Altitudinal variation in organ mass from three mountain systems: The case of mesquite lizard Sceloporus grammicus.

High altitude environments provide a fertile ground for investigating the benefits of phenotypic adjustments at several levels of biological organization. Low oxygen partial pressure and low environmental temperature are the main limiting factors that promote phenotypic variation in different organs, such as the lung and heart. Although high-altitude environments act like natural laboratories, most morphological studies conducted to date lack replication. Here, we evaluated organ mass variation in nine populations of Sceloporus grammicus, throughout three altitudinal gradients (mountains) from the Trans-Mexican volcanic belt. A total of 84 individuals from three different altitudes at three different mountains were collected. Then, we used generalized linear models to analyze the pattern of variation in internal organs mass as a function of altitude and temperature. We observed a striking pattern of altitudinal variation in the size of cardiorespiratory organs: while heart mass increased with altitude and decreased with temperature, the lung showed a significant statistical interaction between mountain transect and temperature. Overall, our results support the hypothesis that cardiorespiratory organs should be bigger in populations occurring at higher altitudes. Moreover, the study of different mountain systems allowed us to observe some differences in one mountain in relation to the other two.

Elevation and blood traits in the mesquite lizard: Are patterns repeatable between mountains?

Ecogeographical patterns describe predictable variation in phenotypic traits between ecological communities. For example, high-altitude animals are expected to show elevated hematological values as an adaptation to the lower oxygen pressure. Mountains act like ecological islands and therefore are considered natural laboratories. However, the majority of ecophysiological studies on blood traits lack replication that would allow us to infer if the pattern reported is a local event or whether it is a widespread pattern resulting from larger-scale ecological processes. In lizards, in fact, the increase of hematological values at high altitudes has received mixed support. Here, for the first time, we compare blood traits in lizards along elevational gradients with replication. We tested the repeatability of blood traits in mesquite lizards between different elevations in three different mountains from the Trans-Mexican Volcanic Belt. We measured hematocrit, hemoglobin concentration, mean corpuscular hemoglobin concentration, and erythrocyte size in blood samples of low, medium, and high-elevation lizards. We obtained similar elevational patterns between mountains, but the blood traits differed among mountains. Middle-altitude populations had greater oxygen-carrying capacity than lizards from low and high altitudes. The differences found between mountain systems could be the result of phenotypic plasticity or genetic differentiation as a consequence of abiotic factors not considered.

Synthesis, characterisation, crystal structure and antimicrobial evaluation of novel 6-alkoxyergosta-4,6,8(14),22-tetraen-3-one derived from natural ergosta-5,7,22-trien-3ß-ol.

In this study, we report a facile transformation starting from 5α-hydroxyergosta-7,22-dien-3,6-dione (1) to afford two novel compounds: 6-methoxyergosta-4,6,8(14),22-tetraen-3-one (2) and 6-ethoxyergosta-4,6,8(14),22-tetraen-3-one (3) using alcoholic acid catalysis. Their structures were elucidated using NMR experiments, FT-IR, MS and X-ray analysis. These compounds were evaluated for antibacterial activity using the disk and broth diffusion test. In those tests, compound 3 was found to be the most significant antibacterial agent. In general, compounds 1-3 showed inhibition zone in the range of 7.00-12.3 mm for S. aureus and S. mutans, meanwhile for Gram-negative bacteria E. coli and Pseudomonas sp. was found to be in the range of 7.00-8.00 mm. For the most active, compound 3, MIC was significantly lower than that reported for ergosterol, in a value of 160 µg/mL. Overall, these compounds were more active than their natural precursor.

Analysis of glutathione-S-transferases from larvae of Galleria mellonella (Lepidoptera, Pyralidae) with potential alkaloid detoxification function.

