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1.
Artigo em Inglês | MEDLINE | ID: mdl-38830263

RESUMO

Older adults are at elevated risk of heat-related mortality due to age-associated declines in thermoregulatory and cardiovascular function. However, the inter-individual factors that exacerbate physiological heat strain during heat exposure remain unclear, making it challenging to identify more heat-vulnerable subgroups. We therefore explored factors contributing to inter-individual variability in physiological responses of older adults exposed to simulated hot weather. Thirty-seven older adults (61-80 years, 16 females) rested for 8 hours in 31°C and 36°C (45% relative humidity). Core (rectal) temperature, heart rate (HR) and HR variability, mean arterial pressure (MAP), and cardiac autonomic responses to standing were evaluated at baseline and end-exposure. Bootstrapped least absolute shrinkage and selection operator (LASSO) regression was used to evaluate whether variation in these responses was related to type 2 diabetes (T2D, n=10), hypertension (n=18), age, sex, body morphology, habitual physical activity levels, and/or heat-acclimatization. T2D was identified as a predictor of end-exposure HR (with vs. without: 13 beats/min [bootstrap 95% CI: 6, 23]), seated MAP (-7 mm Hg [-18, 1]), and the systolic pressure response to standing (20 mm Hg [4, 36]). HR was also influenced by sex (female vs. male: 8 beats/min [1, 16]). No other predictors were identified. The inter-individual factors explored did not meaningfully contribute to the variation in body temperature responses in older adults exposed to simulated indoor overheating. By contrast, cardiovascular responses were exacerbated in females and individuals with T2D. These findings improve understanding of how inter-individual differences contribute to the development of heat-induced physiological strain in older persons.

3.
Chem Mater ; 36(11): 5596-5610, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38883437

RESUMO

Operando synchrotron radiation-based techniques are a precious tool in battery research, as they enable the detection of metastable intermediates and ensure characterization under realistic cycling conditions. However, they do not come exempt of risks. The interaction between synchrotron radiation and samples, particularly within an active electrochemical cell, can induce relevant effects at the irradiated spot, potentially jeopardizing the experiment's reliability and biasing data interpretation. With the aim of contributing to this ongoing debate, a systematic investigation into these phenomena was carried out by conducting a root cause analysis of beam-induced effects during the operando characterization of two of the most commonly employed positive electrode materials in commercial Li-ion batteries: LiNi0.33Mn0.33Co0.33O2 and LiFePO4. The study spans across diverse experimental conditions involving different cell types and absorption and scattering techniques and seeks to correlate beam effects with factors such as radiation energy, photon flux, exposure time, and other parameters associated with radiation dosage. Finally, it provides a comprehensive set of guidelines and recommendations for assessing and mitigating beam-induced effects that may affect the outcome of battery operando experiments.

4.
Emerg Infect Dis ; 30(6): 1240-1244, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38782018

RESUMO

A 2022 canine gastroenteritis outbreak in the United Kingdom was associated with circulation of a new canine enteric coronavirus closely related to a 2020 variant with an additional spike gene recombination. The variants are unrelated to canine enteric coronavirus-like viruses associated with human disease but represent a model for coronavirus population adaptation.


Assuntos
Infecções por Coronavirus , Surtos de Doenças , Doenças do Cão , Gastroenterite , Filogenia , Animais , Cães , Surtos de Doenças/veterinária , Doenças do Cão/virologia , Doenças do Cão/epidemiologia , Reino Unido/epidemiologia , Gastroenterite/virologia , Gastroenterite/epidemiologia , Gastroenterite/veterinária , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Coronavirus Canino/genética , Coronavirus Canino/classificação , Humanos , Glicoproteína da Espícula de Coronavírus/genética
5.
Am Soc Clin Oncol Educ Book ; 44(3): e433298, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38768420

RESUMO

People with advanced lung cancer represent a distinct group whose needs remain understudied, especially compared with people diagnosed with limited-stage disease. Fortunately, novel treatments such as tyrosine kinase inhibitors and immune checkpoint inhibitors are leading to significant advances in prognosis and survival, even among those with advanced disease at the time of diagnosis. However, there are known gaps in symptom management, psychosocial and nutritional support, complex care coordination, health behavior coaching, and health care delivery efforts among patients living with advanced lung cancer. Many of these patients would benefit from survivorship and palliative care approaches. In particular, survivorship care may include health care maintenance, treatment of immune-related adverse events and late- or long-term effects, frailty assessment and rehabilitation, and care coordination. Palliative care may be best suited to discuss ongoing symptom management, advanced care planning, and end-of-life considerations, as well as psychosocial well-being. To this end, we share a review of the current status of the palliative and survivorship care infrastructure for patients with advanced lung cancer and provide suggestions across the care continuum for this diverse group of patients and families.


