Interactive effects of multiscale diversification practices on farmland bird stress.

Farmland diversification practices (i.e., methods used to produce food sustainably by enhancing biodiversity in cropping systems) are sometimes considered beneficial to both agriculture and biodiversity, but most studies of these practices rely on species richness, diversity, or abundance as a proxy for habitat quality. Biodiversity assessments may miss early clues that populations are imperiled when species presence does not imply persistence. Physiological stress indicators may help identify low-quality habitats before population declines occur. We explored how avian stress indicators respond to on-farm management practices and surrounding seminatural area (1-km radius) across 21 California strawberry farms. We examined whether commonly used biodiversity metrics correlate with stress responses in wild birds. We used ∼1000 blood and feather samples and body mass and wing chord measurements, mostly from passerines, to test the effects of diversification practices on four physiological stress indicators: heterophil to lymphocyte ratios (H:L), body condition, hematocrit values, and feather growth rates of individual birds. We then tested the relationship between physiological stress indicators and species richness, abundance, occurrence, and diversity derived from 285 bird point count surveys. After accounting for other biological drivers, landscape context mediated the effect of local farm management on H:L and body condition. Local diversification practices were associated with reduced individual stress in intensive agricultural landscapes but increased it in landscapes surrounded by relatively more seminatural area. Feathers grew more slowly in landscapes dominated by strawberry production, suggesting that nutritional condition was lower here than in landscapes with more crop types and seminatural areas. We found scant evidence that species richness, abundance, occurrence, or diversity metrics were correlated with the individual's physiological stress, suggesting that reliance on these metrics may obscure the impacts of management on species persistence. Our findings underscore the importance of considering landscape context when designing local management strategies to promote wildlife conservation.

Algunas veces se considera a las prácticas de diversificación agrícola (es decir, los métodos usados para producir alimentos de manera sustentable mediante el enriquecimiento de la biodiversidad en los sistemas de cultivo) como benéficas para la agricultura y la biodiversidad, pero la mayoría de los estudios sobre estas prácticas dependen de la riqueza, abundancia o diversidad de especies como indicadores de la calidad del hábitat. Las valoraciones de la biodiversidad pueden ignorar las señales tempranas de una población en peligro cuando la presencia de la especie no implica persistencia. Los indicadores de estrés fisiológico pueden auxiliar en la identificación de hábitats de baja calidad antes de que ocurra la declinación poblacional. Analizamos las respuestas de los indicadores de estrés en aves al manejo en las granjas y áreas seminaturales circundantes (1 km de radio) de 21 cultivos de fresas en California. Evaluamos si las medidas comunes de biodiversidad se correlacionan con las respuestas al estrés de las aves silvestres. Usamos aproximadamente mil muestras de sangre y plumas y medidas de masa corporal y cuerda alar, la mayoría de paseriformes, para analizar los efectos de las prácticas de diversificación sobre cuatro indicadores de estrés fisiológico: la relación heterófilos/linfocitos (H:L), condición corporal; valores hematocritos; y la tasa de crecimiento de las plumas en aves individuales. Después probamos la relación entre los indicadores de estrés fisiológicos y la riqueza, abundancia, presencia y diversidad de especies tomadas de 285 conteos por puntos de aves. Después de considerar otros factores biológicos, el contexto del paisaje medió el efecto de la gestión de las granjas locales sobre la H:L y la condición corporal. Las prácticas locales de diversificación estuvieron asociadas con una reducción en el estrés individual en los paisajes con agricultura intensiva; sin embargo, el estrés aumentó en los paisajes rodeados por áreas relativamente más seminaturales. Encontramos poca evidencia que respalde que las medidas de riqueza, abundancia, presencia y diversidad de especies estuvieran correlacionadas con el estrés fisiológico de los individuos, lo que sugiere que depender de estas medidas puede nublar el impacto de la gestión sobre la persistencia de las especies. Nuestros descubrimientos apuntalan lo importante que es considerar el contexto del paisaje cuando se diseñan las estrategias de gestión local para promover la conservación de la fauna.

Why do we hunger for touch? The impact of daily gentle touch stimulation on maternal-infant physiological and behavioral regulation and resilience.

We report the impact of a Gentle Touch Stimulation (GTS) program. Forty-three mothers provided daily 10-min GTS with C-tactile (CT) afferent optimal stroking touch, for 4 weeks to their 3-12 weeks old infants. CT-afferents are cutaneous unmyelinated, low-threshold mechanosensitive nerves hypothesized to underly the regulatory impact of affective touch. We compared physiological and behavioral responses during a no-touch-baseline (BL), static-touch-baseline (BL-T), intervention/control (GTS/CTRL), Still Face (SF) and Reunion (RU) condition for GTS-infants versus a control-group (CTRL) at the start (T1) and end of (T2) of the program. We collected mother-infant ECG, respiration, cortisol, video-recordings, and diary-reports. At T1, physiological arousal significantly increased during SF in both groups, that is, decreased respiratory sinus arrhythmia (RSA) and R-R interval (RRI). At T2, GTS-infants showed significantly increased RSA, RRI, decreased respiration during GTS, buffering SF-arousal and allowing complete recovery during RU; CTRL-infants showed higher SF-arousal and small recovery, under initial BL-levels. Maternal cardio-respiratory showed a metabolic investment during RU. Cortisol and behavioral analyses showed higher arousal in CTRL-infants than GTS-infants at T2. We suggest that the combination of phasic short-term and tonic long-term responses to CT-optimal stroking touch, delivered in a structured daily manner, contribute to the building of infant stress regulation and resilience.

