Risks of Muscle Atrophy in Patients with Malignant Lymphoma after Autologous Stem Cell Transplantation

Objective: Muscle atrophy is associated with autologous stem cell transplantation (ASCT)-related outcomes in patients with malignant lymphoma (ML). However, the impact of ASCT on muscle mass remains unclear in patients with ML. The aims of this study were to investigate changes in muscle mass and risk profiles for muscle atrophy after ASCT. Method: We enrolled 40 patients with refractory ML (age 58 [20-74] years, female/male 16/24, body mass index (BMI) 21.1 kg/m² [17.1-29.6]). Psoas muscle mass was assessed using the psoas muscle index (PMI) before and after ASCT. Statistical analysis used: Independent factors associated with a severe decrease rate of change in PMI were evaluated by decision-tree analysis, respectively. Results: PMI was significantly decreased after ASCT (4.61 vs. 4.55 cm²/m²; P=0.0425). According to the decision-tree analysis, the regimen was selected as the initial split. The rates of change in PMI were −5.57% and −3.97% for patients administered MCEC and LEED, respectively. In patients who were administered LEED, the second branching factor was BMI. In patients with BMI < 20.3 kg/m², the rate of change in PMI was −7.16%. On the other hand, the rate of change in PMI was 4.05% for patients with BMI ≥ 20.3 kg/m². Conclusion: We demonstrated that muscle mass decreased after ASCT in patients with ML. Patients who received MCEC and patients with low BMI were at risk for a decrease in muscle mass.     

“Helix-in-Helix” Superstructure Formation through Encapsulation of Fullerene-Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

A one-handed 3₁₀-helical hexapeptide is efficiently encapsulated within the helical cavity of st-PMMA when a fullerene (C₆₀) derivative is introduced at the C-terminal end of the peptide. The encapsulation is accompanied by induction of a preferred-handed helical conformation in the st-PMMA backbone with the same-handedness as that of the hexapeptide to form a crystalline st-PMMA/peptide-C₆₀ inclusion complex with a unique optically active helix-in-helix structure. Although the st-PMMA is unable to encapsulate the 3₁₀-helical peptide without the terminal C₆₀ unit, the helical hollow space of the st-PMMA is almost filled by the C₆₀-bound peptides. This result suggests that the C₆₀ moiety can serve as a versatile molecular carrier of specific molecules and polymers in the helical cavity of the st-PMMA for the formation of an inclusion complex, thus producing unique supramolecular soft materials that cannot be prepared by other methods.     

Remote Control of the Planar Chirality in Peptide‐Bound Metallomacrocycles and Dynamic‐to‐Static Planar Chirality Control Triggered by Solvent‐Induced 310‐to‐α‐Helix Transitions

The dynamic planar chirality in a peptide‐bound Ni^II‐salphen‐based macrocycle can be remotely controlled. First, a right‐handed (P)‐3₁₀‐helix is induced in the dynamic helical oligopeptides by a chiral amino acid residue far from the macrocyclic framework. The induced planar chirality remains dynamic in chloroform and acetonitrile, but is almost completely locked in fluoroalcohols as a result of the solvent‐induced transition of the peptide chains from a 3₁₀‐helix to a wider α‐helix, which freezes the rotation of the pendant peptide units around the macrocycle.     

Hydration and phase separation of temperature-sensitive water-soluble polymers

Collapse of a poly(N-isopropylacrylamide)(PNIPAM) chain upon heating and phase diagrams of aqueous PNIPAM solutions with very flat LCST phase separation line are theoretically studied on the basis of cooperative dehydration(simultaneous dissociation of bound water molecules in a group of correlated sequence),and compared with the experimental observation of temperature-induced coil-globule transition by light scattering methods.The transition becomes sharper with the cooperativity parameterσof hydration.Reentrant coil-globule-coil transition in mixed solvent of water and methanol is also studied from the viewpoint of competitive hydrogen bonds between polymer-water and polymer-methanol. The downward shift of the cloud-point curves(LCST cononsolvency) with the mole fraction of methanol due to the competition is calculated and compared with the experimental data.Aqueous solutions of hydophobically-modified PNIPAM carrying short alkyl chains at both chain ends(telechelic PNIPAM) are theoretically and experimentally studied.The LCST of these solutions is found to shift downward along the sol-gel transition curve as a result of end-chain association (association-induced phase separation),and separate from the coil-globule transition line.Associated structures in the solution,such as flower micelles,mesoglobules and higher fractal assembly,are studied by USANS with theoretical modeling of the scattering function.     

