-shore, having the lowest (mean = 2068 OTUs). This survey represents the most in-depth assessment to date of microbes associated with western gulls, and the first study to identify both species-specific and environmentally derived bacteria across multiple populations.
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Bactérias/isolamento & purificação , Charadriiformes/microbiologia , Microbiota , Animais , Bactérias/classificação , Bactérias/genética , California , Cloaca/microbiologia , DNA Bacteriano/genética , Oregon , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
The alphaherpesvirus pseudorabies virus (PRV) is the causative agent of pseudorabies, a disease of great economic and welfare importance in swine. Other alphaherpesviruses, including herpes simplex virus (HSV), utilize low-pH-mediated endocytosis to enter a subset of cell types. We investigated whether PRV used this entry pathway in multiple laboratory model cell lines. Inhibition of receptor-mediated endocytosis by treatment with hypertonic medium prevented PRV entry. PRV entry into several cell lines, including porcine kidney (PK15) cells and African green monkey kidney (Vero) cells, was inhibited by noncytotoxic concentrations of the lysosomotropic agents ammonium chloride and monensin, which block the acidification of endosomes. Inactivation of virions by acid pretreatment is a hallmark of viruses that utilize a low-pH-mediated entry pathway. Exposure of PRV virions to pH 5.0 in the absence of host cell membranes reduced entry into PK15 and Vero cells by >80%. Together, these findings suggest that endocytosis followed by fusion with host membranes triggered by low endosomal pH is an important route of entry for PRV.IMPORTANCE PRV is a pathogen of great economic and animal welfare importance in many parts of the world. PRV causes neurological, respiratory, and reproductive disorders, often resulting in mortality of young and immunocompromised animals. Mortality, decreased production, and trade restrictions result in significant financial losses for the agricultural industry. Understanding the molecular mechanisms utilized by PRV to enter host cells is an important step in identifying novel strategies to prevent infection and spread. A thorough understanding of these mechanisms will contribute to a broader understanding of alphaherpesvirus entry. Here, we demonstrate PRV entry into multiple model cell lines via a low-pH endocytosis pathway. Together, these results provide a framework for elucidating the early events of the PRV replicative cycle.
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Cloreto de Amônio/farmacologia , Herpesvirus Suídeo 1/fisiologia , Monensin/farmacologia , Animais , Linhagem Celular , Membrana Celular/virologia , Chlorocebus aethiops , Endocitose , Concentração de Íons de Hidrogênio , Suínos , Células Vero , Internalização do Vírus/efeitos dos fármacosRESUMO
Bovine herpesvirus 1 (BoHV-1) is an alphaherpesvirus that poses a significant challenge to health and welfare in the cattle industry. We investigated the cellular entry route utilized by BoHV-1. We report that BoHV-1 enters Madin Darby bovine kidney (MDBK) cells, bovine turbinate cells, and African green monkey kidney (Vero) cells via a low-pH-mediated endocytosis pathway. Treatment of MDBK cells with hypertonic medium, which inhibits receptor-mediated endocytosis, prevented infection as measured by a beta-galactosidase reporter assay. Treatment of cells with noncytotoxic concentrations of the lysosomotropic agents ammonium chloride and monensin, which block the acidification of endosomes, inhibited BoHV-1 entry in a concentration-dependent fashion. The kinetics of endocytic uptake of BoHV-1 from the cell surface was rapid (50% uptake by â¼5 min). Time-of-addition experiments indicated that the lysosomotropic agents acted at early times postinfection, consistent with entry. Inactivation of virions by pretreatment with mildly acidic pH is a hallmark characteristic of viruses that utilize a low-pH-activated entry pathway. When BoHV-1 particles were exposed to pH 5.0 in the absence of target membrane, infectivity was markedly reduced. Lastly, treatment of cells with the proteasome inhibitor MG132 inhibited BoHV-1 entry in a concentration-dependent manner. Together, these results support a model of BoHV-1 infection in which low endosomal pH is a critical host trigger for fusion of the viral envelope with an endocytic membrane and necessary for successful infection of the target cell.IMPORTANCE BoHV-1 is a ubiquitous pathogen affecting cattle populations worldwide. Infection can result in complicated, polymicrobial infections due to the immunosuppressive properties of the virus. While there are vaccines on the market, they only limit disease severity and spread but do not prevent infection. The financial and animal welfare ramifications of this virus are significant, and in order to develop more effective prevention and treatment regimens, a more complete understanding of the initial steps in viral infection is necessary. This research establishes the initial entry pathway of BoHV-1, which provides a foundation for future development of effective treatments and preventative vaccines. Additionally, it allows comparisons to the entry pathways of other alphaherpesviruses, such as HSV-1.
