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14 pages, 1179 KiB

Open AccessArticle

Aging Increases Enterocyte Damage during a 3-Hour Exposure to Very Hot and Dry Heat: A Preliminary Study

by Josh Foster, Zachary J. Mckenna, Whitley C. Atkins, Caitlin P. Jarrard and Craig G. Crandall

Biology 2023, 12(8), 1088; https://doi.org/10.3390/biology12081088 - 04 Aug 2023

Cited by 1 | Viewed by 1309

Profound heat stress can damage the gastrointestinal barrier, leading to microbial translocation from the gut and subsequent systemic inflammation. Despite the greater vulnerability of older people to heat wave-related morbidity and mortality, it is unknown if age modulates gastrointestinal barrier damage and inflammation [...] Read more.

Profound heat stress can damage the gastrointestinal barrier, leading to microbial translocation from the gut and subsequent systemic inflammation. Despite the greater vulnerability of older people to heat wave-related morbidity and mortality, it is unknown if age modulates gastrointestinal barrier damage and inflammation during heat stress. Therefore, the aim of this study was to determine if aging impacted enterocyte damage and systemic inflammatory responses to a 3-h exposure to very hot and dry (47 °C, 15% humidity) heat with accompanying activities of daily living (intermittent activity at 3 METS). Data from 16 young (age 21 to 39 years) and 16 older (age 65 to 76 years) humans were used to address this aim. In each group, log-transformed plasma concentrations of intestinal fatty acid binding protein (I-FABP_log), interleukin-8 (IL-8_log), and tissue factor (TF_log) were assessed as indices of enterocyte damage, systemic inflammation, and blood coagulation, respectively, before and after the 3-h heat exposure. In the younger cohort, I-FABP_log concentration did not increase from pre to post heat exposure (p = 0.264, d = 0.20), although it was elevated in the older group (p = 0.014, d = 0.67). The magnitude of the increase in I-FABP_log was greater in the older participants (p = 0.084, d = 0.55). Across all participants, there was no correlation between the change in core temperature and the change in IFABP_log. There was no change in IL-8_log in the younger group (p = 0.193, d = 0.23) following heat exposure, but we observed a decrease in IL-8_log in the older group (p = 0.047, d = 0.48). TF_log decreased in the younger group (p = 0.071, d = 0.41), but did not change in the older group (p = 0.193, d = 0.15). Our data indicate that I-FABP_log concentration (an index of enterocyte damage) is increased in older humans during a 3-h extreme heat exposure. Future studies should determine whether this marker reflects increased gastrointestinal barrier permeability in older individuals during heat exposure. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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14 pages, 2008 KiB

Open AccessArticle

Cardio-Respiratory and Muscle Oxygenation Responses to Submaximal and Maximal Exercise in Normobaric Hypoxia: Comparison between Children and Adults

by Anton Ušaj, Alexandros Sotiridis and Tadej Debevec

Biology 2023, 12(3), 457; https://doi.org/10.3390/biology12030457 - 16 Mar 2023

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Abstract

As differential physiological responses to hypoxic exercise between adults and children remain poorly understood, we aimed to comprehensively characterise cardiorespiratory and muscle oxygenation responses to submaximal and maximal exercise in normobaric hypoxia between the two groups. Following familiarisation, fifteen children (Age = 9 [...] Read more.

As differential physiological responses to hypoxic exercise between adults and children remain poorly understood, we aimed to comprehensively characterise cardiorespiratory and muscle oxygenation responses to submaximal and maximal exercise in normobaric hypoxia between the two groups. Following familiarisation, fifteen children (Age = 9 ± 1 years) and fifteen adults (Age = 22 ± 2 years) completed two graded cycling exercise sessions to exhaustion in a randomized and single-blind manner in normoxia (NOR; F_iO₂ = 20.9) and normobaric hypoxia (HYP; F_iO₂ = 13.0) exercises conditions. Age-specific workload increments were 25 W·3 min⁻¹ for children and 40 W·3 min⁻¹ for adults. Gas exchange and vastus lateralis oxygenation parameters were measured continuously via metabolic cart and near-infrared spectroscopy, respectively. Hypoxia provoked significant decreases in maximal power output P_MAX (children = 29%; adults 16% (F = 39.3; p < 0.01)) and power output at the gas exchange threshold (children = 10%; adults:18% (F = 8.08; p = 0.01)) in both groups. Comparable changes were noted in most respiratory and gas exchange parameters at similar power outputs between groups. Children, however, demonstrated, lower P_ETCO₂ throughout the test at similar power outputs and during the maintenance of