The greater wax moth, Galleria mellonella, is a global pest for beehives, doing damage in the larval stage. Although a significant number of studies have reported on larvae and adults, to date no effective pest control has been implemented. In this study, we tested larval resistance to alkaloids from Berberis microphylla, and the objective was to identify enzymes that participate in alkaloid detoxification through enzymatic assays, bioinformatics analysis and qRT-PCR. Findings suggest glutathione-S-transferases (GSTs), from an increased metabolic mechanism, are responsible for alkaloid detoxification rather than cytochrome P450 (CYP), carboxylesterases (CarE). A bioinformatics analysis from transcriptome data revealed 22 GSTs present in both G. mellonella larvae and adults. The qRT-PCR experiments corroborated the presence of the 22 GSTs in larvae, where GST8 and GST20 stood out with the highest expression after berberine treatment. Structural information around GST8 and GST20 suggests that GST8 could bind berberine stronger than GST20. These findings represent an important advance in the study of detoxification enzymes in G. mellonella, expanding the role of delta-class GSTs towards alkaloids. Likewise, GST inhibition by alkaloid analogs is proposed in the framework of integrated pest management strategies.

Phenological variation in parasite load and inflammatory response in a lizard with an asynchronous reproductive cycle.

We present the first study that compares phenological variation in parasite load and inflammatory response in a lizard with asynchronous male and female gonadal cycles. Other studies have used many species with seasonal and synchronous reproductive cycles, in which it is difficult to decouple the effects of internal and external factors that can affect parasite abundance in each sex. Species with asynchronous reproductive cycles provide the opportunity to study the effects of seasonality and reproductive condition separately, but few studies have documented variation in parasite abundance in these species. We made an extensive comparison of parasite load and inflammatory response of the lizard Sceloporus torquatus, a species with asynchronous reproductive cycles, throughout its active period. We hypothesized that the parasite load would be higher in the period of maximum gonadal activity for each sex, negatively related to body condition and inflammatory response. Our results partially support the hypothesis; males had more parasites in summer than in spring and autumn, while females had more parasites in spring and summer than in autumn; however, we do not find a relationship between parasite load, body condition and inflammatory response. Our results indicated that host-parasite interactions are complex and depend upon both environmental and internal factors. Therefore, longer-term studies may provide a more comprehensive picture of host-parasite dynamics in populations of wild lizards.

Fast and dark: The case of Mezquite lizards at extreme altitude.

Sprint speed is a major performance trait in animal fitness involved in escaping from predators, obtaining food, and defending territory. Biotic and abiotic factors may influence sprint speed in lizards. Temperature decreases at higher altitude. Therefore, lizards at high elevations may require longer basking times to reach optimal body temperatures, increasing their vulnerability to predation and decreasing their time for other activities such as foraging or reproduction. Here, we tested whether the maximum sprint speed of a lizard that shows conservative thermal ecology varied along an altitudinal gradient comprising low (2500 m), middle (3400 m) and high-altitude (4300 m) populations. We also tested whether sprint speed was related to dorsal reflectance at different ecologically relevant temperatures. Given that the lizard Sceloporus grammicus shows conservative thermal ecology with altitude, we expected that overall average sprint speed would not vary with altitude. However, given that darker lizards heat up quicker, we expected that darker lizards would be faster than lighter lizards. Our results suggest that S. grammicus at high altitude are faster and darker at 30 °C, while lizards from low and middle altitude are faster and lighter in color at 20 °C than high altitude lizards. Also, our results suggest a positive relationship between sprint speed and dorsal skin reflectance at 10 and 20 °C. Sprint speed was also affected by snout-vent length, leg length, and leg thickness at 10 °C. These results suggest that, even though predation pressure is lower at extreme altitudes, other factors such as vegetation cover or foraging mode have influenced sprint speed.

Hypoxia by Altitude and Welfare of Captive Beaded Lizards (Heloderma Horridum) in Mexico: Hematological Approaches.

Heloderma horridum is one of the few known venomous lizards in the world. Their populations are in decline due to habitat destruction and capture for the pet trade. In México, many zoos have decided to take care of this species, most of them at altitudes greater than the natural altitudinal distribution. However, we know little about the capacity of the reptiles to face high-altitude environments. The objective of this study was to compare hematological traits of H. horridum in captivity in high and low altitude environments. Our findings show that H. horridum does not respond to hypoxic environments, at least in blood traits, and that the organisms appear to be in homeostasis. Although we cannot know if individual H. horridum housed in high-altitude environments are completely comfortable, it appears hypoxia can be avoid without modifications of blood parameters. We suggest that future work should address changes in metabolic rates and in behavioral aspects to understand how to maintain the health and comfort of the reptiles native to low altitude when they are housed in high-altitude environments.