Reportamos el impacto del programa de Estimulación Táctil Suave (GTS). Cuarenta y tres madres les dieron a sus infantes de 3-12 semanas 10 minutos de GTS con un toque táctil-C (CT) aferente óptimo de caricias por 4 semanas. Los aferentes CT son nervios cutáneos amielínicos mecano-sensibles de bajo impacto que según hipótesis rigen el impacto regulatorio del toque afectivo. Comparamos las respuestas fisiológicas y de comportamiento durante un momento de referencia no táctil (BL), un momento de referencia táctil estático (BL-T), intervención/control (GTS-CTRL), la Cara Seria (SF) y la condición de Reunión (RU) para infantes GTS versus un grupo de control (CTRL) al principio (T1) y al final (T2) del programa. Recogimos información ECG de madre-infante, respiración, cortisol, grabaciones en vídeo, y reportes de un diario. Al T1, la estimulación fisiológica significativamente aumentó durante SF en ambos grupos, v.g., una baja en la arritmia respiratoria paranasal (RSA) y el intervalo R-R (RRI). Al T2, los infantes GTS significativamente mostraron un aumento de RSA, RRI, una baja en la respiración durante GTS, amortiguando la estimulación SF y permitiendo un completo recobro durante RU; los infantes de CTRL mostraron una más alta estimulación SF y un pequeño recobro, bajo los niveles BL iniciales. El aspecto cardio-respiratorio materno mostró inversión metabólica durante RU. Los análisis de cortisol y de comportamiento mostraron más altas estimulaciones de infantes de CTRL que en infantes GTS al T2. Proponemos que la combinación de las respuestas fásicas a corto plazo y tónicas a largo plazo a las caricias táctiles óptimas CT, ofrecidas de una manera estructural diaria, contribuyen a moldear la regulación del estrés y capacidad de resistencia del infante.

Cet article fait état de l'impact du programme Stimulation Toucher en Douceur (an anglais Gentle Touch Stimulation, que nous abrégeons ici GTS). Quarante-trois mères ont procédé chaque jour à un GTS de 10 minutes avec un toucher par caresse optimale C-tactile (CT) afférent, pendant 4 semaines à leurs nourrissons de 3-12 semaines. Les afférents CD sont des nerfs cutanés amyéliniques, à faible seuil et mécano-sensibles, dont on pense qu'ils sous-tendent l'impact régulatoire du toucher affectif. Nous comparons les réponses physiologiques et les réponses comportementales durant la condition à un niveau de référence NR sans toucher, un niveau de référence toucher statique (NR-T), un contrôle/intervention (GTS/CTRL), Visage Impassible (Still Face, soit SF) et la Réunion (RU) pour les bébés GTS par rapport aux bébés du groupe de contrôle (CTRL) au commencement (T1) et à la fin (T2) du programme. Nous avons recueilli l'électrocardiogramme mère-bébé, la respiration, le niveau de cortisol et les rapports-journaux. Au T1 la stimulation physiologique a augmenté de façon importante durant le SF pour les deux groupes, c'est-à-dire une arythmie des sinus respiratoires (RSA) décrue et un intervalle R-R décru (RRI). Au T2 les bébés GTS ont fait preuve d'une RSA et d'un RRI bien plus élevés, une respiration décrue durant le GTS, un éveil SF tampon et ont fait preuve d'un rétablissement complet durant la RU. Les bébés contrôle ont fait preuve de plus d'éveil SF et d'un petit rétablissement, moins élevés que les niveaux BL initiaux. La cardio-respiration maternelle a fait preuve un investissement métabolique durant la RU. Les analyses de cortisol et les analyses comportementales ont montré un éveil plus élevé chez les bébés-CTRL que chez les bébés GTS au T2. Nous suggérons que la combinaison de réactions phasiques à court terme et de réponses toniques à long terme au toucher caresse CT-optimal, donné chaque jour de manière structurée, contribue à la construction de la régulation du stress du bébé et de sa résilience.

Effects training in hypoxia on cardiometabolic parameters in obese people: A systematic review of randomized controlled trial.

