Long-term outcomes of PDT for centrally-located early lung cancers with tumor diameters > 2.0 cm.

BACKGROUND: Photodynamic therapy (PDT) is used for the treatment of centrally-located early lung cancers (CLELCs) and is recommended for tumors ≤ 1.0 cm in diameter. We previously reported that PDT using talaporfin sodium, second-generation photosensitizer, for tumors > 1.0 cm but ≤ 2.0 cm in diameter was able to achieve a therapeutic outcome comparable to that of tumors with a diameter of ≤ 1.0 cm. However, the effectiveness of PDT using talaporfin sodium for tumors > 2.0 cm in diameter remains unclear. We conducted a retrospective analysis of cases in which PDT was performed for flat-type CLELCs with tumor diameters of > 2.0 cm. METHODS: We retrospectively analyzed seven cases (eight lesions) with tumor diameters > 2.0 cm and no evidence of extracartilaginous invasion or lymph node metastasis. RESULTS: All the patients underwent multiple PDT sessions. The PDT treatment results over the study period were partial response in one case (14.3 %), stable disease (SD) in three cases (42.9 %), and progressive disease (PD) in three cases (42.9 %). At the time of writing this report, five of seven cases (71.4 %) are still undergoing treatment. The duration of SD-the time from the start of treatment until the criteria for PD were met (SD or better maintained)-ranged from 7 to 52 months (mean, 25.3 months). CONCLUSIONS: "Maintenance PDT" for CLELCs > 2.0 cm in diameter has the potential to inhibit tumor progression in the long term while maintaining quality of life, rather than simply aiming only for a quick radical cure.

Organic Molecular Conductors Based on Tetramethyl-TTP: Structural and Electrical Properties Modulated by the Anion Size and Shape.

The tetramethyl derivative of bis-fused tetrathiafulvalene, 2,5-bis(4,5-dimethyl-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (TMTTP), has been successfully synthesized. Most of the radical cation salts consisting of TMTTP feature a high electrical conductivity of σrt = 101 to 102 S cm-1 on a single crystal. The anion shape and size of TMTTP conductors modulate the electrical properties. The PF6- and AsF6- salts exhibit metallic conductivity down to 10 K, while the ReO4- and AuI2- salts show metal-to-insulator (MI) transition at 126 and 11 K, respectively. Single-crystal X-ray structure analysis of (TMTTP)2X (X = PF6, AsF6, BF4, and ReO4) and (TMTTP)3AuI2 reveals that the donor packing motif is categorized as the so-called ß-type. The tight-binding band calculations of (TMTTP)2X (X = ReO4, BF4, PF6, and AsF6) suggest these salts are characterized by quasi-one-dimensional Fermi surfaces. The band calculation based on X-ray structure analysis of (TMTTP)2ReO4 at 100 K demonstrates that the MI transition of this salt is associated with the charge ordering with the zigzag stripe pattern.

Functionally modified chitotriosidase catalytic domain for chitin detection based on split-luciferase complementation.

In this study, we applied a luciferase-fragment complementation assay for chitin detection. When luciferase-fragment fused chitin-binding proteins were mixed with chitin, the reconstituted luciferase became active. The recombinant chitin-binding domain (CBD) and a functionally modified catalytic domain (CatD) of human chitotriosidase were employed for this method. We designed the CatD mutant as a chitin-binding protein with diminished chitinolytic activity. The non-wash assay using the CatD mutant had higher sensitivity than CBD for chitin detection and proved to be a structure-specific biosensor for chitin, including crude biomolecules (from fungi, mites, and cockroaches). The CatD mutant recognized a chitin-tetramer as the minimal binding unit and bound chitin at KD 99 nM. Furthermore, a sandwich ELISA using modified CatD showed a low limit of quantification for soluble chitin (13.6 pg/mL). Altogether, our work shows a reliable method for chitin detection using the potential capabilities of CatD.

New Technique for Introducing a Surgical Stapler during Robot-Assisted Lobectomy for Lung Cancer.