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Endossomos/virologia , Herpesvirus Bovino 1/fisiologia , Internalização do Vírus , Animais , Bovinos , Linhagem Celular , Chlorocebus aethiops , Endossomos/química , Concentração de Íons de HidrogênioRESUMO
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and manifests as two major histological subtypes: embryonal and alveolar. The five-year local failure rate for RMS at parameningeal sites (middle ear, mastoid region, nasal cavity, etc.) is around 17% despite multiple Intergroup Rhabdomyosarcoma Study Group (IRS) trials conducted to determine the optimal radiation treatment regimen. This case report explores the use of intensity-modulated proton therapy (IMPT) for a 10-year-old child who presented with left eye irritation, facial pain, and headaches and was found to have an alveolar parameningeal rhabdomyosarcoma. He received systemic therapy as well as radiation therapy to 5,640 cGy and 4,320 cGy over 24 fractions, prescribed for gross tumor extension and adjacent high-risk involved sites, respectively, via simultaneous integrated boost. Approximately two years following treatment, the patient has had no recurrence of his RMS with no distant metastases. In addition, his presenting symptom of left eye irritation has improved. His only side effect from radiation at this point is short stature, possibly due to growth hormone deficiency. The patient's IMPT plan was compared with volumetric-modulated arc therapy (VMAT) and 4π non-coplanar intensity-modulated radiation therapy (IMRT) plans, and comparisons of isodose lines show decreased dose to the distal brain tissue with preserved target conformality by IMPT. IMPT also allowed for increased sparing of the patient's retina, lens, and lacrimal gland. All radiation plans achieved conformal dose coverage to the planning/scanning target volumes, while the IMPT plan is potentially better at sparing the patient from developing long-term optic apparatus side effects and neurocognitive defects. In this case, IMPT is comparable, if not favorable, when long-term side effects can be reduced while maintaining dose conformality and local control.
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Canine oral mucosal melanoma is an aggressive malignant neoplasm and is characterized by local infiltration and a high metastatic potential. The disease progression is similar to that of human oral melanomas. Whereas human cutaneous melanoma is primarily driven by activating mutations in Braf (60%) or Nras (20%), human mucosal melanoma harbors these mutations much less frequently. This makes therapeutic targeting and research modeling of the oral form potentially different from that of the cutaneous form in humans. Similarly, research has found only rare Nras mutations and no activating Braf mutations in canine oral melanomas, but they are still reliant on MAPK signaling. IQGAP1 is a signaling scaffold that regulates oncogenic ERK1/2 MAPK signaling in human Ras- and Raf- driven cancers, including melanomas. To investigate whether IQGAP1 is a potential target in canine melanoma, we examined the expression and localization of IQGAP1 in primary canine melanomas and canine oral melanoma cell lines obtained from the University of California-Davis. Using CRISPR/Cas9 knockout of IQGAP1, we examined effects on downstream ERK1/2 pathway activity and assayed proliferation of cell lines when treated with a peptide that blocks the interaction between IQGAP1 and ERK1/2. We observed that canine IQGAP1 is expressed and localizes to a similar extent in both human and canine melanoma by qPCR, Western blot, and immunofluorescence. Deletion of IQGAP1 reduces MAPK pathway activation in cell lines, similar to effects seen in human BrafV600E cell lines. Additionally, we demonstrated reduced proliferation when these cells are treated with a blocking peptide in vitro.
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Melanoma/patologia , Neoplasias Bucais/patologia , Proteínas Ativadoras de ras GTPase/metabolismo , Animais , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cães , Técnicas de Inativação de Genes , Humanos , Imuno-Histoquímica , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/metabolismo , Camundongos , Microscopia de Fluorescência , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neoplasias Bucais/metabolismo , Mutação , Oncogenes , Fosforilação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridonas/toxicidade , Pirimidinonas/toxicidade , Proteínas Ativadoras de ras GTPase/antagonistas & inibidores , Proteínas Ativadoras de ras GTPase/genéticaRESUMO
Brain metastases are the most common intracranial tumors in the adult population and have been historically treated with whole brain radiation therapy (WBRT). However, as medical advances improve life expectancy, stereotactic radiosurgery (SRS) has replaced WBRT as the standard of care for limited (one to three) brain metastases due to the relative sparing of neurocognitive function (NCF) and therefore quality of life (QoL). The use of SRS has been less documented in the case of multiple (four or more) brain metastases, with literature limited to non-randomized studies showing comparable survival and local control. In this series, we detail the case of two individuals who received SRS at our institution for multiple brain metastases and demonstrated remarkable response. The first patient is a 78-year-old woman who received Gamma Knife (GK) treatment to 17 lesions at our institution. This patient responded very well to treatment and maintains an excellent quality of life, with no deficits on serial neurological examination as she continues to travel and drive for ridesharing businesses. The second patient is an active 44-year-old woman who received SRS to 24 lesions at our institution. The patient has now been free of intracranial failures for two years and continues fulfilling her love for travel and long-distance biking. SRS is emerging as an acceptable alternative to WBRT in treating multiple brain metastases due to its preservation of NCF. Because omission of WBRT may lead to increased probability of distant brain metastasis failure, it is critical to follow these patients closely with frequent neuroimaging. In the event of a failure, it is also possible to use SRS salvage therapy with good response. Some patients who receive SRS alone demonstrate exceptional outcomes with excellent QoL, and it is possible that certain prognostication factors such as performance status, tumor histology, and tumor volume may play a role in identifying these patients. The decision to treat a patient with SRS alone for multiple brain metastases should be made carefully with consideration of systemic therapeutic options, overall prognosis, and the patient's goals of care, with adherence to a careful follow-up plan by the physician and patient.
