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1.
Exp Physiol ; 109(4): 535-548, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38180087

RESUMEN

The human spleen contracts in response to stress-induced catecholamine secretion, resulting in a temporary rise in haemoglobin concentration ([Hb]). Recent findings highlighted enhanced splenic response to exercise at high altitude in Sherpa, possibly due to a blunted splenic response to hypoxia. To explore the potential blunted splenic contraction in Sherpas at high altitude, we examined changes in spleen volume during hyperoxic breathing, comparing acclimatized Sherpa with acclimatized individuals of lowland ancestry. Our study included 14 non-Sherpa (7 female) residing at altitude for a mean continuous duration of 3 months and 46 Sherpa (24 female) with an average of 4 years altitude exposure. Participants underwent a hyperoxic breathing test at altitude (4300 m; barrometric pressure = âˆ¼430 torr; P O 2 ${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$  = âˆ¼90 torr). Throughout the test, we measured spleen volume using ultrasonography and monitored oxygen saturation ( S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). During rest, Sherpa exhibited larger spleens (226 ± 70 mL) compared to non-Sherpa (165 ± 34 mL; P < 0.001; effect size (ES) = 0.95, 95% CI: 0.3-1.6). In response to hyperoxia, non-Sherpa demonstrated 22 ± 12% increase in spleen size (35 ± 17 mL, 95% CI: 20.7-48.9; P < 0.001; ES = 1.8, 95% CI: 0.93-2.66), while spleen size remained unchanged in Sherpa (-2 ± 13 mL, 95% CI: -2.4 to 7.3; P = 0.640; ES = 0.18, 95% CI: -0.10 to 0.47). Our findings suggest that Sherpa and non-Sherpas of lowland ancestry exhibit distinct variations in spleen volume during hyperoxia at high altitude, potentially indicating two distinct splenic functions. In Sherpa, this phenomenon may signify a diminished splenic response to altitude-related hypoxia at rest, potentially contributing to enhanced splenic contractions during physical stress. Conversely, non-Sherpa experienced a transient increase in spleen size during hyperoxia, indicating an active tonic contraction, which may influence early altitude acclimatization in lowlanders by raising [Hb].


Asunto(s)
Mal de Altura , Hiperoxia , Humanos , Femenino , Altitud , Bazo , Aclimatación/fisiología , Hipoxia
2.
Exp Physiol ; 108(1): 111-122, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36404588

RESUMEN

NEW FINDINGS: What is the central question of this study? How does hypoxic pulmonary vasoconstriction and the response to supplemental oxygen change over time at high altitude? What is the main finding and its importance? Lowlanders and partially de-acclimatized Sherpa both demonstrated pulmonary vascular responsiveness to supplemental oxygen that was maintained for 12 days' exposure to progressively increasing altitude. An additional 2 weeks' acclimatization at 5050 m altitude rendered the pulmonary vasculature minimally responsive to oxygen similar to the fully acclimatized non-ascent Sherpa. Additional hypoxic exposure at that time point did not augment hypoxic pulmonary vasoconstriction. ABSTRACT: Prolonged alveolar hypoxia leads to pulmonary vascular remodelling. We examined the time course at altitude, over which hypoxic pulmonary vasoconstriction goes from being acutely reversible to potentially irreversible. Study subjects were lowlanders (n = 20) and two Sherpa groups. All Sherpa were born and raised at altitude. One group (ascent Sherpa, n = 11) left altitude and after de-acclimatization in Kathmandu for ∼7 days re-ascended with the lowlanders over 8-10 days to 5050 m. The second Sherpa group (non-ascent Sherpa, n = 12) remained continuously at altitude. Pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were measured while breathing ambient air and following supplemental oxygen. During ascent PASP and PVR increased in lowlanders and ascent Sherpa; however, with supplemental oxygen, lowlanders had significantly greater decrease in PASP (P = 0.02) and PVR (P = 0.02). After ∼14 days at 5050 m, PASP decreased with supplemental oxygen (mean decrease: 3.9 mmHg, 95% CI 2.1-5.7 mmHg, P < 0.001); however, PVR was unchanged (P = 0.49). In conclusion, PASP and PVR increased with gradual ascent to altitude and decreased via oxygen supplementation in both lowlanders and ascent Sherpa. Following ∼14 days at 5050 m altitude, there was no change in PVR to hypoxia or O2  supplementation in lowlanders or either Sherpa group. These data show that both duration of exposure and residential altitude influence the pulmonary vascular responses to hypoxia.