OBJECTIVE: The aim of the present review is to evaluate effects of intermittent hypoxia and exercise therapy in cardiometabolic parameters on adult obese people. DATABASE: Three well-known databases were selected: EMBASE, MEDLINE and Web of Science. Studies selection: Inclusion criteria were: (a) human healthy overweight or obese adults, (b) study randomized controlled trial, (c) original experimental study, (d) English languages and (e) therapy with intermittent hypoxia and exercise. DESIGN: The assessment of the methodological quality of each study was based upon the risk of bias (PEDro scale) and level of evidence (CBO Guidelines). DATA EXTRACTION: five articles clearly met inclusion criteria and were reviewed to data extraction. RESULTS: In the hypoxia groups, weight, body mass index, waist circumference, waist-hip ratio, fat mass and lean mass improved in at least two studies in comparison with the baseline. Systolic blood pressure improved in one study. The lipid profile and the aerobic capacity were not reduced significantly. CONCLUSIONS: Results suggest that combined hypoxia with exercise may help to improve cardiometabolic parameters in obese people.

Using individual-condition measures to predict the long-term importance of habitat extent for population persistence.

Habitat loss and fragmentation are causing widespread population declines, but identifying how and when to intervene remains challenging. Predicting where extirpations are likely to occur and implementing management actions before losses result may be more cost-effective than trying to reestablish lost populations. Early indicators of pressure on populations could be used to make such predictions. Previous work conducted in 2009 and 2010 identified that the presence of Eastern Yellow Robins (Eopsaltria australis) in 42 sites in a fragmented region of eastern Australia was unrelated to woodland extent within 500 m of a site, but the robins' heterophil:lymphocyte (H:L) ratios (an indicator of chronic stress) were elevated at sites with low levels of surrounding woodland. We resurveyed these 42 sites in 2013 and 2014 for robin presence to determine whether the H:L ratios obtained in 2009 and 2010 predicted the locations of extirpations and whether the previous pattern in H:L ratios was an early sign that woodland extent would become an important predictor of occupancy. We also surveyed for robins at 43 additional sites to determine whether current occupancy could be better predicted by landscape context at a larger scale, relevant to dispersal movements. At the original 42 sites, H:L ratios and extirpations were not related, although only 4 extirpations were observed. Woodland extent within 500 m had become a strong predictor of occupancy. Taken together, these results provide mixed evidence as to whether patterns of individual condition can reveal habitat relationships that become evident as local shifts in occupancy occur but that are not revealed by a single snapshot of species distribution. Across all 85 sites, woodland extent at scales relevant to dispersal (5 km) was not related to occurrence. We recommend that conservation actions focus on regenerating areas of habitat large enough to support robin territories rather than increasing connectivity within the landscape.

[A brief history of the anatomy and physiology of a mysterious and hidden gland called the pancreas]. / Breve historia de la anatomía y fisiología de una recóndita y enigmática glándula llamada páncreas.

Because of its retrogastric location and appearance, which is similar to mesenteric fat, for centuries the pancreas has been a mysterious, hidden organ that has received little attention. However, its importance was intuited and described by Herophilus, Ruphos of Ephesus and Galen. This gland began to appearin distinct medical treatises from the 16th century. There are two important scientists in the history of the pancreas. The fist, Johann Georg Wirsung, described the main pancreatic duct in 1642, a date considered by many to be the start of Pancreatology. The second, Claude Bernard, described pancreatic exocrine function between 1849 and 1856 and is considered the father of pancreatic physiology. Besides these two outstanding figures, there is a constellation of personalities who contributed to improving knowledge of this enigmatic gland with the results of their studies. The aim of this article is to call attention to some of the most notable findings that have enhanced knowledge of this gland over the years.

Prediction of adverse drug reactions in geriatric patients admitted to intensive care units. / [Artículo traducido] Predicción de reacciones adversas a medicamentos en pacientes geriátricos ingresados en unidades de cuidados intensivos.

INTRODUCTION: Intensive Care Units (ICUs) pose challenges in managing critically-ill patients with polypharmacy, potentially leading to Adverse Drug Reactions (ADRs), particularly in the elderly. OBJECTIVE: To evaluate whether the severity and clinical prognosis scores used in ICUs correlate with the prediction of ADRs in aged patients admitted to an ICU. METHODS: A cohort study was conducted in a Brazilian University Hospital ICU. APACHE II and SAPS 3 assessed clinical prognosis, while GerontoNet ADR Risk Score and BADRI evaluated ADR risk at ICU admission. Severity of the patients' clinical conditions was evaluated daily based on the SOFA score. Adverse Drug Reaction (ADR) screening was performed daily through the identification of ADR triggers. RESULTS: 1295 triggers were identified (median 30 per patient, IQR = 28), with 15 suspected ADRs. No correlation was observed between patient severity and ADRs at admission (p=0.26), during hospitalization (p=0.91), or at follow-up (p=0.77). There was also no association between death and ADRs (p=0.28) or worse prognosis and ADRs (p>0.05). Higher BADRI scores correlated with more ADRs (p=0.001). CONCLUSIONS: The data suggest that employing the severity and clinical prognosis scores used in Intensive Care Units is not sufficient to direct active pharmacovigilance efforts, which are therefore indicated for critically ill patients.

Impact of high-flow oxygen therapy via high velocity nasal insufflation on diaphragmatic thickening fraction in healthy subjects.

OBJECTIVE: The primary objective of this study was to evaluate the impact of high-flow nasal cannula oxygen therapy [HFNC] on the diaphragm thickening fraction. DESIGN: Prospective, descriptive, cohort study SETTING: The study was conducted in the Physiology and Respiratory Care Laboratory, Intensive Care Unit, Hospital Británico de Buenos Aires. PARTICIPANTS: Thirteen healthy subjects >18 years old INTERVENTIONS: High-flow nasal cannula oxygen therapy MAIN VARIABLES OF INTEREST: Demographic data (age and gender), anthropometric data (weight, height, and body mass index), and clinical and respiratory variables (Diaphragm thickening fraction [DTf], esophageal pressure swing, respiratory rate [RR], esophageal pressure-time product per minute [PTPes/min]). RESULTS: Median DTf decreased significantly as flow increased (p < 0.05). The baseline DTf measurement was 21.4 %, 18.3 % with 20 L/m, and 16.4 % with 40 L/m. We also observed a significant decrease in RR as flow increased in HFNC (p < 0.05). In the 8 subjects with recordings, the PTPes/min was 81.3 (±30.8) cmH2O/sec/min and 64.4 (±25.3) cmH2O/sec/min at baseline and 40 L/m respectively (p = 0.044). CONCLUSIONS: The use of high-flow oxygen therapy through nasal cannula of HFNC in healthy subjects decreases the DTf and RR in association with increased flow. In addition, the use of 40 L/m flow may reduce the muscular work associated with respiration.

Towards better mortality prediction in cancer patients in the ICU: a comparative analysis of prognostic scales: systematic literature review.

OBJECTIVE: To evaluate the predictive ability of mortality prediction scales in cancer patients admitted to intensive care units (ICUs). DESIGN: A systematic review of the literature was conducted using a search algorithm in October 2022. The following databases were searched: PubMed, Scopus, Virtual Health Library (BVS), and Medrxiv. The risk of bias was assessed using the QUADAS-2 scale. SETTING: ICUs admitting cancer patients. PARTICIPANTS: Studies that included adult patients with an active cancer diagnosis who were admitted to the ICU. INTERVENTIONS: Integrative study without interventions. MAIN VARIABLES OF INTEREST: Mortality prediction, standardized mortality, discrimination, and calibration. RESULTS: Seven mortality risk prediction models were analyzed in cancer patients in the ICU. Most models (APACHE II, APACHE IV, SOFA, SAPS-II, SAPS-III, and MPM II) underestimated mortality, while the ICMM overestimated it. The APACHE II had the SMR (Standardized Mortality Ratio) value closest to 1, suggesting a better prognostic ability compared to the other models. CONCLUSIONS: Predicting mortality in ICU cancer patients remains an intricate challenge due to the lack of a definitive superior model and the inherent limitations of available prediction tools. For evidence-based informed clinical decision-making, it is crucial to consider the healthcare team's familiarity with each tool and its inherent limitations. Developing novel instruments or conducting large-scale validation studies is essential to enhance prediction accuracy and optimize patient care in this population.

Quantitative flow ratio for evaluation of borderline coronary lesions in patients with severe aortic stenosis.

INTRODUCTION AND OBJECTIVES: Quantitative flow ratio (QFR) is a novel noninvasive method for evaluating coronary physiology. However, data on the QFR in patients with aortic stenosis (AS) and coronary artery disease are scarce. Thus, we compared the diagnostic performance of the QFR with that of the resting distal to aortic coronary pressure (Pd/Pa) ratio, fractional flow reserve (FFR), and instantaneous wave-free ratio (iFR), as well as angiographic indices. METHODS: A total of 221 AS patients with 416 vessels undergoing FFR/iFR measurements were enrolled in the study. RESULTS: The mean percent diameter stenosis (%DS) was 58.6%±13.4% and the mean Pd/Pa ratio, FFR, iFR, and QFR were 0.95±0.03, 0.85±0.07, 0.90±0.04, and 0.84±0.07, respectively. A FFR ≤ 0.80 was noted in 26.0% of interrogated vessels, as well as an iFR ≤ 0.89 in 33.2% and QFR ≤ 0.80 in 31.7%. The QFR had better agreement with FFR (intraclass correlation coefficient [ICC], 0.96; 95% confidence interval [95%CI], 0.95-0.96) than with the iFR (ICC, 0.79; 95%CI, 0.75-0.82) and Pd/Pa ratio (ICC, 0.52; 95%CI, 0.44-0.58). In addition, the QFR showed better diagnostic accuracy (98.6% vs 94.2%; P <.001) and discriminant function (area under the curve=0.996 vs 0.988; P <.001) when the iFR was used as the reference instead of FFR. CONCLUSIONS: In patients with AS, the QFR has good agreement with both FFR and iFR. However, the agreement appears to be even better when the iFR is used as the reference, presumably due to the complex nature of the coronary physiology in the assessment of coronary artery disease in patients with severe AS.

Adoption and patterns of use of invasive physiological assessment of coronary artery disease in a large cohort of 40821 real-world procedures over a 12-year period.

