Effective Oral Indicators With Medical and Dental Collaboration in Open Heart Surgery: A Representative Survey.

Purpose Postoperative infections pose an important problem for patients with cardiac disease. Moreover, oral health status is associated with the risk of longer hospital stays. Therefore, the oral health status of patients was assessed before open-heart surgery. This study aimed to determine the relationship between oral health status and postoperative status. Methods The study included 25 patients who underwent open-heart surgery at our university hospital in 2020. Upon admission, dentists conducted an oral examination and assessed the oral health status of the patients, also using the Japanese version of the Oral Health Assessment Tool (OHAT-J), Revised Oral Assessment Guide (ROAG), oral moisture level, oral bacteria, and other relevant factors. The study investigated the association with postoperative status. Findings Significant postoperative infections were found in patients aged ≥70 years, with an OHAT-J score of ≥5, OHAT-J lip score of ≥1, Streptococcus γ count of 1.0 × 10^6 or higher (CFU/mL), and increased Streptococcus γ before and after surgery. The duration of hospitalization correlated with the OHAT-J, OHAT-J gum and tissue, and ROAG scores. The duration of intensive care unit (ICU) stays correlated with the OHAT-J score. Conclusions The study demonstrates that OHAT-J scores are linked with predicting not just postoperative infection but also the length of hospitalization and ICU stay. As OHAT-J scores do not necessitate specialized dental instruments, they are straightforward and beneficial for healthcare professionals outside of dentistry.

Humanization and characterization of an anti-ciguatoxin CTX3C monoclonal antibody.

Ciguatera poisoning (CP), caused by ciguatoxins (CTXs), is one of the most common food-borne diseases, affecting more than 50,000 people each year. In most cases, CP are managed with symptomatic and supportive remedies, and no specific treatment has been devised. In this study, toward the development of therapeutic antibodies for CP, we examined to humanize mouse anti-CTX3C antibody 10C9 (m10C9), which exhibited neutralizing activity against ciguatoxin in vitro and in vivo. The complementarity determining regions were grafted onto a human germline sequence with high sequence identity to m10C9, and the backmutations were examined to maintain the binding affinity. The optimized humanized antibody, Opt.h10C9Fab, showed a strong binding affinity to CTX3C with a high affinity (KD = 19.0 nM), and only two backmutations of ArgL46 and CysH94 in the framework regions were involved in determining the antigen binding affinity.

Fukuoka: Adapting to climate change through urban green space and the built environment?

This paper profiles Fukuoka City in Kyushu, Japan. We focus on the city's local climate change adaptation policies, and in particular the role of urban and greenspace planning in facilitating adaptation actions within Fukuoka. Fukuoka is a humid subtropical city which is currently experiencing significant population and economic growth. It has also made comparatively rigorous advances in climate adaptation, in a country context where local governments have been criticised for focusing more on mitigation. Fukuoka hence may yield lessons for other rapidly urbanising subtropical Asian cities. We illustrate that Fukuoka has a long tradition of science-policy connection towards the creation of a liveable urban environment. This creates a favourable research and policy infrastructure for adaptation, in particular mitigation of heat risk. This is evidenced in consideration of climate issues within the city's greenspace plans since the 1990s, and in an extensive body of underpinning applied research from local institutions into urban thermal environments in particular. Fukuoka's green terraced ACROS building has come to symbolise adaptation via the built environment, and has been followed by the emergence of further green roofs and through citizen and private sector involvement in smaller-scale greening actions. We caution that challenges remain around connecting different sections of local governments, and in maintaining climate and environmental imperatives in the face of ongoing development and expansion pressures.

Negative feedback regulation of ErbB4 tyrosine kinase activity by ERK-mediated non-canonical phosphorylation.

ErbB4 receptor tyrosine kinase has four different isoforms that are classified based on variants in the extracellular juxtamembrane domain (JM-a and JM-b) and the C-terminal region (CYT-1 and CYT-2). Here, we used the JM-b/CYT-1 isoform to investigate the roles of serine/threonine phosphorylation in MEK-ERK-dependent feedback inhibition. TPA as an activator of the ERK pathway markedly induced ErbB4 phosphorylation at Thr-674, the conserved common feedback site in the intracellular JM domain, which resulted in the downregulation of tyrosine autophosphorylation. We also identified Ser-1026 as an ErbB4-specific ERK target site in the CYT-1 region. Moreover, double mutations (Thr-674/Ser-1026 to Ala) significantly upregulated ErbB4 activation, indicating that Thr-674 and Ser-1026 are cooperatively involved in negative feedback regulation. Given the fact that ErbB4 mutation is one of the most common genetic alterations in melanoma cells, we demonstrated that a typical oncogenic ErbB4 mutant was resistant to the negative feedback regulation to maintain a highly active status of tyrosine kinase activity. Together, these findings indicate that feedback mechanisms are key switches determining oncogenic potentials of ErbB receptor kinases.