Asunto(s)
Mal de Altura , Altitud , Humanos , Hipoxia , Aclimatación/fisiología , Oxígeno
3.
Int J Mol Sci ; 24(22)2023 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-38003387

RESUMEN

Endocrine therapy is the main treatment for hormone receptor-positive (HR+) breast cancer. However, advanced tumors develop resistance to endocrine therapy, rendering it ineffective as the disease progresses. There are several molecular mechanisms of primary and secondary endocrine resistance. Resistance can develop due to either alteration of the estrogen receptor pathway (e.g., ESR1 mutations) or upstream growth factors signaling pathways (e.g., PI3K/Akt/mTOR pathway). Despite progress in the development of molecularly targeted anticancer therapies, the emergence of resistance remains a major limitation and an area of unmet need. In this article, we review the mechanisms of acquired endocrine resistance in HR+ advanced breast cancer and discuss current and future investigational therapeutic approaches.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Resistencia a Antineoplásicos/genética , Transducción de Señal
4.
Ergonomics ; 65(12): 1672-1695, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35234574

RESUMEN

Engine damage as a consequence of foreign object debris (FOD) during flight is frequently caused by birds. One approach to minimising disruption caused by this damage is to provide flight crew with accurate information relating to the continuing operational status of the aircraft's engines. Before designing such avionic systems however, understanding of current procedures is needed. Hierarchical Task Analysis (HTA) and Systematic Human Error Reduction and Prediction Approach (SHERPA) were used to identify potential failures that flight crew may make when managing an engine bird strike. Workshops with commercial pilots generated insights into current practice and a commercial pilot SME reviewed outputs for accuracy. Over 200 potential failures were identified, most commonly related to communication. Remedial measures, considering future avionic systems, are proposed to mitigate identified failures. This analysis provides a starting point for future design concepts for assisting flight crew in dealing with engine malfunction due to FOD strikes. Practitioner summary: Hierarchical Task Analysis was conducted to show all tasks involved in dealing with an in-flight aircraft engine bird strike. Systematic Human Error Reduction and Prediction Approach analysis was performed and over 200 possible failures were identified when managing this event. Remedial measures are proposed to help mitigate possible failures.


Asunto(s)
Accidentes de Aviación , Animales , Humanos , Accidentes de Aviación/prevención & control , Aeronaves , Solución de Problemas , Aves
5.
J Physiol ; 599(5): 1685-1708, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33442904

RESUMEN

KEY POINTS: Iron acts as a cofactor in the stabilization of the hypoxic-inducible factor family, and plays an influential role in the modulation of hypoxic pulmonary vasoconstriction. It is uncertain whether iron regulation is altered in lowlanders during either (1) ascent to high altitude, or (2) following partial acclimatization, when compared to high-altitude adapted Sherpa. During ascent to 5050 m, the rise in pulmonary artery systolic pressure (PASP) was blunted in Sherpa, compared to lowlanders; however, upon arrival to 5050 m, PASP levels were comparable in both groups, but the reduction in iron bioavailability was more prevalent in lowlanders compared to Sherpa. Following partial acclimatization to 5050 m, there were differential influences of iron status manipulation (via iron infusion or chelation) at rest and during exercise between lowlanders and Sherpa on the pulmonary vasculature. ABSTRACT: To examine the adaptational role of iron bioavailability on the pulmonary vascular responses to acute and chronic hypobaric hypoxia, the haematological and cardiopulmonary profile of lowlanders and Sherpa were determined during: (1) a 9-day ascent to 5050 m (20 lowlanders; 12 Sherpa), and (2) following partial acclimatization (11 ± 4 days) to 5050 m (18 lowlanders; 20 Sherpa), where both groups received an i.v. infusion of either iron (iron (iii)-hydroxide sucrose) or an iron chelator (desferrioxamine). During ascent, there were reductions in iron status in both lowlanders and Sherpa; however, Sherpa appeared to demonstrate a more efficient capacity to mobilize stored iron, compared to lowlanders, when expressed as a Δhepcidin per unit change in either body iron or the soluble transferrin receptor index, between 3400-5050 m (P = 0.016 and P = 0.029, respectively). The rise in pulmonary artery systolic pressure (PASP) was blunted in Sherpa, compared to lowlanders during ascent; however, PASP was comparable in both groups upon arrival to 5050 m. Following partial acclimatization, despite Sherpa demonstrating a blunted hypoxic ventilatory response and greater resting hypoxaemia, they had similar hypoxic pulmonary vasoconstriction when compared to lowlanders at rest. Iron-infusion attenuated PASP in both groups at rest (P = 0.005), while chelation did not exaggerate PASP in either group at rest or during exaggerated hypoxaemia ( PIO2  = 67 mmHg). During exercise at 25% peak wattage, PASP was only consistently elevated in Sherpa, which persisted following both iron infusion or chelation. These findings provide new evidence on the complex interplay of iron regulation on pulmonary vascular regulation during acclimatization and adaptation to high altitude.


