Bird neurocranial and body mass evolution across the end-Cretaceous mass extinction: The avian brain shape left other dinosaurs behind.

Birds today are the most diverse clade of terrestrial vertebrates, and understanding why extant birds (Aves) alone among dinosaurs survived the Cretaceous-Paleogene mass extinction is crucial to reconstructing the history of life. Hypotheses proposed to explain this pattern demand identification of traits unique to Aves. However, this identification is complicated by a lack of data from non-avian birds. Here, we interrogate survivorship hypotheses using data from a new, nearly complete skull of Late Cretaceous (~70 million years) bird Ichthyornis and reassess shifts in bird body size across the Cretaceous-Paleogene boundary. Ichthyornis exhibited a wulst and segmented palate, previously proposed to have arisen within extant birds. The origin of Aves is marked by larger, reshaped brains indicating selection for relatively large telencephala and eyes but not by uniquely small body size. Sensory system differences, potentially linked to these shifts, may help explain avian survivorship relative to other dinosaurs.

Self-reported Use of K2/Spice for Appetite Stimulation: A Case Report.

This case report explores the use of K2/Spice (synthetic cannabinoids) in a patient as an appetite stimulant. The effects of synthetic cannabinoids range widely but are more commonly known to suppress appetite in the cannabinoid-naive. Our patient was not cannabinoid- naive and had used cannabis before. Rat models have demonstrated results similar to those in this patient, who had prior tetrahydrocannabinol (THC) exposure resulting in appetite stimulation rather than suppression when exposed to a synthetic cannabinoid. This is likely explained by other rat models that have shown long-term use of cannabis resulting in receptor downregulation of cannabinoid receptor type 1 (CB-1).

Tempo and Pattern of Avian Brain Size Evolution.

Relative brain sizes in birds can rival those of primates, but large-scale patterns and drivers of avian brain evolution remain elusive. Here, we explore the evolution of the fundamental brain-body scaling relationship across the origin and evolution of birds. Using a comprehensive dataset sampling> 2,000 modern birds, fossil birds, and theropod dinosaurs, we infer patterns of brain-body co-variation in deep time. Our study confirms that no significant increase in relative brain size accompanied the trend toward miniaturization or evolution of flight during the theropod-bird transition. Critically, however, theropods and basal birds show weaker integration between brain size and body size, allowing for rapid changes in the brain-body relationship that set the stage for dramatic shifts in early crown birds. We infer that major shifts occurred rapidly in the aftermath of the Cretaceous-Paleogene mass extinction within Neoaves, in which multiple clades achieved higher relative brain sizes because of a reduction in body size. Parrots and corvids achieved the largest brains observed in birds via markedly different patterns. Parrots primarily reduced their body size, whereas corvids increased body and brain size simultaneously (with rates of brain size evolution outpacing rates of body size evolution). Collectively, these patterns suggest that an early adaptive radiation in brain size laid the foundation for subsequent selection and stabilization.

New mammalian and avian records from the late Eocene La Meseta and Submeseta formations of Seymour Island, Antarctica.

The middle-late Eocene of Antarctica was characterized by dramatic change as the continent became isolated from the other southern landmasses and the Antarctic Circumpolar Current formed. These events were crucial to the formation of the permanent Antarctic ice cap, affecting both regional and global climate change. Our best insight into how life in the high latitudes responded to this climatic shift is provided by the fossil record from Seymour Island, near the eastern coast of the Antarctic Peninsula. While extensive collections have been made from the La Meseta and Submeseta formations of this island, few avian taxa other than penguins have been described and mammalian postcranial remains have been scarce. Here, we report new fossils from Seymour Island collected by the Antarctic Peninsula Paleontology Project. These include a mammalian metapodial referred to Xenarthra and avian material including a partial tarsometatarsus referred to Gruiformes (cranes, rails, and allies). Penguin fossils (Sphenisciformes) continue to be most abundant in new collections from these deposits. We report several penguin remains including a large spear-like mandible preserving the symphysis, a nearly complete tarsometatarsus with similarities to the large penguin clade Palaeeudyptes but possibly representing a new species, and two small partial tarsometatarsi belonging to the genus Delphinornis. These findings expand our view of Eocene vertebrate faunas on Antarctica. Specifically, the new remains referred to Gruiformes and Xenarthra provide support for previously proposed, but contentious, earliest occurrence records of these clades on the continent.

