Reductive
Dotaz
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Chloroplasts are generally known as eukaryotic organelles whose main function is photosynthesis. They perform other functions, however, such as synthesizing isoprenoids, fatty acids, heme, iron sulphur clusters and other essential compounds. In non-photosynthetic lineages that possess plastids, the chloroplast genomes have been reduced and most (or all) photosynthetic genes have been lost. Consequently, non-photosynthetic plastids have also been reduced structurally. Some of these non-photosynthetic or "cryptic" plastids were overlooked or unrecognized for decades. The number of complete plastid genome sequences and/or transcriptomes from non-photosynthetic taxa possessing plastids is rapidly increasing, thus allowing prediction of the functions of non-photosynthetic plastids in various eukaryotic lineages. In some non-photosynthetic eukaryotes with photosynthetic ancestors, no traces of plastid genomes or of plastids have been found, suggesting that they have lost the genomes or plastids completely. This review summarizes current knowledge of non-photosynthetic plastids, their genomes, structures and potential functions in free-living and parasitic plants, algae and protists. We introduce a model for the order of plastid gene losses which combines models proposed earlier for land plants with the patterns of gene retention and loss observed in protists. The rare cases of plastid genome loss and complete plastid loss are also discussed.
The optimization of sustainable protocols for reductive amination has been a lingering challenge in green synthesis. In this context, a comparative study of different metal-loaded cross-linked cyclodextrins (CDs) were examined for the microwave (MW)-assisted reductive amination of aldehydes and ketones using either H2 or formic acid as a hydrogen source. The Pd/Cu heterogeneous nanocatalyst based on Pd (II) and Cu (I) salts embedded in a β-CD network was the most efficient in terms of yield and selectivity attained. In addition, the polymeric cross-linking avoided metal leaching, thus enhancing the process sustainability; good yields were realized using benzylamine under H2. These interesting findings were then applied to the MW-assisted one-pot synthesis of secondary amines via a tandem reductive amination of benzaldehyde with nitroaromatics under H2 pressure. The formation of a CuxPdy alloy under reaction conditions was discerned, and a synergic effect due to the cooperation between Cu and Pd has been hypothesized. During the reaction, the system worked as a bifunctional nanocatalyst wherein the Pd sites facilitate the reduction of nitro compounds, while the Cu species promote the subsequent imine hydrogenation affording structurally diverse secondary amines with high yields.
- MeSH
- aminace MeSH
- aminy chemie MeSH
- benzaldehydy chemie MeSH
- beta-cyklodextriny chemie MeSH
- cyklodextriny chemie MeSH
- katalýza MeSH
- kovy chemie MeSH
- měď chemie MeSH
- mikrovlny * MeSH
- nanočástice chemie MeSH
- palladium chemie MeSH
- reagencia zkříženě vázaná chemie MeSH
- Publikační typ
- časopisecké články MeSH
The authors used a reductive mammaplasty technique with superior pedicled dermoglandular flap described by Lalardrie in 1972 and modified by Lauro. Twenty-eight patients who presented medium to heavy macromasty were treated. In all these cases the aesthetic result was vety satisfactory and major complications, like extended tissue necrosis, were not encountered. This method proves safe and effective in cases of significant gigantomasty for the following reason: for the efficient vascularization of the flap, it is possible to carry out significant transposition of the areola-nipple complex without risk of complications. This technique can be used in less serious cases in conjunction with other equally easy techniques. Because of its simplicity, this technique also allows younger, less experienced, surgeons to approach this type of surgery with the necessary peace of mind.
- MeSH
- gigantismus chirurgie MeSH
- lidé MeSH
- mamoplastika metody MeSH
- prsy MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
Mitochondrial NADPH-dependent isocitrate dehydrogenase, IDH2, and cytosolic IDH1, catalyze reductive carboxylation of 2-oxoglutarate. Both idh2 and idh1 monoallelic mutations are harbored in grade 2/3 gliomas, secondary glioblastomas and acute myeloid leukemia. Mutant IDH1/IDH2 enzymes were reported to form an oncometabolite r-2-hydroxyglutarate (2HG), further strengthening malignancy. We quantified CO2-dependent reductive carboxylation glutaminolysis (RCG) and CO2-independent 2HG production in HTB-126 and MDA-MB-231 breast carcinoma cells by measuring (13)C incorporation from 1-(13)C-glutamine into citrate, malate, and 2HG. For HTB-126 cells, (13)C-citrate, (13)C-malate, and (13)C-2-hydroxyglutarate were enriched by 2-, 5-, and 15-fold at 5mM glucose (2-, 2.5-, and 13-fold at 25 mM glucose), respectively, after 6 h. Such enrichment decreased by 6% with IDH1 silencing, but by 30-50% upon IDH2 silencing while cell respiration and ATP levels rose up to 150%. Unlike 2HG production RCG declined at decreasing CO2. At hypoxia (5% O2), IDH2-related and unrelated (13)C-accumulation into citrate and malate increased 1.5-2.5-fold with unchanged IDH2 expression; whereas hypoxic 2HG formation did not. (13)C-2HG originated by ∼50% from other than IDH2 or IDH1 reactions, substantiating remaining activity in IDH1&2-silenced cells. Relatively high basal (12)C-2HG levels existed (5-fold higher vs. non-tumor HTB-125 cells) and (13)C-2HG was formed despite the absence of any idh2 and idh1 mutations in HTB-126 cells. Since RCG is enhanced at hypoxia (frequent in solid tumors) and 2HG can be formed without idh1/2 mutations, we suggest 2HG as an analytic marker (in serum, urine, or biopsies) predicting malignancy of breast cancer in all patients.
