The CO-fixing enzyme rubisco is responsible for almost all carbon fixation. This process frequently requires rubisco activase (Rca) machinery, which couples ATP hydrolysis to the removal of inhibitory sugar phosphates, including the rubisco substrate ribulose 1,5-bisphosphate (RuBP). Rubisco is sometimes compartmentalized in carboxysomes, bacterial microcompartments that enable a carbon dioxide concentrating mechanism (CCM).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2020
The vast majority of biological carbon dioxide fixation relies on the function of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). In most cases the enzyme exhibits a tendency to become inhibited by its substrate RuBP and other sugar phosphates. The inhibition is counteracted by diverse molecular chaperones known as Rubisco activases (Rcas).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2019
During photosynthesis the AAA+ protein and essential molecular chaperone Rubisco activase (Rca) constantly remodels inhibited active sites of the CO-fixing enzyme Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) to release tightly bound sugar phosphates. Higher plant Rca is a crop improvement target, but its mechanism remains poorly understood. Here we used structure-guided mutagenesis to probe the Rubisco-interacting surface of rice Rca.
View Article and Find Full Text PDFBackground: Tracheostomy has traditionally been used as a means of facilitated mechanical ventilation in patients requiring respiratory management following cardiac surgery. However in the clinical setting, the advantages of tracheostomy has been questioned by concerns surrounding evidence of its association with increased risk of deep sternal wound infections (DSWI). The present study sought to evaluate retrospectively our experience with post-sternotomy tracheostomy among cardiac surgery patients and association with DSWI.
View Article and Find Full Text PDFBackground: With improving technologies and an increasingly elderly populations, there have been an increasing number of therapeutic options available for patients requiring aortic valve replacement. Recent evidence suggests that transcatheter aortic valve implantation (TAVI) is one suitable option for high risk inoperable patients, as well as high risk operable patients. Sutureless valve technology has also been developed concurrently, with facilitates surgical aortic valve replacement (SUAVR) by allow resection and replacement of the native aortic valve with minimal sutures and prosthesis anchoring required.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2016
The photosynthetic CO-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) is inhibited by nonproductive binding of its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates. Reactivation requires ATP-hydrolysis-powered remodeling of the inhibited complexes by diverse molecular chaperones known as rubisco activases (Rcas). Eukaryotic phytoplankton of the red plastid lineage contain so-called red-type rubiscos, some of which have been shown to possess superior kinetic properties to green-type rubiscos found in higher plants.
View Article and Find Full Text PDFObjectives Heartworm-associated respiratory disease (HARD) is a recently recognised pathological manifestation in cats caused by Dirofilaria immitis exposure. This study aimed to estimate the percentage of cats at risk of developing HARD in a heartworm-endemic area (Taipei, Taiwan), and to test the correlation of heartworm exposure and the presence of lower airway/lung clinical signs (LA/L signs). Methods This was a prospective case-control study.
View Article and Find Full Text PDFThe colloidal complexes composed of grape seed proanthocyanidin (GSP) and gelatin (GLT), as natural antioxidants to improve stability and inhibit lipid oxidation in menhaden fish oil emulsions, were evaluated. The interactions between GSP and GLT, and the chemical structures of GSP/GLT self-assembled colloidal complexes, were characterized by isothermal titration calorimetry (ITC), circular dichroism (CD), and Fourier transform infrared spectroscopic (FTIR) studies. Fish oil was emulsified with GLT to obtain an oil-in-water (o/w) emulsion.
View Article and Find Full Text PDFRibulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) is responsible for almost all biological CO2 assimilation, but forms inhibited complexes with its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates. The distantly related AAA+ proteins rubisco activase and CbbX remodel inhibited rubisco complexes to effect inhibitor release in plants and α-proteobacteria, respectively. Here we characterize a third class of rubisco activase in the chemolithoautotroph Acidithiobacillus ferrooxidans.
View Article and Find Full Text PDFAnn Cardiothorac Surg
March 2015
Background: Sutureless aortic valve replacement (SU-AVR) has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to reduce cross-clamp and cardiopulmonary bypass (CPB) duration and thereby improve surgical outcomes and facilitate a minimally invasive approach suitable for higher risk patients. The present systematic review and meta-analysis aims to assess the safety and efficacy of SU-AVR approach in the current literature.
View Article and Find Full Text PDFBackground: Establishing the relative merits of ministernotomy (MS) and minithoracotomy (MT) approaches to minimally invasive aortic valve replacement (MIAVR) is difficult given the limited available direct evidence. Network meta-analysis is a Bayesian approach that can combine direct and indirect evidence to better define the benefits and risks of MS and MT.
Methods: Electronic searches were performed using six databases from their inception to June 2014.
J Cardiothorac Vasc Anesth
February 2016
Objective: To evaluate the effect of extracorporeal membrane oxygenation (ECMO) on survival and complication rates in adults with refractory cardiogenic shock or cardiac arrest.
Design: Meta-analysis.
Setting: University hospitals.
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the key enzyme involved in photosynthetic carbon fixation, converting atmospheric CO2 to organic compounds. Form I Rubisco is a cylindrical complex composed of eight large (RbcL) subunits that are capped by four small subunits (RbcS) at the top and four at the bottom. Form I Rubiscos are phylogenetically divided into green- and red-type.
View Article and Find Full Text PDFAims: Surgical ablation performed concomitantly with cardiac surgery has emerged as an effective curative strategy for atrial fibrillation (AF). Left atrial (LA) lesion sets for ablation have been suggested to reduce procedural times and post-surgical bradycardia compared with biatrial (BA) lesions. Given the inconclusive literature regarding BA vs.
View Article and Find Full Text PDFObjectives: Concomitant left atrial appendage occlusion (LAAO) during surgical ablation has emerged as a potential treatment strategy to reduce stroke and perioperative mortality in patients with atrial fibrillation (AF). The present meta-analysis aims to assess current evidence on the efficacy and safety between LAAO and LAA preservation cohorts for patients undergoing cardiac surgery.
Methods: Electronic searches were performed using six electronic databases from their inception to November 2013, identifying all relevant comparative randomized and observational studies comparing LAAO with non-LAAO in AF patients undergoing cardiac surgery.
Catalase is an antioxidant enzyme abundant in natural resources. However, the enzyme is usually inactivated by gastric acid and digestive enzymes after oral ingestion. In this study, carboxymethyl chitosan (CM-chitosan) and hyaluronic acid (HA) conjugate hydrogel microspheres have been prepared by an emulsion cross-linking technique to retain the activity of catalase in simulated gastrointestinal (GI) fluids.
View Article and Find Full Text PDFAscorbic acid occurs naturally in many wine-making fruits. The industry also uses ascorbic acid as an antioxidant and color stabilizer in the making of alcoholic beverages including white wine, wine cooler, alcopop, and fruit liqueur. However, the degradation of ascorbic acid itself may cause browning and the deterioration of color quality.
View Article and Find Full Text PDFThe chloroplast chaperonin system of plants and green algae is a curiosity as both the chaperonin cage and its lid are encoded by multiple genes, in contrast to the single genes encoding the two components of the bacterial and mitochondrial systems. In the green alga Chlamydomonas reinhardtii (Cr), three genes encode chaperonin cofactors, with cpn10 encoding a single ∼10-kDa domain and cpn20 and cpn23 encoding tandem cpn10 domains. Here, we characterized the functional interaction of these proteins with the Escherichia coli chaperonin, GroEL, which normally cooperates with GroES, a heptamer of ∼10-kDa subunits.
View Article and Find Full Text PDFThe characteristics of recovery from total intravenous anesthesia (TIVA) with propofol and inhalation anesthesia with isoflurane was clinically compared in 149 client-owned dogs that anesthetized for surgical or diagnostic procedures. In all dogs, anesthesia was induced with an intravenous injection of propofol following premedication with acepromazine or diazepam. As a result, 58 dogs anesthetized with propofol-TIVA showed slower but smoother recovery than 91 dogs anesthetized with isoflurane anesthesia.
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