Estimating Flight Style of Early Eocene Stem Palaeognath Bird Calciavis grandei (Lithornithidae).

Lithornithids are volant stem palaeognaths from the Paleocene-Eocene. Except for these taxa and the extant neotropical tinamous, all other known extinct and extant palaeognaths are flightless. Investigation of properties of the lithornithid wing and its implications for inference of flight style informs understood locomotor diversity within Palaeognathae and may have implications for estimation of ancestral traits in the clade. Qualitative comparisons with their closest extant volant relatives, the burst-flying tinamous, previously revealed skeletal differences suggesting lithornithids were capable of sustained flight, but quantitative work on wing morphology have been lacking. Until comparatively recently, specimens of lithornithids preserving wing feather remains have been limited. Here, we reconstruct the wing of an exceptionally preserved specimen of the Early Eocene lithornithid Calciavis grandei and estimate body mass, wing surface area, and wing span. We then estimate flight parameters and compare our estimates with representatives from across Aves in a statistical framework. We predict that flight in C. grandei was likely marked by continuous flapping, and that lithornithids were capable of sustained flight and migratory behavior. Our results are consistent with previous hypotheses that the ancestor of extant Palaeognathae may also have been capable of sustained flight. Anat Rec, 303:1035-1042, 2020. © 2019 Wiley Periodicals, Inc.

An avian femur from the Late Cretaceous of Vega Island, Antarctic Peninsula: removing the record of cursorial landbirds from the Mesozoic of Antarctica.

In 2006, a partial avian femur (South Dakota School of Mines and Technology (SDSM) 78247) from the Upper Cretaceous (Maastrichtian) Sandwich Bluff Member of the López de Bertodano Formation of Sandwich Bluff on Vega Island of the northern Antarctic Peninsula was briefly reported as that of a cariamiform-a clade that includes extant and volant South American species and many extinct flightless and cursorial species. Although other authors have since rejected this taxonomic assignment, SDSM 78247 had never been the subject of a detailed description, hindering a definitive assessment of its affinities. Here we provide the first comprehensive description, illustration, and comparative study of this specimen. Comparison of characters that may be assessed in this femur with those of avian taxa scored in published character matrices refutes the inclusion of SDSM 78247 within Cariamiformes, instead supporting its assignment to a new, as-yet unnamed large-bodied species within the genus Vegavis, and therefore its referral to a clade of semiaquatic anseriforms. Important character states diagnostic of Vegavis + Polarornis include strong craniocaudal bowing of the femoral shaft, the presence of a distinct fossa just proximal to the fibular trochlea, and the broad and flat shape of the patellar sulcus. Referral to Vegavis is based on the presence of a distinctive proximocaudal fossa and distolateral scar. This genus was previously known only from Vegavis iaai, a smaller-bodied taxon from the same locality and stratigraphic unit. Our reassignment of SDSM 78247 to Vegavis sp. removes the record of cariamiform landbirds from the Antarctic Cretaceous.

Integrating natural history collections and comparative genomics to study the genetic architecture of convergent evolution.

