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1.
J Physiol ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38687185

RESUMO

During acute hypoxic exposure, cerebral blood flow (CBF) increases to compensate for the reduced arterial oxygen content (CaO2). Nevertheless, as exposure extends, both CaO2 and CBF progressively normalize. Haemoconcentration is the primary mechanism underlying the CaO2 restoration and may therefore explain, at least in part, the CBF normalization. Accordingly, we tested the hypothesis that reversing the haemoconcentration associated with extended hypoxic exposure returns CBF towards the values observed in acute hypoxia. Twenty-three healthy lowlanders (12 females) completed two identical 4-day sojourns in a hypobaric chamber, one in normoxia (NX) and one in hypobaric hypoxia (HH, 3500 m). CBF was measured by ultrasound after 1, 6, 12, 48 and 96 h and compared between sojourns to assess the time course of changes in CBF. In addition, CBF was measured at the end of the HH sojourn after hypervolaemic haemodilution. Compared with NX, CBF was increased in HH after 1 h (P = 0.001) but similar at all later time points (all P > 0.199). Haemoglobin concentration was higher in HH than NX from 12 h to 96 h (all P < 0.001). While haemodilution reduced haemoglobin concentration from 14.8 ± 1.0 to 13.9 ± 1.2 g·dl-1 (P < 0.001), it did not increase CBF (974 ± 282 to 872 ± 200 ml·min-1; P = 0.135). We thus conclude that, at least at this moderate altitude, haemoconcentration is not the primary mechanism underlying CBF normalization with acclimatization. These data ostensibly reflect the fact that CBF regulation at high altitude is a complex process that integrates physiological variables beyond CaO2. KEY POINTS: Acute hypoxia causes an increase in cerebral blood flow (CBF). However, as exposure extends, CBF progressively normalizes. We investigated whether hypoxia-induced haemoconcentration contributes to the normalization of CBF during extended hypoxia. Following 4 days of hypobaric hypoxic exposure (corresponding to 3500 m altitude), we measured CBF before and after abolishing hypoxia-induced haemoconcentration by hypervolaemic haemodilution. Contrary to our hypothesis, the haemodilution did not increase CBF in hypoxia. Our findings do not support haemoconcentration as a stimulus for the CBF normalization during extended hypoxia.

2.
Biomolecules ; 14(4)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38672497

RESUMO

BACKGROUND: In military flight operations, during flights, fighter pilots constantly work under hyperoxic breathing conditions with supplemental oxygen in varying hypobaric environments. These conditions are suspected to cause oxidative stress to neuronal organ tissues. For civilian flight operations, the Federal Aviation Administration (FAA) also recommends supplemental oxygen for flying under hypobaric conditions equivalent to higher than 3048 m altitude, and has made it mandatory for conditions equivalent to more than 3657 m altitude. AIM: We hypothesized that hypobaric-hyperoxic civilian commercial and private flight conditions with supplemental oxygen in a flight simulation in a hypobaric chamber at 2500 m and 4500 m equivalent altitude would cause significant oxidative stress in healthy individuals. METHODS: Twelve healthy, COVID-19-vaccinated (third portion of vaccination 15 months before study onset) subjects (six male, six female, mean age 35.7 years) from a larger cohort were selected to perform a 3 h flight simulation in a hypobaric chamber with increasing supplemental oxygen levels (35%, 50%, 60%, and 100% fraction of inspired oxygen, FiO2, via venturi valve-equipped face mask), switching back and forth between simulated altitudes of 2500 m and 4500 m. Arterial blood pressure and oxygen saturation were constantly measured via radial catheter and blood samples for blood gases taken from the catheter at each altitude and oxygen level. Additional blood samples from the arterial catheter at baseline and 60% oxygen at both altitudes were centrifuged inside the chamber and the serum was frozen instantly at -21 °C for later analysis of the oxidative stress markers malondialdehyde low-density lipoprotein (M-LDL) and glutathione-peroxidase 1 (GPX1) via the ELISA test. RESULTS: Eleven subjects finished the study without adverse events. Whereas the partial pressure of oxygen (PO2) levels increased in the mean with increasing oxygen levels from baseline 96.2 mm mercury (mmHg) to 160.9 mmHg at 2500 m altitude and 60% FiO2 and 113.2 mmHg at 4500 m altitude and 60% FiO2, there was no significant increase in both oxidative markers from baseline to 60% FiO2 at these simulated altitudes. Some individuals had a slight increase, whereas some showed no increase at all or even a slight decrease. A moderate correlation (Pearson correlation coefficient 0.55) existed between subject age and glutathione peroxidase levels at 60% FiO2 at 4500 m altitude. CONCLUSION: Supplemental oxygen of 60% FiO2 in a flight simulation, compared to flying in cabin pressure levels equivalent to 2500 m-4500 m altitude, does not lead to a significant increase or decrease in the oxidative stress markers M-LDL and GPX1 in the serum of arterial blood.