Differential expression after UV-B radiation and characterization of chalcone synthase from the Patagonian hairgrass Deschampsia antarctica.

Deschampsiaantarctica inhabits the maritime territory of Antarctica and South Patagonia. It grows under very harsh environmental conditions. The survival of this species in low freezing temperatures and under high levels of UV-B radiation may constitute some of the most remarkable adaptive plant responses and suggests that this plant possesses genes associated with cold and UV tolerance. Frequently, increased levels of flavonoids have been linked to highly UV-B irradiated plants. Studies examining the biosynthesis of flavonoids in D. antarctica may provide clues to its success in this extreme environment. In this study, we characterized the family of genes encoding chalcone synthase, a key enzyme of the flavonoid biosynthetic pathway. DaCHS was cloned, sequenced and characterized by using software tools. CHS contains two domains, the N-terminal domain ranges from amino acid 8 to 231 and the C-terminal domain ranges from amino acid 241 to 391. Sequence analysis of the three family members revealed a high degree of identity after comparison with other monocotyledons such as Oryza sativa L., Zea mays L. and Hordeum vulgare L. According to these results, DaCHS can be grouped together with H. vulgare CHS1 in the same branch. The phylogenetic tree was built using MEGA software and the neighbour join method with 1000 bootstrap replicates. A model of DaCHS was constructed by way of structural tools and key amino acid residues were identified at the active motif site.

Androgen deprivation therapy increases brain ageing.

BACKGROUND: Prostate cancer (PC) is the most frequent neoplasia in the male population and androgen deprivation therapy (ADT) is frequently used in the management of the disease. AIM: To evaluate the effect of ADT exposure on cognitive status, grey matter volume (GMV) and white matter lesion (WML) load. METHODS: Fifty ADT patients and fifteen PC-non-ADT (control) patients were included in the study. A neuropsychological evaluation was performed and a magnetic resonance imaging (MRI), with anatomical T1 and FLAIR sequences, was performed to evaluate the GMV and the WML burden. RESULTS: Most of the patients included in the study presented a significant cognitive impairment (CI). No significant differences were identified in the cognitive assessment between the studied groups, but when considering the educational background intragroup differences were found.No significant difference of GMV and WML volume were identified between groups, but a negative relationship between the ADT period and the GMV was identified. Furthermore, a significant positive association between the age and the lesion volume was found in the ADT group (ß=.406; p=.004). CONCLUSION: PC patients exposed to ADT present an acceleration of age-related brain changes, such as WML development and GMV loss.

Insect Antifeedant Components of Senecio fistulosus var. fistulosus-Hualtata.

From a bioactive methanolic extract of Senecio fistulosus, the antifeedant effects of the alkaloidal and non-alkaloidal fractions were tested against the insects Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi, with the non-alkaloidal fraction being antifeedant. The phytochemical study of the non-alkaloidal fraction of S. fistulosus, resulted in the isolation of four compounds, two 9-oxo-furanoeremophilanes (1, 2), an eremophilanolide, 1ß,10ß-epoxy-6-acetoxy-8α-hydroxy-eremofil-7(11)-en-8ß,12-olide (3) and a maaliol derivative (4). The alkaloidal fraction yielded two known pyrrolizidine alkaloids (5, 6). Compounds 1, 3 and 4 are new natural products. Furanoeremophilane 2 was a strong antifeedant against S. littoralis and maaliane 4 inhibited the settling of M. persicae.

Microgeographic variation in body condition of three Mexican garter snakes in central Mexico.

BACKGROUND: Geographic variation in body size and condition can reveal differential local adaptation to resource availability or climatic factors. Body size and condition are related to fitness in garter snakes (Thamnophis), thus good body condition may increase survival, fecundity in females, and mating success in males. Phylogenetically related species in sympatry are predicted to exhibit similar body condition when they experience similar environmental conditions. We focused on interspecific and geographical variation in body size and condition in three sympatric Mexican garter snakes from the highlands of Central Mexico. METHODS: We assessed SVL, mass, and body condition (obtained from Major axis linear regression of ln-transformed body mass on ln-transformed SVL) in adults and juveniles of both sexes of Thamnophis eques, T. melanogaster, and T. scalaris sampled at different locations and ranges from 3-11 years over a 20-year period. RESULTS: We provide a heterogeneous pattern of sexual and ontogenic reproductive status variations of body size and condition among local populations. Each garter snake species shows locations with good and poor body condition; juvenile snakes show similar body condition between populations, adults show varying body condition between populations, and adults also show sex differences in body condition. We discuss variations in body condition as possibly related to the snakes' life cycle differences.