Assuntos
Neoplasias Pulmonares , Cuidados Paliativos , Sobrevivência , Humanos , Neoplasias Pulmonares/terapia , Sobreviventes de Câncer , Estadiamento de Neoplasias , Qualidade de Vida
6.
Adv Colloid Interface Sci ; 328: 103161, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38728771

RESUMO

Complex fluids encompass a significant proportion of the materials that we use today from feedstocks such as cellulose fibre dispersions, materials undergoing processing or formulation, through to consumer end products such as shampoo. Such systems exhibit intricate behaviour due to their composition and microstructure, particularly when analysing their texture and response to flow (rheology). In particular, these fluids when flowing may undergo transitions in their nano- to microstructure, potentially aligning with flow fields, breaking and reassembling or reforming, or entirely changing phase. This manifests as macroscopic changes in material properties, such as core-annular flow of concentrated emulsions in pipelines or the favourable texture of liquid soaps. Small-angle scattering provides a unique method for probing underlying changes in fluid nano- to microstructure, from a few angströms to several microns, of complex fluids under flow. In particular, the alignment of rigid components or shape changes of soft components can be explored, along with local inter-particle ordering and global alignment with macroscopic flow fields. This review highlights recent important developments in the study of such complex fluid systems that couple flow or shear conditions with small-angle scattering measurements, and highlights the physical insight obtained by these experiments. Recent results from neutron scattering measurements made using a simple flow cell are presented, offering a facile method to explore alignment of complex fluids in an easily accessible geometry, and contextualised within existing and potential future research questions.

7.
J Appl Behav Anal ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709201

RESUMO

We assessed whether novel praise statements could be used to (a) maintain and increase responses with existing reinforcement histories and (b) teach a previously untaught response among children diagnosed with autism spectrum disorder across two experiments. During response-stimulus pairing, two responses resulted in preferred edibles but only one also produced a praise statement. In the absence of edibles, the response continuing to produce praise tended to persist more. Next, reversing the praise contingency tended to increase the other response. However, in no case did contingent delivery of those same praise statements result in the acquisition of untaught responses. These findings suggest that conditioning praise statements could serve different functions (antecedent or consequence) depending on the reinforcement history for particular responses.

8.
Pathology ; 56(4): 459-467, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38580613

RESUMO

The classification of myeloid neoplasms continues to evolve along with advances in molecular diagnosis, risk stratification and treatment of disease. An approach for disease classification has been grounded in international consensus that has facilitated understanding, identification and management of molecularly heterogeneous entities, as well as enabled consistent patient stratification into clinical trials and clinical registries over time. The new World Health Organization (WHO) and International Consensus Classification (ICC) Clinical Advisory Committee releasing separate classification systems for myeloid neoplasms in 2022 precipitated some concern amongst haematopathology colleagues both locally and internationally. While both classifications emphasise molecular disease classification over the historical use of morphology, flow cytometry and cytogenetic based diagnostic methods, notable differences exist in how morphological, molecular and cytogenetic criteria are applied for defining myelodysplastic neoplasms (MDS) and acute myeloid leukaemias (AML). Here we review the conceptual advances, diagnostic nuances, and molecular platforms required for the diagnosis of MDS and AML using the new WHO and ICC 2022 classifications. We provide consensus recommendations for reporting bone marrow biopsies. Additionally, we address the logistical challenges encountered implementing these changes into routine laboratory practice in alignment with the National Pathology Accreditation Advisory Council reporting requirements for Australia and New Zealand.