Assuntos
Altitude , Estresse Oxidativo , Oxigênio , Humanos , Masculino , Feminino , Adulto , Oxigênio/metabolismo , COVID-19 , Hiperóxia/sangue , Aeronaves , Oxigenoterapia Hiperbárica
3.
Postgrad Med J ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38298001

RESUMO

PURPOSE: 'Low-value' clinical care and medical services are 'questionable' activities, being more likely to cause harm than good or with disproportionately low benefit relative to cost. This study examined the predictive ability of the QUestionable In Training Clinical Activities Index (QUIT-CAI) for general practice (GP) registrars' (trainees') performance in Australian GP Fellowship examinations (licensure/certification examinations for independent GP). METHODS: The study was nested in ReCEnT, an ongoing cohort study in which Australian GP registrars document their in-consultation clinical practice. Outcome factors in analyses were individual registrars' scores on the three Fellowship examinations ('AKT', 'KFP', and 'OSCE' examinations) and pass/fail rates during 2012-21. Analyses used univariable and multivariable regression (linear or logistic, as appropriate). The study factor in each analysis was 'QUIT-CAI score percentage'-the percentage of times a registrar performed a QUIT-CAI clinical activity when 'at risk' (i.e. when managing a problem where performing a QUIT-CAI activity was a plausible option). RESULTS: A total of 1265, 1145, and 553 registrars sat Applied Knowledge Test, Key Features Problem, and Objective Structured Clinical Exam examinations, respectively. On multivariable analysis, higher QUIT-CAI score percentages (more questionable activities) were significantly associated with poorer Applied Knowledge Test scores (P = .001), poorer Key Features Problem scores (P = .003), and poorer Objective Structured Clinical Exam scores (P = .005). QUIT-CAI score percentages predicted Royal Australian College of General Practitioner exam failure [odds ratio 1.06 (95% CI 1.00, 1.12) per 1% increase in QUIT-CAI, P = .043]. CONCLUSION: Performing questionable clinical activities predicted poorer performance in the summative Fellowship examinations, thereby validating these examinations as measures of actual clinical performance (by our measure of clinical performance, which is relevant for a licensure/certification examination).

4.
J Physiol ; 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38408065

RESUMO

Hypoxia at high altitude facilitates changes in ventilatory control that can lead to nocturnal periodic breathing (nPB). Here, we introduce a placebo-controlled approach to prevent nPB by increasing inspiratory CO2 and used it to assess whether nPB contributes to the adverse effects of hypoxia on sleep architecture. In a randomized, single-blinded, crossover design, 12 men underwent two sojourns (three days/nights each, separated by 4 weeks) in hypobaric hypoxia corresponding to 4000 m altitude, with polysomnography during the first and third night of each sojourn. During all nights, subjects' heads were encompassed by a canopy retaining exhaled CO2 , and CO2 concentration in the canopy (i.e. inspiratory CO2 concentration) was controlled by adjustment of fresh air inflow. Throughout the placebo sojourn inspiratory CO2 was ≤0.2%, whereas throughout the other sojourn it was increased to 1.76% (IQR, 1.07%-2.44%). During the placebo sojourn, total sleep time (TST) with nPB was 54.3% (37.4%-80.8%) and 45.0% (24.5%-56.5%) during the first and the third night, respectively (P = 0.042). Increased inspiratory CO2 reduced TST with nPB by an absolute 38.1% (28.1%-48.1%), the apnoea-hypopnoea index by 58.1/h (40.1-76.1/h), and oxygen desaturation index ≥3% by 56.0/h (38.9.1-73.2/h) (all P < 0.001), whereas it increased the mean arterial oxygen saturation in TST by 2.0% (0.4%-3.5%, P = 0.035). Increased inspiratory CO2 slightly increased the percentage of N3 sleep during the third night (P = 0.045), without other effects on sleep architecture. Increasing inspiratory CO2 effectively prevented hypoxia-induced nPB without affecting sleep macro-architecture, indicating that nPB does not explain the sleep deterioration commonly observed at high altitudes. KEY POINTS: Periodic breathing is common during sleep at high altitude, and it is unclear how this affects sleep architecture. We developed a placebo-controlled approach to prevent nocturnal periodic breathing (nPB) with inspiratory CO2 administration and used it to assess the effects of nPB on sleep in hypobaric hypoxia. Nocturnal periodic breathing was effectively mitigated by an increased inspiratory CO2 fraction in a blinded manner. Prevention of nPB did not lead to relevant changes in sleep architecture in hypobaric hypoxia. We conclude that nPB does not explain the deterioration in sleep architecture commonly observed at high altitude.

