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1.
S Afr Fam Pract (2004) ; 66(1): e1-e4, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38708744

RESUMO

Healthcare practitioners are regularly faced with treating patients at the end of their life, and this can be very daunting. This article hopes to help the practitioner have an approach to managing end-of-life care that makes it less distressing. The symptoms at the end-of-life include delirium and/or agitation, breathing changes, skin changes, sleeping more, decrease in need for food and drink, incontinence, and increased secretions. These symptoms are discussed and practical ways of management are given. The article further discusses how to approach the difficult conversation with the family and gives guidance as to what needs to be discussed. A number of tips are discussed on how to prepare the family to handle a death at home. It is essential to look at coping mechanisms and selfcare for practitioners dealing with end-of-life care as the death of a patient not only affects the family but also the practitioner.


Assuntos
Relações Profissional-Família , Assistência Terminal , Humanos , Assistência Terminal/psicologia , Família/psicologia , Adaptação Psicológica , Cuidados Paliativos , Comunicação
2.
S Afr Fam Pract (2004) ; 66(1): e1-e15, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38708750

RESUMO

BACKGROUND:  Learning portfolios (LPs) provide evidence of workplace-based assessments (WPBAs) in clinical settings. The educational impact of LPs has been explored in high-income countries, but the use of portfolios and the types of assessments used for and of learning have not been adequately researched in sub-Saharan Africa. This study investigated the evidence of learning in registrars' LPs and the influence of the training district and year of training on assessments. METHODS:  A cross-sectional study evaluated 18 Family Medicine registrars' portfolios from study years 1-3 across five decentralised training sites affiliated with the University of the Witwatersrand. Descriptive statistics were calculated for the portfolio and quarterly assessment (QA) scores and self-reported clinical skills competence levels. The competence levels obtained from the portfolios and university records served as proxy measures for registrars' knowledge and skills. RESULTS:  The total LP median scores ranged from 59.9 to 81.0, and QAs median scores from 61.4 to 67.3 across training years. The total LP median scores ranged from 62.1 to 83.5 and 62.0 to 67.5, respectively in QAs across training districts. Registrars' competence levels across skill sets did not meet the required standards. Higher skills competence levels were reported in the women's health, child health, emergency care, clinical administration and teaching and learning domains. CONCLUSION:  The training district and training year influence workplace-based assessment (WPBA) effectiveness. Ongoing faculty development and registrar support are essential for WPBA.Contribution: This study contributes to the ongoing discussion of how to utilise WPBA in resource-constrained sub-Saharan settings.


Assuntos
Competência Clínica , Avaliação Educacional , Medicina de Família e Comunidade , Local de Trabalho , Humanos , Estudos Transversais , Medicina de Família e Comunidade/educação , Avaliação Educacional/métodos , Feminino , Masculino , África do Sul , Aprendizagem , Adulto
3.
Front Bioinform ; 4: 1329144, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638123

RESUMO

Introduction: DNA methylation, specifically the formation of 5-methylcytosine at the C5 position of cytosine, undergoes reproducible changes as organisms age, establishing it as a significant biomarker in aging studies. Epigenetic clocks, which integrate methylation patterns to predict age, often employ linear models based on penalized regression, yet they encounter challenges in handling missing data, count-based bisulfite sequence data, and interpretation. Methods: To address these limitations, we introduce BayesAge, an extension of the scAge methodology originally designed for single-cell DNA methylation analysis. BayesAge employs maximum likelihood estimation (MLE) for age inference, models count data using binomial distributions, and incorporates LOWESS smoothing to capture non-linear methylation-age dynamics. This approach is tailored for bulk bisulfite sequencing datasets. Results: BayesAge demonstrates superior performance compared to scAge. Notably, its age residuals exhibit no age association, offering a less biased representation of epigenetic age variation across populations. Furthermore, BayesAge facilitates the estimation of error bounds on age inference. When applied to down-sampled data, BayesAge achieves a higher coefficient of determination between predicted and actual ages compared to both scAge and penalized regression. Discussion: BayesAge presents a promising advancement in epigenetic age prediction, addressing key challenges encountered by existing models. By integrating robust statistical techniques and tailored methodologies for count-based data, BayesAge offers improved accuracy and interpretability in predicting age from bulk bisulfite sequencing datasets. Its ability to estimate error bounds enhances the reliability of age inference, thereby contributing to a more comprehensive understanding of epigenetic aging processes.