\dot{V} C O

₂ at the maximal power output. These data indicate that, while most cardiorespiratory responses to acute hypoxic exercise are comparable between children and adults, there exist age-related differential responses in select respiratory and muscle oxygenation parameters. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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15 pages, 2651 KiB

Open AccessArticle

Changes in Body Mass, Physical Activity, and Dietary Intake during the COVID-19 Pandemic Lockdowns in Canadian University Students

by Madison Bell, Markus J. Duncan, Karen A. Patte, Brian D. Roy, David S. Ditor and Panagiota Klentrou

Biology 2023, 12(2), 326; https://doi.org/10.3390/biology12020326 - 17 Feb 2023

Cited by 3 | Viewed by 1886

Abstract

This study examined changes in body mass and body mass index (BMI), physical activity, and dietary intake in Canadian university students during the first year of the COVID-19 pandemic. Two self-reported recall surveys were conducted: after the first lockdown in September 2020 (T1) [...] Read more.

This study examined changes in body mass and body mass index (BMI), physical activity, and dietary intake in Canadian university students during the first year of the COVID-19 pandemic. Two self-reported recall surveys were conducted: after the first lockdown in September 2020 (T1) and following the second lockdown in March 2021 (T2). Eligible participants were full-time undergraduate students attending a Canadian university and residing in Canada during the first year of the pandemic. At T1, 510 students (99 male, 411 female) completed the survey, and of those, 135 (32 males, 103 females) completed the survey at T2 (73% attrition). At both T1 and T2, most participants were 18–24 years of age (93% and 90%, respectively), Caucasian (73% and 78%, respectively), and resided in the province of Ontario (79% and 80%, respectively). Body mass increased from T1 to T2 (+0.91 ± 3.89 kg t(132) = −2.7, p = 0.008). BMI also increased from T1 to T2 (+0.30 ± 1.33 kg/m² [t(130) = −2.5, p = 0.012), with a greater number of participants within the overweight range (19.8% versus 24.4%, respectively). At T1, 38% of the participants reported a decrease in physical activity, while the number of students reporting a decrease in activity increased to 56% at T2. Dietary energy intake decreased from 1678 ± 958 kcal/day at T1 to 1565 ± 842 kcal/day at T2 [c²(1) = 7.2, p = 0.007]. Diet quality also decreased, with participants not meeting the recommended daily allowance for essential macro and micronutrients. A decrease was observed in daily servings of fruits (−27%, p < 0.001), vegetables (−72%, p < 0.001), and grains (−68%, p < 0.001). In conclusion, despite a small decrease in dietary energy intake, a modest weight gain occurred during the first year of the COVID-19 pandemic in this cohort of Canadian university students, which was potentially related to decreased physical activity and diet quality. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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31 pages, 18836 KiB

Open AccessArticle

A Database of Static Thermal Insulation and Evaporative Resistance Values of Dutch Firefighter Clothing Items and Ensembles

by Kalev Kuklane, Jakob Eggeling, Maurice Kemmeren and Ronald Heus

Biology 2022, 11(12), 1813; https://doi.org/10.3390/biology11121813 - 13 Dec 2022

Cited by 3 | Viewed by 1707

Abstract

The rescue operations’ environment can impair firefighters’ performance and increase the risk of injuries, e.g., burns and hyperthermia. The bulk and carried weight of heavy protection contributes to lower physical performance, higher metabolic load and internal body heat production. For recommending optimal protection [...] Read more.

The rescue operations’ environment can impair firefighters’ performance and increase the risk of injuries, e.g., burns and hyperthermia. The bulk and carried weight of heavy protection contributes to lower physical performance, higher metabolic load and internal body heat production. For recommending optimal protection for the tasks and incident scenarios, knowledge of clothing thermal properties is needed. However, detailed data on firefighter protective clothing systems are not available. The aim of the study was to provide scientific background and a dataset that would allow for validation of thermo-physiological models for task-specific conditions of rescue work. Thermal insulation of 37 single items and their variations and 25 realistic protective clothing ensembles were measured on a thermal manikin. Twelve (12) ensembles that evenly covered the whole insulation range were selected for evaporative resistance testing. The equations for summing up individual item’s insulation to ensemble insulation and calculating clothing area factor were derived from the dataset. The database of a firefighter clothing system was created. In addition, the local and regional thermal properties of the clothing ensembles were provided for use in future validation of advanced thermo-physiological models for rescue worker exposure predictions and for designing decision aid tools. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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13 pages, 2338 KiB

Open AccessArticle

Striated Muscle Evaluation Based on Velocity and Amortization Ratio of Mechanical Impulse Propagation in Simulated Microgravity Environment

by Alexandru Nistorescu, Stefan Sebastian Busnatu, Adrian Dinculescu, Gabriel Olteanu, Mihaela Marin, Cosmina Elena Jercalau, Cristian Vizitiu and Ioana Raluca Papacocea

Biology 2022, 11(11), 1677; https://doi.org/10.3390/biology11111677 - 18 Nov 2022

Viewed by 1487

Abstract

Long-duration space flight missions impose extreme physiological stress and/or changes, such as musculoskeletal function degradation, on the crew due to the microgravity exposure. A great deal of research studies have been conducted in order to understand these physiological stress influences and to provide [...] Read more.

Long-duration space flight missions impose extreme physiological stress and/or changes, such as musculoskeletal function degradation, on the crew due to the microgravity exposure. A great deal of research studies have been conducted in order to understand these physiological stress influences and to provide countermeasures to minimize the observed negative effects of weightlessness exposure on musculoskeletal function. Among others, studies and experiments have been conducted in DI analogue Earth-based facilities in order to reproduce the weightlessness negative effects on the human body. This paper presents a complex muscular analysis of mechanical wave propagation in striated muscle, using MusTone, a device developed in-house at the Institute of Space Science, Romania. The data were collected during a 21-day DI campaign in order to investigate muscle fibers’ behavior in longitudinal direction, after applying a mechanical impulse, taking into account two particular parameters, namely propagation velocity and amortization ratio. The parameters were determined based on the wave-propagation data collected from five points (one impact point, two distal direction points, and two proximal direction points) along the muscle fiber. By statistically analyzing propagation velocity and amortization ratio parameters, the study revealed that muscle deconditioning is time dependent, the amortization ratio is more significant in the distal direction, and the lower fibers are affected the most. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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14 pages, 1704 KiB

Open AccessArticle

Calibrating a Comprehensive Immune Age Metric to Analyze the Cross Sectional Age-Related Decline in Cardiorespiratory Fitness

by Peter Bröde, Maren Claus, Patrick D. Gajewski, Stephan Getzmann, Klaus Golka, Jan G. Hengstler, Edmund Wascher and Carsten Watzl

Biology 2022, 11(11), 1576; https://doi.org/10.3390/biology11111576 - 27 Oct 2022

Cited by 3 | Viewed by 2772

Abstract

Cardiorespiratory fitness (CRF) is essential for sustained work ability in good health, but declines with aging, as does the functionality of the immune system, the latter process commonly referred to as immunosenescence. This study aimed to compare the capacity of immunosenescence biomarkers with [...] Read more.