Structures of endo-1,5-α-L-arabinanase mutants from Bacillus thermodenitrificans TS-3 in complex with arabino-oligosaccharides.

The thermostable endo-1,5-α-L-arabinanase from Bacillus thermodenitrificans TS-3 (ABN-TS) hydrolyzes the α-1,5-L-arabinofuranoside linkages of arabinan. In this study, the crystal structures of inactive ABN-TS mutants, D27A and D147N, were determined in complex with arabino-oligosaccharides. The crystal structures revealed that ABN-TS has at least six subsites in the deep V-shaped cleft formed across one face of the propeller structure. The structural features indicate that substrate recognition is profoundly influenced by the remote subsites as well as by the subsites surrounding the active center. The `open' structure of the substrate-binding cleft of the endo-acting ABN-TS is suitable for the random binding of several sugar units in polymeric substrates.

Robust Surface Plasmon Resonance Chips for Repetitive and Accurate Analysis of Lignin-Peptide Interactions.

We have developed novel surface plasmon resonance (SPR) sensor chips whose surfaces bear newly synthesized functional self-assembled monolayer (SAM) anchoring lignin through covalent chemical bonds. The SPR sensor chips are remarkably robust and suitable for repetitive and accurate measurement of noncovalent lignin-peptide interactions, which is of significant interest in the chemical or biochemical conversion of renewable woody biomass to valuable chemical feedstocks. The lignin-anchored SAMs were prepared for the first time by click chemistry based on an azide-alkyne Huisgen cycloaddition: mixed SAMs are fabricated on gold thin film using a mixture of alkynyl and methyl thioalkyloligo(ethylene oxide) disulfides and then reacted with azidated milled wood lignins to furnish the functional SAMs anchoring lignins covalently. The resulting SAMs were characterized using infrared reflection-absorption, Raman, and X-ray photoelectron spectroscopies to confirm covalent immobilization of the lignins to the SAMs via triazole linkages and also to reveal that the SAM formation induces a helical conformation of the ethylene oxide chains. Further, SPR measurements of the noncovalent lignin-peptide interactions using lignin-binding peptides have demonstrated high reproducibility and durability of the prepared lignin-anchored sensor chips.

Site-Directed Chemical Mutations on Abzymes: Large Rate Accelerations in the Catalysis by Exchanging the Functionalized Small Nonprotein Components.

Taking advantage of antibody molecules to generate tailor-made binding sites, we propose a new class of protein modifications, termed as "site-directed chemical mutation." In this modification, chemically synthesized catalytic components with a variety of steric and electronic properties can be noncovalently and nongenetically incorporated into specific sites in antibody molecules to induce enzymatic activity. Two catalytic antibodies, 25E2 and 27C1, possess antigen-combining sites which bind catalytic components and act as apoproteins in catalytic reactions. By simply exchanging these components, antibodies 25E2 and 27C1 can catalyze a wide range of chemical transformations including acyl-transfer, ß-elimination, aldol, and decarboxylation reactions. Although both antibodies were generated with the same hapten, phosphonate diester 1, they showed different catalytic activity. When phenylacetic acid 4 was used as the catalytic component, 25E2 efficiently catalyzed the elimination reaction of ß-haloketone 2, whereas 27C1 showed no catalytic activity. In this work, we focused on the ß-elimination reaction and examined the site-directed chemical mutation of 27C1 to induce activity and elucidate the catalytic mechanism. Molecular models showed that the cationic guanidyl group of ArgH52 in 27C1 makes a hydrogen bond with the P═O oxygen in the hapten. This suggested that during ß-elimination, ArgH52 of 27C1 would form a salt bridge with the carboxylate of 4, thus destroying reactivity. Therefore, we utilized site-directed chemical mutation to change the charge properties of the catalytic components. When amine components 7-10 were used, 27C1 efficiently catalyzed the ß-elimination reaction. It is noteworthy that chemical mutation with secondary amine 8 provided extremely high activity, with a rate acceleration [(kcat/Km 2)/kuncat] of 1 000 000. This catalytic activity likely arises from the proximity effect, plus general-base catalysis associated the electrostatic interactions. In 27C1, the cationic guanidyl group of ArgH52 is spatially close to the nitrogen of the amine components. In this microenvironment, the intrinsic pKa of the amine is perturbed and shifts to a lower pKa, which efficiently abstracts the α-proton during the reaction. This mechanism is consistent with the observed kinetic isotope effect (E2 or E1cB mechanism). Thus, site-directed chemical mutation provides a better understanding of enzyme functions and opens new avenues in biocatalyst research.

Discovery of 12-mer peptides that bind to wood lignin.

Lignin, an abundant terrestrial polymer, is the only large-volume renewable feedstock composed of an aromatic skeleton. Lignin has been used mostly as an energy source during paper production; however, recent interest in replacing fossil fuels with renewable resources has highlighted its potential value in providing aromatic chemicals. Highly selective degradation of lignin is pivotal for industrial production of paper, biofuels, chemicals, and materials. However, few studies have examined natural and synthetic molecular components recognizing the heterogeneous aromatic polymer. Here, we report the first identification of lignin-binding peptides possessing characteristic sequences using a phage display technique. The consensus sequence HFPSP was found in several lignin-binding peptides, and the outer amino acid sequence affected the binding affinity of the peptides. Substitution of phenylalanine7 with Ile in the lignin-binding peptide C416 (HFPSPIFQRHSH) decreased the affinity of the peptide for softwood lignin without changing its affinity for hardwood lignin, indicating that C416 recognised structural differences between the lignins. Circular dichroism spectroscopy demonstrated that this peptide adopted a highly flexible random coil structure, allowing key residues to be appropriately arranged in relation to the binding site in lignin. These results provide a useful platform for designing synthetic and biological catalysts selectively bind to lignin.

High-resolution structure of exo-arabinanase from Penicillium chrysogenum.

Arabinanase Abnx from Penicillium chrysogenum 31B, which belongs to the GH93 family, releases arabinobiose from the nonreducing terminus of α-1,5-L-arabinan, which is distributed in the primary cell walls of higher plants. Crystal structures of Abnx and of its complex with arabinobiose were determined at the high resolutions of 1.14 Što an R(work) of 10.7% (R(free) = 12.8%) and 1.04 Što an R(work) of 10.4% (R(free) = 12.5%). Abnx has a six-bladed ß-propeller fold with a typical ring-closure mode called `Velcro', in which the last four-stranded ß-sheet is completed by the incorporation of a strand from the N-terminus. Catalytic residues which act as a nucleophile and an acid/base were proposed from the structures and confirmed by site-directed mutagenesis. The substrate-binding groove is enclosed at one end by two residues, Glu64 and Tyr66, which contribute to the recognition of the nonreducing chain end of the polysaccharide. A comparison with the related enzyme Arb93A which has a quite similar overall structure suggested that Abnx has different mechanisms to funnel substrates to the active site and/or to stabilize the transition state.

Luminescence imaging of regenerating free bone graft in rats.

BACKGROUND: Bone transplantation is an important procedure often used for bone defect reconstruction after trauma and malignancies. However, the kinetics of free bone graft-derived cells remains unclarified. The authors examined the kinetics of graft-derived cells using transgenic rats systemically expressing firefly luciferase. METHODS: Free iliac bone grafts (5 × 5 × 2 mm, n = 10) derived from luciferase transgenic rats were transplanted into the subcutaneous space of the back of wild-type Lewis rats, and the kinetics of graft-derived cells were evaluated over time by determining the level of luminescence emission. RESULTS: Although the luminescence level emitted by luciferase decreased after transplantation, a substantial luminescence level (mean, 1.6 × 10(7) photons/second) was emitted from donor-derived cells even at 180 days after transplantation, suggesting a long-term survival of graft-derived cells. In a computed tomographic image analysis of bone grafts retrieved 180 days after transplantation, high-luminescence grafts with a sufficient number of viable graft-derived cells (mean, 2.6 × 10(7) photons/second; n = 4) showed significantly higher bone graft volume (3.1-fold) and polar moment of inertia of area (7.2-fold) than low-luminescence grafts (mean, 1.0 × 10(7) photons/second; n = 4), indicating that high-luminescence grafts maintain better conditions. CONCLUSION: These results suggest that bone graft-derived cells can survive for a long time and that the presence of a sufficient number of viable graft-derived cells is essential for graft engraftment and remodeling.