Asunto(s)
Altitud , Vasoconstricción , Aclimatación , Humanos , Hipoxia , Hierro
6.
Am J Physiol Renal Physiol ; 320(3): F249-F261, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33356957

RESUMEN

Patients treated with hemodialysis (HD) repeatedly undergo intradialytic low arterial oxygen saturation and low central venous oxygen saturation, reflecting an imbalance between upper body systemic oxygen supply and demand, which are associated with increased mortality. Abnormalities along the entire oxygen cascade, with impaired diffusive and convective oxygen transport, contribute to the reduced tissue oxygen supply. HD treatment impairs pulmonary gas exchange and reduces ventilatory drive, whereas ultrafiltration can reduce tissue perfusion due to a decline in cardiac output. In addition to these factors, capillary rarefaction and reduced mitochondrial efficacy can further affect the balance between cellular oxygen supply and demand. Whereas it has been convincingly demonstrated that a reduced perfusion of heart and brain during HD contributes to organ damage, the significance of systemic hypoxia remains uncertain, although it may contribute to oxidative stress, systemic inflammation, and accelerated senescence. These abnormalities along the oxygen cascade of patients treated with HD appear to be diametrically opposite to the situation in Tibetan highlanders and Sherpa, whose physiology adapted to the inescapable hypobaric hypoxia of their living environment over many generations. Their adaptation includes pulmonary, vascular, and metabolic alterations with enhanced capillary density, nitric oxide production, and mitochondrial efficacy without oxidative stress. Improving the tissue oxygen supply in patients treated with HD depends primarily on preventing hemodynamic instability by increasing dialysis time/frequency or prescribing cool dialysis. Whether dietary or pharmacological interventions, such as the administration of L-arginine, fermented food, nitrate, nuclear factor erythroid 2-related factor 2 agonists, or prolyl hydroxylase 2 inhibitors, improve clinical outcome in patients treated with HD warrants future research.


Asunto(s)
Aclimatación , Altitud , Hipoxia/sangre , Fallo Renal Crónico/terapia , Riñón/fisiopatología , Consumo de Oxígeno , Oxígeno/sangre , Diálisis Renal , Animales , Biomarcadores/sangre , Hemodinámica , Humanos , Hipoxia/mortalidad , Hipoxia/fisiopatología , Hipoxia/prevención & control , Riñón/metabolismo , Fallo Renal Crónico/sangre , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/fisiopatología , Diálisis Renal/efectos adversos , Diálisis Renal/mortalidad , Factores de Riesgo , Resultado del Tratamiento
7.
Am J Physiol Regul Integr Comp Physiol ; 318(3): R493-R502, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31913686