4.
Appl Environ Microbiol ; : e0028824, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38651928

RESUMO

In many frankia, the ability to nodulate host plants (Nod+) and fix nitrogen (Fix+) is a common strategy. However, some frankia within the Pseudofrankia genus lack one or two of these traits. This phenomenon has been consistently observed across various actinorhizal nodule isolates, displaying Nod- and/or Fix- phenotypes. Yet, the mechanisms supporting the colonization and persistence of these inefficient frankia within nodules, both with and without symbiotic strains (Nod+/Fix+), remain unclear. It is also uncertain whether these associations burden or benefit host plants. This study delves into the ecological interactions between Parafrankia EUN1f and Pseudofrankia inefficax EuI1c, isolated from Elaeagnus umbellata nodules. EUN1f (Nod+/Fix+) and EuI1c (Nod+/Fix-) display contrasting symbiotic traits. While the prediction suggests a competitive scenario, the absence of direct interaction evidence implies that the competitive advantage of EUN1f and EuI1c is likely contingent on contextual factors such as substrate availability and the specific nature of stressors in their respective habitats. In co-culture, EUN1f outperforms EuI1c, especially under specific conditions, driven by its nitrogenase activity. Iron-depleted conditions favor EUN1f, emphasizing iron's role in microbial competition. Both strains benefit from host root exudates in pure culture, but EUN1f dominates in co-culture, enhancing its competitive traits. Nodulation experiments show that host plant preferences align with inoculum strain abundance under nitrogen-depleted conditions, while consistently favoring EUN1f in nitrogen-supplied media. This study unveils competitive dynamics and niche exclusion between EUN1f and EuI1c, suggesting that host plant may penalize less effective strains and even all strains. These findings highlight the complex interplay between strain competition and host selective pressure, warranting further research into the underlying mechanisms shaping plant-microbe-microbe interactions in diverse ecosystems. IMPORTANCE: While Pseudofrankia strains typically lack the common traits of ability to nodulate the host plant (Nod-) and/or fix nitrogen (Fix-), they are still recovered from actinorhizal nodules. The enigmatic question of how and why these unconventional strains establish themselves within nodule tissue, thriving either alongside symbiotic strains (Nod+/Fix+) or independently, while considering potential metabolic costs to the host plant, remains a perplexing puzzle. This study endeavors to unravel the competitive dynamics between Pseudofrankia inefficax strain EuI1c (Nod+/Fix-) and Parafrankia strain EU1Nf (Nod+/Fix+) through a comprehensive exploration of genomic data and empirical modeling, conducted both in controlled laboratory settings and within the host plant environment.

5.
Br J Gen Pract ; 74(742): e283-e289, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38621806

RESUMO

BACKGROUND: There are not enough GPs in England. Access to general practice and continuity of care are declining. AIM: To investigate whether practice characteristics are associated with life expectancy of practice populations. DESIGN AND SETTING: A cross-sectional ecological study of patient life expectancy from 2015-2019. METHOD: Selection of independent variables was based on conceptual frameworks describing general practice's influence on outcomes. Sixteen non-correlated variables were entered into multivariable weighted regression models: population characteristics (Index of Multiple Deprivation, region, % White ethnicity, and % on diabetes register); practice organisation (total NHS payments to practices expressed as payment per registered patient, full-time equivalent fully qualified GPs, GP registrars, advanced nurse practitioners, other nurses, and receptionists per 1000 patients); access (% seen on the same day); clinical performance (% aged ≥45 years with blood pressure checked, % with chronic obstructive pulmonary disease vaccinated against flu, % with diabetes in glycaemic control, and % with coronary heart disease on antiplatelet therapy); and the therapeutic relationship (% continuity). RESULTS: Deprivation was strongly negatively associated with life expectancy. Regions outside London and White ethnicity were associated with lower life expectancy. Higher payment per patient, full-time equivalent fully qualified GPs per 1000 patients, continuity, % with chronic obstructive pulmonary disease having the flu vaccination, and % with diabetes with glycaemic control were associated with higher life expectancy; the % being seen on the same day was associated with higher life expectancy in males only. The variable aged ≥45 years with blood pressure checked was a negative predictor in females. CONCLUSION: The number of GPs, continuity of care, and access in England are declining, and it is worrying that these features of general practice were positively associated with life expectancy.