Cardiorespiratory fitness (CRF) is essential for sustained work ability in good health, but declines with aging, as does the functionality of the immune system, the latter process commonly referred to as immunosenescence. This study aimed to compare the capacity of immunosenescence biomarkers with chronological age for predicting low CRF in a cross-sectional sample recruited from the regional working population. CRF was determined by submaximal bicycle ergometer testing in a cross-sectional sample of 597 volunteers aged 20–70 years from the ’Dortmund Vital Study’ (DVS, ClinicalTrials.gov Identifier: NCT05155397). Low CRF was scored if the ergometer test was not completed due to medical reasons or if the power output projected to a heart rate of 130 bpm divided by body mass was below sex-specific reference values of 1.25 W/kg for females and 1.5 W/kg for males, respectively. In addition to established biomarkers of immunosenescence, we calibrated a comprehensive metric of immune age to our data and compared its predictive capacity for low CRF to chronological age, while adjusting our analysis for the influence of sex, obesity, and the level of regular physical activity, by applying univariate and multiple logistic regression. While obesity, low physical activity, chronological and immune age were all associated with increased probability for low CRF in univariate analyses, multiple logistic regression revealed that obesity and physical activity together with immune age, but not chronological age, were statistically significant predictors of low CRF outcome. Sex was non-significant due to the applied sex-specific reference values. These results demonstrate that biological age assessed by our immunological metric can outperform chronological age as a predictor for CRF and indicate a potential role for immunosenescence in explaining the inter-individual variability of the age-related decline in cardiorespiratory fitness. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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16 pages, 1185 KiB

Open AccessArticle

Effect of Intermittent Hypoxic Training on Selected Biochemical Indicators, Blood Rheological Properties, and Metabolic Activity of Erythrocytes in Rowers

by Aneta Teległów, Mateusz Mardyła, Michał Myszka, Tomasz Pałka, Marcin Maciejczyk, Przemysław Bujas, Dariusz Mucha, Bartłomiej Ptaszek and Jakub Marchewka

Biology 2022, 11(10), 1513; https://doi.org/10.3390/biology11101513 - 15 Oct 2022

Cited by 5 | Viewed by 1936

Abstract

The study assessed the effect of 3-week intermittent hypoxic training on blood biochemical indicators (blood morphology, fibrinogen), blood rheological properties (erythrocyte deformability, aggregation), erythrocyte enzymatic activity (acetylcholinesterase), and maximal oxygen uptake in competitive rowers. Fourteen male rowers were divided into two equal groups: [...] Read more.

The study assessed the effect of 3-week intermittent hypoxic training on blood biochemical indicators (blood morphology, fibrinogen), blood rheological properties (erythrocyte deformability, aggregation), erythrocyte enzymatic activity (acetylcholinesterase), and maximal oxygen uptake in competitive rowers. Fourteen male rowers were divided into two equal groups: experimental, training on ergometers under normobaric hypoxia (FiO₂ = 16.0%), and control, training on ergometers under normoxia (FiO₂ = 21%). Fasting blood was taken before and after training. A significant between-group difference in neutrophil levels before training was noted and a significant decrease in white blood cells in the hypoxia group. Both groups exhibited an increase in elongation index. In the normoxia group, a significant increase in erythrocyte aggregation amplitude was revealed. No significant changes occurred in the other biochemical indicators or those evaluating erythrocyte metabolic activity. Normobaric hypoxia increased erythrocyte deformability, improving blood rheological properties. Maximal oxygen uptake significantly increased only in the experimental group. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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23 pages, 2827 KiB

Open AccessArticle

The Protective Performance of Process Operators’ Protective Clothing and Exposure Limits under Low Thermal Radiation Conditions

by Ronald Heus, Boris R. M. Kingma, Birgit M. A. van Berlo, Douwe Mol, Hein A. M. Daanen and Kalev Kuklane

Biology 2022, 11(8), 1222; https://doi.org/10.3390/biology11081222 - 16 Aug 2022

Cited by 1 | Viewed by 2495

Abstract

During the early stage of a fire, a process operator often acts as the first responder and may be exposed to high heat radiation levels. The present limit values of long- (>15 min) and short-term exposure (<5 min), 1.0 and 1.5 kW/m² [...] Read more.