5.
Int J Qual Health Care ; 35(4): 0, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37757860

RESUMO

Nonevidence-based and 'low-value' clinical care and medical services are 'questionable' clinical activities that are more likely to cause harm than good or whose benefit is disproportionately low compared with their cost. This study sought to establish general practitioner (GP), patient, practice, and in-consultation associations of an index of key nonevidence-based or low-value 'questionable' clinical practices. The study was nested in the Registrar Clinical Encounters in Training study-an ongoing (from 2010) cohort study in which Australian GP registrars (specialist GP trainees) record details of their in-consultation clinical and educational practice 6-monthly. The outcome factor in analyses, performed on Registrar Clinical Encounters in Training data from 2010 to 2020, was the score on the QUestionable In-Training Clinical Activities Index (QUIT-CAI), which incorporates recommendations of the Australian Choosing Wisely campaign. A cross-sectional analysis used negative binomial regression (with the model including an offset for the number of times the registrar was at risk of performing a questionable activity) to establish associations of QUIT-CAI scores. A total of 3206 individual registrars (response rate 89.9%) recorded 406 812 problems/diagnoses where they were at risk of performing a questionable activity. Of these problems/diagnoses, 15 560 (3.8%) involved questionable activities being performed. In multivariable analyses, higher QUIT-CAI scores (more questionable activities) were significantly associated with earlier registrar training terms: incidence rate ratios (IRRs) of 0.91 [95% confidence interval (CI) 0.87, 0.95] and 0.85 (95% CI 0.80, 0.90) for Term 2 and Term 3, respectively, compared to Term 1. Other significant associations of higher scores included the patient being new to the registrar (IRR 1.27; 95% CI 1.12, 1.45), the patient being of non-English-speaking background (IRR 1.24; 95% CI 1.04, 1.47), the practice being in a higher socioeconomic area decile (IRR 1.01; 95% CI 1.00, 1.02), small practice size (IRR 1.05; 95% CI 1.00, 1.10), shorter consultation duration (IRR 0.99 per minute; 95% CI 0.99, 1.00), and fewer problems addressed in the consultation (IRR 0.84; 95% CI 0.79, 0.89) for each additional problem]. Senior registrars' clinical practice entailed less 'questionable' clinical actions than junior registrars' practice. The association of lower QUIT-CAI scores with a measure of greater continuity of care (the patient not being new to the registrar) suggests that continuity should be supported and facilitated during GP training (and in established GPs' practice).


Assuntos
Medicina Geral , Clínicos Gerais , Cuidados de Baixo Valor , Humanos , Austrália , Estudos de Coortes , Estudos Transversais
6.
Jt Comm J Qual Patient Saf ; 49(12): 712-715, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37599137

RESUMO

BACKGROUND: Outpatient clinic letters are recognized as an important component of patient care. This project aimed to coproduce clinic letters that have meaning and relevance for key stakeholders. METHODS: This health care improvement project was conducted in one musculoskeletal therapy (physiotherapy and osteopathy) department in southern England using a Lean Six Sigma Define, Measure, Analyze, Improve, and Control-inspired framework. The views and experiences of key stakeholders, including therapists, general practitioners, and patients, were explored using surveys and group meeting methods. New letter designs were coproduced with stakeholders, including patient partners and personalized care lead staff, and were refined through a pilot phase. Qualitative data were analyzed thematically, and quantitative data were analyzed descriptively. RESULTS: Overall, patients and therapists found the clinic letters an important and meaningful part of care. However, therapists reported that they often did not write the letters, and time was identified as the main barrier. The main theme identified from patient feedback was that patients wanted to write the letters in collaboration with the clinician. The pilot phase demonstrated that, on average, the new letters took less time to write. CONCLUSION: This project has coproduced new clinic letters and operational processes centered on the needs of key stakeholders. This article will help other outpatient departments reflect on their own clinic letters and consider their meaning and relevance for their stakeholders.


Assuntos
Atenção à Saúde , Alta do Paciente , Humanos , Instituições de Assistência Ambulatorial , Pacientes Ambulatoriais
7.
High Alt Med Biol ; 24(2): 94-103, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37339401

RESUMO

Kammerer, Tobias, Anna Walzl, Thomas Müller, Philipp Groene, Giulia Roveri, Rachel Turner, Johanna Roche, Hannes Gatterer, Christoph Siebenmann, and Simon T. Schäfer. Effects of hypobaric hypoxia on coagulation in healthy subjects exposed to 3,500 m altitude. High Alt Med Biol. 24:94-103, 2023. Background: Hypoxia is discussed as a trigger for prothrombotic changes both in intensive care and high altitude medicine. This research study aimed to evaluate the effect of isolated hypobaric hypoxia (HH) on coagulation in females in a highly standardized setting. Methods: Twelve healthy female subjects were studied under HH (equivalent to 3,500 m) and normoxia (NX) during two 4-day sojourns, in a strictly controlled crossover design. Nutrition, fluid intake, hormonal status (i.e., menstrual cycle variation), and physical stress were standardized. Functional coagulation and blood lysis were measured by viscoelastometry and compared between HH and NX. In addition, plasma-based coagulation tests (PBCTs), namely prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII coagulation activity (FVIII:C), von Willebrand factor antigen (vWF:Ag), and von Willebrand factor ristocetin cofactor activity (vWF:RCo) were measured. Results: Neither for Viscoelastic Haemostatic Assays nor for PBCTs significant changes were found for HH compared with NX (all p > 0.05). Specifically, the lysis ability, as well as clotting time, clot formation, clot amplitude, and maximum clot firmness unchanged were similar between HH and NX. This also applied to all other variables. Conclusion: We demonstrate that moderate HH per se has no influence on blood coagulation in healthy females.


