Cerebrospinal fluid-contacting neurons of the central canal and terminal ventricle in various vertebrates

Cell and Tissue Research - Cerebrospinal fluid (CSF)-contacting neurons were studied by means of electron microscopy in the spinal cord and/or terminal ventricle of the ray, Raja clavata...     

Resveratrol Prevents Oxidative Stress-Induced Senescence and Proliferative Dysfunction by Activating the AMPK-FOXO3 Cascade in Cultured Primary Human Keratinocytes

The aging process is perceived as resulting from a combination of intrinsic factors such as changes in intracellular signaling and extrinsic factors, most notably environmental stressors. In skin, the relationship between intrinsic changes and keratinocyte function is not clearly understood. Previously, we found that increasing the activity of AMP-activated protein kinase (AMPK) suppressed senescence in hydrogen peroxide (H₂O₂)-treated human primary keratinocytes, a model of oxidative stress-induced cellular aging. Using this model in the present study, we observed that resveratrol, an agent that increases the activities of both AMPK and sirtuins, ameliorated two age-associated phenotypes: cellular senescence and proliferative dysfunction. In addition, we found that treatment of keratinocytes with Ex527, a specific inhibitor of sirtuin 1 (SIRT1), attenuated the ability of resveratrol to suppress senescence. In keeping with the latter observation, we noted that compared to non-senescent keratinocytes, senescent cells lacked SIRT1. In addition to these effects on H₂O₂-induced senescence, resveratrol also prevented the H₂O₂-induced decrease in proliferation (as indicated by ³H-thymidine incorporation) in the presence of insulin. This effect was abrogated by inhibition of AMPK but not SIRT1. Compared to endothelium, we found that human keratinocytes expressed relatively high levels of Forkhead box O3 (FOXO3), a downstream target of both AMPK and SIRT1. Treatment of keratinocytes with resveratrol transactivated FOXO3 and increased the expression of its target genes including catalase. Resveratrol’s effects on both senescence and proliferation disappeared when FOXO3 was knocked down. Finally, we performed an exploratory study which showed that skin from humans over 50 years old had lower AMPK activity than skin from individuals under age 20. Collectively, these findings suggest that the effects of resveratrol on keratinocyte senescence and proliferation are regulated by the AMPK-FOXO3 pathway and in some situations, but not all, by SIRT1.     

Preliminary analysis of reproductive success in a large mammal with alternative mating tactics,the Northern chamois,Rupicapra rupicapra

In polygynous mating systems, reproductive skew depends on the ability of males to monopolize females, which in turn may promote the development of contrasting traits in the two sexes. Although dominant individuals normally enjoy a higher reproductive success (RS) than subordinates, the use of genetic markers has shown that behavioural observations of male mating success may not provide reliable clues of RS. We report the preliminary results of the first DNA‐based paternity analysis on the Northern chamois (Rupicapra rupicapra), a scarcely dimorphic mountain ungulate described as highly polygynous, in relation to mating tactic and age. Because of sampling difficulties, the success in parentage assignment was low, and the interpretation of results requires caution. Territorial males had a greater RS than nonterritorial ones but they were unable to monopolize mating events. Age had a weak effect on paternity outcome but only males ≥ 6 years showed siring success. Although future studies are needed to assess the opportunity for sexual selection in male chamois, the concurrence of limited sexual size dimorphism, compensatory growth, unbiased sex‐specific survival, RS of alternative mating tactics and, possibly, long breeding tenure, may hint at the adoption of a conservative mating strategy in this species.     

Population-level impacts of natural and anthropogenic causes-of-death for Hawaiian monk seals in the main Hawaiian Islands

Identifying, assessing, and ranking the impact of individual threats is fundamental to the conservation and recovery of rare and endangered species. In this analysis, we quantify not only the frequency of specific causes-of-death (CODs) among Main Hawaiian Island (MHI) monk seals, but also assess the impact of individual CODs on the intrinsic growth rate, λ, of the MHI population. We used gross necropsy results, histopathology, and other evidence to assign probabilities of 11 COD types to each mortality and then used Monte Carlo sampling to evaluate the influence of each COD on λ. By right censoring realizations involving specific CODs, we were able to estimate λ (and its associated uncertainty) when CODs were selectively removed from influencing survival. Applying the analysis to all known and inferred deaths believed to have occurred 2004–2019, the CODs with the largest influence on λ were anthropogenic trauma, anthropogenic drowning, and protozoal disease. In aggregate, anthropogenic CODs had a larger effect on the growth rate than either natural or disease CODs. Possible bias associated with differential carcass detection, recovery, and COD classification are discussed.     