Assuntos
Medicina Geral , Clínicos Gerais , Expectativa de Vida , Humanos , Estudos Transversais , Inglaterra/epidemiologia , Clínicos Gerais/provisão & distribuição , Acessibilidade aos Serviços de Saúde , Masculino , Feminino , Pessoa de Meia-Idade , Continuidade da Assistência ao Paciente , Medicina Estatal
6.
Ann Bot ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38535525

RESUMO

BACKGROUND AND AIMS: Pollinators provide critical ecosystem services, maintaining biodiversity and benefiting global food production. However, plants, pollinators, and their mutualistic interactions may be affected by drought, which has increased in severity and frequency under climate change. Using two annual, insect-pollinated wildflowers (Phacelia campanularia and Nemophila menziesii), we asked how drought impacts floral traits and foraging preferences of a solitary bee (Osmia lignaria) and explore potential implications for plant reproduction. METHODS: In greenhouses, we experimentally subjected plants to drought to induce water stress, as verified by leaf water potential. To assess the impact of drought on floral traits, we measured flower size, floral display size, nectar volume, and nectar sugar concentration. To explore how drought-induced effects on floral traits affected bee foraging preferences, we performed choice trials. Individual female bees were placed into foraging arenas with two conspecific plants, one droughted and one non-droughted, and were allowed to forage freely. KEY RESULTS: We determined that P. campanularia is more drought-tolerant than N. menziesii based on measures of turgor loss point, and confirmed that droughted plants were more drought-stressed than non-droughted plants. For droughted plants of both species, floral display size was reduced, and flowers were smaller and produced less, more-concentrated nectar. We found that bees preferred non-droughted flowers of N. menziesii. However, bee preference for non-droughted P. campanularia flowers depended on the time of day and was detected only in the afternoon. CONCLUSIONS: Our findings indicate that bees prefer visiting non-droughted flowers, likely reducing pollination success for drought-stressed plants. Lack of preference for non-droughted P. campanularia flowers in the morning may reflect the higher drought tolerance of this species. This work highlights the potentially intersecting, short-term physiological and pollinator behavioral responses to drought and suggests that such responses may reshape plant-pollinator interactions, ultimately reducing reproductive output for less drought-tolerant wildflowers.

7.
MicroPubl Biol ; 20242024.
Artigo em Inglês | MEDLINE | ID: mdl-38495587

RESUMO

Obesity reflects an imbalance in nutrient storage resulting in excess fat accumulation. The molecules that tissues use to regulate nutrient storage are not well understood. A previously published genetic screen using Drosophila melanogaster larvae identified Glut1 , a transmembrane glucose transporter, as a potential obesity gene. To identify the adipose-specific functions of this gene, Glut1 levels were decreased using RNAi targeted to fly fat tissue. Adult Glut1 RNAi flies have lower glycogen and triglyceride levels, as well as decreased FASN1 RNA expression. This suggests that Glut1 functions to promote glycogen and triglyceride storage and fatty acid synthesis in Drosophila adipose tissue.

8.
ACS Appl Mater Interfaces ; 16(12): 14457-14466, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38488736

RESUMO

Most in vitro models use culture medium to apply fluid shear stress to endothelial cells, which does not capture the interaction between blood and endothelial cells. Here, we describe a new system to characterize whole blood flow through a 3D-printed, endothelialized vascular topology that induces flow separation at a bifurcation. Drag-reducing polymers, which have been previously studied as a potential therapy to reduce the pressure drop across the vascular bed, are evaluated for their effect on mitigating the disturbed flow. Polymer concentrations of 1000 ppm prevented recirculation and disturbed flow at the wall. Proteomic analysis of plasma collected from whole blood recirculated through the vascularized channel with and without drag-reducing polymers provides insight into the effects of flow regimes on levels of proteins indicative of the endothelial-blood interaction. The results indicate that blood flow alters proteins associated with coagulation, inflammation, and other processes. Overall, these proof-of-concept experiments demonstrate the importance of using whole blood flow to study the endothelial response to perfusion.


