[Effects of postural control upon anti-saccade error rate in older people]. / Efectos del control postural en la tasa de error anti-sacádico en personas mayores.

BACKGROUND: The anti-saccadic (AS) error-rate is used to diagnose neurological disorders. The natural aging process could generate difficulty in carrying out parallel neural processes of conscious motor inhibition and eye movement. Therefore, if balance control is imposed on an elderly person in biped positions during an AS movement, an increase in the AS error-rate is expected. OBJECTIVE: To study the effects of postural control on the AS error-rate in older people. METHODS: An intra and intergroup comparison was made of AS error-rate in an experimental group of older people (PM) and another control group of young people (PJ). For this, blocks of AS and pro-saccadic movements (control) were used randomly in four different postures: (1)sitting (SENT), (2)standing normally (NORMAL), (3)feet together (REDUC), and (4)feet in line (TANDEM). RESULTS: The PM group, compared to the PJ group, showed a progressive increase in the AS error-rate from the sitting position to all standing positions, with the maximum AS error-rate in more complex vertical postures. In contrast, the PJ group did not present significative variability of this AS error-rate in all positions. CONCLUSIONS: It is confirmed that the aging process is associated with an increase in the AS error-rate. This study reveals for the first time a significant increase in the AS error-rate when control of body balance is required for PM, implying a decrease in the multiple processing capacity in PM for the execution of complex and parallel tasks.

Diversity of Culturable Bacteria from Endemic Medicinal Plants of the Highlands of the Province of Parinacota, Chile.

Endemic medicinal plants that grow at altitudes in northern Chile have been traditionally used for therapeutic applications by Aymara doctors. Several studies have analyzed the biological properties of these plants for therapeutic purposes. The aim was to characterize at molecular and biochemical levels the bacteria that live in the rhizosphere and roots from endemic medicinal plants that grow between 3681-5104 m.a.s.l. in the province of Parinacota. Thirty-nine bacteria were isolated from nine medicinal plants under our laboratory conditions. These bacteria were characterized by Gram stain, hydrolase production, plant-growth promotion, anti-fungal and antibacterial activities, and 16S rDNA sequencing. A phylogenetic study revealed the presence of three major phyla, Actinomycetota (46.2%), Bacillota (43.6%), and Pseudomonadota (10.3%). The rhizobacteria strains associated with the Aymara medicinal plant exhibited several interesting biological activities, such as hydrolytic enzymes, plant-growth-promoting traits, and antibacterial and antifungal properties, indicating their potential for developing new bio-based products for agricultural or clinical applications. These results are promising and highlight the need to point toward the search for explanations of the bio-molecular basis of the therapeutic effects of medicinal plants.

Cardiovascular Risk Is Increased in Miner's Chronic Intermittent Hypobaric Hypoxia Exposure From 0 to 2,500 m?

Over the past 40 years, mining activities in Chile have relocated miners who normally live at sea level to work at high altitudes. This results in a form of chronic intermittent hypobaric hypoxia (CIHH) characterized by alternating periods of work at high altitude and rest periods at sea level. Previous studies performed in our laboratory showed that aerobic capacity is reduced at 3,800 m, even when oxygen content is maintained. Our study aimed to determine the corporal composition, food intake, maximum oxygen uptake, and concentration of high sensitivity C reactive protein (hsCRP) in an acclimatized miner population that work from 0 to 2,500 m with CIHH exposure over 4 years. All miners recruited for our study were operators of heavy trucks with CIHH for over 4 years (shiftwork 7*7 days), and our experimental population was composed of 54 miners at sea level, 61 at 1,600 m, and 38 at 2,500 m. All evaluations were performed on the 3rd or 4th day of diurnal shiftwork. To determine corporal composition, we measured weight and height (to calculate body mass index, BMI), skinfolds (to calculate body fatty, BF), and waist circumference (WC); maximal aerobic capacity was evaluated using a ramp-incremental cycling to exhaustion protocol and a venous blood sample before the exercise test to measure (hsCRP) via an ELISA test. We found higher values of BMI, BF, and WC, in the miners' population but observed no significant difference between populations. We found a decrease in VO2 of 11.6% at 1,600 m and 25.9% at 2,500 m compared to miners at sea level. An increase in (hsCRP) at 1,600 and 2,500 m regards sea level. We observed a high prevalence of overweight and obese subjects, which was related to the ad libitum availability of food and low physical activity (sedentarism). We found that work capacity was maintained despite a decreased VO2 max at moderate altitude. However, overweight and obesity support an increased risk of cardiometabolic disease in miner's which is unrelated to altitude. In contrast, an increased hsCRP level could be associated with increased inflammatory mechanisms at 1,600 and 2,500 m.