Assuntos
Fator VIII , Fator de von Willebrand , Humanos , Feminino , Altitude , Voluntários Saudáveis , Coagulação Sanguínea , Hipóxia
8.
PLoS One ; 18(1): e0280668, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662823

RESUMO

INTRODUCTION: Second-line pharmacotherapy for Type 2 Diabetes Mellitus ('diabetes') is necessary for optimal glycaemic control and preventing longer-term complications. We aimed to describe temporal trends in, and associations of, Australian general practitioner (GP) registrars' prescription, and initiation, of 'new' second-line oral agents (dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 agonists) compared to sulphonylureas. MATERIALS AND METHODS: A longitudinal analysis (2010-2018) of data from the Registrar Clinical Encounters in Training project. Analysis included any diabetes problem/diagnosis that involved prescription of sulphonylureas or 'new' oral agents. Simple and multiple logistic regression models were fitted within the generalised estimating equations framework. RESULTS: 2333 registrars recorded 6064 diabetes problems/diagnoses (1.4%). 835 problems/diagnoses involved sulphonylurea or 'new' medication prescription. Of these, 61.0% [95% CI:57.4-64.4] involved 'new' medication prescription. 230 problems/diagnoses involved sulphonylurea or 'new' medication initiation, with 77% [95%CI:70.8-82.1] involving a 'new' medication. There was a significant 52% per year increase in prescribing (OR = 1.52[95% CI:1.38-1.68],p<0.001), and a 77% per (two-to-three-year) time-interval increase in initiation (OR = 1.77,[95% CI:1.30-2.43],p = <0.001) of 'new' medications compared to sulphonylureas. 'New' medications were prescribed less for non-English-speaking patients. There was some regional variation in prescribing. CONCLUSION: Registrar uptake of 'new' oral agents compared to sulphonylureas has increased rapidly.


Assuntos
Diabetes Mellitus Tipo 2 , Clínicos Gerais , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Austrália/epidemiologia , Compostos de Sulfonilureia/uso terapêutico , Prescrições de Medicamentos , Hipoglicemiantes/uso terapêutico
9.
J Appl Physiol (1985) ; 134(1): 133-141, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36476162

RESUMO

Altitude exposure may suppress appetite and hence provide a viable weight-loss strategy. While changes in food intake and availability as well as physical activity may contribute to altered appetite at altitude, herein we aimed to investigate the isolated effects of hypobaric hypoxia on appetite regulation and sensation. Twelve healthy women (age: 24.0 ± 4.2 years, body mass: 60.6 ± 7.0 kg) completed two 4-day sojourns in a hypobaric chamber, one in normoxia [PB = 761 mmHg, 262 m (NX)] and one in hypobaric hypoxia [PB = 493 mmHg (HH)] equivalent to 3,500-m altitude. Energy intake was standardized 4 days prior and throughout both sojourns. Plasma concentrations of leptin, acylated ghrelin, cholecystokinin (CCK), and cytokine growth differentiation factor 15 (GDF15) were determined every morning. Before and after breakfast, lunch, and dinner, appetite was assessed using visual analog scales. Body mass was significantly decreased following HH but not NX (-0.71 ± 0.32 kg vs. -0.05 ± 0.54 kg, condition: P < 0.001). Compared to NX, acylated ghrelin decreased throughout the HH sojourn (condition × time: P = 0.020), while leptin was higher throughout the entire HH sojourn (condition: P < 0.001). No differences were observed in CCK and GDF15 between the sojourns. Feelings of satiety and fullness were higher (condition: P < 0.001 and P = 0.013, respectively), whereas prospective food consumption was lower in HH than in NX (condition: P < 0.001). Our findings suggest that hypoxia exerts an anorexigenic effect on appetite-regulating hormones, suppresses subjective appetite sensation, and can induce weight loss in young healthy women. Among the investigated hormones, acylated ghrelin and leptin most likely explain the observed HH-induced appetite suppression.NEW & NOTEWORTHY This study investigated the effects of hypoxia on appetite regulation in women while strictly controlling for diet, physical activity, menstrual cycle, and environmental conditions. In young women, 4 days of altitude exposure (3,500 m) decreases body weight and circulating acylated ghrelin levels while preserving leptin concentrations. In line with the hormonal changes, altitude exposure induces alterations in appetite sensation, consisting of a decreased feeling of hunger and prospective food intake and an increased feeling of fullness and satiety.