Assuntos
Medula Óssea , Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Humanos , Austrália , Biópsia , Medula Óssea/patologia , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/classificação , Síndromes Mielodisplásicas/classificação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/patologia , Organização Mundial da Saúde
9.
Nano Lett ; 24(21): 6240-6246, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38578061

RESUMO

Monolayer 2D semiconductors, such as WS2, exhibit uniquely strong light-matter interactions due to exciton resonances that enable atomically thin optical elements. Similar to geometry-dependent plasmon and Mie resonances, these intrinsic material resonances offer coherent and tunable light scattering. Thus far, the impact of the excitons' temporal dynamics on the performance of such excitonic metasurfaces remains unexplored. Here, we show how the excitonic decay rates dictate the focusing efficiency of an atomically thin lens carved directly out of exfoliated monolayer WS2. By isolating the coherent exciton radiation from the incoherent background in the focus of the lens, we obtain a direct measure of the role of exciton radiation in wavefront shaping. Furthermore, we investigate the influence of exciton-phonon scattering by characterizing the focusing efficiency as a function of temperature, demonstrating an increased optical efficiency at cryogenic temperatures. Our results provide valuable insights into the role of excitonic light scattering in 2D nanophotonic devices.

10.
Ann Epidemiol ; 94: 33-41, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38631438

RESUMO

PURPOSE: In occupational epidemiology, the healthy worker survivor effect can manifest as a time-dependent confounder because healthier workers can accrue greater amounts of exposure over longer periods of employment. For example, in occupational studies of radiation exposure that focus on cumulative annualized radiation dose, workers can accrue greater amounts of cumulative radiation exposure over longer periods of employment, while workers with longer periods of employment can transition into jobs with a reduced potential for annualized radiation exposure. The extent to which confounding arising from the healthy worker survivor effect impacts radiation risk estimates is unknown. METHODS: We assessed the impact of the healthy worker survivor effect on estimates of radiation risk among nuclear workers in a Million Person Study cohort. In simulation studies, we contrasted the ability of marginal structural Cox models with inverse probability weighting and Cox proportional hazards models to account for time-dependent confounding arising from the healthy worker survivor effect. RESULTS: Marginal structural Cox models and Cox proportional hazards models with flexible functional forms for duration of employment provided reliable results. CONCLUSIONS: It is crucial to flexibly adjust for duration of employment to account for confounding arising from the healthy worker survivor effect in occupational epidemiology.


Assuntos
Emprego , Exposição Ocupacional , Modelos de Riscos Proporcionais , Humanos , Exposição Ocupacional/efeitos adversos , Emprego/estatística & dados numéricos , Efeito do Trabalhador Sadio , Fatores de Tempo , Masculino , Feminino , Fatores de Confusão Epidemiológicos , Adulto , Pessoa de Meia-Idade , Estudos de Coortes
11.
Appl Plant Sci ; 12(2): e11578, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638615

RESUMO

Premise: Traditional moist chamber cultures (MCs) prepared in aseptic laboratory environments using sterile Petri dishes are commonly used to quantify the microbiota of rough-bark tree species and woody vines. MCs are typically expensive and may be difficult to make, so a less expensive option made from easily available supplies was developed. These cost-friendly MCs were compared with standard laboratory methods to demonstrate their efficacy. Methods and Results: Modified MCs were made using inexpensive, store-bought supplies; compared to a standard laboratory setting, the modified MCs are shown to be less expensive with a faster setup time and larger size that facilitates a variety of tree and woody vine species. MC use resulted in the discovery of new species of fungi and myxomycetes with associated locality records. We provide detailed instructions for creating modified MCs, as well as a list of myxomycete species and their associated bark characteristics, pH values, and water-holding capacity. Conclusions: This new, low-cost MC technique makes the study of microbiota more inclusive and accessible for those in research laboratories, classrooms, and homes, including both amateurs and professionals. MCs are easy to prepare, versatile, and applicable for many areas of botany and the biological sciences, potentially allowing exploration into unexplored areas in urban ecosystems.