Tris(hydroxymethyl)aminomethane induces conformational change and crystal-packing contraction of porcine pancreatic elastase.

Porcine pancreatic elastase (PPE) was crystallized under new sulfate-free conditions containing 0.3 M NaCl and 50 mM tris(hydroxymethyl)aminomethane-HCl at pH 7.0. The crystal structure determined at 1.5 angstroms resolution had a unique conformation in four regions which contained loop portions. A chloride ion was bound near the catalytic triad instead of the sulfate ion in PDB entry 1qnj, a typical PPE crystal structure. However, the chloride ion did not affect the configuration of the catalytic triad. A tris(hydroxymethyl)aminomethane (Tris) molecule was bound to the S4 and S5 subsites in place of the adjacent molecule in the 1qnj crystal and played a significant role in the structural change of the region. The distortion in this region may subsequently have induced conformational changes in the other three regions. The fact that Tris and these four regions make a diagonal line in the ac plane may have affected the crystal-packing contraction along the a and c axes in the crystal compared with the typical crystal.

Structural basis for thermostability of endo-1,5-alpha-L-arabinanase from Bacillus thermodenitrificans TS-3.

The crystal structure of a thermostable endo-1,5-alpha-L-arabinanase, ABN-TS, from Bacillus thermodenitrificans TS-3 was determined at 1.9 A to an R-factor of 18.3% and an R-free-factor of 22.5%. The enzyme molecule has a five-bladed beta-propeller fold. The substrate-binding cleft formed across one face of the propeller is open on both sides to allow random binding of several sugar units in the polymeric substrate arabinan. The beta-propeller fold is stabilized through a ring closure. ABN-TS exhibits a new closure-mode involving residues in the N-terminal region: Phe7 to Gly21 exhibit hydrogen bonds and hydrophobic interactions with the first and last blades, and Phe4 links the second and third blades through a hydrogen bond and an aromatic stacking interaction, respectively. The role of the N-terminal region in the thermostability was confirmed with a mutant lacking 16 amino acid residues from the N-terminus of ABN-TS.

Crystallization and preliminary X-ray diffraction analysis of a thermostable endo-1,5-alpha-L-arabinanase from Bacillus thermodenitrificans TS-3.

A thermostable endo-1,5-alpha-L-arabinanase ABN-TS from Bacillus thermodenitrificans TS-3 with a molecular weight of 35 kDa was crystallized by the hanging-drop vapour-diffusion method using sodium citrate as a precipitant. The crystals were loop-mounted in a cryoprotectant solution containing 28%(w/v) sucrose and 1 M sodium citrate pH 6.0 and flash-cooled. Sucrose was selected as the most suitable cryoprotectant. The crystal belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 40.3, b = 77.8, c = 89.7 angstroms. The calculated VM based on one molecule per asymmetric unit was 2.0 angstroms3 Da(-1). A complete data set from a frozen crystal was collected to 1.9 angstroms resolution using synchrotron radiation at SPring-8. A molecular-replacement solution was obtained using the structure of alpha-arabinanase 43A from Cellvibrio japonicus.

Molecular cloning of the gene encoding thermostable endo-1,5-alpha-L-arabinase of Bacillus thermodenitrificans TS-3 and its expression in Bacillus subtilis.

The gene that encodes a thermostable endo-arabinase (called ABN-TS) from Bacillus thermodenitrificans TS-3 was cloned, sequenced, and expressed in the mesophilic B. subtilis. The gene contained an open reading frame consists of 939 bp, which encodes 313 amino acids. The deduced amino acid sequence of the enzyme showed 50, 46, and 36% similarity with endo-arabinase from B. subtilis IFO 3134 (PPase-C), Pseudomonas fluorescens (ArbA), and Aspergillus niger (ABNA), respectively. The hydrophobic and acidic amino acids making up ABN-TS outnumbered those in PPase-C. The gene product expressed in B. subtilis, as the host, had substantially the same characteristics, and was stable up to 70 degrees C, and the reaction was optimal around 70 degrees C, as well as native ABN-TS.