Assuntos
Altitude , Apetite , Humanos , Feminino , Adulto Jovem , Adulto , Apetite/fisiologia , Grelina , Leptina , Hipóxia , Ingestão de Energia , Redução de Peso , Sensação
10.
J Patient Rep Outcomes ; 6(1): 128, 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36547735

RESUMO

BACKGROUND: To understand our performance with respect to the collection and reporting of patient-reported outcome (PRO) measure (PROM) data, we examined the protocol content, data completeness and publication of PROs from interventional trials conducted at the Royal Marsden NHS Foundation Trust (RM) and explored factors associated with data missingness and PRO publication. DESIGN: From local records, we identified closed, intervention trials sponsored by RM that opened after 1995 and collected PROMs as primary, secondary or exploratory outcomes. Protocol data were extracted by two researchers and scored against the SPIRIT-PRO (PRO protocol content checklist; score 0-100, higher scores indicate better completeness). For studies with locally held datasets, the information team summarized for each study, PRO completion defined as the number of expected (as per protocol) PRO measurements versus the number of actual (i.e. completed) PRO measurements captured in the study data set. Relevant publications were identified by searching three online databases and chief investigator request. Data were extracted and each publication scored against the CONSORT-PRO (PRO manuscript content checklist; scored as SPIRIT-PRO above). Descriptive statistics are presented with exploratory comparisons of point estimates and 95% confidence intervals. RESULTS: Twenty-six of 65 studies were included in the review. Nineteen studies had accessible datasets and 18 studies published at least one article. Fourteen studies published PRO results. Most studies had a clinical (rather than PRO) primary outcome (16/26). Across all studies, responses in respect of 35 of 69 PROMs were published. Trial protocols scored on average 46.7 (range 7.1-92.9) on the SPIRIT-PRO. Among studies with accessible data, half (10/19) had less than 25% missing measurements. Publications scored on average 80.9 (range 36-100%) on the CONSORT-PRO. Studies that published PRO results had somewhat fewer missing measurements (19% [7-32%] vs 60% [- 26 to 146%]). For individual PROMs within studies, missing measurements were lower for those that were published (17% [10-24%] vs 41% [18-63%]). Studies with higher SPIRIT-PRO scores and PROs as primary endpoints (13% [4-22%] vs 39% [10-58%]) had fewer missing measurements. CONCLUSIONS: Missing data may affect publication of PROs. Extent of inclusion of SPIRIT-PRO protocol items and PROs as primary endpoints may improve data completeness. Preliminary evidence from the study suggests a future larger study examining the relationship between PRO completion and publication is warranted.

11.
Am J Physiol Heart Circ Physiol ; 323(5): H1048-H1054, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240437

RESUMO

We sought to determine the effects of prolonged moderate hypobaric hypoxia (HH) on cardiac baroreflex sensitivity (cBRS) in young women and whether these effects are a consequence of the reduced arterial oxygen (O2) tension and/or increased pulmonary ventilation in HH. We hypothesized that HH would reduce cBRS and that this effect would be counteracted by acute restoration of the inspiratory partial pressure of O2 ([Formula: see text]) and/or voluntary attenuation of pulmonary ventilation. Twelve healthy women (24.0 ± 4.2 yr) were studied before (day 0) and twice during a sojourn in a hypobaric chamber (∼8 h, day 1; 4 days, day 4) where barometric pressure corresponded to ∼3,500-m altitude. Minute ventilation (V̇e; pneumotachometer), heart rate (electrocardiogram), and arterial pressure (finger volume clamp method) were recorded. cBRS was calculated using transfer function analysis between systolic pressure and RR interval. Assessments were made during 1) spontaneous breathing and (in HH only), 2) controlled breathing (reducing V̇e by ∼1 to 2 L/min), and 3) breathing a hyperoxic gas mixture that normalized [Formula: see text]. During spontaneous breathing, HH decreased cBRS (12.5 ± 7.1, 8.9 ± 4.4, and 7.4 ± 3.0 ms/mmHg on days 0, 1, and 4, respectively; P = 0.018). The normalization of [Formula: see text] increased cBRS (10.6 ± 3.3 and 10.7 ± 6.1 ms/mmHg on days 1 and 4) in HH compared with values observed during spontaneous breathing (P < 0.001), whereas controlled breathing had no effect on cBRS (P = 0.708). These findings indicate that ongoing arterial chemoreflex activation by the reduced arterial O2 tension, independently of the hypoxic ventilatory response, reduces cBRS in young women exposed to extended HH.NEW & NOTEWORTHY We examined the effects of prolonged hypobaric hypoxia (corresponding to ∼3,500-m altitude) on cardiac baroreflex sensitivity (cBRS) in young women and investigated underlying mechanisms. We found that cBRS was reduced in hypoxia and that this reduction was attenuated by acute restoration of inspiratory oxygen partial pressure but not by volitional restraint of pulmonary ventilation. These findings help to elucidate the role of arterial chemoreflex mechanisms in the control of cBRS during hypobaric hypoxia in young women.