INTRODUCTION AND OBJECTIVES: Use of invasive physiological assessment in patients with coronary artery disease varies widely and is perceived to be low. We aimed to examine adoption rates as well as patterns and determinants of use in an unselected population undergoing invasive coronary angiography over a long time frame. METHODS: We retrospectively determined the per-procedure prevalence of physiological assessment in 40821 coronary cases performed between 2007 and 2018 in two large-volume centers. Adoption was examined according to procedure type and patient- and operator-related variables. Its association with relevant scientific landmarks, such as the release of clinical trial results and practice guidelines, was also assessed. RESULTS: Overall adoption was low, ranging from 0.6% in patients undergoing invasive coronary angiography due to underlying valve disease, to 6% in the setting of stable coronary artery disease (CAD); it was 3.1% in patients sustaining an acute coronary syndrome. Of scientific landmarks, FAME 1, the long-term results of FAME 2 and the 2014 European myocardial revascularization guidelines were associated with changes in practice. Publication of instantaneous wave-free ratio (iFR) trials had no influence on adoption rates, except for a higher proportion of iFR use. In 42.9% of stable CAD patients undergoing percutaneous coronary intervention there was no objective non-invasive evidence of ischemia, nor was physiological assessment performed. Younger operator age (4.5% vs. 4.0% vs. 0.9% for ages <40, 40-55 and >55 years, respectively; p<0.001) and later time of procedure during the day (2.9% between 6 and 8 p.m. vs. 4.4% at other times) were independent correlates of use of invasive physiology. CONCLUSIONS: Our study confirms the low use of invasive physiology in routine practice. The availability of resting indices did not increase adoption. Strategies are warranted to promote guideline implementation and to improve patient care and clinical outcomes.

Caffeine slows heart rate autonomic recovery following strength exercise in healthy subjects.

INTRODUCTION AND OBJECTIVES: Studies assessing the effects of caffeine (CAF) on the cardiovascular system have demonstrated that CAF can delay cardiac recovery following exercise. This study intended to assess the impact of CAF intake before physical exercise on heart rate variability (HRV) and cardiovascular parameters. METHODS: This is a prospective, crossover, controlled clinical trial conducted at the University of Pernambuco, Petrolina, PE, Brazil. The experimental protocol was split into three stages with a minimum of 48 hours between them. Exercises intensity was standardized based on the one repetition maximum test (1RM), obtaining the load of each volunteer for the intensity of 75% of 1RM. In the second and third phases, the control protocols were applied and 300 mg caffeine was given 45 minutes before training. HRV indices were determined at the subsequent times: 0 to 5 minutes of rest (before) and during 30 minutes of recovery (Rec) (after exercise), divided into six intervals, each of 5 minutes. RESULTS: The final sample involved 30 volunteers. CAF delayed HRV recovery after resistance exercise. In general, CAF impaired recovery of HRV after resistance exercise. Significant changes were observed in the RMSSD, SDNN, TINN, SD1, low frequency and high frequency indices between the control and CAF group. CONCLUSION: CAF protocol delayed parasympathetic regulation of heart rhythm following exercise, slowing recovery of HR, blood pressure and HRV indices after exercise.

Adoption and patterns of use of invasive physiological assessment of coronary artery disease in a large cohort of 40821 real-world procedures over a 12-year period.

INTRODUCTION AND OBJECTIVES: Use of invasive physiological assessment in patients with coronary artery disease varies widely and is perceived to be low. We aimed to examine adoption rates as well as patterns and determinants of use in an unselected population undergoing invasive coronary angiography over a long time frame. METHODS: We retrospectively determined the per-procedure prevalence of physiological assessment in 40821 coronary cases performed between 2007 and 2018 in two large-volume centers. Adoption was examined according to procedure type and patient- and operator-related variables. Its association with relevant scientific landmarks, such as the release of clinical trial results and practice guidelines, was also assessed. RESULTS: Overall adoption was low, ranging from 0.6% in patients undergoing invasive coronary angiography due to underlying valve disease, to 6% in the setting of stable coronary artery disease (CAD); it was 3.1% in patients sustaining an acute coronary syndrome. Of scientific landmarks, FAME 1, the long-term results of FAME 2 and the 2014 European myocardial revascularization guidelines were associated with changes in practice. Publication of instantaneous wave-free ratio (iFR) trials had no influence on adoption rates, except for a higher proportion of iFR use. In 42.9% of stable CAD patients undergoing percutaneous coronary intervention there was no objective non-invasive evidence of ischemia, nor was physiological assessment performed. Younger operator age (4.5% vs. 4.0% vs. 0.9% for ages <40, 40-55 and >55 years, respectively; p<0.001) and later time of procedure during the day (2.9% between 6 and 8 p.m. vs. 4.4% at other times) were independent correlates of use of invasive physiology. CONCLUSIONS: Our study confirms the low use of invasive physiology in routine practice. The availability of resting indices did not increase adoption. Strategies are warranted to promote guideline implementation and to improve patient care and clinical outcomes.

Cholinergic synovitis: Description of four cases. / Sinovitis colinérgica: descripción de 4 casos.