Assuntos
Células Endoteliais , Polímeros , Polímeros/farmacologia , Proteômica , Hemodinâmica/fisiologia , Impressão Tridimensional , Estresse Mecânico
9.
J Neurol Sci ; 458: 122907, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38309251

RESUMO

INTRODUCTION: Glucocorticoids (GCs) are associated with multiple toxicities that have substantial impact on patients. We conducted qualitative interviews with patients to identify the toxicities that are most relevant from their perspective, with the goal of creating a patient-reported companion measure to the Glucocorticoid Toxicity Index (GTI), a clinician-facing instrument. METHODS: Thirty-one patients with recent or current GC use participated in concept elicitation interviews. Participants received GC treatment for myasthenia gravis, chronic inflammatory demyelinating polyradiculoneuropathy, vasculitis, or systemic lupus erythematosus. Transcripts were coded following a thematic analysis approach. RESULTS: Participants reported more than 100 toxicities they believed to be associated with their GC medications. Common toxicities included weight gain (87%), increased appetite (84%), insomnia/sleep problems (77%), cognitive impairment/brain fog (71%), easy bruising (68%), anxiety (65%), irritability/short temper (65%), and osteoporosis (39%). These toxicities often centered on self-esteem, neuropsychiatric effects, skin toxicities, and musculoskeletal function. They can be categorized into domains such emphasizing neuropsychiatric, metabolic/endocrine, musculoskeletal, and dermatological effects, highlighting aspects of GC toxicity that patients are uniquely positioned to appreciate and report. CONCLUSION: Our results confirm that the toxicities associated with GCs are pervasive and diverse, with substantial impact on patients' lives. These data will be used to inform the development of a patient-reported outcome measure assessing GC toxicity. This patient-reported instrument will be designed to complement the clinician-reported GTI, facilitating a more detailed understanding of the nuances of change in GC toxicity.


Assuntos
Lúpus Eritematoso Sistêmico , Vasculite , Humanos , Glucocorticoides/uso terapêutico , Medidas de Resultados Relatados pelo Paciente
10.
bioRxiv ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38370771

RESUMO

Engineering of embryonic strategies for tissue-building has extraordinary promise for regenerative medicine. This has led to a resurgence in interest in the relationship between cell biophysical properties and morphological transitions. However, mapping gene or protein expression data to cell biophysical properties to physical morphogenesis remains challenging with current techniques. Here we present MATCHY (multiplexed adhesion and traction of cells at high yield). MATCHY advances the multiplexing and throughput capabilities of existing traction force and cell-cell adhesion assays using microfabrication and an automated computation scheme with machine learning-driven cell segmentation. Both biophysical assays are coupled with serial downstream immunofluorescence to extract cell type/signaling state information. MATCHY is especially suited to complex primary tissue-, organoid-, or biopsy-derived cell mixtures since it does not rely on a priori knowledge of cell surface markers, cell sorting, or use of lineage-specific reporter animals. We first validate MATCHY on canine kidney epithelial cells engineered for RET tyrosine kinase expression and quantify a relationship between downstream signaling and cell traction. We go on to create a biophysical atlas of primary cells dissociated from the mouse embryonic kidney and use MATCHY to identify distinct biophysical states along the nephron differentiation trajectory. Our data complement expression-level knowledge of adhesion molecule changes that accompany nephron differentiation with quantitative biophysical information. These data reveal an 'energetic ratchet' that explains spatial nephron progenitor cell condensation from the niche as they differentiate, which we validate through agent-based computational simulation. MATCHY offers automated cell biophysical characterization at >104-cell throughput, a highly enabling advance for fundamental studies and new synthetic tissue design strategies for regenerative medicine.

11.
ACS Nano ; 18(9): 6908-6926, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38381620

RESUMO

The durability of a protective immune response generated by a vaccine depends on its ability to induce long-term T cell immunity, which tends to decline in aging populations. The longest protection appears to arise from T memory stem cells (TMSCs) that confer high expandability and effector functions when challenged. Here we engineered artificial antigen presenting cells (aAPC) with optimized size, stiffness and activation signals to induce human and mouse CD8+ TMSCs in vitro. This platform was optimized as a vaccine booster of TMSCs (Vax-T) with prolonged release of small-molecule blockade of the glycogen synthase kinase-3ß together with target antigens. By using SARS-CoV-2 antigen as a model, we show that a single injection of Vax-T induces durable antigen-specific CD8+ TMSCs in young and aged mice, and generates humoral responses at a level stronger than or similar to soluble vaccines. This Vax-T approach can boost long-term immunity to fight infectious diseases, cancer, and other diseases.