Evolutionary convergence has been long considered primary evidence of adaptation driven by natural selection and provides opportunities to explore evolutionary repeatability and predictability. In recent years, there has been increased interest in exploring the genetic mechanisms underlying convergent evolution, in part, owing to the advent of genomic techniques. However, the current 'genomics gold rush' in studies of convergence has overshadowed the reality that most trait classifications are quite broadly defined, resulting in incomplete or potentially biased interpretations of results. Genomic studies of convergence would be greatly improved by integrating deep 'vertical', natural history knowledge with 'horizontal' knowledge focusing on the breadth of taxonomic diversity. Natural history collections have and continue to be best positioned for increasing our comprehensive understanding of phenotypic diversity, with modern practices of digitization and databasing of morphological traits providing exciting improvements in our ability to evaluate the degree of morphological convergence. Combining more detailed phenotypic data with the well-established field of genomics will enable scientists to make progress on an important goal in biology: to understand the degree to which genetic or molecular convergence is associated with phenotypic convergence. Although the fields of comparative biology or comparative genomics alone can separately reveal important insights into convergent evolution, here we suggest that the synergistic and complementary roles of natural history collection-derived phenomic data and comparative genomics methods can be particularly powerful in together elucidating the genomic basis of convergent evolution among higher taxa. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Nocturnal giants: evolution of the sensory ecology in elephant birds and other palaeognaths inferred from digital brain reconstructions.

The recently extinct Malagasy elephant birds (Palaeognathae, Aepyornithiformes) included the largest birds that ever lived. Elephant bird neuroanatomy is understudied but can shed light on the lifestyle of these enigmatic birds. Palaeoneurological studies can provide clues to the ecologies and behaviours of extinct birds because avian brain shape is correlated with neurological function. We digitally reconstruct endocasts of two elephant bird species, Aepyornis maximus and A. hildebrandti, and compare them with representatives of all major extant and recently extinct palaeognath lineages. Among palaeognaths, we find large olfactory bulbs in taxa generally occupying forested environments where visual cues used in foraging are likely to be limited. We detected variation in olfactory bulb size among elephant bird species, possibly indicating interspecific variation in habitat. Elephant birds exhibited extremely reduced optic lobes, a condition also observed in the nocturnal kiwi. Kiwi, the sister taxon of elephant birds, have effectively replaced their visual systems with hyperdeveloped olfactory, somatosensory and auditory systems useful for foraging. We interpret these results as evidence for nocturnality among elephant birds. Vision was likely deemphasized in the ancestor of elephant birds and kiwi. These results show a previously unreported trend towards decreased visual capacity apparently exclusive to flightless, nocturnal taxa endemic to predator-depauperate islands.

Implementation of Fee-Free Maternal Health-Care Policy in Ghana: Perspectives of Users of Antenatal and Delivery Care Services From Public Health-Care Facilities in Accra.

In 2008, the government of Ghana implemented a national user fee maternal care exemption policy through the National Health Insurance Scheme to improve financial access to maternal health services and reduce maternal as well as perinatal deaths. Although evidence shows that there has been some success with this initiative, there are still issues relating to cost of care to beneficiaries of the initiative. A qualitative study, comprising 12 focus group discussions and 6 interviews, was conducted with 90 women in six selected urban neighborhoods in Accra, Ghana, to examine users' perspectives regarding the implementation of this policy initiative. Findings showed that direct cost of delivery care services was entirely free, but costs related to antenatal care services and indirect costs related to delivery care still limit the use of hospital-based midwifery and obstetric care. There was also misunderstanding about the initiative due to misinformation created by the government through the media.We recommend that issues related to both direct and indirect costs of antenatal and delivery care provided in public health-care facilities must be addressed to eliminate some of the lingering barriers relating to cost hindering the smooth operation and sustainability of the maternal care fee exemption policy.

Best practices for digitally constructing endocranial casts: examples from birds and their dinosaurian relatives.

The rapidly expanding interest in, and availability of, digital tomography data to visualize casts of the vertebrate endocranial cavity housing the brain (endocasts) presents new opportunities and challenges to the field of comparative neuroanatomy. The opportunities are many, ranging from the relatively rapid acquisition of data to the unprecedented ability to integrate critically important fossil taxa. The challenges consist of navigating the logistical barriers that often separate a researcher from high-quality data and minimizing the amount of non-biological variation expressed in endocasts - variation that may confound meaningful and synthetic results. Our purpose here is to outline preferred approaches for acquiring digital tomographic data, converting those data to an endocast, and making those endocasts as meaningful as possible when considered in a comparative context. This review is intended to benefit those just getting started in the field but also serves to initiate further discussion between active endocast researchers regarding the best practices for advancing the discipline. Congruent with the theme of this volume, we draw our examples from birds and the highly encephalized non-avian dinosaurs that comprise closely related outgroups along their phylogenetic stem lineage.