The Effect of Chronic Intermittent Hypobaric Hypoxia on Sleep Quality and Melatonin Serum Levels in Chilean Miners.

High-altitude mining is an important economic resource for Chile. These workers are exposed to chronic intermittent hypobaric hypoxia (CIHH), which reduces their sleep quality and increases the risk of accidents and long-term illnesses. Melatonin, a hormone produced by the pineal gland, is a sleep inducer that regulates the circadian cycle and may be altered in populations subjected to CIHH. This work aimed to assess the relationship between altitude, sleep quality, and plasma melatonin concentrations in miners with CIHH exposure. 288 volunteers were recruited from five altitudes (0, 1,600, 2,500, 3,500, and 4,500 m). All volunteers worked for 7 days at altitude, followed by 7 days of rest at sea level. We performed anthropometric assessments, nocturnal oximetry, sleep quality and sleepiness surveys, and serum melatonin levels upon awakening. Although oxygen saturation progressively decreased and heart rate increased at higher altitudes, subjective perception of sleep quality was not significantly different, and sleepiness increased in all groups compared to population at sea level. Similarly, melatonin levels increased at all assessed altitudes compared to the population at sea level. These data confirm that sleep disturbances associated with CIHH increase morning melatonin levels. Therefore, this hormone and could potentially serve as a biomarker of sleep quality.

A key for hypoxia genetic adaptation in alpaca could be a HIF1A truncated bHLH protein domain / Una clave para la adaptacion genética de la hypoxia en las alpacas podria ser un dominio de proteina bHLH truncado con HIF1A

Animals exposed to hypobaric hypoxia triggers a physiological hypoxia response via Hypoxia Inducible Factor (HIF) proteins that functions as transcriptional complexes. As the South American camelids inhabit at high Andean altitudes we have asked if they have developed genetic adaptations to live at high altitudes. In the present study we investigate genetic structures of the HIF1A proteins carried by members of the superorder Cetartiodactyla. During our investigation we discovered the existence of a genetic event that caused the loss of most of the bHLH domain in the proteins borne by the Alpaca and other members of the Cetartiodactyla superorder; we designate them as bHLH short sequences. Further analysis at the nucleotide level revealed in the 12 short sequences included in the study the presence at the 5´end of the bHLH domains stop codons. Seven out of the 12 short HIF1A proteins, have an identical or almost identical nucleotide sequence at their 5´end with a same TAA stop codon and at the same position. As the mutations affects to both the Artiodactyls and Cetaceans, we postulate that the mutation(s) occurred before their divergence about 55 million years ago. The relevance of these findings for genetic adaptation of Alpacas to hypobaric hypoxia of high altitude conditions is discussed.

Los animales expuestos a hypoxia hipobárica generan una respuesta hipóxica fisiológica debido a unas proteinas de Factor-Hipoxia Inducible (HIF) que funcionan como complejos transcripcionales. Debido a que los camelidos Americanos habitan en las grandes alturas andinas, nos hemos preguntado si han desarrollado una adaptación genética para vivir a grandes alturas. Eneste estudio hemos investigado la estructura genética de las proteinas HIF1A que llevan consigo los miembros de la superorden de los cetartiodáctilos. Durante nuestra investigación, descubrimos la existencia de un evento genético que causó la perdida de la mayoría del dominio bHLH en las proteinas transmitidas por la alpaca y otros miembros de la superorden de los cetartiodáctilos; las hemos designado como secuencias cortas de bHLH. Análisis posteriores a nivel nucleótido revelaron que en la doceava secuencia corta incluida en el studio, hubo presencia de codones de terminación en el extreme 5' del dominio de bHLH. Siete de las doce proteinas cortas HIF1A, tiene una secuencia idéntica o casi idéntica de nucleotidos en su extremo 5', con el mismo codón de terminación TAA y en la misma posición. Debido a que la mutación afecta tanto a Artiodáctilos como Cetáceos, proponemos que la mutación(es) ocurrió antes de su divergencia hace unos 55 millones de años. Analizamos la relevancia de estos descubrimientos sobre la adaptación genética de las alpacas a la hipoxia hipobárica en condiciones de grandes alturas.