RESUMEN

Lowland-dwelling populations exhibit persistent sympathetic hyperactivity at altitude that alters vascular function. High-altitude populations, such as Sherpa, have previously exhibited greater peripheral blood flow in response to acute stress than Lowlanders, which may be explained through lower sympathetic activity. Our purpose was to determine whether Sherpa exhibit lower sympathetic reactivity to stress than Lowlanders. Muscle sympathetic nerve activity (MSNA; microneurography) was measured at rest in Lowlanders (n = 14; age = 27 ± 6 yr) at 344 m and between 1 and 10 days at 5,050 m. Sherpa (age = 32 ± 11 yr) were tested at 5,050 m (n = 8). Neurovascular reactivity (i.e., change in MSNA patterns) was measured during maximal end-expiratory apnea, isometric hand grip (IHG; 30% maximal voluntary contraction for 2-min), and postexercise circulatory occlusion (PECO; 3 min). Burst frequency (bursts/min) and incidence (bursts/100 heartbeats) and total normalized SNA (arbitrary units/min) were analyzed at rest, immediately before apnea breakpoint, and during the last minute of IHG and PECO. Vascular responses to apnea, IHG, and PECO were also measured. MSNA reactivity to apnea was smaller in Sherpa than Lowlanders at 5,050 m, although blood pressure responses were similar between groups. MSNA increases in Lowlanders during apnea at 5,050 m were significantly lower than at 344 m (P < 0.05), indicating that a possible sympathetic ceiling was reached in Lowlanders at 5,050 m. MSNA increased similarly during IHG and PECO in Lowlanders at both 334 m and 5,050 m and in Sherpa at 5,050 m, while vascular changes (mean brachial arterial pressure, contralateral brachial flow and resistance) were similar between groups. Sherpa demonstrate overall lower sympathetic reactivity that may be a result of heightened vascular responsiveness to potential apneic stress at altitude.


Asunto(s)
Altitud , Ejercicio Físico/fisiología , Músculo Esquelético/fisiología , Sistema Nervioso Simpático/fisiología , Adaptación Fisiológica/fisiología , Adulto , Femenino , Fuerza de la Mano/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino
8.
J Physiol ; 597(12): 2993-3008, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31026348

RESUMEN

KEY POINTS: Sherpa have lived in the Nepal Himalaya for 25-40 thousand years and display positive physiological adaptations to hypoxia. Sherpa have previously been demonstrated to suffer less negative cerebral side effects of ascent to extreme altitude, yet little is known as to whether or not they display differential regulation of oxygen delivery to the brain compared to lowland natives. We demonstrate that Sherpa have lower brain blood flow during ascent to and acclimatization at high altitude compared to lowlanders and that this difference in flow is not attributable to factors such as mean arterial pressure, blood viscosity and pH. The observed lower cerebral oxygen delivery in Sherpa likely represents a positive adaptation that may indicate a cerebral hypometabolic conservation of energy at altitude and/or decreased risk of other cerebral consequences such as vasogenic oedema. ABSTRACT: Debilitating side effects of hypoxia manifest within the central nervous system; however, high-altitude natives of the Tibetan plateau, the Sherpa, experience negligible cerebral effects compared to lowland natives at extreme altitude. Phenotypical optimization of the oxygen cascade has been demonstrated in the systemic circulation of Tibetans and Sherpa, likely underscoring their adapted capacity to thrive at altitude. Yet, little is known as to how the cerebral circulation of Sherpa may be adapted. To examine potential differences in cerebral oxygen delivery in Sherpa compared to lowlanders we measured arterial blood gases and global cerebral blood flow (duplex ultrasound) during a 9 day ascent to 5050 m. Although cerebral oxygen delivery was maintained during ascent in lowlanders, it was significantly reduced in the Sherpa at 3400 m (-30.3 ± 21.6%; P < 0.01) and 4371 m (-14.2 ± 10.7%; P = 0.03). Furthermore, linear mixed effects modelling indicated that independent of differences in mean arterial pressure, pH and blood viscosity, race accounts for an approximately 100 mL min-1 (∼17-34%) lower cerebral blood flow in Sherpa compared to lowlanders across ascent to altitude (P = 0.046). To ascertain the role of chronic hypoxia independent of the ascent, Sherpa who had not recently descended were also examined at 5050 m. In these Sherpa, cerebral oxygen delivery was also lower compared to lowlanders (∼22% lower; P < 0.01). We highlight new information about the influence of race and genetic adaptation in the regulation of cerebral oxygen delivery. The lower cerebral oxygen delivery in the Sherpa potentially represents a positive adaptation considering Sherpa endure less deleterious cerebral consequences than lowlanders at altitude.