Potential for bias and low precision in molecular divergence time estimation of the Canopy of Life: an example from aquatic bird families.

Uncertainty in divergence time estimation is frequently studied from many angles but rarely from the perspective of phylogenetic node age. If appropriate molecular models and fossil priors are used, a multi-locus, partitioned analysis is expected to equally minimize error in accuracy and precision across all nodes of a given phylogeny. In contrast, if available models fail to completely account for rate heterogeneity, substitution saturation and incompleteness of the fossil record, uncertainty in divergence time estimation may increase with node age. While many studies have stressed this concern with regard to deep nodes in the Tree of Life, the inference that molecular divergence time estimation of shallow nodes is less sensitive to erroneous model choice has not been tested explicitly in a Bayesian framework. Because of available divergence time estimation methods that permit fossil priors across any phylogenetic node and the present increase in efficient, cheap collection of species-level genomic data, insight is needed into the performance of divergence time estimation of shallow (<10 MY) nodes. Here, we performed multiple sensitivity analyses in a multi-locus data set of aquatic birds with six fossil constraints. Comparison across divergence time analyses that varied taxon and locus sampling, number and position of fossil constraint and shape of prior distribution showed various insights. Deviation from node ages obtained from a reference analysis was generally highest for the shallowest nodes but determined more by temporal placement than number of fossil constraints. Calibration with only the shallowest nodes significantly underestimated the aquatic bird fossil record, indicating the presence of saturation. Although joint calibration with all six priors yielded ages most consistent with the fossil record, ages of shallow nodes were overestimated. This bias was found in both mtDNA and nDNA regions. Thus, divergence time estimation of shallow nodes may suffer from bias and low precision, even when appropriate fossil priors and best available substitution models are chosen. Much care must be taken to address the possible ramifications of substitution saturation across the entire Tree of Life.

Punto de corte de espesor de tejido adiposo epicárdico para predecir síndrome metabólico en población venezolana / Cut-off point of epicardial adipose tissue thickness for predicting metabolic syndrome in Venezuelan population

Objetivo Definir un punto de corte de espesor de tejido adiposo epicárdico (TAE) medido por ecocardiografía asociado con los componentes del síndrome metabólico (SM) en sujetos venezolanos. Metodología Se seleccionaron 52 sujetos de entre 20 y 65 años con diagnóstico de SM según la Federación Internacional de Diabetes y 45 controles, comparables en edad y sexo. Se midieron glucemia y lípidos plasmáticos. Se determinaron el espesor del TAE y la masa del ventrículo izquierdo mediante ecocardiografía. Resultados No hubo diferencias significativas en edad y sexo entre ambos grupos, y el peso, el índice de masa corporal, la circunferencia abdominal, la presión arterial sistólica y la diastólica fueron significativamente más altos (p = 0,0001) en el grupo con SM. Este grupo presentó niveles significativamente más altos de glucemia en ayunas (p = 0,0001), colesterol total (p = 0,002), c-LDL (p = 0,007), c-noHDL (p = 0,0001), triglicéridos (p = 0,0001), cociente triglicéridos/c-HDL (p = 0,0001) y más bajos de c-HDL (p = 0,0001) que el grupo control. El espesor del TAE (p = 0,0001) y la masa del ventrículo izquierdo (p = 0,017) fueron significativamente mayores en el grupo con SM. La curva operador receptor (COR) demostró un AUC de 0,852 (p = 0,0001), con un poder del test de 0,99. El valor de 5 mm de TAE mostró una sensibilidad del 84,62% (IC 95%: 71,9-93,1) y una especificidad del 71,11% (IC 95%: 55,7-83,6) para predecir SM. La odds ratio de presentar SM en esta población por tener un espesor de TAE ≥ 5 mm fue de 8,25 (IC 95%: 3,15-21,56; p = 0,0001).Conclusión Un valor de TAE ≥ 5 mm presenta una buena sensibilidad y especificidad para predecir SM en población venezolana (AU)

Objective To define an echocardiographically-assessed cut-off point for epicardial adipose tissue (EAT) thickness associated to metabolic syndrome (MS) components in Venezuelan subjects. Methods Fifty-two subjects aged 20-65 years diagnosed with MS according to International Diabetes Federation criteria and 45 sex- and age-matched controls were selected. Blood glucose and plasma lipids were tested; EAT thickness and left ventricular mass were measured by echocardiography. Results No significant age and sex differences were found between the two groups. Body weight, body mass index, waist circumference, and systolic and diastolic blood pressure were significantly higher (P = .0001) in the MS group. This group showed significantly higher levels of fasting blood glucose (P = .0001), total cholesterol (P = .002), LDL-C (P = .007), non-HDL-C (P = .0001), triglycerides (P = .0001), Tg-HDL-C ratio (P = .0001), and lower HDL-C levels (P = .0001) as compared to the control group. EAT thickness (P = .0001) and left ventricular mass (P = .017) were significantly higher in the MS group. The ROC curve showed an AUC of 0.852 (P = .0001) with a power of the test of 0.99. A 5-mm EAT thickness showed a sensitivity of 84.62% (95% CI: 71.9-93.1) and a specificity of 71.11% (95% CI: 55.7-83.6) for predicting MS. The odds ratio of this population for experiencing MS due to an EAT ≥ 5 mm was 8.25 (95% CI: 3.15-21.56; P = .0001).Conclusion An EAT value ≥ 5 mm has good sensitivity and specificity for predicting MS in the Venezuelan population (AU)

[Cut-off point of epicardial adipose tissue thickness for predicting metabolic syndrome in Venezuelan population]. / Punto de corte de espesor de tejido adiposo epicárdico para predecir síndrome metabólico en población venezolana.

OBJECTIVE: To define an echocardiographically-assessed cut-off point for epicardial adipose tissue (EAT) thickness associated to metabolic syndrome (MS) components in Venezuelan subjects. METHODS: Fifty-two subjects aged 20-65 years diagnosed with MS according to International Diabetes Federation criteria and 45 sex- and age-matched controls were selected. Blood glucose and plasma lipids were tested; EAT thickness and left ventricular mass were measured by echocardiography. RESULTS: No significant age and sex differences were found between the two groups. Body weight, body mass index, waist circumference, and systolic and diastolic blood pressure were significantly higher (P=.0001) in the MS group. This group showed significantly higher levels of fasting blood glucose (P=.0001), total cholesterol (P=.002), LDL-C (P=.007), non-HDL-C (P=.0001), triglycerides (P=.0001), Tg-HDL-C ratio (P=.0001), and lower HDL-C levels (P=.0001) as compared to the control group. EAT thickness (P=.0001) and left ventricular mass (P=.017) were significantly higher in the MS group. The ROC curve showed an AUC of 0.852 (P=.0001) with a power of the test of 0.99. A 5-mm EAT thickness showed a sensitivity of 84.62% (95%CI: 71.9-93.1) and a specificity of 71.11% (95%CI: 55.7-83.6) for predicting MS. The odds ratio of this population for experiencing MS due to an EAT ≥ 5 mm was 8.25 (95%CI: 3.15-21.56; P=.0001). CONCLUSION: An EAT value ≥ 5 mm has good sensitivity and specificity for predicting MS in the Venezuelan population.

Tejido adiposo epicárdico y su asociación con niveles plasmáticos de adrenomedulina en pacientes con síndrome metabólico / Epicardial adipose tissue and its association to plasma adrenomedullin levels in patients with metabolic syndrome

Estudiar la asociación del espesor del tejido adiposo epicárdico (TAE) con los niveles plasmáticos de adrenomedulina en pacientes con síndrome metabólico (SM). Metodología Se seleccionaron 21 sujetos, 12 de sexo femenino y 9 de masculino, entre 22 y 58 años, con diagnóstico de SM según la Federación Internacional de Diabetes (IDF), y 19 controles, comparables en edad y sexo. Se midieron glicemia, lípidos y adrenomedulina plasmática. Se determinaron espesor del TAE, masa del ventrículo izquierdo y espesor íntima-media carotídeo mediante ecocardiografía transtorácica. Resultados No hubo diferencias estadísticamente significativas en edad, sexo y talla entre ambos grupos, y el peso, IMC, circunferencia abdominal (CA), presión arterial sistólica (PAS) y diastólica (PAD) fueron significativamente más altos (p=0,0001) en el grupo con SM. Este grupo presentó niveles significativamente más altos de glicemia (p=0,001), colesterol total (p=0,01), C-LDL (p=0,03), C-VLDL (p=0,005), triglicéridos (p=0,002), cociente Tg/C-HDL (p=0,0001) y adrenomedulina (3,49±1,21 vs 1,69±0,92 ng/mL; p=0,0001) y más bajos de C-HDL (p=0,02) que el grupo control. El espesor del TAE en los pacientes con SM fue significativamente más alto que en el grupo control (8,45±3,14 vs 5,43±0,96mm; p=0,0001), y mostró una correlación positiva con IMC (r=0,347; p=0,02), CA (r=0,350; p=0,02), PAD (r=0,346; p=0,02) y adrenomedulina (r=0,741; p=0,0001). En el análisis de regresión lineal múltiple, la adrenomedulina fue la variable explicativa del espesor del TAE (R2=0,550; p=0,0001).Conclusión En este limitado grupo de pacientes existe una asociación significativa entre espesor de TAE y niveles plasmáticos de adrenomedulina, los cuales pudieran ser utilizados como biomarcadores de SM (AU)

Objective: To assess the association between epicardial adipose tissue thickness (EAT) and plasma adrenomedullin plasma levels in patients with metabolic syndrome (MS).Methods: Twenty-one patients (12 females and 9 males) with MS according to the International Diabetes Federation guidelines, aged 22-58 years, were enrolled into the study and compared to19 age-matched control subjects without MS. Plasma glucose, lipid, and adrenomedullin levelswere assessed. EAT, left ventricular mass, and carotid intima-media thickness were evaluatedby transthoracic two-dimensional echocardiography. Results: No statistically significant differences were found between the groups in age, sex,and height. Body weight, abdominal circumference (AC), body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were significantly higher (p = 0.0001)in MS patients; this group also showed significantly higher glucose (p = 0.001), total cholesterol(p = 0.01), LDL-C (p = 0.03), VLDL-C (p = 0.005), triglyceride (p = 0.002), Tg/HDL ratio(p = 0.0001), and plasma adrenomedullin (3.49±1.21 vs 1.69±0.92 ng/mL; p = 0.0001) levels and lower HDL-C (p = 0.02) levels as compared to the control group. EAT was significantly thickerin MS patients compared to the control group (8.45±3.14 vs 5.43±0.96; p = 0.0001), showed a positive correlation to BMI (r = 0.347; p = 0.02), AC (r = 0.350; p = 0.02), DBP (r = 0.346;p = 0.02), and adrenomedullin levels (r = 0.741; p = 0.0001). In multiple linear regression analysis, adrenomedullin was the only parameter associated to EAT (R2 = 0.550; p = 0.0001).Conclusion: In this small patient group, a statistically significant association was found between EAT and plasma adrenomedullin levels, which may be considered as a potential biomarker of MS (AU)

[Epicardial adipose tissue and its association to plasma adrenomedullin levels in patients with metabolic syndrome]. / Tejido adiposo epicárdico y su asociación con niveles plasmáticos de adrenomedulina en pacientes con síndrome metabólico.