A set of biogenetically interesting polyhalogenated acetogenins from Ptilonia magellanica.

Ptilonines A-F, pyranosylmagellanicus D-E and magellenediol are previously undescribed acetogenins isolated from the red alga Ptilonia magellanica. Their structures were determined from spectroscopic evidence. The absolute configuration of the known pyranosylmagellanicus A, was established by derivatization with (R)- and (S)-α-methoxy -α-phenylacetic acids (MPA). Ptilonines exhibit an unusual halogenation pattern, that may confer evolutionary advantages to Ptilonia magellanica, for which a biogenetic origin is proposed. The antimicrobial effect of some of these compounds was evaluated.

A new antifungal and antiprotozoal bibenzyl derivative from Gavilea lutea.

A new bibenzyl derivative (4), together with two glycosylated flavonoids (1 and 2), batatasin III (3) and the phenanthrene isohircinol (5) were isolated from the aerial parts of Gavilea lutea. Their structures were elucidated on the basis of spectroscopic studies including 1D and 2D NMR, UV, IR and HRESIMS. All isolated compounds were evaluated for their antifungal activity towards Candida albicans. The new compound 4 showed inhibitory activity with a MIQ of 50 µg. In addition, compound 4 exhibited a selective activity (IC50 = 2.3 µg/mL) against Leishmania donovani.

Histological characteristics of gills and dorsal skin in ambystoma leorae and ambystoma rivulare: morphological changes for living at high altitude / Características histológicas de la piel del dorso y las branquias en ambystoma leorae y ambystoma rivulare: cambios morfológicos para vivir a gran altitud

SUMMARY: Vertebrates exhibit structural changes in their cardiovascular and gas exchange systems in response to hypoxic conditions in high altitude environments. In highland neotenic mole salamanders, as other amphibians, the majority of gases exchange is carried out for skin and gills. But, in high altitude environments, the available oxygen is lower than it is in the air thus, the scarcity of oxygen limits the survival of organisms. Many studies on this subject have focused on understanding the hematological mechanisms that amphibians exhibit in response to hypoxia. However, little is known about possible morphological changes in respiratory structures that may permit increased gas exchange during respiration in high altitude amphibians like Ambystoma leorae and A. rivulare, two threatened Mexican salamander species. The aim of the present study was to describe and compare the histological characteristics of the gills and dorsal skin of A. leorae and A. rivulare from populations at low and high altitudes. We found that, in comparison to lowland organisms, highland ones exhibited more pronounced skin folds, greater numbers of secondary branches in the gills, thinner dorsal and gill epidermises, and greater quantity of melanin surrounding the gill blood vessels. These differences permit a greater capacity for gas exchange and also increase thermoregulatory capacity in high altitude environments.

RESUMEN: Los anfibios que viven en ambientes de altitud se enfrentan a factores abióticos que limitan la vida, tales como la disminución de la presión barométrica con la consecuente disminución de la presión parcial de oxígeno (O2). Conocer los mecanismos que optimizan la obtención del O2 en estos animales es de gran importancia para entender las diferencias en la sensibilidad a la hipoxia de las diferentes especies. Ambystoma rivulare y A. leorae son anfibios endémicos del Estado de México que viven en ambientes de alta altitud por lo que se cree presentan estrategias fenotípicas para asimilar eficazmente el O2 y poder subsistir en los ambientes de altitud. El objetivo de este trabajo fue analizar las características histológicas de branquias y piel cefálica (que son las principales estructuras que se encargan del intercambio gaseoso) provenientes de tres poblaciones con diferente altitud. Nuestros resultados muestran que los organismos que habitan a mayor altitud tienden a aumentar la superficie de intercambio gaseoso, como es el caso de pliegues epidérmicos y ramas branquiales secundarias. Las diferencias histológicas de branquias y piel cefálica tanto interespecíficas como intraespecíficas respecto a la altitud parecen apoyar la idea de que los organismos modifican sus estructuras para contrarrestar las limitantes de la vida en ambientes de altitud.

A Mountain or a Plateau? Hematological Traits Vary Nonlinearly with Altitude in a Highland Lizard.

High-altitude organisms exhibit hematological adaptations to augment blood transport of oxygen. One common mechanism is through increased values of blood traits such as erythrocyte count, hematocrit, and hemoglobin concentration. However, a positive relationship between altitude and blood traits is not observed in all high-altitude systems. To understand how organisms adapt to high altitudes, it is important to document physiological patterns related to hypoxia gradients from a greater variety of species. Here, we present an extensive hematological description for three populations of Sceloporus grammicus living at 2,500, 3,400, and 4,300 m. We did not find a linear increase with altitude for any of the blood traits we measured. Instead, we found nonlinear relationships between altitude and the blood traits erythrocyte number, erythrocyte size, hematocrit, and hemoglobin concentration. Erythrocyte number and hematocrit leveled off as altitude increased, whereas hemoglobin concentration and erythrocyte size were highest at intermediate altitude. Additionally, lizards from our three study populations are similar in blood pH, serum electrolytes, glucose, and lactate. Given that the highest-altitude population did not show the highest levels of the variables we measured, we suggest these lizards may be using different adaptations to cope with hypoxia than lizards at low or intermediate altitudes. We discuss future directions that research could take to investigate such potential adaptations.

Visceral branches of the abdominal aorta in the New Zealand rabbit: ten different patterns / Ramas viscerales de la aorta abdominal en el conejo neozelandés: diez patrones de presentación

The abdominal aorta of the rabbit has been in the focus of research to develop new platforms of training diagnostic and therapeutic protocols; and for testing endovascular devices and materials, however, few descriptions of the anatomy of the abdominal aorta and its emerging visceral branches has been reported on the scientific literature for this specie. Anatomical variations are common and should have in mind during research and clinical trials. The aim of this study was to describe the different patterns that can occur in the visceral branches arising from the abdominal aorta in the rabbit.

La aorta abdominal del conejo ha sido objeto de estudio e investigación para desarrollar nuevas plataformas de entrenamiento para protocolos diagnósticos y terapéuticos así como para probar las virtudes de materiales y equipos endovasculares, sin embargo, existen muy pocas descripciones en la literatura de las ramas viscerales que emergen de la aorta abdominal en esta especie. Las variaciones anatómicas son eventos de ocurrencia común y por lo tanto deben ser considerados para realizar investigación y ensayos clínicos. El objetivo del presente estudio ha sido describir los diferentes patrones que pueden presentar las ramas viscerales que emergen de la aorta abdominal en el conejo.

Antibacterial Activity of Alkaloid Fractions from Berberis microphylla G. Forst and Study of Synergism with Ampicillin and Cephalothin.

Berberis microphylla is a native plant that grows in Patagonia and is commonly used by aboriginal ethnic groups in traditional medicine as an antiseptic for different diseases. The present study evaluated the antibacterial and synergistic activity of alkaloid extracts of B. microphylla leaves, stems and roots used either individually or in combination with antibiotics against Gram-positive and Gram-negative bacteria. The in vitro antibacterial activities of leaf, stem and root alkaloid extracts had significant activity only against Gram-positive bacteria. Disc diffusion tests demonstrated that the root extract showed similar activity against B. cereus and S. epidermidis compared to commercial antibiotics, namely ampicillin and cephalothin, and pure berberine, the principal component of the alkaloid extracts, was found to be active only against S. aureus and S. epidermidis with similar activity to that of the root extract. The minimum inhibitory concentrations (MICs) of the alkaloid extracts ranged from 333 to 83 µg/mL, whereas minimum bactericidal concentrations (MBCs) varied from 717 to 167 µg/mL. In addition, synergistic or indifferent effects between the alkaloid extracts and antibiotics against bacterial strains were confirmed.

