Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Efficacy and Tolerability of 6-Month Treatment with Tamsulosin Plus the Hexanic Extract of Serenoa repens versus Tamsulosin Plus 5-Alpha-Reductase Inhibitors for Moderate-to-Severe LUTS-BPH Patients: Results of a Paired Matched Clinical Study

The objective of this subset analysis was to evaluate and compare the efficacy and tolerability of two combination treatments for men with moderate-to-severe lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). Data were from a real-world, open-label, prospective, and multicenter study performed in outpatient urology clinics. Men with moderate-to-severe LUTS/BPH received 6-month treatment with tamsulosin (TAM) in combination with either the hexanic extract of S. repens (HESr) or a 5-alpha-reductase inhibitor (5ARI). Changes in urinary symptoms and quality of life were measured using the IPSS and BII questionnaires, respectively. Treatment tolerability was assessed by recording adverse effects (AEs). Patients in the two study groups were matched using iterative and propensity score matching approaches. After iterative matching, data were available from 136 patients (n = 68 treated with TAM + 5ARI, n = 68 with TAM + HESr). After 6 months of treatment, mean (SD) IPSS total score improved by 7.7 (6.3) and 6.7 (5.0) points in the TAM + 5ARI and TAM + HESr groups, respectively (p = 0.272); mean BII total scores improved by 3.1 (2.9) and 2.9 (2.4) points (p = 0.751), respectively. AEs were reported by 26.5% and 10.3% of patients in the same groups, mostly affecting sexual function (p < 0.027). When used in a real-world setting to treat patients with moderate-severe LUTS/BPH, 6-month treatment with TAM + HESr was as effective as TAM + 5ARI, but with better tolerability. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Do differences in understory light contribute to species distributions along a tropical rainfall gradient?

In tropical forests, regional differences in annual rainfall correlate with differences in plant species composition. Although water availability is clearly one factor determining species distribution, other environmental variables that covary with rainfall may contribute to distributions. One such variable is light availability in the understory, which decreases towards wetter forests due to differences in canopy density and phenology. We established common garden experiments in three sites along a rainfall gradient across the Isthmus of Panama in order to measure the differences in understory light availability, and to evaluate their influence on the performance of 24 shade-tolerant species with contrasting distributions. Within sites, the effect of understory light availability on species performance depended strongly on water availability. When water was not limiting, either naturally in the wetter site or through water supplementation in drier sites, seedling performance improved at higher light. In contrast, when water was limiting at the drier sites, seedling performance was reduced at higher light, presumably due to an increase in water stress that affected mostly wet-distribution species. Although wetter forest understories were on average darker, wet-distribution species were not more shade-tolerant than dry-distribution species. Instead, wet-distribution species had higher absolute growth rates and, when water was not limiting, were better able to take advantage of small increases in light than dry-distribution species. Our results suggest that in wet forests the ability to grow fast during temporary increases in light may be a key trait for successful recruitment. The slower growth rates of the dry-distribution species, possibly due to trade-offs associated with greater drought tolerance, may exclude these species from wetter forests

Effect of mineral-enriched diet and medicinal herbs on Fe, Mn, Zn, and Cu uptake in chicken

<p>Abstract</p> <p>Background</p> <p>The goal of our study was to evaluate the effects of different medicinal herbs rich in polyphenol (Lemon balm, Sage, St. John's wort and Small-flowered Willowherb) used as dietary supplements on bioaccumulation of some essential metals (Fe, Mn, Zn and Cu) in different chicken meats (liver, legs and breast).</p> <p>Results</p> <p>In different type of chicken meats (liver, legs and breast) from chickens fed with diets enriched in minerals and medicinal herbs, beneficial metals (Fe, Mn, Zn and Cu) were analysed by flame atomic absorption spectrometry. Fe is the predominant metal in liver and Zn is the predominant metal in legs and breast chicken meats. The addition of metal salts in the feed influences the accumulations of all metals in the liver, legs and breast chicken meat with specific difference to the type of metal and meat. The greatest influences were observed in legs meat for Fe and Mn. Under the influence of polyphenol-rich medicinal herbs, accumulation of metals in the liver, legs and breast chicken meat presents specific differences for each medicinal herb, to the control group that received a diet supplemented with metal salts only. Great influence on all metal accumulation factors was observed in diet enriched with sage, which had significantly positive effect for all type of chicken meats.</p> <p>Conclusions</p> <p>Under the influence of medicinal herbs rich in different type of polyphenol, accumulation of metals in the liver, legs and breast chicken meat presents significant differences from the group that received a diet supplemented only with metal salts. Each medicinal herb from diet had a specific influence on the accumulation of metals and generally moderate or poor correlations were observed between total phenols and accumulation of metals. This may be due to antagonism between metal ions and presence of other chelating agents (amino acids and protein) from feeding diets which can act as competitor for complexation of metals and influence accumulation of metals in chicken meat.</p> <p><b>Graphical abstract</b></p