OBJECTIVE: To assess the association between epicardial adipose tissue thickness (EAT) and plasma adrenomedullin plasma levels in patients with metabolic syndrome (MS). METHODS: Twenty-one patients (12 females and 9 males) with MS according to the International Diabetes Federation guidelines, aged 22-58 years, were enrolled into the study and compared to 19 age-matched control subjects without MS. Plasma glucose, lipid, and adrenomedullin levels were assessed. EAT, left ventricular mass, and carotid intima-media thickness were evaluated by transthoracic two-dimensional echocardiography. RESULTS: No statistically significant differences were found between the groups in age, sex, and height. Body weight, abdominal circumference (AC), body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were significantly higher (p=0.0001) in MS patients; this group also showed significantly higher glucose (p=0.001), total cholesterol (p=0.01), LDL-C (p=0.03), VLDL-C (p=0.005), triglyceride (p=0.002), Tg/HDL ratio (p=0.0001), and plasma adrenomedullin (3.49±1.21 vs 1.69±0.92 ng/mL; p=0.0001) levels and lower HDL-C (p=0.02) levels as compared to the control group. EAT was significantly thicker in MS patients compared to the control group (8.45±3.14 vs 5.43±0.96; p=0.0001), showed a positive correlation to BMI (r=0.347; p=0.02), AC (r=0.350; p=0.02), DBP (r=0.346; p=0.02), and adrenomedullin levels (r=0.741; p=0.0001). In multiple linear regression analysis, adrenomedullin was the only parameter associated to EAT (R(2)=0.550; p=0.0001). CONCLUSION: In this small patient group, a statistically significant association was found between EAT and plasma adrenomedullin levels, which may be considered as a potential biomarker of MS.

Adrenomedulina: ¿Más que una simple hormona?

La adrenomedulina es un péptido vasodilatador, presente en el sistema cardiovascular, riñón, pulmón, glándula adrenal y en el adipocito. Este péptido ha venido adquiriendo una importancia creciente en los últimos años, ya que se han descrito niveles elevados del mismo en patologías como el síndrome metabólico, diabetes mellitus tipo 2, hipertensión arterial y en aterosclerosis, lo cual pone de manifiesto su relevancia en la fisiopatología de estos trastornos y su posible uso como marcador de riesgo cardiometabólico. A nivel cardíaco, el efecto inotrópico positivo de este péptido parece estar mediado por un aumento del calcio citosólico, independiente de AMP cíclico; reduce la hipertrofia de los miocardiocitos y en la insuficiencia cardíaca los niveles plasmáticos de adrenomedulina están incrementados. La adrenomedulina tiene efecto vasodilatador sistémico y pulmonar y se encuentra incrementada en el plasma de sujetos con hipertensión arterial esencial y en hipertensos con hiperaldosteronismo primario. En riñón, la adrenomedulina induce efecto diurético y natriurético, aumento de la filtración glomerular y disminución de la reabsorción tubular distal de sodio; sus niveles están elevados en la insuficiencia renal crónica. La adrenomedulina está elevada en pacientes diabéticos con mal control metabólico, pero su papel patogénico en la enfermedad no está claro.

Adrenomedullin is a vasodilatory peptide found in the cardiovascular system, kidneys, lungs, adrenal glands and adipocytes. This peptide has been rising interest during the last years because increased plasma levels of it have been found in several pathological conditions such as the metabolic syndrome, type 2 diabetes mellitus, arterial hypertension and atherosclerosis, pointing to a possible physiopathologic role in these diseases and the potential use as a clinical cardiometabolic marker. In the heart, adrenomedullin has a positive inotropic action, probably mediated through cytosolic increase of calcium concentration, independent of cyclic AMP; it also can reduce cardiomyocites hypertrophy. In heart failure, adrenomedullin levels are increased and show systemic and pulmonar vasodilator effect; its plasma levels are increased in patients with essential arterial hypertension and hypertensives with primary hyperaldosteronism. In the kidneys, adrenomedullin is natriuretic and diuretic, it elevates glomerular filtration rate and reduce distal tubules sodium reabsorption; in patients with renal failure, adrenomedullin levels are increased. In diabetic patients, adrenomedullin plasma levels are increased; however, its pathogenic role in this disease is not yet clear.