12.
Vet Res Commun ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662316

RESUMO

Despite the worldwide occurrence and high genetic diversity of Bartonella spp. in bats, few studies investigate their occurrence in bat-associated mites. To date, 26 species of Macronyssidae mite species have been reported from Brazil, and 15 of which were found parasitizing bats. The present study aimed to investigate the presence of Bartonella DNA in bat-associated macronyssid mites from Brazil. For this purpose, 393 macronyssid specimens were selected by convenience from the tissue bank of the Acari Collection of the Instituto Butantan (IBSP). These mites were collected from 14 different bat species in three different Brazilian States (Minas Gerais, Paraná, and Rio de Janeiro). Out of 165 mites positive in the PCR for the endogenous 18S rRNA gene, only eight were positive in the qPCR for Bartonella spp. based on the nuoG gene, and we were able to obtain two sequences base in this same gene, and one sequence based on the 16S rRNA gene. The phylogenetic inference based on the nuoG gene grouped the obtained sequences with Bartonella genotypes previously detected in bats and associated bat flies, while the phylogeny based on the 16S rRNA grouped the obtained sequence in the same clade of Bartonella genotypes previously detected in Dermanyssus gallinae. These findings suggest that macronyssid mites might be associated with the maintenance of bartonellae among bats.

13.
Artigo em Inglês | MEDLINE | ID: mdl-38679632

RESUMO

PURPOSE: This paper reports a life cycle impact assessment (LCIA) to calculate the environmental footprint of a dental appointment using N2O, comparing single-use equipment with reusable equipment. Nitrous oxide (N2O) is used successfully in dentistry to provide sedation and pain relief to anxious patients, most commonly in children. However, N2O is a powerful climate pollutant 298 times more damaging than carbon dioxide over a 100-year estimate. METHODS: The functional unit chosen for this LCIA was 30 min delivery of N2O to oxygen in a 50:50 ratio at 6 L per minute flow rate as inhalation sedation to one patient. Two types of equipment were compared to deliver the anaesthetic gas: reusable and disposable items. RESULTS: The use of disposable equipment for N2O sedation produces a significantly larger environmental impact across nearly all of the environmental impact scores, but the overall global warming potential is comparable for both types of equipment due to the vast environmental pollution from N2O itself. CONCLUSION: N2O sedation is a reliable treatment adjunct but contributes to climate change. Single-use equipment has a further deleterious effect on the environment, though this is small compared to the overall impact of N2O. Dental priorities should be to deliver safe and effective care to patients that protects staff, minimises waste and mitigates impact on the environment alongside promoting research into alternatives.

14.
Blood Adv ; 8(9): 2248-2258, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38429096

RESUMO

ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening, hyperinflammatory syndrome. Emapalumab, a fully human monoclonal antibody that neutralizes the proinflammatory cytokine interferon gamma, is approved in the United States to treat primary HLH (pHLH) in patients with refractory, recurrent, or progressive disease, or intolerance with conventional HLH treatments. REAL-HLH, a retrospective study, conducted across 33 US hospitals, evaluated real-world treatment patterns and outcomes in patients treated with ≥1 dose of emapalumab between 20 November 2018 and 31 October 2021. In total, 46 patients met the pHLH classification criteria. Median age at diagnosis was 1.0 year (range, 0.3-21.0). Emapalumab was initiated for treating refractory (19/46), recurrent (14/46), or progressive (7/46) pHLH. At initiation, 15 of 46 patients were in the intensive care unit, and 35 of 46 had received prior HLH-related therapies. Emapalumab treatment resulted in normalization of key laboratory parameters, including chemokine ligand 9 (24/33, 72.7%), ferritin (20/45, 44.4%), fibrinogen (37/38, 97.4%), platelets (39/46, 84.8%), and absolute neutrophil count (40/45, 88.9%). Forty-two (91.3%) patients were considered eligible for transplant. Pretransplant survival was 38 of 42 (90.5%). Thirty-one (73.8%) transplant-eligible patients proceeded to transplant, and 23 of 31 (74.2%) of those who received transplant were alive at the end of the follow-up period. Twelve-month survival probability from emapalumab initiation for the entire cohort (N = 46) was 73.1%. There were no discontinuations because of adverse events. In conclusion, results from the REAL-HLH study, which describes treatment patterns, effectiveness, and outcomes in patients with pHLH treated with emapalumab in real-world settings, are consistent with the emapalumab pivotal phase 2/3 pHLH trial.