Assuntos
Linfócitos T CD8-Positivos , Vacinas , Camundongos , Humanos , Animais , Memória Imunológica , Materiais Biocompatíveis , Células-Tronco
12.
Eur J Health Econ ; 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38409492

RESUMO

INTRODUCTION: Acid sphingomyelinase deficiency (ASMD) type B is a rare genetic disorder leading to enlargement of the spleen and liver, pulmonary dysfunction, and other symptoms. Cost-utility analyses are often conducted to quantify the value of new treatments, and these analyses require health state utilities. Therefore, the purpose of this study was to estimate utilities associated with varying levels of severity of adult and pediatric ASMD type B. METHODS: Seven adult and seven child health state vignettes describing ASMD were developed based on published literature, clinical trial results, and interviews with clinicians, patients with ASMD, and parents of children with ASMD. The health states were valued in time trade-off interviews with adult general population respondents in the UK. RESULTS: Interviews were completed with 202 participants (50.0% female; mean age = 41.3 years). The health state representing ASMD without impairment had the highest mean utility for both the adult and child health states (0.92/0.94), and severe ASMD had the lowest mean utility (0.33/0.45). Every child health state had a significantly greater utility than the corresponding adult health state. Differences between adult/child paired states ranged from 0.02 to 0.13. Subgroup analyses explored the impact of parenting status on valuation of child health states. DISCUSSION: Greater severity of ASMD was associated with lower mean utility. Results have implications for valuation of pediatric health states. The resulting utilities may be useful in cost-utility modeling estimating the value of treatment for ASMD.

13.
EClinicalMedicine ; 69: 102487, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38420219

RESUMO

Childhood, adolescent, and young adult (CAYA) cancer survivors are at risk of pulmonary dysfunction. Current follow-up care guidelines are discordant. Therefore, the International Late Effects of Childhood Cancer Guideline Harmonization Group established and convened a panel of 33 experts to develop evidence-based surveillance guidelines. We critically reviewed available evidence regarding risk factors for pulmonary dysfunction, types of pulmonary function testing, and timings of surveillance, then we formulated our recommendations. We recommend that CAYA cancer survivors and healthcare providers are aware of reduced pulmonary function risks and pay vigilant attention to potential symptoms of pulmonary dysfunction, especially among survivors treated with allogeneic haematopoietic stem cell transplantation, thoracic radiotherapy, and thoracic surgery. Based on existing limited evidence and current lack of interventions, our panel recommends pulmonary function testing only for symptomatic survivors. Since scarce existing evidence informs our recommendation, we highlight the need for prospective collaborative studies to address pulmonary function knowledge gaps among CAYA cancer survivors.

14.
J Med Econ ; 27(1): 370-380, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38347819

RESUMO

AIMS: Health state utilities associated with weight change are needed for cost-utility analyses (CUAs) examining the value of treatments for type 2 diabetes and obesity. Previous studies have estimated the utility benefits associated with various amounts of weight reduction in the US and Europe, but preferences for weight change in Asian cultures may differ from these published values. The purpose of this study was to estimate utilities associated with reductions in body weight based on preferences of individuals with type 2 diabetes and obesity in Japan. METHODS: Health state vignettes represented type 2 diabetes with respondents' own current weight and weight reductions of 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, and 20%. Utilities were elicited in time trade-off interviews with a sample of respondents in Japan with type 2 diabetes and body mass index (BMI) ≥25 kg/m2 (the cutoff for obesity in Japan). RESULTS: Analyses were conducted with data from 138 respondents (84.8% male; mean age = 58.0 years; mean BMI = 29.4 kg/m2) from all eight regions of Japan. Utility gains gradually increased with rising percentage of weight reductions ranging from 2.5% to 15%. Weight reductions of 2.5% to 15% resulted in utility increases of 0.013 to 0.048. The health state representing a 20% weight reduction yielded a wide range of preferences (mean utility increase of 0.044). Equations are recommended for estimating utility change based on any percentage of weight reduction (up to 20%) in Japanese people with type 2 diabetes and obesity. LIMITATIONS: This study was conducted in a sample with limited representation of patients with BMI >35 kg/m2 (n = 13) and relatively few women (n = 21). CONCLUSION: Results may be used to provide inputs for CUAs examining the value of treatments that are associated with weight loss in patients with type 2 diabetes and obesity in Japan.