Theoretical studies on model reaction pathways of prostaglandin H<Subscript>2</Subscript> isomerization to prostaglandin D<Subscript>2</Subscript>/E<Subscript>2</Subscript>

Model reaction mechanisms in the biosynthesis of prostaglandin D₂ (PGD₂) and prostaglandin E₂ (PGE₂) from prostaglandin H₂ with PGD₂/E₂ synthase were examined using the ab initio second-order Møller–Plesset perturbation method and density functional theory. The reaction was modeled similar to the isomerization of 2,3-dioxabicyclo[2.2.1]heptane to 3-hydroxycyclopentanone in the presence of MeS^?. An explicit solvation of two H₂O molecules was also considered, and two probable types of reaction mechanisms were demonstrated. One mechanism starts with proton abstraction from an oxygen-bound carbon at the endoperoxide by a thiolate ion and the other is stepwise and involves attack of a thiolate anion on an oxygen of the endoperoxide group in the first step with protonation of the other oxygen, followed by deprotonation from a carbon-attached oxygen to break an O–S bond to yield PGD₂ or PGE₂. We also found that the mPW1LYP hybrid method was superior to the B3LYP functional for systems with respect to the state-of-the-art CCSD(T) energetics.     

A new synthetic strategy for catechin-class polyphenols: concise synthesis of (-)-epicatechin and its 3-O-gallate

Concise synthesis of (-)-epicatechin and its 3-O-gallate is described, illustrating efficacy of the new strategy for catechin-class polyphenols based on assembly of lithiated fluorobenzene and epoxy alcohol followed by a pyran cyclization. 1,3,5-Trifluorobenzene serves as the A-ring equivalent for functionalization and the pyran annulation.     

An electrospray-ionization mass spectrometry analysis of the pH-dependent dissociation and denaturation processes of a heterodimeric protein

Electrospray ionization mass spectrometry (ESI-MS) was applied to the analysis of the dissociation and denaturation processes of a heterodimeric yeast killer toxin SMKT. The two distinct subunits of SMKT noncovalently associate under acidic conditions, but become dissociated and denatured under neutral and basic conditions. In order to understand the unique pH-dependent denaturation mechanism of this protein, a pH titration was performed by utilizing ESI-MS. The molecular ions of the heterodimer which possesses the highly ordered structure, were mainly observed below pH 4.6. However, the two subunits immediately dissociated at this pH. The spectra measured with various settings of the mass spectrometer indirectly demonstrated that the pH-dependent dissociation occurs in the liquid phase. The current result as well as the three-dimensional structure of SMKT suggest that the deprotonation of a specific carboxyl group triggers a cooperative dissociation process of this protein. In conclusion, the pH titration of a protein by ESI-MS is particularly effective, when the unfolding process or the biological function of the protein is related to the interaction with other molecules.     

Alkaline metal ion-enhanced chemiluminescence of bicyclic dioxetanes bearing a hydroxyaryl group with an ‘even’ substitution pattern

Bicyclic dioxetane 5 bearing a 3-hydroxynaphthalen-2-yl group and its analogs 14 and 15 decomposed to give light with efficiencies of only 0.002-0.005% in a tetrabutylammonium fluoride (TBAF)/THF system, which was as expected for dioxetanes with a so-called ‘even’ substitution pattern. However, the chemiluminescence efficiencies (Φ^CL) markedly increased when these dioxetanes were decomposed with alkaline metal t-butoxide in THF. This enhancement of Φ^CL by alkaline metal ion was most likely due to the highly ordered conformation of an aromatic ring by chelate formation of the metal ion with both an oxido anion and oxygen atom of a tetrahydrofuran ring in an intermediary dioxetane like 12. Alkaline metal ion-enhanced chemiluminescence was similarly observed for dioxetane 6 bearing a 2-hydroxyphenyl group.     

Spectral analysis of scattered light from flowers’ petals

A new method was developed for studying absorption characteristics of opaque samples based on the light scattering spectroscopy. Measurements were made in white, red and violet petals of Petunia hybrida, and gave the absorption spectra in a non-destructive manner without damaging the cell structures of the petal. The red petal has absorption peak at 550 nm and the violet has three absorption peaks: at 450, 670, and 550 nm. The results were discussed in correlation with the microscopic cell structures of the petal observed with optical microscope and transmission electron microscopy (TEM). Only the cells placed in the surface have the pigments giving the color of the petal.