Assuntos
Linfo-Histiocitose Hemofagocítica , Humanos , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Linfo-Histiocitose Hemofagocítica/mortalidade , Linfo-Histiocitose Hemofagocítica/etiologia , Feminino , Masculino , Resultado do Tratamento , Adolescente , Criança , Estudos Retrospectivos , Pré-Escolar , Lactente , Adulto Jovem , Anticorpos Monoclonais/uso terapêutico , Adulto
15.
Neurooncol Adv ; 6(1): vdae025, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38486856

RESUMO

Glioblastoma multiforme (GBM) is an aggressive cancer that has been difficult to treat and often requires multimodal therapy consisting of surgery, radiotherapy, and chemotherapy. Chimeric antigen receptor-expressing (CAR-T) cells have been efficacious in treating hematological malignancies, resulting in several FDA-approved therapies. CAR-T cells have been more recently studied for the treatment of GBM, with some promising preclinical and clinical results. The purpose of this literature review is to highlight the commonly targeted antigens, results of clinical trials, novel modifications, and potential solutions for challenges that exist for CAR-T cells to become more widely implemented and effective in eradicating GBM.

16.
Sci Adv ; 10(10): eadj8803, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457494

RESUMO

Philadelphia chromosome-positive B cell acute lymphoblastic leukemia (B-ALL), characterized by the BCR::ABL1 fusion gene, remains a poor prognosis cancer needing new therapeutic approaches. Transcriptomic profiling identified up-regulation of oncogenic transcription factors ERG and c-MYC in BCR::ABL1 B-ALL with ERG and c-MYC required for BCR::ABL1 B-ALL in murine and human models. Profiling of ERG- and c-MYC-dependent gene expression and analysis of ChIP-seq data established ERG and c-MYC coordinate a regulatory network in BCR::ABL1 B-ALL that controls expression of genes involved in several biological processes. Prominent was control of ribosome biogenesis, including expression of RNA polymerase I (POL I) subunits, the importance of which was validated by inhibition of BCR::ABL1 cells by POL I inhibitors, including CX-5461, that prevents promoter recruitment and transcription initiation by POL I. Our results reveal an essential ERG- and c-MYC-dependent transcriptional network involved in regulation of metabolic and ribosome biogenesis pathways in BCR::ABL1 B-ALL, from which previously unidentified vulnerabilities and therapeutic targets may emerge.


Assuntos
Proteínas de Fusão bcr-abl , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Regulador Transcricional ERG , Animais , Humanos , Camundongos , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Proteínas de Fusão bcr-abl/uso terapêutico , Redes Reguladoras de Genes , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras , Fatores de Transcrição/genética , Regulador Transcricional ERG/genética
18.
Appl Physiol Nutr Metab ; 49(6): 855-867, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38394645

RESUMO

To protect vulnerable populations during heat waves, public health agencies recommend maintaining indoor air temperature below ∼24-28 °C. While we recently demonstrated that maintaining indoor temperatures ≤26 °C mitigates the development of hyperthermia and cardiovascular strain in older adults, the cellular consequences of prolonged indoor heat stress are poorly understood. We therefore evaluated the cellular stress response in 16 adults (six females) aged 66-78 years during 8 h rest in ambient conditions simulating homes maintained at 22 °C (control) and 26 °C (indoor temperature upper limit proposed by health agencies), as well as non-air-conditioned domiciles during hot weather and heat waves (31 and 36 °C, respectively; all 45% relative humidity). Western blot analysis was used to assess changes in proteins associated with the cellular stress response (autophagy, apoptosis, acute inflammation, and heat shock proteins) in peripheral blood mononuclear cells harvested prior to and following exposure. Following 8 h exposure, no cellular stress response-related proteins differed significantly between the 26 and 22 °C conditions (all, P ≥ 0.056). By contrast, autophagy-related proteins were elevated following exposure to 31 °C (p62: 1.5-fold; P = 0.003) and 36 °C (LC3-II, LC3-II/I, p62; all ≥2.0-fold; P ≤ 0.002) compared to 22 °C. These responses were accompanied by elevations in apoptotic signaling in the 31 and 36 °C conditions (cleaved-caspase-3: 1.8-fold and 3.7-fold, respectively; P ≤ 0.002). Furthermore, HSP90 was significantly reduced in the 36 °C compared to 22 °C condition (0.7-fold; P = 0.014). Our findings show that older adults experience considerable cellular stress during prolonged exposure to elevated ambient temperatures and support recommendations to maintain indoor temperatures ≤26 °C to prevent physiological strain in heat-vulnerable persons.


Assuntos
Autofagia , Temperatura Alta , Humanos , Idoso , Autofagia/fisiologia , Feminino , Masculino , Leucócitos Mononucleares/metabolismo , Apoptose , Resposta ao Choque Térmico/fisiologia , Proteínas de Choque Térmico/metabolismo , Habitação , Estresse Fisiológico
19.
PNAS Nexus ; 3(2): pgae008, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38390215

RESUMO

Linking individual and stand-level dynamics during forest development reveals a scaling relationship between mean tree size and tree density in forest stands, which integrates forest structure and function. However, the nature of this so-called scaling law and its variation across broad spatial scales remain unquantified, and its linkage with forest demographic processes and carbon dynamics remains elusive. In this study, we develop a theoretical framework and compile a broad-scale dataset of long-term sample forest stands (n = 1,433) from largely undisturbed forests to examine the association of temporal mean tree size vs. density scaling trajectories (slopes) with biomass accumulation rates and the sensitivity of scaling slopes to environmental and demographic drivers. The results empirically demonstrate a large variation of scaling slopes, ranging from -4 to -0.2, across forest stands in tropical, temperate, and boreal forest biomes. Steeper scaling slopes are associated with higher rates of biomass accumulation, resulting from a lower offset of forest growth by biomass loss from mortality. In North America, scaling slopes are positively correlated with forest stand age and rainfall seasonality, thus suggesting a higher rate of biomass accumulation in younger forests with lower rainfall seasonality. These results demonstrate the strong association of the transient mean tree size vs. density scaling trajectories with forest demography and biomass accumulation rates, thus highlighting the potential of leveraging forest structure properties to predict forest demography, carbon fluxes, and dynamics at broad spatial scales.

20.
Environ Health Perspect ; 132(2): 27003, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38329752

RESUMO

BACKGROUND: Health agencies recommend that homes of heat-vulnerable occupants (e.g., older adults) be maintained below 24-28°C to prevent heat-related mortality and morbidity. However, there is limited experimental evidence to support these recommendations. OBJECTIVE: To aid in the development of evidence-based guidance on safe indoor temperatures for temperate continental climates, we evaluated surrogate physiological outcomes linked with heat-related mortality and morbidity in older adults during simulated indoor overheating. METHODS: Sixteen older adults [six women; median age: 72 y, interquartile range (IQR): 70-73 y; body mass index: 24.6 (IQR: 22.1-27.0) kg/m2] from the Ottawa, Ontario, Canada, region (warm summer continental climate) completed four randomized, 8-h exposures to conditions experienced indoors during hot weather in continental climates (e.g., Ontario, Canada; 64 participant exposures). Ambient conditions simulated an air-conditioned environment (22°C; control), proposed indoor temperature upper limits (26°C), and temperatures experienced in homes without air-conditioning (31°C and 36°C). Core temperature (rectal) was monitored as the primary outcome; based on previous recommendations, between-condition differences >0.3°C were considered clinically meaningful. RESULTS: Compared with 22°C, core temperature was elevated to a meaningful extent in 31°C [+0.7°C; 95% confidence interval (CI): 0.5, 0.8] and 36°C (+0.9°C; 95% CI: 0.8, 1.1), but not 26°C (+0.2°C, 95% CI: 0.0, 0.3). Increasing ambient temperatures were also associated with elevated heart rate and reduced arterial blood pressure and heart rate variability at rest, as well as progressive impairments in cardiac and blood pressure responses to standing from supine. DISCUSSION: Core temperature and cardiovascular strain were not appreciably altered following 8-h exposure to 26°C but increased progressively in conditions above this threshold. These data support proposals for the establishment of a 26°C indoor temperature upper limit for protecting vulnerable occupants residing in temperate continental climates from indoor overheating. https://doi.org/10.1289/EHP13159.


Assuntos
Sistema Cardiovascular , Coração , Idoso , Feminino , Humanos , Estudos Cross-Over , Ontário , Temperatura , Masculino
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