Assuntos
Diabetes Mellitus Tipo 2 , População do Leste Asiático , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/complicações , Japão , Obesidade/complicações , Redução de Peso
15.
Afr J Prim Health Care Fam Med ; 16(1): e1-e9, 2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38299546

RESUMO

BACKGROUND: Palliative care (PC) is a priority in South Africa, focussing on integrating PC into primary health care. Few examples exist showing how this is done. In 2018, a rural PC project was implemented, which subsequently evolved into an integrated service between the hospital and the community. AIM: The aim was to review the PC project over 4 years. SETTING: The setting was the George subdistrict of the Garden Route district in South Africa. Community-based services were offered to all patients with PC needs by three non-governmental organisations who deliver home community-based care via community health workers. They were supplemented by primary health care clinics, an intermediate care facility and two hospitals. METHODS: This was a retrospective descriptive study. Inpatient ward round data and patient referrals between 2018 and 2022 were analysed using descriptive statistics. Variables included patient demographics, diagnosis, home visits and place of death. RESULTS: A total of 819 patients were referred. Inpatients were reviewed on weekly ward rounds by a multidisciplinary team. The most common diagnosis was cancer (57%). Home visits enabled patient follow-ups, of which 152 were recorded. CONCLUSION: The programme has become sustainable and integrated in the public healthcare system. Contributing factors included dedicated staff, using simple tools and continuous training. The findings may be useful to PC programmes in similar contexts elsewhere.Contribution: This work adds new knowledge to the field of PC in an underresourced rural healthcare environment in sub-Saharan Africa, by describing how system-wide integration of a new service was navigated to become sustainable.


Assuntos
Serviços de Assistência Domiciliar , Cuidados Paliativos , Humanos , África do Sul , Estudos Retrospectivos
16.
Artigo em Inglês | MEDLINE | ID: mdl-38323945

RESUMO

PURPOSE: Radiation myelitis (RM) is a rare complication of radiation therapy (RT). The Pediatric Normal Tissue Effects in the Clinic spinal cord task force aimed to identify RT dose effects and assess risk factors for RM in children. Through systematic review, we analyzed RT dose, fraction size, latency between completion of RT and toxicity, chemotherapy use, age when irradiated, and sex. METHODS AND MATERIALS: We conducted literature searches of peer-reviewed manuscripts published from 1964 to June 2017 evaluating RM among children. Normality of variables was assessed with Kolmogorov-Smirnov or Shapiro-Wilk tests. Spearman's rank correlation coefficients were used to test correlations between RT dose/fraction size and latency between RT and development of toxicity. RESULTS: Of 1329 identified and screened reports, 144 reports were fully reviewed and determined to have adequate data for analysis; 16 of these reports had a total of 33 cases of RM with a median age of 13 years (range, 0.2-18) at the time of RT. The most common primary tumor histologies were rhabdomyosarcoma (n = 9), medulloblastoma (n = 5), and Hodgkin lymphoma (n = 2); the most common chemotherapy agents given were vincristine (n = 15), intrathecal methotrexate (n = 12), and intrathecal cytarabine (n = 10). The median RT dose and fraction size were 40 Gy (range, 24-57.4 Gy) and 1.8 Gy (range, 1.3-2.6 Gy), respectively. RT dose resulting in RM in patients who also received chemotherapy was lower than in those not receiving chemotherapy (mean 39.6 vs 49.7 Gy; P = .04). There was no association of age with RT dose. The median latency period was 7 months (range, 1-29). Higher RT dose was correlated with longer latency periods (P = .03) to RM whereas sex, age, fraction size, and chemotherapy use were not. Two of 17 patients with adequate follow-up recovered from RM; unfortunately, it was fatal in 6 of 15 evaluable patients. Complication probability modeling was not possible because of the rarity of events. CONCLUSIONS: This report demonstrates a relatively short latency from RT (with or without chemotherapy) to RM and a wide range of doses (including fraction sizes) associated with RM. No apparent association with age at the time of RT could be discerned. Chemotherapy appears to reduce spinal cord tolerance. Recovery from RM is rare, and it is often fatal.