BACKGROUND: The da Vinci Si version robot lacks a vascular stapler that can be controlled by the operating surgeon at the surgical console when dividing pulmonary vessels. Therefore, to initiate and safely perform robotic anatomical lobectomy for lung cancer, it is important to develop a safe method for introducing a surgical stapler. METHODS: We performed a retrospective study of the first 42 consecutive patients who underwent robotic lobectomy for lung cancer at Nippon Medical School Hospital between January 2019 and December 2020. RESULTS: Up to case 18, we performed robot-assisted thoracoscopic surgery (RATS) lobectomy by using a four-arm approach with two assistant ports. For dividing pulmonary vessels, the surgical stapler was introduced through the assist ports. However, since this is not the port position usually used in video-assisted thoracoscopic surgery (VATS), there were many difficult situations. For RATS lobectomy case 19 and all subsequent cases, we utilized a total port approach that uses three robotic arms and two assistant ports. To resect the pulmonary vessels or bronchi with endoscopic staplers, the port for the robotic arm was removed and the endoscopic staplers were placed through a 12-mm Xcel bladeless port. This change reduced operation time, blood loss, and robotic arm interference. No patient developed intraoperative complications during RATS lobectomy. CONCLUSION: The present total port approach, with three robotic arms, appears to be feasible for introducing surgical staplers during RATS with the da Vinci Si robotic system.

Development of small high-voltage AC power supply for a dielectric barrier discharge plasma actuator.

A dielectric-barrier discharge plasma actuator (DBDPA) is a promising flow control device that can prevent flow separation around an airfoil using electrical discharges. Miniaturizing the DBDPA power supply remains a crucial technological challenge because its size and weight determine the performance of fluid devices equipped with this type of actuator. In this study, we propose a compact high-voltage AC power supply for a DBDPA intended for installation on small airplanes, including unmanned aerial vehicles. The power supply, which consists of a power supply board, a main control board, and a DC/AC converter board, is ∼110 g in weight. It can drive a 300-mm long DBDPA without any substantial voltage drop. The power consumption in standby remains below 1 W, and the maximum consumption during discharge in burst mode at a burst ratio of 5% is 24 W. The power supply uses a lithium-ion battery with a capacity of 1800 mA h, which allows continuous DBDPA operation for ∼1.5 h. An experiment was conducted in a wind tunnel using an airfoil model whose cross-section corresponds to that of an airfoil from a commercial glider airplane. Experimental results reveal that the surface pressure around the airfoil is modified by DBDPA operation, clearly demonstrating the effectiveness of the developed power supply for operating a DBDPA as a flow control device. The size and weight of the proposed power supply can be established as a benchmark to further miniaturize and optimize DBDPA power supplies.

[Therapeutic Strategies for Metachronous Multiple Primary Lung Cancer].

BACKGROUNDS: It is not uncommon to encounter metachronous primary lung cancer after surgical treatment along with the increase in the elderly patients. In consideration of increasing number of such patients, it is necessary to take various treatment strategies. METHODS: In order to establish a treatment strategy for multiple lung cancer, we retrospectively examined multiple lung cancer cases operated for primary lung cancer in our department from January 2013 to December 2019, and the future treatment strategy was examined. RESULTS: Of 821 patients who underwent surgery for primary lung cancer, 61 were multiple lung cancers, 31 were synchronous multiple lung cancers, and 30 were metachronous multiple lung cancers. Among the cases of metachronous multiple lung cancer, 28 cases had undergone lobectomy or more in the first operation, 1 case of segmental resection, and 1 case of partial resection. As for the treatment of secondary lung cancer lesions, 21 lesions were performed surgery( lobectomy;2, segmental resection;2, partial resection;17), 6 lesions of photodynamic therapy (PDT), and 3 lesions of stereotactic body radiation therapy (SBRT). Among the surgical cases, there were three cases on the same side as the first cancer and 18 cases on the opposite side. The three cases underwent partial resection. Among 21 patients, postoperative home oxygen therapy was introduced in 2 patients. Regarding the prognosis, three patients who had surgical resection, died of recurrence of the first lesion. One of the six PDT patients died of recurrence of the first lung cancer and another died of other disease. All three patients who underwent SBRT are alive without recurrence. CONCLUSIONS: If early detection and early diagnosis are made as a treatment strategy for metachronous multiple lung cancer, it may be possible to preserve lung function by reducing surgery or SBRT, PDT, and to cure without damaging the quality of life.

Hydration Effect on Positron Binding Ability of Proline: Positron Attachment Induces Proton-Transfer To Form Zwitterionic Structure.

The positron binding abilities of proline and its hydrated clusters were theoretically studied using multicomponent molecular orbital (MC_MO) calculations. Low-lying equilibrium structures of the neutral proline·(H2O) n ( n = 0-2) clusters were systematically explored with the aid of global reaction route mapping code. The positron binding energies were then calculated for the equilibrium structures. We found that the zwitterionic forms generally displayed high positron binding energies owing to their highly polar nature. We also found that nonzwitterionic forms can exhibit high positron binding energies if the addition of water significantly increases the total electric dipole moment. These results demonstrate that the most stable positron-bound proline·(H2O) n ( n = 1 and 2) structures are more stable than the most stable neutral structures, which implies that the attachment of a positron to a neutral hydrated proline cluster can induce structural changes if the positron-electron annihilation lifetime is sufficiently long relative to the time scale of nuclear motion. We also examined the influence of positron binding on the energy profiles of the proton transfer reactions from the nonzwitterionic form to the zwitterionic form.