- MeSH
- glutaráty metabolismus MeSH
- hypoxie buňky fyziologie MeSH
- isocitrátdehydrogenasa genetika metabolismus MeSH
- kyslík metabolismus MeSH
- lidé MeSH
- nádorové biomarkery genetika metabolismus MeSH
- nádorové buněčné linie MeSH
- nádory prsu enzymologie genetika metabolismus MeSH
- parciální tlak MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tiaprofenic acid is a widely used anti-inflammatory drug; however, the reductive metabolism of tiaprofenic acid is not yet well understood. Here, we compared the reduction of tiaprofenic acid in microsomes and cytosol from the human liver. The microsomes exhibited lower Km value toward tiaprofenic acid than the cytosol (Km = 164 ± 18 μM vs. 569 ± 74 μM, respectively), whereas the cytosol showed higher specific activity during reduction than the microsomes (Vmax = 728 ± 52 pmol mg of protein-1 min-1 vs. 285 ± 11 pmol mg of protein-1 min-1, respectively). Next, a panel of recombinant carbonyl reducing enzymes from AKR and SDR superfamilies has been studied to find the enzymes responsible for the cytosolic reduction of tiaprofenic acid. CBR1 was identified as the reductase of tiaprofenic acid with high specific activity (56,965 ± 6741 pmol mg of protein-1 min-1). Three other enzymes, AKR1A1, AKR1B10, and AKR1C4, were also able to reduce tiaprofenic acid, but with very low activity. Thus, CBR1 was shown to be a tiaprofenic acid reductase in vitro and was also suggested to be the principal tiaprofenic acid reductase in vivo.
- MeSH
- alkoholoxidoreduktasy chemie genetika metabolismus MeSH
- biokatalýza MeSH
- cytosol enzymologie MeSH
- dehydrogenasy/reduktasy s krátkým řetězcem chemie genetika metabolismus MeSH
- játra enzymologie metabolismus MeSH
- kinetika MeSH
- lidé MeSH
- mikrozomy enzymologie MeSH
- propionáty chemie metabolismus MeSH
- rekombinantní proteiny biosyntéza chemie izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- benz(a)anthraceny * metabolismus MeSH
- látky znečišťující životní prostředí MeSH
- lidé MeSH
- mutageny * MeSH
- NAD(P)H dehydrogenasa (chinon) MeSH
- NADPH-cytochrom c-reduktasa MeSH
- vysokoúčinná kapalinová chromatografie metody využití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Chirurgické riešenie ťažkého pľúcneho emfyzému je vážnou kapitolou hrudníkovej chirurgie. Pre anesteziológa títo pacienti predstavujú vysoké riziko peroperačných komplikácií, ktoré vyplývajú z patofyziológie ochorenia. Hemodynamicky je u pacientov s ťažkým emfyzémom výrazný nárast pľúcnej vaskulárnej rezistencie z rozvratu mikrocirkulácie - strata integrity alveolovej steny, strata pľúcnych kapilár. Odpor v pľúcnom krvnom riečisku u pacientov S emfyzémom je v tesnom a nepriamo úmernom vzťahu k DᶫCO, čo naznačuje, že ťažká porucha výmeny plynov je doležitým prekurzorom pľúcnej hypertenzie. Pozornosť upriamujeme na predoperačný, peroperačný a pooperačný manažment prípravy, monitorovania ventilácie a pooperačnej starostlivosti o pacientov, ktorí sa podrobia obojstrannej objemovej pľúcnej redukcii.
Surgical management of extensive pulmonary emphysema is a difficult task in thoracic surgery. From the anesthesiologist's point of view these patients present a high risk of perioperative complications group which result from the pathophysiology of the disease. Hemodynamically these patients have a significant increase of vascular resistance caused by a break - loss of lung capillars. Pulmonary vascular resistance in patients with emphysema is in a close and indirect relation to DᶫCO, which suggest that serious gas exchange disturbance is an important predictor of pulmonary hypertension. We pay attention to pre-, peri- and postoperative management, ventilation monitoring and postoperative care in patients who undergo bilateral lung volume reduction.
In the presence of a Pd catalyst and a base, 6- and 2-iodopurine derivatives undergo reductive C-C dimerization with the formation of the corresponding 6,6'- or 2,2'-dimers. The best results of the dimerization were obtained in the presence of i-Pr2NEt as a base in DMF. Phosphine-free catalysts as well as catalysts containing phosphines can be used. In the presence of catalytic systems containing PPh3 the dimerization does not proceed. This dimerization may become an important side reaction in the Stille or the Suzuki-Miyaura reactions of iodopurines.