During the early stage of a fire, a process operator often acts as the first responder and may be exposed to high heat radiation levels. The present limit values of long- (>15 min) and short-term exposure (<5 min), 1.0 and 1.5 kW/m², respectively, have been set using physiological models and manikin measurements. Since human validation is essentially lacking, this study investigated whether operators’ protective clothing offers sufficient protection during a short-term deployment. Twelve professional firefighters were exposed to three radiation levels (1.5, 2.0, and 2.5 kW/m²) when wearing certified protective clothing in front of a heat radiation panel in a climatic chamber (20 °C; 50% RH). The participants wore only briefs (male) or panties and a bra (female) and a T-shirt under the operators’ clothing. Skin temperatures were continuously measured at the chest, belly, forearm, thigh, and knee. The test persons had to stop if any skin temperature reached 43 °C, at their own request, or when 5 min of exposure was reached. The experiments showed that people in operators’ clothing can be safely exposed for 5 min to 1.5 kW/m², up to 3 min to 2.0 kW/m², and exposure to 2.5 kW/m² or above must be avoided unless the clothing can maintain an air gap. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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26 pages, 6712 KiB

Open AccessArticle

Cardiovascular Stress and Characteristics of Cold-Induced Vasodilation in Women and Men during Cold-Water Immersion: A Randomized Control Study

by Lydia Tsoutsoubi, Leonidas G. Ioannou, Konstantinos Mantzios, Styliani Ziaka, Lars Nybo and Andreas D. Flouris

Biology 2022, 11(7), 1054; https://doi.org/10.3390/biology11071054 - 13 Jul 2022

Cited by 5 | Viewed by 3764

Abstract

Background: Cold-induced vasodilation (CIVD) is a phenomenon that refers to a paradoxical increase in finger temperature that sometimes occurs during cold exposure. The aim of this study was to compare CIVD responses between women and men, during exposure to different environmental conditions. Methods: [...] Read more.

Background: Cold-induced vasodilation (CIVD) is a phenomenon that refers to a paradoxical increase in finger temperature that sometimes occurs during cold exposure. The aim of this study was to compare CIVD responses between women and men, during exposure to different environmental conditions. Methods: Seven men and seven women participated in a matched controlled study consisting of a familiarization protocol followed by three experimental sessions (cool (10.8 °C WBGT), thermoneutral (17.2 °C WBGT), and hot (27.2 °C WBGT)). In each session, participants were asked to immerse their left hand and foot in warm water (35 ± 1 °C) for five minutes. Thereafter, the left hand and foot were immersed in cold water (8 ± 1 °C) for 40 min. After that, the left hand and foot were removed from the water and participants remained seated for five minutes. Results: For a matched thermal stress, women experienced an elevated cardiovascular strain (heart rate and in some cases mean arterial pressure) and higher frequency of CIVD reactions (men: 31 vs. women: 60) in comparison to their male counterparts. Conclusions: The present study demonstrated that women experienced elevated cardiovascular strain and higher frequency of CIVD reactions, particularly in the toes, compared to their male counterparts during cold-water immersion. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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20 pages, 20225 KiB

Open AccessArticle

Possible Ameliorative Effects of the Royal Jelly on Hepatotoxicity and Oxidative Stress Induced by Molybdenum Nanoparticles and/or Cadmium Chloride in Male Rats

by Reham Z. Hamza, Rasha A. Al-Eisa and Nahla S. El-Shenawy

Biology 2022, 11(3), 450; https://doi.org/10.3390/biology11030450 - 16 Mar 2022

Cited by 13 | Viewed by 2911

Abstract

The present study aimed to investigate the effect of the royal jelly (RJ) on hepatotoxicity induced by molybdenum nanoparticles (MoO₃-NPs), cadmium chloride (CdCl₂), or their combination in male rats at biochemical, inflammation, immune response, histological, and ultrastructural levels. The [...] Read more.