Assuntos
Doença da Altitude , Barorreflexo , Humanos , Feminino , Hipóxia , Altitude , Oxigênio , Frequência Cardíaca/fisiologia
12.
Tumour Biol ; 44(1): 205-213, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189508

RESUMO

BACKGROUND: CA125 is the gold standard serum biomarker for monitoring patients with epithelial ovarian cancer (EOC). Human epididymal protein 4 (HE4) is a novel serum biomarker for EOC patients. OBJECTIVE: The objective of this trial was to examine the utility of measuring serum HE4 levels for monitoring EOC patients and to compare HE4 performance parameters to serum CA125. METHODS: A retrospective trial using residual longitudinal serum samples drawn during treatment and monitoring from EOC patients. Serum CA125 and HE4 levels were analyzed at each time point, and a velocity of change was calculated and correlated with clinical status. The null hypothesis was that HE4 is inferior to CA125, and this was tested using concordance and two-sided Fisher's exact testing. McNemar's test was used to assess the overall agreement of the two assays with the clinical status. RESULTS: A total of 129 patients with 272 separate clinical periods and 1739 events (serum samples) were evaluated. Using a 25% change in serum biomarker levels to indicate change in disease status, the accuracy and NPV determined for HE4 versus CA125 were 81.8% versus 82.6% (p = 0.846) and 87.4% versus 89.7% (p = 0.082), respectively. Concordance comparison of HE4 accuracy / CA125 accuracy was 0.990, indicating HE4 was not inferior to CA125 (McNemar's test p-value = 0.522). Performing a velocity of change analysis, the accuracy and NPV determined for HE4 versus CA125 were 78.3% versus 78.6% (p = 0.995) and 74.9% versus 76.3% (p = 0.815), respectively. Concordance comparison of HE4 velocity accuracy / CA125 velocity accuracy was 0.996, again indicating HE4 was not inferior to CA125 (McNemar's test p-value = 0.884). The combination of HE4 and CA125 velocity changes showed a similar accuracy of 81.3% (p = 0.797 compared to HE4 and CA125 alone) and NPV of 81.1% (p≥0.172 compared to HE4 and CA125 alone), and an increased sensitivity of 70.5% (p≤0.070 compared to HE4 and CA125 alone). CONCLUSION: HE4 is equivalent to CA125 for monitoring of EOC patients. The combination of CA125 and HE4 velocities is superior to either marker alone.


Assuntos
Neoplasias Epiteliais e Glandulares , Neoplasias Ovarianas , Biomarcadores Tumorais , Antígeno Ca-125 , Carcinoma Epitelial do Ovário , Feminino , Humanos , Proteínas de Membrana , Estudos Retrospectivos
13.
Am J Physiol Heart Circ Physiol ; 323(6): H1068-H1079, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36269645

RESUMO

We have recently reported that hypobaric hypoxia (HH) reduces plasma volume (PV) in men by decreasing total circulating plasma protein (TCPP). Here, we investigated whether this applies to women and whether an inflammatory response and/or endothelial glycocalyx shedding could facilitate the TCCP reduction. We further investigated whether acute HH induces a short-lived diuretic response that was overlooked in our recent study, where only 24-h urine volumes were evaluated. In a strictly controlled crossover protocol, 12 women underwent two 4-day sojourns in a hypobaric chamber: one in normoxia (NX) and one in HH equivalent to 3,500-m altitude. PV, urine output, TCPP, and markers for inflammation and glycocalyx shedding were repeatedly measured. Total body water (TBW) was determined pre- and postsojourns by deuterium dilution. PV was reduced after 12 h of HH and thereafter remained 230-330 mL lower than in NX (P < 0.0001). Urine flow was 45% higher in HH than in NX throughout the first 6 h (P = 0.01) but lower during the second half of the first day (P < 0.001). Twenty-four-hour urine volumes (P ≥ 0.37) and TBW (P ≥ 0.14) were not different between the sojourns. TCPP was lower in HH than in NX at the same time points as PV (P < 0.001), but inflammatory or glycocalyx shedding markers were not consistently increased. As in men, and despite initially increased diuresis, HH-induced PV contraction in women is driven by a loss of TCPP and ensuing fluid redistribution, rather than by fluid loss. The mechanism underlying the TCPP reduction remains unclear but does not seem to involve inflammation or glycocalyx shedding.NEW & NOTEWORTHY This study is the first to investigate the mechanisms underlying plasma volume (PV) contraction in response to hypoxia in women while strictly controlling for confounders. PV contraction in women has a similar time course and magnitude as in men and is driven by the same mechanism, namely, oncotically driven redistribution rather than loss of fluid. We further report that hypoxia facilitates an increase in diuresis, that is, however, short-lived and of little relevance for PV regulation.


Assuntos
Hipóxia , Volume Plasmático , Masculino , Humanos , Feminino , Volume Plasmático/fisiologia , Altitude , Diurese , Inflamação
14.
Vet Dermatol ; 33(4): 356-360, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35644588

RESUMO

Carbon dioxide (CO2 ) lasers are used for a variety of soft tissue procedures. This report describes their use in dermatitis associated with feline herpesvirus-1 (FHV) in two cheetahs. To the best of the authors' knowledge, this is the first report describing CO2 laser use to adjunctively treat FHV-associated skin lesions.


Les lasers au dioxyde de carbone (CO2) sont utilisés pour une variété de procédures sur les tissus mous. Ce rapport décrit leur utilisation dans la dermatite associée à l'herpèsvirus félin-1 (FHV) chez deux guépards. À la connaissance des auteurs, il s'agit du premier article décrivant l'utilisation du laser CO2 pour traiter de manière complémentaire les lésions cutanées associées au FHV.