Abdominal distension alters regional pleural pressures and chest wall mechanics in pigs in vivo

Abdominal distension (AD) occurs in pregnancy and is also commonly seen in patients with ascites from various causes. Because the abdomen forms part of the "chest wall," the purpose of this study was to clarify the effects of AD on ventilatory mechanics. Airway pressure, four (vertical) regional pleural pressures, and abdominal pressure were measured in five anesthetized, paralyzed, and ventilated upright pigs. The effects of AD on the lung and chest wall were studied by inflating a liquid-filled balloon placed in the abdominal cavity. Respiratory system, chest wall, and lung pressure-volume (PV) relationships were measured on deflation from total lung capacity to residual volume, as well as in the tidal breathing range, before and 15 min after abdominal pressure was raised. Increasing abdominal pressure from 3 to 15 cmH2O decreased total lung capacity and functional residual capacity by approximately 40% and shifted the respiratory system and chest wall PV curves downward and to the right. Much smaller downward shifts in lung deflation curves were seen, with no change in the transdiaphragmatic PV relationship. All regional pleural pressures increased (became less negative) and, in the dependent region, approached 0 cmH2O at functional residual capacity. Tidal compliances of the respiratory system, chest wall, and lung were decreased 43, 42, and 48%, respectively. AD markedly alters respiratory system mechanics primarily by "stiffening" the diaphragm/abdomen part of the chest wall and secondarily by restricting lung expansion, thus shifting the lung PV curve as seen after chest strapping. The less negative pleural pressures in the dependent lung regions suggest that nonuniformities of ventilation could also be accentuated and gas exchange impaired by AD.     

The Role of Historical Barriers in the Diversification Processes in Open Vegetation Formations during the Miocene/Pliocene Using an Ancient Rodent Lineage as a Model

The Neotropics harbors a high diversity of species and several hypotheses have been proposed to account for this pattern. However, while species of forested domains are frequently studied, less is known of species from open vegetation formations occupying, altogether, a larger area than the Amazon Forest. Here we evaluate the role of historical barriers and the riverine hypothesis in the speciation patterns of small mammals by analyzing an ancient rodent lineage (Thrichomys, Hystricomorpha). Phylogenetic and biogeographic analyses were carried out with mitochondrial and nuclear DNA markers to analyze the evolutionary relationships between Thrichomys lineages occurring in dry domains along both banks of the Rio São Francisco. This river is one of the longest of South America whose course and water flow have been modified by inland tectonic activities and climate changes. Molecular data showed a higher number of lineages than previously described. The T. inermis species complex with 2n = 26, FN = 48 was observed in both banks of the river showing a paraphyletic arrangement, suggesting that river crossing had occurred, from east to west. A similar pattern was also observed for the T. apereoides complex. Thrichomys speciation occurred in Late Miocene when the river followed a different course. The current geographic distribution of Thrichomys species and their phylogenetic relationships suggested the existence of frequent past connections between both banks in the middle section of the Rio São Francisco. The extensive palaeodune region found in this area has been identified as a centre of endemism of several vertebrate species and is likely to be a center of Thrichomys diversification.     

Immunochemical studies on blood groups: The internal structure and immunological properties of water-soluble human blood group A substance studied by Smith degradation,liberation, and fractionation of oligosaccharides and reaction with lectins

Carbohydrate structures in the interior of a blood group A active substance (MSS) were exposed by one and by two Smith degradations. Reactivities of the original glycoprotein and its Smith degraded products with 13 different lectins and with anti-I Ma were studied by quantitative precipitin assay. MSS and its first Smith degraded product completely precipitated Ricinus communis hemagglutinin with five times less of the first Smith degraded glycoprotein being required for 50% precipitation. The second Smith degraded material precipitated only 90% of the lectin. MSS did not precipitate peanut lectin, whereas its first and second Smith degraded products completely precipitated the lectin. The first Smith degraded glycoprotein also reacted well with Wistaria floribunda, Maclura pomifera, Bauhinia purpurea alba, and Geodia lectins indicating that its carbohydrate moiety could contain dGalNAc, dGalβ1 → 3dGalNAc, dGalβ1 → 4dGlcNAc, dGalβ1 → 3dGlcNAcβ1 → 3dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGalNAc determinants at nonreducing ends. The second Smith degraded material precipitated well with Ricinus communis hemagglutinin, Arachis hypogaea, Geodia cydonium, Maclura pomifera, and Helix pomatia lectins showing that dGalNAc, dGalβ1 → 3dGalNAc, dGalβ1 → 4dGlcNAc residues at terminal nonreducing ends could be involved. Monoclonal anti-I Ma (group 1) serum reacted strongly with the first Smith degraded product indicating large numbers of anti-I Ma determinants, dGalβ1 → 4dGlcNAcβ1 → d 6dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGalNAc at nonreducing ends. The comparable activities of the native and Smith degraded products with wheat germ lectin indicate capacity to react with DGlcNAc residues at nonreducing ends and/or at positions in the interior of the chain. The totality of lectin reactivities indicates heterogeneity of the carbohydrate side chains. Oligosaccharides with ³H at their reducing ends released from the protein core of the first and second Smith degraded products were obtained by treatment with 0.05 m NaOH and 1 M NaB³H₄ at 50 °C for 16 h (Carlson degradation). The liberated reduced oligosaccharides were fractionated by dialysis, followed by retardion, Bio-Gel P-2, P-4, and P-6 columns. They were further purified on charcoal-celite columns, and by preparative paper chromatography and high-pressure liquid chromatography. Their distribution by size was estimated by the yields on dialysis, Bio-Gel P-2, and Bio-Gel P-6 chromatography, and from the radioactivity of the reduced sugars. Of the oligosaccharide fractions from the first Smith degraded product, about 77% of the carbohydrate side chain residues contained from 1 to 6 sugars, 13% from 7 to perhaps 12 sugars, and 10% was nondialyzable (polysaccharides and glycopeptide fragments). Of the second Smith degraded product, approximately 82% of carbohydrate residues had from 1 to 6 sugars, 14% from 7 to perhaps 20 sugars and 4% was nondialyzable. The biological activity profile of the two Smith degraded products together with the size distributions of the oligosaccharides indicated that their carbohydrate side chains, comprised a heterogeneous population ranging in size from 1 to about 12 sugars. When most of these chains that are shorter than hexasaccharides are fully characterized it may be possible to reconstruct the overall structure of the carbohydrate moiety of the blood group substances and account for their biological activities.     