The present study aimed to investigate the effect of the royal jelly (RJ) on hepatotoxicity induced by molybdenum nanoparticles (MoO₃-NPs), cadmium chloride (CdCl₂), or their combination in male rats at biochemical, inflammation, immune response, histological, and ultrastructural levels. The physicochemical properties of MoO₃-NPs have been characterized, as well as their ultrastructural organization. A rat experimental model was employed to assess the liver toxicity of MoO₃-NPs, even in combination with CdCl₂. Different cellular studies indicate divergent mechanisms, from increased reactive oxygen species production to antioxidative damage and cytoprotective activity. Seventy male rats were allocated to groups: (i) control; (ii) MoO₃-NPs (500 mg/kg); (iii) CdCl₂ (6.5 mg/kg); (iv) RJ (85 mg/kg diluted in saline); (v) MoO₃-NPs followed by RJ (30 min after the MoO₃-NPs dose); (vi) CdCl₂ followed by RJ; and (vii) a combination of MoO₃-NPs and CdCl₂, followed by RJ, for a total of 30 successive days. Hepatic functions, lipid profile, inflammation marker (CRP), antioxidant biomarkers (SOD, CAT, GPx, and MDA), and genotoxicity were examined. Histological changes, an immunological marker for caspase-3, and transmission electron microscope variations in the liver were also investigated to indicate liver status. The results showed that RJ alleviated the hepatotoxicity of MoO₃-NPs and/or CdCl₂ by improving all hepatic vitality markers. In conclusion, the RJ was more potent and effective as an antioxidant over the oxidative damage induced by the combination of MoO₃-NPs and CdCl₂. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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12 pages, 684 KiB

Open AccessSystematic Review

Population Characteristics, Symptoms, and Risk Factors of Idiopathic Chilblains: A Systematic Review, Meta-Analysis, and Meta-Regression

by Areti K. Kapnia, Styliani Ziaka, Leonidas G. Ioannou, Irini Flouri, Petros C. Dinas and Andreas D. Flouris

Biology 2022, 11(11), 1651; https://doi.org/10.3390/biology11111651 - 11 Nov 2022

Viewed by 2333

Abstract

Background: Chilblains/perniosis is a non-freezing cold injury causing painful inflammatory skin lesions. Its pathogenesis remains poorly understood because it is often studied as secondary to other underlying conditions. Methods: We systematically investigated the population characteristics, symptoms, and predisposing factors of chilblains in healthy [...] Read more.

Background: Chilblains/perniosis is a non-freezing cold injury causing painful inflammatory skin lesions. Its pathogenesis remains poorly understood because it is often studied as secondary to other underlying conditions. Methods: We systematically investigated the population characteristics, symptoms, and predisposing factors of chilblains in healthy adults exposed to cool/cold environments. We screened PubMed, Embase, and Cochrane Library, and we adopted PRISMA reporting guidelines (PROSPERO: CRD42021245307). The risk of bias was assessed by two independent reviewers (RTI item bank). Random-effects model meta-analyses were performed to calculate the pooled prevalence of histopathological features. Mixed-effects meta-regressions were used to assess other sources of between-study heterogeneity. Results: Thirteen studies (477 patients) were included. Chilblains affect more women than men, up to 12% of the body skin surface, and most frequently, the hands and fingers. Meta-analyses of nine studies (303 patients) showed a frequent presence of perivascular lymphocytic infiltrate (81%), basal epidermal-cell layer vacuolation (67%), papillary dermal edema (66%), and perieccrine lymphocytic infiltrate (57%). Meta-regressions (p ≤ 0.05) showed that smoking and frequent occupational exposure to water increase the likelihood of histopathological features. Conclusions: The population characteristics, symptoms, and predisposing factors of chilblains revealed in this analysis should be incorporated in medical care to improve the condition’s diagnosis and management. Full article

(This article belongs to the Special Issue Effects of Environmental Factors on Human Health and Performance)

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