Oxygen saturation and heart rate in children at high altitude: a different response of Aymaras and non-Aymaras with chronic exposure at 3500 m / Saturación de oxígeno y ritmo cardiaco de niños en zonas de gran altitud: una respuesta distinta entre Aymaras y no Aymaras con exposición crónica a 3500 m

This work aims to determine if there is a difference between the cardiorespiratory response of children who chronically live at high altitude (Aymaras and non-Aymaras) compared to children that arrive as tourist at a high altitude of 3500 m (Putre, Chile). The subjects were children (Aymaras and non-Aymaras) who were born and live in Putre and children who came to the same location for a tourist visit. We used Oxygen saturation (%) and heart rate (HR, bpm) were evaluated by pulse oxymetry in children from Putre. The results showed similar levels of oxygen saturation were observed among chronic Aymaras and non-Aymara children. A lower oxygen saturation was found in children with acute exposure when compared with chronic children (p<0.0001). The HR of Aymaras and non-Aymara chronic children was lower than that observed in the non-native children (p<0.05). In contrast acute children had a higher HR than chronic children (p<0.001). Negative relationships were observed with correlation values (p<0.01) between oxygen saturation and HR in all groups. We concluded that chronic Aymara children exhibited a higher slope and correlation between oxygen saturation vs HR compared to chronic children who are non-Aymaras, suggesting that chronic natives are more sensitive to hypoxia. And, chronic non-Aymara children have an early blunting response to hypoxia. Further studies are needed to understand the physiological mechanisms in this population group.

El objetivo de este trabajo es determinar si existe alguna diferencia entre la respuesta cardiorespiratoria de niños que han vivido crónicamente a gran altitud (Aymaras y no Aymaras) comparados con niños llegados como turistas en grandes alturas de 3500m (Putre, Chile). Los sujetos fueron niños (Aymaras y no Aymaras) que nacieron y vivieron en Putre y niños que llegaron a la zona por una visita turística. Utilizamos saturación de oxígeno (%) y ritmo cardíaco (HR, bpm). Los niños de Putre fueron evaluados utilizando la pulsioximetría. Los resultados mostraron niveles similares de saturación de oxígeno entre los niños crónicos Aymaras y no Ayamaras. En los niños con exposición aguda se encontró una baja saturación de oxígeno al compararse con los niños crónicos (p<0.0001). El HR de los niños crónicos Aymaras y no Aymaras fue menor que el observado en niños no nativos (p<0.05). En cambio, los niños con síntomas agudos tenían una mayor HR que los niños crónicos (p<0.001). Se observaron relaciones negativas con los valores de correlación (p<0.01) entre la saturación de oxígeno y HR en todos los grupos. Concluimos que los niños crónicos Aymaras mostraban una gran pendiente y correlacion entre la saturación de oxígeno contra el HR comparado con los niños crónicos no Aymaras, sugiriendo que los nativos crónicos son más susceptibles a la hipoxia, y que los niños crónicos no Aymaras tiene una respuesta temprana a la hipoxia. Se necesitan estudios posteriores para entender los mecanismos fisiológicos en este grupo de población.

Aerobic Capacity, Lactate Concentration, and Work Assessment During Maximum Exercise at Sea Level and High Altitude in Miners Exposed to Chronic Intermittent Hypobaric Hypoxia (3,800 m).

We previously showed that arterial oxygen content during maximum exercise remains constant at high altitude (HA) in miners exposed to chronic intermittent hypobaric hypoxia (CIHH). Nevertheless, information about VO2, lactate concentration [Lac], and work efficiency are absent in this CIHH miner population. Our aim was to determine aerobic capacity, [Lac], and work efficiency at sea level (SL) and HA during maximum exercise in miners acclimatized to CIHH at 3,800 m. Eight volunteer miners acclimatized to CIHH at HA (> 4 years) performed an exercise test at SL and HA. The test was performed on the 4th day at HA or SL and consisted of three phases: Rest (5 min); Exercise test, where the load was increased by 50 W every 3 min until exhaustion; and a Recovery period of 30 min. During the procedure VO2, transcutaneous arterial saturation (SpO2, %), and HR (bpm) were assessed at each step by a pulse oximeter and venous blood samples were taken to measure [Lac] and hemoglobin concentration. No differences in VO2 and [Lac] in SL vs. HA were observed in this CIHH miner population. By contrast, a higher HR and lower SpO2 were observed at SL compared with HA. During maximum exercise, a reduction in VO2 and [Lac] was observed without differences in intensity (W) and HR. A decrease in [Lac] was observed at maximum effort (250 W) and recovery at HA vs. SL. These findings are related to an increased work efficiency assessment such as gross and net efficiency. This study is the first to show that miners exposed to CIHH maintain their work capacity (intensity) with a fall in oxygen consumption and a decrease in plasmatic lactate concentration at maximal effort at HA. These findings indicate that work efficiency at HA is enhanced.

Occupational injuries among children and adolescents in Cusco Province: a cross-sectional study.

BACKGROUND: Although the number of child laborers in Latin America is generally high, data on occupational hazards and injuries is insufficient. The objective of this study was therefore to determine the lifetime prevalence of and risk factors for occupational injuries among working students (10-17 years old) in Cusco Province. METHODS: A cross-sectional study was conducted at five public night schools. 375 students (response 91.5%) completed an interview-based questionnaire on socio-demographics, work-related factors, and lifetime prevalence of occupational injuries. Multiple logistic regression analyses were performed to estimate risk factors for different types and causes of occupational injuries. RESULTS: Falls (11%), car accidents (9%) and physical violence (3%) were common causes of injuries in this population. Severe injuries (fractures, luxation or amputations) were reported by 3% of the population. A high daily income (≥20 PEN, ~15 USD) was a statistically significant predictor for injuries caused by falls [OR 2.8; 95% CI 1.2-6.5] and physical violence at work [12.1; 1.3-115.9] whereas children born in Cusco and those working in the service sector were at higher risk of injuries caused by car accidents [3.7; 1.5-9.3 and 4.2; 1.2-15.3]. CONCLUSIONS: Occupational accidents among child workers attending public night schools are common in Cusco with a lifetime prevalence of 3% for severe injuries. High income seems to convince child laborers to accept poor working conditions.

Characterization, mapping, and mitigation of mercury vapour emissions from artisanal mining gold shops.

Artisanal miners sell their gold to shops that are usually located in the urban core, where the mercury-gold amalgam is burned to evaporate the mercury that was added during ore processing. People living and working near these gold shops are exposed to intermittent and extreme concentrations of mercury vapour. In the urban centres of Segovia, Colombia, and Andacollo, Chile, the average concentrations measured by mobile mercury vapour analyzer transects taken repeatedly over several weeks were 1.26 and 0.338µgm(-3), respectively. By World Health Organization standards, these towns are exposed to significant health hazard, and globally, the millions of miners, as well as non-miners who live near gold shops, are at serious risk of neurological and renal deficits. Measurements taken in Suriname, Ecuador and Peru reveal this to be a widespread phenomenon with unique regional variations and myriad attempts at remediation. Maps of average mercury concentrations show the spatial distribution of the hazard in relation to residential buildings and schools. Measurements from towers show the temporal variability of mercury concentrations, and suggest that large quantities of mercury are available for long-range atmospheric transport. Mercury mapping in Segovia in 2011 suggest a 10% reduction in airborne mercury concentrations over 2010, despite a 30% increase in gold production. This is attributable to the adoption of retorts by miners and regulations banning new processing centres to the rural periphery. This is the first full description of artisanal mining gold shop practices and of the character, quantity, and remediation of mercury emissions within urban mining centres.