We present the clinical and ultrasound findings of four patients with moderate synovitis and urticarial skin lesions associated with sports activity in warm environments. We include progress after treatment with hydroxycin. We suggest a causal relationship similar to cholinergic urticaria where the neighbouring synovium responds with effusion that self-limits once the triggering process has been halted.

Historical review of the Department of Physiology on the 75th anniversary of the Instituto Nacional de Cardiología "Ignacio Chávez".

The Physiology Department has played an important role in the development of physiology in Mexico since its beginnings. It was founded by Dr. Arturo Rosenblueth in 1947. Many of the original researchers participated in the formation of the Mexican Society of Physiological Sciences. Researchers belonging to this department have given origin to an important national research center (CINVESTAV) and to numerous groups and departments within the Instituto Nacional de Cardiología such as the Valves department in the basement of the main building of the institute, the department of molecular biology situated in the Anexo de Investigación, and a laboratory in the translational medicine unit. The physiology department has importantly contributed to the development of research in the Instituto Nacional de Cardiología.

El Departamento de Fisiología ha desempeñado un papel importante en el desarrollo de la fisiología en México desde sus inicios. Fue fundado por el Dr. Arturo Rosenblueth en 1947. Muchos de sus investigadores originales participaron en el nacimiento de la Sociedad Mexicana de Ciencias Fisiológicas. Fue el origen de un importante centro de investigación a nivel nacional (CINVESTAV) y ha dado lugar a numerosos grupos y departamentos dentro del Instituto Nacional de Cardiología, como el Departamento de Válvulas en el basamento del edificio principal, el Departamento de Biología Molecular ubicado en el Anexo de Investigación y un laboratorio en la Unidad de Medicina Traslacional. El Departamento de Fisiología ha contribuido de manera importante al desarrollo de la investigación en el Instituto Nacional de Cardiología.

Historical review of the Department of Physiology on the 75th anniversary of the Instituto Nacional de Cardiología "Ignacio Chávez".

The Physiology Department has played an important role in the development of physiology in Mexico since its beginnings. It was founded by Dr. Arturo Rosenblueth in 1947. Many of the original researchers participated in the formation of the Mexican Society of Physiological Sciences. Researchers belonging to this department have given origin to an important national research center (CINVESTAV) and to numerous groups and departments within the Instituto Nacional de Cardiología such as the Valves department in the basement of the main building of the institute, the department of molecular biology situated in the Anexo de Investigación, and a laboratory in the translational medicine unit. The physiology department has importantly contributed to the development of research in the Instituto Nacional de Cardiología.

El Departamento de Fisiología ha desempeñado un papel importante en el desarrollo de la fisiología en México desde sus inicios. Fue fundado por el Dr. Arturo Rosenblueth en 1947. Muchos de sus investigadores originales participaron en el nacimiento de la Sociedad Mexicana de Ciencias Fisiológicas. Fue el origen de un importante centro de investigación a nivel nacional (CINVESTAV) y ha dado lugar a numerosos grupos y departamentos dentro del Instituto Nacional de Cardiología, como el Departamento de Válvulas en el basamento del edificio principal, el Departamento de Biología Molecular ubicado en el Anexo de Investigación y un laboratorio en la Unidad de Medicina Traslacional. El Departamento de Fisiología ha contribuido de manera importante al desarrollo de la investigación en el Instituto Nacional de Cardiología.

Anatomical Correlation of the Helical Structure of the Ventricular Myocardium Through Echocardiography.

INTRODUCTION AND OBJECTIVES: The helical structure of the ventricular myocardium provides a simple view of cardiac anatomy, based on physiological evidence that has been broadly demonstrated in experimental and imaging studies, and helps to explain the electromechanical contraction of the myocardium during the cardiac cycle. The aim of this study was to standardize and provide a detailed description of the technique for preparing and manually dissecting the myocardium proposed empirically by Torrent-Guasp. A further aim was to anatomically and topographically correlate the helical band with echocardiographic long-axis, short-axis, and 4-chamber projections. METHODS: We dissected 42 hearts-20 bovine, 20 porcine and 2 human hearts-to standardize the myocardial dissection technique. Subsequently, the distinct segments were color coded to correlate the anatomical specimens with echocardiographic projections. RESULTS: Loss of 38% of the myocardial mass after boiling was sufficient to standardize myocardial dissection and allowed an efficient technique. No morphological differences were found between the bands of the hearts studied. The 4 myocardial segments could be identified in the echocardiographic projections. CONCLUSIONS: Standardization of the technique is useful to dissect any type of heart. Echocardiography is useful to assess the distinct segments that compose the myocardium. More research is needed to generate practical applications of this knowledge to echocardiography and other fields.