Medicinal value of the Berberis genus as hypoglycemic agent / Valor medicinal del género Berberis como agente hipoglicemiante

Type 2 diabetes mellitus (T2DM) is a common chronic disease whose prevalence is currently increasing worldwide. Nowadays, the main antidiabetic agent used is metformin. However, between 10 and 30 percent of patients undergoing metformin therapy have nonspecific gastric alterations as an undesired secondary effect. Therefore, the search for new therapeutic alternatives is especially useful, where plant- derived products emerge as an excellent phytochemical resource. The objective of this review is to present and discuss the state of the art of current research conducted on the Berberis gender with hypoglycemic activity, which is normally used in alternative medicine therapy for the treatment of T2DM, and its possible mechanisms of action described in literature.

La diabetes mellitus tipo 2 (DM2) es una enfermedad crónica común, cuya prevalencia está actualmente aumentando en todo el mundo. Al presente, el principal fármaco antidiabético utilizado es la metformina. Sin embargo, entre un 10 y 30 por ciento de los pacientes tratados presentan como efecto no deseado de alteraciones gástricas inespecíficas. Por lo tanto, la búsqueda de nuevas alternativas terapéuticas es de gran utilidad, en donde los productos derivados de plantas emergen como un excelente recurso fitoquímico. El objetivo de esta revisión es presentar y discutir sobre el estado del arte de investigaciones realizadas en las especies del género Berberis con actividad hipoglicemiante, las cuales son normalmente utilizadas en medicina alternativa como terapia para el tratamiento de DM, y sus posibles mecanismos de acción descritos en la literatura.

Sesquiterpenes, flavonoids, shikimic acid derivatives and pyrrolizidine alkaloids from Senecio kingii Hook.

Twenty-four compounds including eleven eremophilanolides (1-11), one eremophilane (13), five shikimic acid derivatives (14-18), six flavonoids (19-24), and the macrocyclic unsaturated pyrrolizidine alkaloid integerrimine (25) were isolated from Senecio kingii, an endemic species from the Magallanes Region (Chile). Compounds 3, 5, 6, 8-11 and 13-18 have not been previously reported as natural products. Their molecular structures were determined by NMR spectroscopic analysis and comparison with published NMR data. An X-ray-analysis of compound 3 has been performed. Their insecticidal and antifungal activities were tested, being compound 3 the strongest insect antifeedant. Compounds 6, 9 and 18 were moderate antifungals.

Identification of isoquinoline alkaloids from Berberis microphylla by HPLC ESI-MS/MS / Identificación de alcaloides isoquinolínicos en Berberis microphylla G. Forst mediante CLAE IES-MS/MS

Berberis microphylla (G. Forst) is a native plant growing in Patagonia. In recent years Patagonia Berberis are becoming important due to their interesting biological properties related to their alkaloids content. The aim of this study was determine the distribution and proportion of isoquinoline alkaloids in leaves, stems and roots of B. microphylla collected in two different climatic zones from Chilean Patagonia. Using by HPLC ESI-MS/MS isocorydine, jatrorrhizine, palmatine, reticuline, scoulerine, tetrahydroberberine and thalifendine were detected for the first time in this specie, and the presence of allocryptopine, berberine, calafatine and protopine, previously isolated in B. microphylla was corroborated. The alkaloids profile showed differences of compounds in samples collected in two climatic zones, where more compounds were detected in plants from Lago Deseado than Cerro Sombrero. Furthermore, a greater number of alkaloids were found in stem and root extracts and berberine and thalifendine were detected in higher proportion in these structures.

Berberis microphylla (G. Forst) es un arbusto nativo que crece en la Patagonia. Actualmente, esta planta ha sido foco de estudio dada las propiedades biológicas que presenta, atribuidas principalmente al contenido de alcaloides. El objetivo de este estudio fue determinar la distribución y proporción de alcaloides isoquinolínicos en hojas, tallos y raíces de B. microphylla colectadas en dos zonas climáticas de la Patagonia chilena. Mediante CLAE IES-MS/MS se informa por primera vez la presencia de isocoridina jatrorrizina, palmatina, reticulina, escoulerina, tetrahidroberberina y talifendina en esta especie y se confirma la presencia de allocriptopina, berberina, calafatina y protopina, identificados previamente en B. microphylla. El perfil de alcaloides mostró diferencias en la presencia de compuestos en las muestras colectas en las dos zonas climáticas, observándose un mayor número de compuestos en plantas provenientes de Lago Deseado. Además, un mayor número de compuestos se identificó en extractos de tallos y raíces donde berberina y talifendina fueron detectados en mayor proporción.