17.
Artigo em Inglês | MEDLINE | ID: mdl-38300187

RESUMO

PURPOSE: Reirradiation is increasingly used in children and adolescents/young adults (AYA) with recurrent primary central nervous system tumors. The Pediatric Normal Tissue Effects in the Clinic (PENTEC) reirradiation task force aimed to quantify risks of brain and brain stem necrosis after reirradiation. METHODS AND MATERIALS: A systematic literature search using the PubMed and Cochrane databases for peer-reviewed articles from 1975 to 2021 identified 92 studies on reirradiation for recurrent tumors in children/AYA. Seventeen studies representing 449 patients who reported brain and brain stem necrosis after reirradiation contained sufficient data for analysis. While all 17 studies described techniques and doses used for reirradiation, they lacked essential details on clinically significant dose-volume metrics necessary for dose-response modeling on late effects. We, therefore, estimated incidences of necrosis with an exact 95% CI and qualitatively described data. Results from multiple studies were pooled by taking the weighted average of the reported crude rates from individual studies. RESULTS: Treated cancers included ependymoma (n = 279 patients; 7 studies), medulloblastoma (n = 98 patients; 6 studies), any CNS tumors (n = 62 patients; 3 studies), and supratentorial high-grade gliomas (n = 10 patients; 1 study). The median interval between initial and reirradiation was 2.3 years (range, 1.2-4.75 years). The median cumulative prescription dose in equivalent dose in 2-Gy fractions (EQD22; assuming α/ß value = 2 Gy) was 103.8 Gy (range, 55.8-141.3 Gy). Among 449 reirradiated children/AYA, 22 (4.9%; 95% CI, 3.1%-7.3%) developed brain necrosis and 14 (3.1%; 95% CI, 1.7%-5.2%) developed brain stem necrosis with a weighted median follow-up of 1.6 years (range, 0.5-7.4 years). The median cumulative prescription EQD22 was 111.4 Gy (range, 55.8-141.3 Gy) for development of any necrosis, 107.7 Gy (range, 55.8-141.3 Gy) for brain necrosis, and 112.1 Gy (range, 100.2-117 Gy) for brain stem necrosis. The median latent period between reirradiation and the development of necrosis was 5.7 months (range, 4.3-24 months). Though there were more events among children/AYA undergoing hypofractionated versus conventionally fractionated reirradiation, the differences were not statistically significant (P = .46). CONCLUSIONS: Existing reports suggest that in children/AYA with recurrent brain tumors, reirradiation with a total EQD22 of about 112 Gy is associated with an approximate 5% to 7% incidence of brain/brain stem necrosis after a median follow-up of 1.6 years (with the initial course of radiation therapy being given with conventional prescription doses of ≤2 Gy per fraction and the second course with variable fractionations). We recommend a uniform approach for reporting dosimetric endpoints to derive robust predictive models of late toxicities following reirradiation.

18.
Tree Physiol ; 44(3)2024 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-38284819

RESUMO

As climate change exacerbates drought stress in many parts of the world, understanding plant physiological mechanisms for drought survival is critical to predicting ecosystem responses. Stem net photosynthesis, which is common in arid environments, may be a drought survival trait, but whether the additional carbon fixed by stems contributes to plant hydraulic function and drought survival in arid land plants is untested. We conducted a stem light-exclusion experiment on saplings of a widespread North American desert tree species, Parkinsonia florida L., and after shading acclimation, we then subjected half of the plants to a drought treatment to test the interaction between light exclusion and water limitation on growth, leaf and stem photosynthetic gas exchange, xylem embolism assessed with micro-computed tomography and gravimetric techniques, and survival. Growth, stem photosynthetic gas exchange, hydraulic function and survival all showed expected reductions in response to light exclusion. However, stem photosynthesis mitigated the drought-induced reductions in gas exchange, xylem embolism (percent loss of conductivity, PLC) and mortality. The highest mortality was in the combined light exclusion and drought treatment, and was related to stem PLC and native sapwood-specific hydraulic conductivity. This research highlights the integration of carbon economy and water transport. Our results show that additional carbon income by photosynthetic stems has an important role in the growth and survival of a widespread desert tree species during drought. This shift in function under conditions of increasing stress underscores the importance of considering stem photosynthesis for predicting drought-induced mortality not only for the additional supply of carbon, but also for its extended benefits for hydraulic function.