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Glaucoma is an incurable disease of the eye that affects 2% of over 40s in the United Kingdom and 5% of those over 80. The National Institute for Health and Care Excellence (NICE) estimates that the disease affects around 480,000 people in the United Kingdom, with over a million glaucoma-related hospital outpatient appointments each year. This paper aims to establish the care pathways for glaucoma across the United Kingdom and the perceived value of imaging. A questionnaire was distributed to members of the Ophthalmic Imaging Association to identify imaging protocols with glaucoma; results indicated that there was variation between hospitals. The perceived clinical value of imaging from staff involved in the pathway was also explored.
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Glaucoma/diagnóstico por imagem , Padrões de Prática Médica , Humanos , Inquéritos e Questionários , Reino UnidoRESUMO
Recently, using the medial forebrain bundle (MFB) 6-hydroxydopmaine (6-OHDA) lesion rat model of Parkinson's disease (PD), we have demonstrated that blockade of central IGF-1 receptors (IGF-1R) attenuated estrogen neuroprotection of substantia nigra pars compacta (SNpc) DA neurons, but exacerbated 6-OHDA lesions in IGF-1 only treated rats (Quesada and Micevych [2004]: J Neurosci Res 75:107-116). This suggested that the IGF-1 system is a central mechanism through which estrogen acts to protect the nigrostriatal DA system. Moreover, these results also suggest that IGF-1R-induced intracellular signaling pathways are involved in the estrogen mechanism that promotes neuronal survival. In vitro, two convergent intracellular signaling pathways used by estrogen and IGF-1, the mitogen-activated protein kinase (MAPK/ERK), and phosphatidyl-inositol-3-kinase/Akt (PI3K/Akt), have been demonstrated to be neuroprotective. Continuous central infusions of MAPK/ERK and PI3K/Akt inhibitors were used to test the hypothesis that one or both of these signal transduction pathways mediates estrogen and/or IGF-1 neuroprotection of SNpc DA neurons after a unilateral administration of 6-OHDA into the MFB of rats. Motor behavior tests and tyrosine hydroxylase immunoreactivity revealed that the inhibitor of the PI3K/Akt pathway (LY294002) blocked the survival effects of both estrogen and IGF-1, while an inhibitor of the MAPK/ERK signaling (PD98059) was ineffective. Western blot analyses showed that estrogen and IGF-1 treatments increased PI3K/Akt activation in the SN; however, MAPK/ERK activation was decreased in the SN. Indeed, continuous infusions of inhibitors blocked phosphorylation of PI3K/Akt and MAPK/ERK. These findings indicate that estrogen and IGF-1-mediated SNpc DA neuronal protection is dependent on PI3K/Akt signaling, but not on the MAPK/ERK pathway.
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Dopamina/fisiologia , Estrogênios/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Neurônios/fisiologia , Proteína Oncogênica v-akt/metabolismo , Doença de Parkinson Secundária/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Substância Negra/fisiologia , Animais , Western Blotting , Contagem de Células , Ativação Enzimática/efeitos dos fármacos , Estradiol/farmacologia , Feminino , Injeções Intraventriculares , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Fibras Nervosas/enzimologia , Ovariectomia , Doença de Parkinson Secundária/induzido quimicamente , Ratos , Ratos Long-Evans , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Substância Negra/citologia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
The events that took place in medieval English birthing chambers were witnessed and assisted by a company of women. Although these events may have been isolated, they did not exist in isolation. Rather, they interacted in complex ways with the lives and activities of the men in the manor hall. This article examines those interactions as they are evidenced in proof-of-age inquests, legal documents that record the recollections of husbands, fathers, and male relatives and neighbors regarding the events surrounding the birth of an heir to crown land. It concludes that even though men rarely entered the birthing chamber, their dynastic interests and social politics routinely penetrated its walls, blurring the boundary between private and public spheres, female and male space.