Los láseres de dióxido de carbono (CO2 ) se utilizan para una variedad de procedimientos de tejidos blandos. Este informe describe su uso en la dermatitis asociada con el herpesvirus felino-1 (FHV) en dos guepardos. A entender de los autores, este es el primer informe que describe el uso del láser de CO2 para tratar de forma complementaria las lesiones cutáneas asociadas con infección con FHV.


Lasers de dióxido de carbono (CO2 ) são utilizados em uma grande variedade de procedimentos de tecidos moles. Este relato descreve a sua utilização na dermatite associada ao herpesvírus felino (HVF)-1 em duas chitas. De acordo com o conhecimento dos autores, este é o primeiro relato descrevendo a utilização do laser de CO2 no tratamento adjunto de lesões cutâneas associadas o HVF.


Assuntos
Acinonyx , Doenças do Gato , Dermatite , Lasers de Gás , Animais , Animais de Zoológico , Dióxido de Carbono , Doenças do Gato/cirurgia , Gatos , Dermatite/cirurgia , Dermatite/veterinária , Lasers de Gás/uso terapêutico , Varicellovirus
15.
BMJ Health Care Inform ; 29(1)2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35738723

RESUMO

OBJECTIVE: Colorectal cancer is a common cause of death and morbidity. A significant amount of data are routinely collected during patient treatment, but they are not generally available for research. The National Institute for Health Research Health Informatics Collaborative in the UK is developing infrastructure to enable routinely collected data to be used for collaborative, cross-centre research. This paper presents an overview of the process for collating colorectal cancer data and explores the potential of using this data source. METHODS: Clinical data were collected from three pilot Trusts, standardised and collated. Not all data were collected in a readily extractable format for research. Natural language processing (NLP) was used to extract relevant information from pseudonymised imaging and histopathology reports. Combining data from many sources allowed reconstruction of longitudinal histories for each patient that could be presented graphically. RESULTS: Three pilot Trusts submitted data, covering 12 903 patients with a diagnosis of colorectal cancer since 2012, with NLP implemented for 4150 patients. Timelines showing individual patient longitudinal history can be grouped into common treatment patterns, visually presenting clusters and outliers for analysis. Difficulties and gaps in data sources have been identified and addressed. DISCUSSION: Algorithms for analysing routinely collected data from a wide range of sites and sources have been developed and refined to provide a rich data set that will be used to better understand the natural history, treatment variation and optimal management of colorectal cancer. CONCLUSION: The data set has great potential to facilitate research into colorectal cancer.


Assuntos
Neoplasias Colorretais , Registros Eletrônicos de Saúde , Neoplasias Colorretais/terapia , Humanos , Armazenamento e Recuperação da Informação , Processamento de Linguagem Natural , Projetos Piloto
16.
Conserv Biol ; 36(5): e13933, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35574654

RESUMO

To understand and address the failures of reef governance, it is critical to understand the perceptions of diverse policy makers and practitioners about the challenges they face in achieving their goals. Examining the discourse of policy makers and practitioners can reveal the extent to which these perceptions capture the full spectrum of potential governance challenges, including those related to management, institutional structures and processes, the values and principles underpinning governance, and the social and environmental context. We conducted semistructured interviews with 110 policy makers and practitioners across multiple sectors, scales, and contexts in Barbados, St Kitts and Nevis, Belize, and Honduras. We used thematic qualitative analysis informed by theories of interactive governance and governability to examine the challenges perceived by governance actors. Perceived governance challenges were broadly consistent across countries, but differed by sector (V = 0.819, F6,60 = 1.502, p = 0.01) and by level (community compared with national) (V = 0.194, F1,10 = 2.178, = 0.026). Management inputs and outputs, challenges relating to the socioeconomic context, issues of leadership and power, and stakeholder engagement were commonly cited challenges (>75%). Few respondents discussed challenges relating to the ecological context, governance processes, or the values and principles underpinning governance. We argue that examining perceptions can inform efforts to improve governance and assess the appropriateness of particular management tools under context-specific governance constraints. Furthermore, expanding the narratives of governance challenges to encompass the subtle values and images underpinning governance, and the scale of the challenges faced, can help identify a wider set of opportunities for change.


