Preparation of polyaniline by oxidation of aniline using H2O2 in the presence of an iron(II) catalyst

Oxidative polymerization of aniline using the H₂O₂-FeSO₄ system gave polyaniline under mild conditions. The prepared powdery emeraldine base, a form of polyaniline, is blue black and shows high solubility in organic solvents (e.g., ca. 200 mg/mL in N-methylpyrrolidone). The number-average molecular weight (M _n) of the polymer obtained was 1,3–1,7 · 10⁴ (via gel permeation chromatography vs. polystyrene) and M _w/M _n = 1,6–2,2. Poly(2-ethylaniline) and poly-(2-propylaniline) with high molecular weights were also synthesized by this procedure in high yield.     

Assessment of donor liver steatosis: pathologist or automated software?

Steatosis in donor liver biopsy specimens has been shown to correlate with graft dysfunction after orthotopic liver transplantation. This 2-part (laboratory pilot, clinical retrospective) study compared the traditional interpretation of steatosis by a pathologist with an automated measurement determined by an image analysis system. In our pilot study, Sprague-Dawley rats were studied prospectively by feeding them a choline-deficient diet for up to 7 days. In our clinical group, data from 49 consecutive recipients of cadaveric liver transplantation were reviewed retrospectively. In both studies, the percentages of microvesicular fat, macrovesicular fat, and total fat content within liver biopsy specimens were determined by an automated image analysis software program and a pathologist using the same set of slides. The association between fat content of the donor liver and patient survival and graft survival, along with levels of aspartate aminotransferase, alanine aminotransferase, prothrombin time, and total bilirubin after transplantation, were also examined in the clinical study. A direct correlation was observed between levels of macrovesicular fat determined by a pathologist and the automated software using livers from rats fed a choline-deficient diet and livers from deceased donors. A significant association was observed between macrovesicular fat content in the donor liver biopsy and graft survival by both techniques. We conclude that an image analysis system can be used to automate the determination of fat content in liver biopsy specimens, and that its findings correlate with both the visual interpretation by a pathologist and graft survival. Further study is needed to determine the role of an automated technique in the evaluation of donor livers for transplantation.     

Preparation and photo-induced activities of water-soluble amyloid β-C60 complexes

We have shown that fullerene (C₆₀) becomes soluble in water by mixing fullerene and amyloid β peptide (Aβ40) whose fibril structures are considered to be associated with Alzheimer''s disease. The water-solubility of fullerene arises from the generation of a nanosized complex between fullerene and the monomer species of Aβ40 (Aβ40-C₆₀). The prepared Aβ40-C₆₀ exhibits photo-induced activity with visible light to induce the inhibition of Aβ40 fibrillation and the cytotoxicity for cultured HeLa cells. The observed photo-induced phenomena result from the generation of singlet oxygen via photoexcitation, inducing oxidative damage to Aβ40 and HeLa cells. The oxidized Aβ40 following photoexcitation of Aβ40-C₆₀ was confirmed by mass spectrometry.

We have shown that fullerene (C₆₀) becomes soluble in water by mixing fullerene and amyloid β peptide (Aβ40) whose fibril structures are considered to be associated with Alzheimer''s disease.     

Correction to: Detection of acute rib fractures on CT images with convolutional neural networks: effect of location and type of fracture and reader’s experience

Emergency Radiology -     

Direct demonstration of the cross-bridge recovery stroke in muscle thick filaments in aqueous solution by using the hydration chamber

Despite >50 years of research work since the discovery of sliding filament mechanism in muscle contraction, structural details of the coupling of cyclic cross-bridge movement to ATP hydrolysis are not yet fully understood. An example would be whether lever arm tilting on the myosin filament backbone will occur in the absence of actin. The most direct way to elucidate such movement is to record ATP-induced cross-bridge movement in hydrated thick filaments. Using the hydration chamber, with which biological specimens can be kept in an aqueous environment in an electron microscope, we have succeeded in recording ATP-induced cross-bridge movement in hydrated thick filaments consisting of rabbit skeletal muscle myosin, with gold position markers attached to the cross-bridges. The position of individual cross-bridges did not change appreciably with time in the absence of ATP, indicating stability of time-averaged cross-bridge mean position. On application of ATP, individual cross-bridges moved nearly parallel to the filament long axis. The amplitude of the ATP-induced cross-bridge movement showed a peak at 5–7.5 nm. At both sides of the filament bare region, across which the cross-bridge polarity was reversed, the cross-bridges were found to move away from, but not toward, the bare region. Application of ADP produced no appreciable cross-bridge movement. Because ATP reacts rapidly with the cross-bridges (M) to form complex (M·ADP·Pi) with an average lifetime >10 s, the observed cross-bridge movement is associated with reaction, M + ATP → M·ADP·Pi. The cross-bridges were observed to return to their initial position after exhaustion of ATP. These results constitute direct demonstration of the cross-bridge recovery stroke.     

