Melatonin, corticosterone, stress and phagocytic activity

ABSTRACT: The present study was conducted to detct the direct reletionships between melatonin and corticosterone under stress condition and possible actions of the two hormones on phagocitic activity of rat peritoneal macrophages. Two experiments were performed. In the first one stress increased the corticosterone plasma concentration to 287+-23 ng/ml while nocturnal melatonin levels were depressed. Clear rise in macrophages capacity to ingest latex beads was noticed when they were incubated with maximum melatonin added (115 pg/ml) and combination of melatonin and corticosterone combinations investigated. The results concerning phagocytic efficiency showed that only significant differences were when phagocytes were received from unstressed rats. РЕЗЮМЕ: Настоящото изследване бе проведено за да се изяснят взаимоотношенията между нивото на мелатонина и кортикостерона в кръвта на плъхове по време на стрес и влиянието на двата хормона върху фагоцитната активност на макрофаги получени от стресирани плъхове. За целта бяха проведени два експеримента. При първия нивото на кортикостерона в кръвта по време на стрес достигна 287 +- 23 ng/ml, докато нивото на мелатонина през нощта бе подтиснато. Повишение на фагоцитната активност бе отбелязана след добавяне на максималното тестирано количество мелатонин (115 pg/ml) или комбинации от мелатонин и кортикостерон. Резултатите отнасящи се до фагоцитната активност показват, че единствено статистически достоверно различие се получава когато фагоцитите бяха получавани от несъпресирани плъхове

In Silico and Biochemical Analysis of Physcomitrella patens Photosynthetic Antenna: Identification of Subunits which Evolved upon Land Adaptation

Background. In eukaryotes the photosynthetic antenna system is composed of subunits encoded by the light harvesting complex (Lhc) multigene family. These proteins play a key role in photosynthesis and are involved in both light harvesting and photoprotection. The moss Physcomitrella patens is a member of a lineage that diverged from seed plants early after land colonization and therefore by studying this organism, we may gain insight into adaptations to the aerial environment. Principal Findings. In this study, we characterized the antenna protein multigene family in Physcomitrella patens, by sequence analysis as well as biochemical and functional investigations. Sequence identification and analysis showed that some antenna polypeptides, such as Lhcb3 and Lhcb6, are present only in land organisms, suggesting they play a role in adaptation to the sub-aerial environment. Our functional analysis which showed that photo-protective mechanisms in Physcomitrella patens are very similar to those in seed plants fits with this hypothesis. In particular, Physcomitrella patens also activates Non Photochemical Quenching upon illumination, consistent with the detection of an ortholog of the PsbS protein. As a further adaptation to terrestrial conditions, the content of Photosystem I low energy absorbing chlorophylls also increased, as demonstrated by differences in Lhca3 and Lhca4 polypeptide sequences, in vitro reconstitution experiments and low temperature fluorescence spectra. Conclusions. This study highlights the role of Lhc family members in environmental adaptation and allowed proteins associated with mechanisms of stress resistance to be identified within this large family

Analysis of LhcSR3, a Protein Essential for Feedback De-Excitation in the Green Alga Chlamydomonas reinhardtii

To prevent photodamage by excess light, plants use different proteins to sense pH changes and to dissipate excited energy states. In green microalgae, however, the LhcSR3 gene product is able to perform both pH sensing and energy quenching functions

Cardiopoietic cell therapy for advanced ischemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort

XI ANNIVERSARY SCIENTIFIC CONFERENCE SPECIAL EDITION/ON-LINE 120 YEARS OF ACADEMIC EDUCATION IN BIOLOGY 45 YEARS FACULTY OF BIOLOGY ACTIVE BIOMONITORING OF ECOTOXICOLOGICAL EFFECTS FROM TROPOSPHERIC OZONE IMPACT ON REPRESENTATIVE TREE SPECIES

ABSTRAC

Determination of Configuration and Conformation of a Reserpine Derivative with Seven Stereogenic Centers Using Molecular Dynamics with RDC‐Derived Tensorial Constraints**

NMR-based determination of the configuration of complex molecules containing many stereocenters is often not possible using traditional NOE data and coupling patterns. Making use of residual dipolar couplings (RDCs), we were able to determine the relative configuration of a natural product containing seven stereocenters, including a chiral amine lacking direct RDC data. To identify the correct relative configuration out of 32 possible ones, experimental RDCs were used in three different approaches for data interpretation: by fitting experimental data based singular value decomposition (SVD) using a single alignment tensor and either (i) a single conformer or (ii) multiple conformers, or alternatively (iii) using molecular dynamics simulations with tensorial orientational constraints (MDOC). Even though in all three approaches one and the same configuration could be selected and clear discrimination between possible configurations was achieved, the experimental data was not fully satisfied by the methods based on single tensor approaches. While these two approaches are faster, only MDOC is able to fully reproduce experimental results, as the obtained conformational ensemble adequately covers the conformational space necessary to describe the molecule with inherent flexibility.ISSN:0947-6539ISSN:1521-376