Asunto(s)
Aclimatación/fisiología , Altitud , Circulación Cerebrovascular , Hipoxia/fisiopatología , Adulto , Encéfalo/irrigación sanguínea , Expediciones , Femenino , Humanos , Hipoxia/etnología , Masculino , Persona de Mediana Edad , Nepal , Oxígeno/fisiología , Fenotipo , Grupos Raciales , Adulto Joven
9.
Am J Hum Genet ; 99(3): 580-594, 2016 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27569548

RESUMEN

The origin of Tibetans remains one of the most contentious puzzles in history, anthropology, and genetics. Analyses of deeply sequenced (30×-60×) genomes of 38 Tibetan highlanders and 39 Han Chinese lowlanders, together with available data on archaic and modern humans, allow us to comprehensively characterize the ancestral makeup of Tibetans and uncover their origins. Non-modern human sequences compose ∼6% of the Tibetan gene pool and form unique haplotypes in some genomic regions, where Denisovan-like, Neanderthal-like, ancient-Siberian-like, and unknown ancestries are entangled and elevated. The shared ancestry of Tibetan-enriched sequences dates back to ∼62,000-38,000 years ago, predating the Last Glacial Maximum (LGM) and representing early colonization of the plateau. Nonetheless, most of the Tibetan gene pool is of modern human origin and diverged from that of Han Chinese ∼15,000 to ∼9,000 years ago, which can be largely attributed to post-LGM arrivals. Analysis of ∼200 contemporary populations showed that Tibetans share ancestry with populations from East Asia (∼82%), Central Asia and Siberia (∼11%), South Asia (∼6%), and western Eurasia and Oceania (∼1%). Our results support that Tibetans arose from a mixture of multiple ancestral gene pools but that their origins are much more complicated and ancient than previously suspected. We provide compelling evidence of the co-existence of Paleolithic and Neolithic ancestries in the Tibetan gene pool, indicating a genetic continuity between pre-historical highland-foragers and present-day Tibetans. In particular, highly differentiated sequences harbored in highlanders' genomes were most likely inherited from pre-LGM settlers of multiple ancestral origins (SUNDer) and maintained in high frequency by natural selection.


Asunto(s)
Pueblo Asiatico/genética , Flujo Génico/genética , Genoma Humano/genética , Filogenia , Altitud , Animales , China/etnología , Etnicidad/genética , Pool de Genes , Genética de Población , Haplotipos/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Modelos Genéticos , Hombre de Neandertal/genética , Oceanía/etnología , Selección Genética , Tibet
11.
J Phycol ; 54(5): 703-719, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30014469

RESUMEN

Semiautomated methods for microscopic image acquisition, image analysis, and taxonomic identification have repeatedly received attention in diatom analysis. Less well studied is the question whether and how such methods might prove useful for clarifying the delimitation of species that are difficult to separate for human taxonomists. To try to answer this question, three very similar Fragilariopsis species endemic to the Southern Ocean were targeted in this study: F. obliquecostata, F. ritscheri, and F. sublinearis. A set of 501 extended focus depth specimen images were obtained using a standardized, semiautomated microscopic procedure. Twelve diatomists independently identified these specimen images in order to reconcile taxonomic opinions and agree upon a taxonomic gold standard. Using image analyses, we then extracted morphometric features representing taxonomic characters of the target taxa. The discriminating ability of individual morphometric features was tested visually and statistically, and multivariate classification experiments were performed to test the agreement of the quantitatively defined taxa assignments with expert consensus opinion. Beyond an updated differential diagnosis of the studied taxa, our study also shows that automated imaging and image analysis procedures for diatoms are coming close to reaching a broad applicability for routine use.


Asunto(s)
Clasificación/métodos , Curaduría de Datos , Diatomeas/clasificación
12.
Ergonomics ; 61(1): 104-121, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28498024

RESUMEN

Increasingly, medication is being administered at home by family and friends of the care-recipient. This study aims to identify and analyse risks associated with potential drug administration errors made by informal carers at home. We mapped medication administration at home with a multidisciplinary team that included carers, health care professionals and patients. Evidence-based risk-analysis methodologies were applied: Healthcare Failure Modes and Effect Analysis (HFMEA), Systematic Human Error Reduction and Prediction Analysis (SHERPA) and Systems-Theoretic Accident Model and Processes (STAMP). The process of administration comprises seven sub-processes. Thirty-four possible failure modes were identified and six of these were rated as high risk. These highlighted that medications may be given with a wrong dose, stored incorrectly, not discontinued as instructed, not recorded, or not ordered on time, and often caused by communication and support problems. Combined risk analyses contributed unique information helpful to better understand the medication administration risks and causes within homecare. Practitioner Summary: Increasingly, medication is being administered at home by family and friends of the care-recipient. This study identifies risks associated with potential drug administration errors made by informal carers at home through consensus-based quantitative techniques. The different analyses contribute unique information helpful to better understand the administration risks and causes.