Modelling the regulation of telomere length: the effects of telomerase and G-quadruplex stabilising drugs

Telomeres are guanine-rich sequences at the end of chromosomes which shorten during each replication event and trigger cell cycle arrest and/or controlled death (apoptosis) when reaching a threshold length. The enzyme telomerase replenishes the ends of telomeres and thus prolongs the life span of cells, but also causes cellular immortalisation in human cancer. G-quadruplex (G4) stabilising drugs are a potential anticancer treatment which work by changing the molecular structure of telomeres to inhibit the activity of telomerase. We investigate the dynamics of telomere length in different conformational states, namely t-loops, G-quadruplex structures and those being elongated by telomerase. By formulating deterministic differential equation models we study the effects of various levels of both telomerase and concentrations of a G4-stabilising drug on the distribution of telomere lengths, and analyse how these effects evolve over large numbers of cell generations. As well as calculating numerical solutions, we use quasicontinuum methods to approximate the behaviour of the system over time, and predict the shape of the telomere length distribution. We find those telomerase and G4-concentrations where telomere length maintenance is successfully regulated. Excessively high levels of telomerase lead to continuous telomere lengthening, whereas large concentrations of the drug lead to progressive telomere erosion. Furthermore, our models predict a positively skewed distribution of telomere lengths, that is, telomeres accumulate over lengths shorter than the mean telomere length at equilibrium. Our model results for telomere length distributions of telomerase-positive cells in drug-free assays are in good agreement with the limited amount of experimental data available

Intravenous injection of neural progenitor cells improved depression-like behavior after cerebral ischemia

Poststroke depression (PSD) occurs in approximately one-third of stroke survivors and is one of the serious sequelae of stroke. The onset of PSD causes delayed functional recovery by rehabilitation and also increases cognitive impairment. However, appropriate strategies for the therapy against ischemia-induced depression-like behaviors still remain to be developed. Such behaviors have been associated with a reduced level of brain-derived neurotrophic factor (BDNF). In addition, accumulating evidence indicates the ability of stem cells to improve cerebral ischemia-induced brain injuries. However, it remains to be clarified as to the effect of neural progenitor cells (NPCs) on PSD and the association between BDNF level and PSD. Using NPCs, we investigated the effect of intravenous injection of NPCs on PSD. We showed that injection of NPCs improved ischemia-induced depression-like behaviors in the forced-swimming test and sucrose preference test without having any effect on the viable area between vehicle- and NPC-injected ischemic rats. The injection of NPCs prevented the decrease in the level of BDNF in the ipsilateral hemisphere. The levels of phosphorylated CREB, ERK and Akt, which have been implicated in events downstream of BDNF signaling, were also decreased after cerebral ischemia. NPC injection inhibited these decreases in the phosphorylation of CREB and ERK, but not that of Akt. Our findings provide evidence that injection of NPCs may have therapeutic potential for the improvement of depression-like behaviors after cerebral ischemia and that these effects might be associated with restoring BDNF-ERK-CREB signaling

The Neutrophil-Lymphocyte Ratio is an Independent Prognostic Factor for Overall Survival in Hispanic Patients with Gastric Adenocarcinoma

Introduction High values of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are related with poor prognosis in patients with gastric cancer. However, this association has been rarely assessed in Hispanic populations that show important clinicopathological differences to Asian and Caucasian patients. In this study, we determined the prognostic value of these biomarkers in Hispanic patients from Costa Rica. Materials and Methods We retrieved data regarding pre-treatment NLR and PLR, as well as clinical variables from medical records of 381 consecutive gastric cancer patients treated in four major hospitals in Costa Rica between 2009 and 2012. Univariate and multiple Cox regression analyses were performed to assess the value of NLR and PLR as predictors of overall survival (OS) and disease-free survival (DFS). The best cutoff point was based on the maximization of the Log-rank test. Results Median follow-up was 13.21 months. In univariate analysis, a NLR ≥ 5 was associated with reduced DFS (hazard ratio (HR) 2.31; 95% confidence interval (CI) 1.78–3.00; p < 0.001) and poor OS (HR 2.24; 95% CI 1.72–2.92; p < 0.001). Similarly, a PLR ≥ 350 was associated with worse DFS (HR 2.28; 95% CI 1.70–3.06; p < 0.001) and poor OS (HR 2.33; 95% CI 1.73–3.13; p < 0.001). After adjustment for potential confounders, multivariate analysis revealed that only the NLR ≥ 5 was independently associated with worse DFS (HR 1.97; 95% CI 1.44–2.47) and OS (HR 1.59; 95%CI 1.15–2.28). Conclusions NLR ≥ 5 was independently associated with worse OS and DFS in Hispanic patients with gastric cancer.Universidad de Costa Rica/[817-B2-371]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones Farmacéuticas (INIFAR)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC