Carbon-13 nmr spectra of some ent-rosane diterpenoids

The ¹³C NMR signals of the parent hydrocarbon ent-rosa-5,15-diene (ent-(8,5-friedo-pimara-5,15-diene)and some of their oxygenated derivatives have been assigned.     

Synthesis and evaluation of diverse analogs of amygdalin as potential peptidomimetics of peptide T

Peptide T (ASTTTNYT) is a promising molecule to prevent the neuropsychometric symptoms of patients suffering AIDS and for the treatment of psoriasis. In order to fully prove its therapeutic benefits, efforts were put forward to design peptidomimetics of the peptide. In this direction, in a recent computational study the natural product amygdalin was identified as a prospective peptidomimetic of the peptide and later proved to exhibit a similar chemotactic profile to the peptide. However, the cyanide moiety of amygdalin provides to the molecule a toxic profile. The present study reports the synthesis of a set of amygdalin analogs lacking the cyanide group with improved chemotactic profiles.     

Regulation of Lef-mediated transcription and p53-dependent pathway by associating beta-catenin with CBP/p300

CBP and its homologue p300 play significant roles in cell differentiation, cell cycle, and anti-oncogenesis. We demonstrated that beta-catenin, recently known as a potent oncogene, and CBP/p300 are associated through its CH3 region, which is a primary target of adenoviral oncoprotein E1A and various nuclear proteins, such as p53, cyclin E, and AP-1, and both are colocalized in the nuclear bodies. CBP/p300 potentiated Lef-mediated transactivation of beta-catenin, and E1A, a potent inhibitor of CBP/p300, repressed its transactivation. Furthermore, overexpression of stable beta-catenin mutant competitively suppressed the p53-dependent pathway. These may be a key mechanism of beta-catenin involved in oncogenic events underlying disruption of tumor suppressor function through CBP/p300.     

Assessing the feasibility of linkage disequilibrium methods for mapping complex traits: an initial screen for bipolar disorder loci on chromosome 18.

Linkage disequilibrium (LD) analysis has been promoted as a method of mapping disease genes, particularly in isolated populations, but has not yet been used for genome-screening studies of complex disorders. We present results of a study to investigate the feasibility of LD methods for genome screening using a sample of individuals affected with severe bipolar mood disorder (BP-I), from an isolated population of the Costa Rican central valley. Forty-eight patients with BP-I were genotyped for markers spaced at approximately 6-cM intervals across chromosome 18. Chromosome 18 was chosen because a previous genome-screening linkage study of two Costa Rican families had suggested a BP-I locus on this chromosome. Results of the current study suggest that LD methods will be useful for mapping BP-I in a larger sample. The results also support previously reported possible localizations (obtained from a separate collection of patients) of BP-I-susceptibility genes at two distinct sites on this chromosome. Current limitations of LD screening for identifying loci for complex traits are discussed, and recommendations are made for future research with these methods.     

Gamma carbonic anhydrases in plant mitochondria

Three genes from Arabidopsis thaliana with high sequence similarity to gamma carbonic anhydrase (γCA), a Zn containing enzyme from Methanosarcina thermophila(CAM), were identified and characterized. Evolutionary and structural analyses predict that these genes code for active forms of γCA. Phylogenetic analyses reveal that these Arabidopsis gene products cluster together with CAM and related sequences from α and γ proteobacteria, organisms proposed as the mitochondrial endosymbiont ancestor. Indeed, in vitro and in vivo experiments indicate that these gene products are transported into the mitochondria as occurs with several mitochondrial protein genes transferred, during evolution, from the endosymbiotic bacteria to the host genome. Moreover, putative CAM orthologous genes are detected in other plants and green algae and were predicted to be imported to mitochondria. Structural modeling and sequence analysis performed in more than a hundred homologous sequences show a high conservation of functionally important active site residues. Thus, the three histidine residues involved in Zn coordination (His 81, 117 and 122), Arg 59, Asp 61, Gin 75, and Asp 76 of CAM are conserved and properly arranged in the active site cavity of the models. Two other functionally important residues (Glu 62 and Glu 84 of CAM) are lacking, but alternative amino acids that might serve to their roles are postulated. Accordingly, we propose that photosynthetic eukaryotic organisms (green algae and plants) contain γCAs and that these enzymes codified by nuclear genes are imported into mitochondria to accomplish their biological function.     

The Effects of Hyperbaric Oxygen Therapy on Post-Training Recovery in Jiu-Jitsu Athletes

Objectives

The present study aimed to evaluate the effects of using hyperbaric oxygen therapy during post-training recovery in jiu-jitsu athletes.

Methods

Eleven experienced Brazilian jiu-jitsu athletes were investigated during and following two training sessions of 1h30min. Using a cross-over design, the athletes were randomly assigned to passive recovery for 2 hours or to hyperbaric oxygen therapy (OHB) for the same duration. After a 7-day period, the interventions were reversed. Before, immediately after, post 2 hours and post 24 hours, blood samples were collected to examine hormone concentrations (cortisol and total testosterone) and cellular damage markers [creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH)]. Moreover, the rating of perceived exertion (RPE) and recovery (RPR) scales were applied.

Results

Final lactate [La] values (control: 11.9 ± 1.4 mmol/L, OHB: 10.2 ± 1.4 mmol/L) and RPE [control: 14 (13–17 a.u.), OHB: 18 (17–20 a.u.)] were not significantly different following the training sessions. Furthermore, there was no difference between any time points for blood lactate and RPE in the two experimental conditions (P>0.05). There was no effect of experimental conditions on cortisol (F_1,20 = 0.1, P = 0.793, η² = 0.00, small), total testosterone (F_1,20 = 0.03, P = 0.877, η² = 0.00, small), CK (F_1,20 = 0.1, P = 0.759, η² = 0.01, small), AST (F_1,20 = 0.1, P = 0.761, η² = 0.01, small), ALT (F_1,20 = 0.0, P = 0.845, η² = 0.00, small) or LDH (F_1,20 = 0.7, P = 0.413, η² = 0.03, small). However, there was a difference between the two experimental conditions in RPR with higher values at post 2 h and 24 h in OHB when compared to the control condition (P<0.05).

Conclusions

Thus, it can be concluded that OHB exerts no influence on the recovery of hormonal status or cellular damage markers. Nonetheless, greater perceived recovery, potentially due to the placebo effect, was evident following the OHB condition.     

Metabolism of 25-hydroxyvitamin D3 by microsomal and mitochondrial vitamin D3 25-hydroxylases (CYP2D25 and CYP27A1): a novel reaction by CYP27A1

The metabolism of 25-hydroxyvitamin D(3) was studied with a crude mitochondrial cytochrome P450 extract from pig kidney and with recombinant human CYP27A1 (mitochondrial vitamin D(3) 25-hydroxylase) and porcine CYP2D25 (microsomal vitamin D(3) 25-hydroxylase). The kidney mitochondrial cytochrome P450 catalyzed the formation of 1alpha,25-dihydroxyvitamin D(3), 24,25-dihydroxyvitamin D(3) and 25,27-dihydroxyvitamin D(3). An additional metabolite that was separated from the other hydroxylated products on HPLC was also formed. The formation of this 25-hydroxyvitamin D(3) metabolite was dependent on NADPH and the mitochondrial electron transferring protein components. A monoclonal antibody directed against purified pig liver CYP27A1 immunoprecipitated the 1alpha- and 27-hydroxylase activities towards 25-hydroxyvitamin D(3) as well as the formation of the unknown metabolite. These results together with substrate inhibition experiments indicate that CYP27A1 is responsible for the formation of the unknown 25-hydroxyvitamin D(3) metabolite in kidney. Recombinant human CYP27A1 was found to convert 25-hydroxyvitamin D(3) into 1alpha,25-dihydroxyvitamin D(3), 25,27-dihydroxyvitamin D(3) and a major metabolite with the same retention time on HPLC as that formed by kidney mitochondrial cytochrome P450. Gas chromatography-mass spectrometry (GC-MS) analysis of the unknown enzymatic product revealed it to be a triol different from other known hydroxylated 25-hydroxyvitamin D(3) metabolites such as 1alpha,25-, 23,25-, 24,25-, 25,26- or 25,27-dihydroxyvitamin D(3). The product had the mass spectrometic properties expected for 4beta,25-dihydroxyvitamin D(3). Recombinant porcine CYP2D25 converted 25-hydroxyvitamin D(3) into 1alpha,25-dihydroxyvitamin D(3) and 25,26-dihydroxyvitamin D(3). It can be concluded that both CYP27A1 and CYP2D25 are able to carry out multiple hydroxylations of 25-hydroxyvitamin D(3).     

Caffeine Ingestion Increases Estimated Glycolytic Metabolism during Taekwondo Combat Simulation but Does Not Improve Performance or Parasympathetic Reactivation

ObjectivesThe aim of this study was to evaluate the effect of caffeine ingestion on performance and estimated energy system contribution during simulated taekwondo combat and on post-exercise parasympathetic reactivation.MethodsTen taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed a capsule containing either caffeine (5 mg∙kg^-1) or placebo (cellulose) one hour before the combat simulation (3 rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration and rating of perceived exertion were measured before and after each round, while heart rate (HR) and the estimated contribution of the oxidative (W_AER), ATP-PCr (W_PCR), and glycolytic (W_[La-]) systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was evaluated through 1) taking absolute difference between the final HR observed at the end of third round and the HR recorded 60-s after (HRR_60s), 2) taking the time constant of HR decay obtained by fitting the 6-min post-exercise HRR into a first-order exponential decay curve (HRR_τ), or by 3) analyzing the first 30-s via logarithmic regression analysis (T30).ResultsCaffeine ingestion increased estimated glycolytic energy contribution in relation to placebo (12.5 ± 1.7 kJ and 8.9 ± 1.2 kJ, P = 0.04). However, caffeine did not improve performance as measured by attack number (CAF: 26. 7 ± 1.9; PLA: 27.3 ± 2.1, P = 0.48) or attack time (CAF: 33.8 ± 1.9 s; PLA: 36.6 ± 4.5 s, P = 0.58). Similarly, RPE (CAF: 11.7 ± 0.4 a.u.; PLA: 11.5 ± 0.3 a.u., P = 0.62), HR (CAF: 170 ± 3.5 bpm; PLA: 174.2 bpm, P = 0.12), oxidative (CAF: 109.3 ± 4.5 kJ; PLA: 107.9 kJ, P = 0.61) and ATP-PCr energy contributions (CAF: 45.3 ± 3.4 kJ; PLA: 46.8 ± 3.6 kJ, P = 0.72) during the combat simulation were unaffected. Furthermore, T30 (CAF: 869.1 ± 323.2 s; PLA: 735.5 ± 232.2 s, P = 0.58), HRR_60s (CAF: 34 ± 8 bpm; PLA: 38 ± 9 bpm, P = 0.44), HRRτ (CAF: 182.9 ± 40.5 s, PLA: 160.3 ± 62.2 s, P = 0.23) and HRR_amp (CAF: 70.2 ± 17.4 bpm; PLA: 79.2 ± 17.4 bpm, P = 0.16) were not affected by caffeine ingestion.ConclusionsCaffeine ingestion increased the estimated glycolytic contribution during taekwondo combat simulation, but this did not result in any changes in performance, perceived exertion or parasympathetic reactivation.