Fisiología del ejercicio y pedagogía vocal: reflexiones calisténicas

Introducción: El método de calistenia gimnástica se configura como una modalidad de ejercicios específicos que involucra la adopción de posturas artificiales a través de movimientos particulares. Estos movimientos están diseñados para producir efectos higiénicos y educativos claramente definidos. Esta modalidad de ejercicio guarda notables similitudes con el modus operandi de los vocalise en la pedagogía vocal. Objetivo: El objetivo de este trabajo es investigar las relaciones potenciales entre los principios técnico-científicos que guían el sistema de calistenia gimnástica y los principios técnico-pedagógicos que rigen los ejercicios vocales realizados por cantantes durante su proceso de enseñanza-aprendizaje. Asimismo, se busca explorar las conexiones entre los objetivos y propósitos del sistema de calistenia gimnástica y los de los ejercicios vocales en dicho proceso. Método: Para abordar este objetivo, se llevó a cabo una investigación bibliográfica que implicó el análisis detallado de fuentes pertinentes. Se examinaron publicaciones académicas y literatura especializada relacionada con la calistenia gimnástica y la pedagogía vocal. Reflexión: La calistenia gimnástica y los ejercicios vocales comparten una estructura fundamental de ejercicios específicos que implican posturas artificiales y movimientos específicos. Ambos buscan un refinamiento en la higienización y educación, permitiendo a los individuos, ya sea en el ámbito físico o vocal, desarrollarse de manera adecuada y saludable. Conclusión: A partir de la investigación bibliográfica, se concluye que los ejercicios vocales en el proceso de enseñanza-aprendizaje de los cantantes pueden considerarse una suerte de calistenia vocal. Esta conclusión se fundamenta en las relaciones intrínsecas observadas entre los principios y objetivos del sistema de calistenia gimnástica y el modus operandi de los ejercicios vocales. Esta reflexión aporta perspectivas valiosas a la pedagogía vocal, con el fin de ofrecer una comprensión más específicamente fisiológica y biomecánica de los ejercicios vocales, orientando mejor la aplicación de las vocalizaciones en el proceso de educación y entrenamiento vocal.

Introduction: The gymnastic calisthenics method is configured as a specific form of exercises involving the adoption of artificial postures through specific movements. These movements are designed to produce clearly defined hygienic and educational effects. This mode of exercise bears notable similarities to the modus operandi of vocalises in vocal pedagogy. Objective: The objective of this work is to investigate the potential relationships between the technical-scientific principles that guide the gymnastic calisthenics system and the technical-pedagogical principles governing vocal exercises practiced by singers during their teaching and learning process. Additionally, it aims to explore the connections between the objectives and purposes of the gymnastic calisthenics system and those of vocal exercises in this process. Method: To address this objective, a bibliographic research was conducted, involving a detailed analysis of relevant sources. Academic publications and specialized literature related to gymnastic calisthenics and vocal pedagogy were examined. Reflection: Gymnastic calisthenics and vocal exercises share a fundamental structure of specific exercises involving artificial postures and specific movements. Both seek refinement in hygiene and education, enabling individuals, either in the physical or vocal realm, to develop appropriately and healthily. Conclusion: Based on the bibliographic research, it is concluded that vocal exercises in the teaching and learning process of singers can be considered a form of vocal calisthenics. This conclusion is based on the intrinsic relationships observed between the principles and objectives of the gymnastic calisthenics system and the modus operandi of vocal exercises. This reflection provides valuable insights into vocal pedagogy, aiming to offer a more specifically physiological and biomechanical understanding of vocal exercises. This effectively guides the application of vocalizations in the process of vocal education and training.

Disc-foveal angle and ocular counterrolling as a key in its interpretation. / El ángulo papila-fóvea y la torsión ocular compensatoria, clave en su interpretación.

PURPOSE: Describe a time-sparing technique to measure disc-foveal angle (DFA), determine normal values and its role when analyzing paired fundus photographs. METHODS: DFA was analysed using the software program Keynote v.6.2.2 on 440 fundus photographs (3D OCT 2000, Topcon Corporation, Tokio, Japan) of 20 individuals. The 11 different head positions were determined with the cervical range of motion device (CROM, Performance Attainment Associates). A reproducibility and correlation study between two fundus cameras (OCT 3D-2000 and TRC-50EX, Topcon Corporation, Tokio, Japan) was performed. RESULTS: Mean DFA of the right and left eye was 5.5±3.4° and 8.6±2.9°, with a difference of 3.1° (P=0.001 Wilcoxon signed-rank test) in the upright head position. Mean absolute difference in DFA between eyes was 3.5±2.6°; an increase was seen with increasing head tilt (P=0.000 Wilcoxon signed-rank test). Mean sum of DFA in both eyes was 14.1±5.4°. On head-tilt of 20° and 40° to the right, mean ocular counterrolling (OCR) was 7.1° and 12.2° in the right eye and 7.7° and 12.1° in the left eye. On head-tilt of 20° and 40° to the left, OCR was 4.4° and 8° in the right eye and 4.2° and 8.7° in the left eye (P=0.000 Wilcoxon signed-rank test). The two cameras showed strong correlation and high reproducibility. CONCLUSIONS: Our DFA measurement technique is time-sparing and reproducible. Left eye shows higher DFA than right eye. OCR occurs only in the roll plane. This information is of value when analyzing paired fundus photographs.