Reduction of OH vibrational frequencies in amino acids by positron attachment.

Positron affinities have been calculated for five amino acid molecules (asparagine, cysteine, glycine, proline, and serine) with the intramolecular COOH···NH2  hydrogen-bonded motif as a function of the OH distance using two computational methods, namely multicomponent molecular orbital theory and pseudopotential model. Since the elongation of the carboxylic OH bond leads to the formation of highly polarized zwitterionic amino acid with COO- ···NH3+  structure, the calculated positron affinity significantly increases with the elongation of the OH distance. This indicates that the OH bond strength is significantly weakened by positron attachment. We discuss the reduction of OH vibrational frequencies using effective one-dimensional potential energy curves for neutral and positron-attached amino acid molecules. © 2018 Wiley Periodicals, Inc.

Nuclear quantum effects in the direct ionization process of pure helium clusters: path-integral and ring-polymer molecular dynamics simulations on the diatomics-in-molecule potential energy surfaces.

The direct photoionization of pure helium clusters, Hen (n = 100, 200 and 300), and its subsequent short-time process have been studied by path integral molecular dynamics (PIMD) and ring-polymer molecular dynamics (RPMD) simulations that can effectively describe the nuclear quantum effects in large systems. The modified diatomics-in-molecule (DIM) model [Calvo et al., J. Chem. Phys., 2011, 135, 124308] has been used to describe the electronic structures of Hen+ clusters. The PIMD simulations were able to reproduce the experimental ionization spectra having a broad and asymmetric nature, which can be ascribed to the inhomogeneity of the energy levels of He atoms in the inner and outer regions of the cluster. From the RPMD simulations, it is found that the ionized helium cluster in the higher excited state is followed by fast electronic state relaxation via nonadiabatic charge transfer including a small contribution of nuclear motions, and subsequently by slow relaxation of the cluster structure.

Bayesian Estimation of Phase Dynamics Based on Partially Sampled Spikes Generated by Realistic Model Neurons.

A dynamic system showing stable rhythmic activity can be represented by the dynamics of phase oscillators. This would provide a useful mathematical framework through which one can understand the system's dynamic properties. A recent study proposed a Bayesian approach capable of extracting the underlying phase dynamics directly from time-series data of a system showing rhythmic activity. Here we extended this method to spike data that otherwise provide only limited phase information. To determine how this method performs with spike data, we applied it to simulated spike data generated by a realistic neuronal network model. We then compared the estimated dynamics obtained based on the spike data with the dynamics theoretically derived from the model. The method successfully extracted the modeled phase dynamics, particularly the interaction function, when the amount of available data was sufficiently large. Furthermore, the method was able to infer synaptic connections based on the estimated interaction function. Thus, the method was found to be applicable to spike data and practical for understanding the dynamic properties of rhythmic neural systems.

Molecular characterization and validation of commercially available methods for haptoglobin measurement in bottlenose dolphin.

Haptoglobin (Hp) is a positive acute-phase protein and a valuable marker of inflammation in both human and veterinary medicine. The aim of this study was to validate the molecular characterization of Hp in dolphins and to validate commercially available Hp measurement methods such as Hp-ELISA (originally designed for pigs) and Hp-hemoglobin (Hb) binding assay. The dolphin Hp (dHp) amino acid sequence appeared most similar to pig Hp by sequence homology and phylogenetic clustering. Amino acid sequence analysis revealed that dHp comprises the Hp1 form of α1 and ß chains. The anti-pig Hp antibody cross-reacted with both recombinant dHp, expressed by Escherichia coli, and dHp from serum. The intra- and inter-assay levels of imprecision of pig Hp-ELISA and the Hp-Hb binding assay were found to be tolerable for the determination of Hp in dolphin, and there was no significant discrepancy between the two determination methods. The ability of the assay to differentiate between healthy and inflammation groups was investigated, and a significant increase in Hp concentration was detected in inflammatory conditions. Thus, Hp is a useful inflammation marker for dolphin, and the Hp concentration in dolphin serum samples can be reliably measured using commercially available pig Hp-ELISA and Hp-Hb binding assay.