Unilateral pulmonary agenesis associated with oesophageal atresia and tracheoesophageal fistula: A case report with prenatal diagnosis

We describe herein a case of unilateral pulmonary agenesis (PA) with oesophageal atresia (EA)/tracheoesophageal fistula (TEF) that was diagnosed prenatally and repaired by esophagoesophagostomy with stable postoperative course. The patient was born at 34 weeks gestation, after ultrasonography at 22 weeks gestation showed possible right-sided diaphragmatic eventration or PA and EA was subsequently suspected due to hydramnios. The initial X-ray showed mediastinal shift to the right, and coil up sign of the nasogastric tube, without intracardiac anomaly. Immediately after the diagnosis of EA/TEF and unilateral PA on day 0, the patient was intubated in the operating room, and a gastrostomy tube was placed. After pulmonary status stabilized, at 4 days old, EA/TEF was repaired through a thoracotomy in the right 4^th intercostal space. The right main bronchus was noted to continue into the distal oesophagus; this fistula was ligated and divided, and a single-layer esophagoesophagostomy was performed under mild tension with one vertebral gap. The neonate was maintained on mechanical ventilation and gradually weaned to extubation at 7 days old. The postoperative course was uneventful, with the exception of prolonged jaundice that emerged at 3 months old. Laparoscopic cholangiography at that time excluded biliary atresia, and jaundice resolved spontaneously. The patient has not shown any respiratory symptoms or feeding difficulties as of the 12-month follow-up.     

Relationship between occlusal curvatures and bite force in humans

PurposeIt is clinically believed that humans with a broad and rounded dental arch accompanied by a shallow curve of Spee have good masticatory function. However, the relationship between them has not been elucidated fully. The purpose of this study was to quantitatively examine the relationship between occlusal curvatures and bite force.Materials and methodsBite force was measured and analyzed in 20 young adults with healthy permanent dentition and normal stomatognathic function using a bite force recording system. Study models of the mandibular dental arch were scanned with CCD cameras, and X, Y and Z coordinates of the cusp tips of the molars were recorded. Their occlusal curvatures were analyzed using a three-dimensional measurement system.ResultsBite force showed significant positive correlations (0.52 < R < 0.57) with the radius of the anteroposterior occlusal arc of the molar region and the radii of the translateral occlusal arcs in the second premolar, first molar and second molar regions, and showed significant positive correlation (R = 0.71) with the radius of the occlusal sphere of the molar region.ConclusionsIt was suggested that occlusal curvatures is related with the magnitude of bite force, and that the three dimensional spherical analysis of occlusal curvatures is useful predictor of the masticatory function.     

Recognition of bisphosphonate-related osteonecrosis of the jaw among oral and maxillofacial radiologists: results from a questionnaire-based survey in Japan

Objectives

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is becoming common in Japan. Oral and maxillofacial radiologists must diagnose BRONJ in general practice. However, little information on how to recognise BRONJ is available. The purpose of this study, therefore, was to confirm the recognition of BRONJ among Japanese oral and maxillofacial radiologists.

Methods

A questionnaire including 14 main queries and relevant branch queries was created and sent to 29 Japanese institutions employing oral and maxillofacial radiologists.

Results

A large number of patients (705) with BRONJ during the last 3 years were reported by 23 institutions (25 responders) that participated in our survey. The rate of osteonecrosis of the jaw associated with intravenous bisphosphonates was almost identical to that associated with oral bisphosphonates. This finding was inconsistent with worldwide data. About half of the responders felt that the diagnosis of BRONJ based on imaging was difficult. No specific modality was selected for identifying the early signs of BRONJ, although 19 responders selected multi-detector computed tomography followed by magnetic resonance imaging as the best modality for determining the extent of BRONJ. Almost all responders felt that the detection of early signs and determination of lesion extent on imaging were important roles of oral and maxillofacial radiologists.

Conclusions

Oral and maxillofacial radiologists recognised their roles in BRONJ diagnosis; however, insufficient evidence regarding the accomplishment of these roles is available. Japanese oral and maxillofacial radiologists must accumulate a large number of BRONJ images, analyse them in cooperation with one another and share the information obtained from their analysis.