Anthropometric Characteristics, Training Intensity Distribution, Physiological Profile and Performance of an Elite Trail Runner: A Longitudinal Case Study / Características Antropométricas, Distribución de la Intensidad del Entrenamiento, Perfil Fisiológico y Rendimiento de un Corredor de Montaña de Élite: Un Estudio de Caso Longitudinal

SUMMARY: Trail running (TR), an extreme endurance sport, presents unique challenges due to the variety of terrain and distances, where physiological capacity and body composition have been considered better predictors of performance. This longitudinal case study examines the impact of training intensity distribution (TID) on an elite trail runner's physiological profile and performance over four years. Two TID models were implemented: polarized (POL) and pyramidal (PYR). Physiological assessments included maximal oxygen consumption (VO2max), lactate thresholds (LT1 and LT2), and anthropometric characteristics. The training was classified according to the 3-zone intensity model (zone 1: below the first lactate threshold; zone 2: between the first and second lactate threshold; zone 3: above the second lactate threshold). During the four years, the average TID distribution was 75 % zone 1, 18 % zone 2, and 7 % zone 3. Physiological capacity increased by 7.14 % (14 to 15 km/h) for velocity at LT1 (vLT1) and 8.13 % (16 to 17.3 km/h) for velocity at LT2 (vLT2). The most significant increases were observed during the second year when the percentage of training time in zone 1 was lower (65 %) and in zone 2 greater (30 %) than those reported in other years. Consequently, vLT1 and vLT2 increased by 3.5 % (from 14.1 to 14.6 km/h) and 3.6 % (from 16.5 to 17.1 km/h), respectively. In conclusion, this case study revealed that emphasizing training in zone 2 (moderate intensity) and increasing the training load significantly improved performance at lactate thresholds. Despite modifying body composition, no influence on improving endurance performance was observed. These findings underscore the importance of TID in elite trail runners and highlight the potential to optimize physiological adaptations and performance outcomes.

Trail running (TR), un deporte de resistencia extrema, presenta desafíos únicos debido a la variedad de terrenos y distancias, donde la capacidad fisiológica y la composición corporal se han considerado mejores predictores del rendimiento. Este estudio de caso longitudinal examina el impacto de la distribución de la intensidad del entrenamiento (TID) en el perfil fisiológico y el rendimiento de un corredor de montaña de élite durante cuatro años. Se implementaron dos modelos TID: polarizado (POL) y piramidal (PYR). Las evaluaciones fisiológicas incluyeron el consumo máximo de oxígeno (VO2max), los umbrales de lactato (LT1 y LT2) y las características antropométricas. El entrenamiento se clasificó según el modelo de intensidad de 3 zonas (zona 1: por debajo del primer umbral de lactato; zona 2: entre el primer y segundo umbral de lactato; zona 3: por encima del segundo umbral de lactato). Durante los cuatro años, la distribución TID promedio fue 75 % zona 1, 18 % zona 2 y 7 % zona 3. La capacidad fisiológica aumentó un 7,14 % (14 a 15 km/h) para la velocidad en LT1 (vLT1) y un 8,13 % (16 a 17,3 km/h) para velocidad en LT2 (vLT2). Los incrementos más significativos se observaron durante el segundo año cuando el porcentaje de tiempo de entrenamiento en la zona 1 fue menor (65 %) y en la zona 2 mayor (30 %) que los reportados en otros años. En consecuencia, vLT1 y vLT2 aumentaron un 3,5 % (de 14,1 a 14,6 km/h) y un 3,6 % (de 16,5 a 17,1 km/h), respectivamente. En conclusión, este estudio reveló que enfatizar el entrenamiento en la zona 2 (intensidad moderada) y aumentar la carga de entrenamiento mejoró significativamente el rendimiento en los umbrales de lactato. A pesar de modificar la composición corporal, no se observó influencia en la mejora del rendimiento de resistencia. Estos hallazgos subrayan la importancia del TID en los corredores de trail de élite y resaltan el potencial para optimizar las adaptaciones fisiológicas y los resultados de rendimiento.

Fisiología respiratoria: el pulmón al momento de nacer / Respiratory Physiology - the lung at the moment of birth

La adaptación fisiológica de los recién nacidos de la vida intrauterina a la extrauterina incluye cambios fisiológicos complejos. Para que se complete con éxito la transición fetal a neonatal, los recién nacidos deben lograr el aclaramiento de líquido pulmonar, la generación de CRF e inicio de la respiración, para permitir el intercambio de gases y la oxigenación de los tejidos. En este artículo se describen estos mecanismos, algunas bases del desarrollo pulmonar y de la circulación fetal; y las medidas que se requieren para asistir al recién nacido cuando no logran completar esta transición espontáneamente, lo que ocurre en el 5 al 10 % de los casos.

The physiological adaptation of newborns from intrauterine to extrauterine life includes complex physiological changes. For the fetal to neonatal transition to be successfully completed, neonates must achieve lung fluid clearance, FRC generation, and initiation of respiration to allow gas exchange and tissue oxygenation. This article describes these mechanisms, some bases of lung development and fetal circulation; and the measures required to assist the newborn, when they fail to complete this transition spontaneously, which occurs in the 5 to 10% of cases.