Assuntos
Secas , Embolia , Ecossistema , Microtomografia por Raio-X , Fotossíntese/fisiologia , Água/fisiologia , Folhas de Planta/fisiologia , Árvores/fisiologia , Carbono , Caules de Planta , Xilema/fisiologia
19.
JAMA Netw Open ; 7(1): e2351062, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38241048

RESUMO

Importance: Contemporary North American trials for children with Hodgkin lymphoma (HL) have decreased radiation therapy (RT) use and increased pharmacologic cardioprotection but also increased the cumulative doxorubicin dose, making overall treatment consequences for late cardiac toxic effects uncertain. Objective: To estimate the risk of cardiac toxic effects associated with treatments used in modern pediatric HL clinical trials. Design, Setting, and Participants: For this cohort study, Fine and Gray models were fitted using survivors in the Childhood Cancer Survivor Study who were diagnosed with HL between January 1, 1970, and December 31, 1999, and were followed for a median of 23.5 (range, 5.0-46.3) years. These models were applied to the exposures in the study population to estimate the 30-year cumulative incidence of cardiac disease. The study population comprised patients with intermediate-risk or high-risk HL treated in 4 consecutive Children's Oncology Group clinical trials from September 2002 to October 2022: AHOD0031, AHOD0831, AHOD1331, and S1826. Data analysis was performed from April 2020 to February 2023. Exposures: All patients received chemotherapy including doxorubicin, and some patients received mediastinal RT, dexrazoxane, or mediastinal RT and dexrazoxane. Main Outcomes and Measures: Estimated 30-year cumulative incidence of grade 3 to 5 cardiac disease. Results: The study cohort comprised 2563 patients, with a median age at diagnosis of 15 (range, 1-22) years. More than half of the patients were male (1357 [52.9%]). All 2563 patients received doxorubicin, 1362 patients (53.1%) received mediastinal RT, and 307 patients (12.0%) received dexrazoxane. Radiation therapy use and the median mean heart dose among patients receiving RT decreased, whereas the planned cumulative dose of doxorubicin and use of dexrazoxane cardioprotection increased. For patients treated at age 15 years, the estimated 30-year cumulative incidence of severe or fatal cardiac disease was 9.6% (95% CI, 4.2%-16.4%) in the AHOD0031 standard treatment group (enrolled 2002-2009), 8.6% (95% CI, 3.8%-14.9%) in the AHOD0831 trial (enrolled 2009-2012), 8.2% (95% CI, 3.6%-14.3%) in the AHOD1331 trial (enrolled 2015-2019), and 6.2% (95% CI, 2.7%-10.9%) in the S1826 trial (enrolled 2019-2022), whereas the expected rate in an untreated population was 5.0% (95% CI, 2.1%-9.3%). Despite the estimated reduction in late cardiac morbidity, the frequency of recommended echocardiographic screening among survivors will increase based on current guidelines. Conclusions and Relevance: In this cohort study of sequential HL trials, reductions in the proportion of children receiving mediastinal RT and increases in dexrazoxane use were estimated to offset the increased doxorubicin dose and produce a net reduction in late cardiac disease. Further studies on dexrazoxane are warranted to confirm whether its role in reducing cardiac toxic effects is maintained long term. These findings suggest that survivorship follow-up guidelines should be refined to align with the risks associated with treatment.


Assuntos
Dexrazoxano , Cardiopatias , Doença de Hodgkin , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Adulto Jovem , Cardiotoxicidade/epidemiologia , Cardiotoxicidade/etiologia , Protocolos Clínicos , Estudos de Coortes , Dexrazoxano/uso terapêutico , Doxorrubicina/efeitos adversos , Cardiopatias/induzido quimicamente , Cardiopatias/epidemiologia , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/epidemiologia , Doença de Hodgkin/radioterapia
20.
J Genomics ; 12: 6-13, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38164509

RESUMO

Streptomyces Strain San01 is isolated from the soil of ant-nest found in the tea estate of Darjeeling, India. The morphology, biochemical, as well as the molecular characteristics, proved that San01 belonged to the genus Streptomyces. The average nucleotide identity (ANI) value between the genome sequence of the studied strain and its closest phylogenetic neighbors were very low and also could be distinguished from its closest neighbour with broad range of phenotypic data. The draft genome sequence of isolate San01 (NZ_RZYA00000000.1) was estimated to be 9.12 Mbp in size with 71.2% of GC content and it encompasses 39 biosynthetic gene clusters that emphasize the biotechnological potential of this isolate.Based on the phenotypic, genetic and genomic data, isolate San01 (=JCM 34633 = NCTC 14543) merits to be recognized as a type strain of a novel species and hereby propose the name Streptomyces antnestii sp. nov. Incidentally, this is the first report on Streptomyces genomes from Darjeeling, India.

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