Sistema Renina Angiotensina Y Riesgo Cardio-Metabólico

En años recientes el concepto clásico del sistema renina angiotensina ha experimentado cambios sustanciales. La identificación de los nuevos componentes del sistema renina angiotensina ha contribuido a modificar nuestro entendimiento acerca de su función en condiciones fisiológicas así como en diversas enfermedades. En este artículo de revisión nos enfocaremos en el papel de este sistema endocrino en el riesgo cardiometabólico.

In the past few years the classical concept of the reninangiotensin system has experienced substantial changes. The identification of the new components of the reninangiotensin system have contributed to switch our understanding about its function in physiological situations and in several diseases. In this review we will focus on the role of this endocrine system in the cardiometabolic risk.

Asociación de la insulina y el factor de crecimiento semejante a la insulina tipo 1 (IGF-1) en el cáncer de mama / Association between insulin and the insulin-like growth factor-I (IGF-I)in breast cancer

Con el objetivo de evaluar la asociación de la insulina y el factor de crecimiento insulino similar tipo 1 (IGF-1) en pacientes con cáncer de mama, se eligió una muestra de 15 pacientes con diagnóstico histopatológico de cáncer de mama durante el período enero-agosto de 2008, y se determinaron los niveles de glicemia en ayunas, insulina basal e IGF-1. Se evaluó el grado de insulino-sensibilidad mediante el método HOMA en esta muestra, comparándose posteriormente con pacientes sin cáncer y de edades similares. Encontramos que la concentración plasmática de insulina en las pacientes con cáncer fue de 11,53 ± 1,91 µU/mL; mientras que los controles presentaron 5,1 ± 0,98 µU/mL, lo cual resultó estadísticamente significativo (P<0,01). Además, las pacientes con cáncer de mama exhibieron glicemia de 108,57 ± 12,33 mg/dL, en comparación con los controles quienes obtuvieron 80,92 ± 1,40 mg/dL. Con estos resultados se calculó el HOMA, obteniendo valores de 3,15 y 1,00 respectivamente. Adicionalmente, al determinar IGF-1 observamos niveles de 219,64 ± 17,03 ng/mL en las pacientes con cáncer y de 178,47 ± 12,78 ng/mL en controles. Se concluye que las pacientes con cáncer de mama presentan el fenómeno de resistencia a la insulina, el cual de manera sinérgica con el IGF-1 promueve la proliferación y diferenciación de células mamarias

Samples from 15 patients who had been diagnosed with breast cancer during January-August 2008 were assayed for the purpose of evaluating the association of insulin and insulin-like growth factor-1 (IGF-1) in women with this type of cancer. Assays were performed to measure fasting blood glucose, basal insulin, and IGF-1. A homeostatic model assessment test (HOMA) was also performed to assess insulin sensitivity, and the results were matched against those of healthy women of the same age group. Insulin plasma concentration in the former group was 11.53 ± 1.91 µU/mL whereas that of the control group was 5.1 ± 0.98 µU/mL, a statistically significant finding. (P<0.01). In addition, the glucose level in the sick women was 108.57 ± 12.33 mg/dL as compared to 80.92 ± 1.40 mg/dL in those without cancer. HOMA was 3.15 and 1.00, and IGF.1 levels were 219.64 ± 17.03 ng/mL and 178.47 ± 12.78 ng/mL for sick and healthy women, respectively. It is thus concluded that women with cancer develop insulin resistance, which in synergy with IGF-1, promotes breast cell proliferation and differentiation