Expansión de las Narrativas de los Límites de la Gobernanza para Mejorar la Conservación de los Arrecifes de Coral Resumen Es muy importante entender las percepciones que tienen los practicantes y los formuladores de políticas sobre los retos que enfrentan para alcanzar sus objetivos para poder entender y abordar los fracasos en la gobernanza de los arrecifes. El análisis del discurso de los formuladores y los practicantes puede revelar la extensión a la que estas percepciones capturan el espectro completo de los retos potenciales para la gobernanza, incluidos aquellos relacionados con el manejo, las estructuras y los procesos institucionales, los valores y principios que apuntalan la gobernanza y el contexto social y ambiental. Realizamos entrevistas semiestructuradas a 110 formuladores y practicantes de múltiples sectores, escalas y contextos en Barbados, San Cristóbal y Nieves, Belice y Honduras. Usamos un análisis cualitativo temático informado por las teorías de la gobernanza interactiva y la gobernabilidad para examinar los retos percibidos por los actores de gobernanza. A grandes rasgos, los retos percibidos en la gobernanza fueron coherentes entre los países, pero difirieron por sector (V = 0.819, F6,60 = 1.502, p = 0.01) y por nivel (comunitario comparado con nacional) (V = 0.194, F1,10 = 2.178, = 0.026). Las aportaciones y producciones del manejo, los retos relacionados con el contexto socioeconómico, los temas de liderazgo y poder y la participación de los actores fueron los retos mencionados comúnmente (>75%). Pocos respondientes discutieron los retos relacionados con el contexto ecológico, los procesos de gobernanza o los valores y principios que apuntalan la gobernanza. Alegamos que el análisis de las percepciones puede guiar a los esfuerzos para mejorar la gobernanza y evaluar cuán apropiadas son las herramientas particulares de manejo bajo los límites de gobernanza específicos al contexto. Además, expandir las narrativas de los retos de gobernanza para englobar los valores e imágenes sutiles que apuntalan la gobernanza, y la escala del reto al que se enfrenta, puede ayudar a identificar un conjunto más amplio de oportunidades de cambio.


Assuntos
Conservação dos Recursos Naturais , Recifes de Corais
18.
Fam Syst Health ; 40(3): 397-402, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35604723

RESUMO

INTRODUCTION: Persons with cystic fibrosis (CF) have higher rates of depression and anxiety compared to the general population. The Cystic Fibrosis Foundation guidelines recommend annual screening for depression and anxiety for people with CF. COVID-19 and related social distancing has created challenges for administration of mental health screening by CF centers. The aim of this quality improvement project was to evaluate the feasibility of implementing mental health screening during multidisciplinary telehealth appointments for adult patients with CF during COVID-19, adoption of screening by CF mental health providers, and patient screening results before and after introduction of telehealth. METHOD: Patients were screened via telehealth using the PHQ-9 and GAD-7 between April and October 2020. RESULTS: CF mental health providers implemented a mental health screening process via telehealth and 93.9% of patients seen during that time completed the screening. The screening did not increase clinic visit length and no significant differences were found between rates of depression and anxiety and 2019 clinic rates. DISCUSSION: Implementation of mental health screening during a multidisciplinary telehealth clinic is feasible and can be adopted by providers and patients, even when health systems operations are impacted by COVID-19. It allows CF centers to maintain adherence to mental health screening and treatment guidelines. This method of screening can be applied to other patient populations and systems of care to expand access to mental health services during COVID-19 and beyond. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
COVID-19 , Fibrose Cística , Telemedicina , Adulto , Fibrose Cística/complicações , Fibrose Cística/diagnóstico , Fibrose Cística/psicologia , Estudos de Viabilidade , Humanos , Saúde Mental
20.
J Wildl Dis ; 58(1): 1-7, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34780647

RESUMO

Austwickia (Dermatophilus) chelonae is a filamentous, Gram-positive Actinobacteria in the Dermatophilaceae family. It has caused fatal granulomatous disease in diverse captive reptile species on three continents, but its presence in wild or free-ranging populations was unknown. An adult female gopher tortoise (Gopherus polyphemus) was presented euhydrated, but cachectic and infested with ticks, with two firm, encapsulated masses over the cranioventral neck and right stifle. The tortoise had moderate nonregenerative anemia and evidence of inflammation; plasma biochemistry data was within normal limits. Fine needle aspirate of the neck lesion revealed abundant necrosis and aggregates of cocci. Computed tomography delineated the masses and revealed an additional mass adjacent to the left zygomatic bone. After surgical excision, histology identified chronic granulomas with intralesional filamentous bacteria. Pan-bacterial 16S rRNA PCR and sequencing of the masses identified A. chelonae. Despite treatment with oxytetracycline and ceftazidime, the tortoise deteriorated and was euthanatized. An esophageal lesion consistent with A. chelonae was seen on postmortem examination, although it was determined that the tortoise ultimately succumbed to fungal pneumonia caused by Metarhizium robertsii, an entomopathogenic biotoxin sprayed as insect control. This case reveals A. chelonae is present in free-ranging chelonians in North America. This organism produces a toxin gene similar to diphtheria toxin, one of the most potent known biotoxins, which has not been previously identified outside the genus Corynebacterium. Novel PCR primers were designed for the toxin and rpoB genes, which were amplified and sequenced from two cases and compared with two available genomes. Selection analysis revealed that the toxin gene is under positive selection, which implies it interacts significantly with the immune system, making it a good candidate for immunodiagnostic test development.


Assuntos
Difteria , Tartarugas , Animais , Feminino , Actinobacteria , Corynebacterium , Difteria/veterinária , RNA Ribossômico 16S/genética , Tartarugas/microbiologia
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