Protein phosphatases in higher plants: multiplicity of type 2A phosphatases in Arabidopsis thaliana

Two DNA fragments, AP-1 and AP-2, encoding amino acid sequences closely related to Ser/Thr protein phosphatases were amplified from Arabidopsis thaliana genomic DNA. Fragment AP-1 was used to screen. A. thaliana cDNA libraries and several positive clones were isolated. Clones EP8a and EP14a were sequenced and found to encode almost identical proteins (97% identity). Both proteins are 306 amino acids in length and are very similar (79–80% identity) to the mammalian isotypes of the catalytic subunit of protein phosphatase 2A. Therefore, they have been designated PP2A-1 and PP2A-2. A third cDNA clone, EP7, was isolated and sequenced. The polypeptide encoded (308 amino acids, lacking the initial Met codon) is 80% identical with human phosphatases 2A and was named PP2A-3. The PP2A-3 protein is extremely similar (95% identity) to the predicted protein from a cDNA clone previously found in Brassica napus. Southern blot analysis of genomic DNA using AP-1 and AP-2 probes, as well as probes derived from clones EP7, EP8a and EP14a strongly indicates that at least 6 genes closely related to type 2A phosphatases are present in the genome of A. thaliana. Northern blot analysis using the same set of probes demonstrates that, at the seedling stage, the mRNA levels for PP2A-1, PP2A-3 and the gene containing the AP-1 sequence are much higher than those of PP2A-2 and AP-2. These results demonstrate that a multiplicity of type 2A phosphatases might be differentially expressed in higher plants.     

Spatial, temporal, and species variation in prevalence of influenza A viruses in wild migratory birds

Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes; this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus-host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location; this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds.     

Effects of Intra-Operative Total Intravenous Anaesthesia with Propofol versus Inhalational Anaesthesia with Sevoflurane on Post-Operative Pain in Liver Surgery: A Retrospective Case-Control Study

Background

Patients receiving total intravenous anesthesia (TIVA) with propofol have been shown to experience less postoperative pain. We evaluated the post-operative analgesic effects of propofol compared with sevoflurane maintenance of anesthesia in liver surgery. This study was registered at ClinicalTrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT02179437","term_id":"NCT02179437"}}NCT02179437).

Methods

In this retrospective study, records of patients who underwent liver surgery between 2010 and 2013 were reviewed. Ninety-five patients anesthetized with propofol TIVA were matched with 95 patients anesthetized with sevoflurane. Numeric pain rating scale (NRS) pain scores, postoperative morphine consumption, side effects and patients’ satisfaction with pain relief were evaluated.

Results

The TIVA group reported lower NRS pain scores during coughing on postoperative days 1 and 2 but not 3 (p = 0.0127, p = 0.0472, p = 0.4556 respectively). They also consumed significantly less daily (p = 0.001 on day 1, p = 0.0231 on day 2, p = 0.0004 on day 3), accumulative (p = 0.001 on day 1, p<0.0001 on day 2 and p = 0.0064 on day 3) and total morphine (p = 0.03) when compared with the sevoflurane group. There were no differences in total duration of intravenous patient controlled analgesia (PCA) morphine use and patient satisfaction. No difference was found in reported side effects.

Conclusion

Patients anesthetized with propofol TIVA reported less pain during coughing and consumed less daily, accumulative and total morphine after liver surgery.