Asunto(s)
Cuidadores/estadística & datos numéricos , Servicios de Atención de Salud a Domicilio/estadística & datos numéricos , Errores de Medicación/estadística & datos numéricos , Medición de Riesgo/estadística & datos numéricos , Humanos , Estudios Prospectivos , Medición de Riesgo/métodos
13.
BMC Genomics ; 18(1): 102, 2017 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-28103797

RESUMEN

BACKGROUND: We set out to describe the fine-scale population structure across the Eastern region of Nepal. To date there is relatively little known about the genetic structure of the Sherpa residing in Nepal and their genetic relationship with the Nepalese. We assembled dense genotype data from a total of 1245 individuals representing Nepal and a variety of different populations resident across the greater Himalayan region including Tibet, China, India, Pakistan, Kazakhstan, Uzbekistan, Tajikistan and Kirghizstan. We performed analysis of principal components, admixture and homozygosity. RESULTS: We identified clear substructure across populations resident in the Himalayan arc, with genetic structure broadly mirroring geographical features of the region. Ethnic subgroups within Nepal show distinct genetic structure, on both admixture and principal component analysis. We detected differential proportions of ancestry from northern Himalayan populations across Nepalese subgroups, with the Nepalese Rai, Magar and Tamang carrying the greatest proportions of Tibetan ancestry. CONCLUSIONS: We show that populations dwelling on the Himalayan plateau have had a clear impact on the Northern Indian gene pool. We illustrate how the Sherpa are a remarkably isolated population, with little gene flow from surrounding Nepalese populations.


Asunto(s)
Pueblo Asiatico/genética , Etnicidad/genética , Cromosomas Humanos Y/genética , ADN/aislamiento & purificación , ADN/metabolismo , ADN Mitocondrial/genética , Flujo Génico , Genotipo , Humanos , Leucocitos/metabolismo , Funciones de Verosimilitud , Nepal , Análisis de Componente Principal
14.
Adv Exp Med Biol ; 903: 65-81, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27343089

RESUMEN

In hypoxia aerobic exercise performance of high-altitude natives is suggested to be superior to that of lowlanders; i.e., for a given altitude natives are reported to have higher maximal oxygen uptake (VO2max). The likely basis for this is a higher pulmonary diffusion capacity, which in turn ensures higher arterial O2 saturation (SaO2) and therefore also potentially a higher delivery of O2 to the exercising muscles. This review focuses on O2 transport in high-altitude Aymara. We have quantified femoral artery O2 delivery, arterial O2 extraction and calculated leg VO2 in Aymara, and compared their values with that of acclimatizing Danish lowlanders. All subjects were studied at 4100 m. At maximal exercise SaO2 dropped tremendously in the lowlanders, but did not change in the Aymara. Therefore arterial O2 content was also higher in the Aymara. At maximal exercise however, fractional O2 extraction was lower in the Aymara, and the a-vO2 difference was similar in both populations. The lower extraction levels in the Aymara were associated with lower muscle O2 conductance (a measure of muscle diffusion capacity). At any given submaximal exercise intensity, leg VO2 was always of similar magnitude in both groups, but at maximal exercise the lowlanders had higher leg blood flow, and hence also higher maximum leg VO2. With the induction of acute normoxia fractional arterial O2 extraction fell in the highlanders, but remained unchanged in the lowlanders. Hence high-altitude natives seem to be more diffusion limited at the muscle level as compared to lowlanders. In conclusion Aymara preserve very high SaO2 during hypoxic exercise (likely due to a higher lung diffusion capacity), but the effect on VO2max is reduced by a lower ability to extract O2 at the muscle level.


Asunto(s)
Altitud , Células Musculares/metabolismo , Oxígeno/metabolismo , Grupos de Población , Metabolismo Energético , Ejercicio Físico/fisiología , Humanos
15.
Int J Occup Saf Ergon ; 21(3): 382-90, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26327157

RESUMEN

Accidents caused by human error are prominent in the medical field. The present study identified medical errors in the emergency triage area by assessing the tasks of all healthcare workers employed in the triage area of an educational hospital in Tehran, Iran in 2014. Data were collected using the systematic human error reduction and prediction approach (SHERPA). The tasks and sub-tasks were determined and analyzed using hierarchical analysis and the errors were extracted. A total of 199 human errors were identified in the different tasks. The rate of error for action was 46.8%, checking was 25.6%, retrieval was 8.5%, communication was 12.1% and selection was 7%. Rate of unacceptable and unfavorable risks were 21.1% and 38.6%, respectively. SHERPA was shown to be an appropriate technique for detecting medical errors. The establishment of control programs should be a high priority in the management and implementation of health facilities in triage areas.


Asunto(s)
Errores Médicos/estadística & datos numéricos , Triaje/normas , Adulto , Estudios Transversales , Femenino , Hospitales de Enseñanza , Humanos , Irán , Masculino
16.
J Ethnopharmacol ; 334: 118555, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38996950

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The people of the Pan-Himalayan region are among the most isolated and economically disadvantaged populations worldwide. The Sherpa people, located along the China and Nepal border, rely largely on the natural environment to access essential healthcare services. The region's ongoing economic and social developments threaten indigenous medicinal practices and biodiversity. However, there has been limited comprehensive investigation and documentation of traditional medicine and its associated knowledge in this region. AIM OF THE STUDY: The aims are to document the traditional medicinal knowledge of the Sherpa community, assess the conservation status of medicinal plants, and explore the historical factors that have influenced their traditional medicine practices. MATERIAL AND METHODS: Semi-structured interviews with 78 Sherpa people were conducted in Chenthang Town, Xizang, China. Use reports (URs) was used to determine the most frequently mentioned medicinal plants or a specific ailment or disease category. The International Classification of Primary Care-2nd edition (ICPC-2) was used to transform the original records into an internationally unified classification. RESULTS: A total of 51 plant species, one fungus (Ophiocordyceps sinensis (Berk.) G.H.Sung, J.M.Sung, Hywel-Jones & Spatafora), two lichens (Flavopunctelia soredica (Nyl.) Hale and Parmotrema cetratum (Ach.) Hale), and four minerals were documented, resulting in 824 URs. Ranunculaceae had the most species (5 spp.). The most commonly used method for preparing medicinal substances was decoction (23 species, 40%). Oral application was the preferred route of administration for 81% (41 medicinal substances). Forty-four ailments across 14 ICPC-2 disease categories were documented. Respiratory (320 URs) and digestive (122 URs) categories are among the most common diseases. The top-five ailments were influenza (18 substances; URs = 227), injury blood/lymph/spleen other (11 substances; URs = 66), cough (10 substances; URs = 62), headache (7 substances; URs = 63), and abdominal pain/cramps general (6 substances; URs = 37). The most frequently reported medicinal substances were Panax pseudoginseng Wall. (URs = 128) and Neopicrorhiza scrophulariiflora (Pennell) D. Y. Hong (URs = 79). Two special therapies (hot spring therapy and dietary therapy) were described. In-depth ethnographic information on the livelihood and exchange history of Sherpa people were documented. A total of 25 species were sold, of which four species were listed as VU in the IUCN Red List (2023-1), six species were listed as VU, four species were NT, and one species was EN in the China Biodiversity Red list 2021. CONCLUSION: This study provides the first comprehensive documentation of the 58 traditional medicine substances and two special therapies (hot spring therapy and dietary therapy) used by the Sherpa people in Chenthang. Sherpa's medicinal knowledge has been shaped by historical interactions and contemporary trade practices. To better protect the biocultural diversity of the Himalayan region, priority should be given to the rapid assessment of medicinal plants, knowledge, and use status in this area.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Plantas Medicinales , Humanos , China , Femenino , Masculino , Adulto , Persona de Mediana Edad , Medicina Tradicional China , Anciano , Adulto Joven , Fitoterapia , Pueblos Indígenas
17.
Heliyon ; 10(11): e32043, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38873672

RESUMEN

In the realm of air-maritime SAR missions, technical errors are relatively rare compared to human errors due to the multifaceted nature of these missions that standard checklists may not fully encompass. Thus, prioritizing pilot training and implementing a systematic approach are vital to mitigate pilot errors in SAR missions. To mitigate and predict human errors during maritime SAR helicopter hoist tasks, SHERPA methodology is applied in this study. This analysis uncovered a comprehensive total of 54 potential errors, most applicable to countries utilizing rescue aircraft similar to those in Taiwan. The errors identified in this analysis suggest opportunities for enhancing the design of maritime SAR helicopter hoisting tasks through the application of SHERPA, with the potential to decrease their occurrence in the future.

18.
Appl Ergon ; 106: 103870, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35988302

RESUMEN

Future visions of transport systems include both a drive towards automated vehicles and the need for sustainable, active, modes of travel. The combination of these requirements needs careful consideration to ensure the integration of automated vehicles does not compromise vulnerable road users. Transport networks need to be resilient to automation integration, which requires foresight of possible challenges in their interaction with other road users. Focusing on a cyclist overtake scenario, the application of operator event sequence diagrams and a predictive systems failure method provide a novel way to analyse resilience. The approach offers the opportunity to review how automation can be positively integrated into road transportation to overcome the shortfalls of the current system by targeting organisational, procedural, equipment and training measures.


Asunto(s)
Accidentes de Tránsito , Conducción de Automóvil , Humanos , Automatización , Transportes , Viaje , Ingeniería
19.
J R Coll Physicians Edinb ; 53(2): 117-118, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36905249

RESUMEN

Foreign body aspiration is a rare clinical finding in adults, among which very few are reported, probably due to absence of classical clinical features in adults when compared to children and due to lack of awareness. We present a 57-year-old with chronic productive cough who was diagnosed to have pulmonary tuberculosis (TB), complicated by long-standing foreign body in the tracheobronchial tree. There are many cases reported in literature where there have been misdiagnosis with respect to pulmonary TB as foreign body or foreign bodies as pulmonary TB. However, this is the first case where retained foreign body and pulmonary TB coexisted in a patient.


Asunto(s)
Cuerpos Extraños , Tuberculosis Pulmonar , Niño , Masculino , Adulto , Humanos , Persona de Mediana Edad , Broncoscopía/efectos adversos , Broncoscopía/métodos , Bronquios/diagnóstico por imagen , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico , Tos/etiología , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico , Estudios Retrospectivos
20.
Acta Physiol (Oxf) ; 234(4): e13788, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35007386

RESUMEN

Ascent to high altitude is accompanied by a reduction in partial pressure of inspired oxygen, which leads to interconnected adjustments within the neuromuscular system. This review describes the unique challenge that such an environment poses to neuromuscular fatigability (peripheral, central and supraspinal) for individuals who normally reside near to sea level (SL) (<1000 m; ie, lowlanders) and for native highlanders, who represent the manifestation of high altitude-related heritable adaptations across millennia. Firstly, the effect of acute exposure to high altitude-related hypoxia on neuromuscular fatigability will be examined. Under these conditions, both supraspinal and peripheral fatigability are increased compared with SL. The specific mechanisms contributing to impaired performance are dependent on the exercise paradigm and amount of muscle mass involved. Next, the effect of chronic exposure to high altitude (ie, acclimatization of ~7-28 days) will be considered. With acclimatization, supraspinal fatigability is restored to SL values, regardless of the amount of muscle mass involved, whereas peripheral fatigability remains greater than SL except when exercise involves a small amount of muscle mass (eg, knee extensors). Indeed, when whole-body exercise is involved, peripheral fatigability is not different to acute high-altitude exposure, due to competing positive (haematological and muscle metabolic) and negative (respiratory-mediated) effects of acclimatization on neuromuscular performance. In the final section, we consider evolutionary adaptations of native highlanders (primarily Himalayans of Tibet and Nepal) that may account for their superior performance at altitude and lesser degree of neuromuscular fatigability compared with acclimatized lowlanders, for both single-joint and whole-body exercise.


Asunto(s)
Mal de Altura , Altitud , Aclimatación/fisiología , Fatiga , Humanos , Hipoxia , Oxígeno
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