Synthetic and computational investigation of neighboring group participation by a nucleophilic disulfide bond.

Disulfide bonds of 2-isocyanatophenyl methyl disulfide and 2-endo-isocyanato-6-endo-(methyldisulfanyl)bicyclo[2.2.1]heptane showed neighboring group participation in the formation of thiocarbamates. Natural Bond Orbital (NBO) analyses revealed that the unusual nucleophilicity requires a rigid through-space interaction between a lone pair of the disulfide bond and an antibonding orbital of isocyanate.

Alternative Route Triggering Multistep Spin Crossover with Hysteresis in an Iron(II) Family Mediated by Flexible Anion Ordering.

Multistep spin crossover (SCO) compounds have attracted much attention, since they can be great candidates for high-density multinary memory devices. The introduction of substituents, such as methyl (Me), chloro (Cl), bromo (Br), and methoxy (MeO) groups, at para positions to the phenyl-substituted tripodal N6 ligand-coordinated SCO FeII material, [FeLPh](NTf2)2 [where LPh = tris(2-{[(1-phenyl-1H-1,2,3-triazol-4-yl)methylidene]amino}ethyl)amine and NTf2 = bis(trifluoromethanesulfonyl)imide], affords a new family of solvent-free FeII complexes: [FeL4-R-Ph](NTf2)2 {where L4-R-Ph = tris[2-({[1-(4-R-phenyl)-1H-1,2,3-triazol-4-yl]methylidene}amino)ethyl]amine, where R = Me (1), Cl (2), Br (3), and MeO (4)}. 1 shows temperature invariant high-spin (HS) state, whereas the others show spin transitions with different characteristics, such as half-SCO (4), two-step SCO (3), and unusual three-step SCO with hysteresis (2). Mössbauer and X-ray absorption fine structure (XAFS) spectroscopic studies of them support the magnetic susceptibilities results. Density functional theory calculations indicate that the electronic effect of different substituents on magnetic properties is negligible in this FeII family. Single-crystal X-ray diffraction studies reveal that 1-4 has a similar packing arrangement with three-dimensional supramolecular network via intermolecular π-π and CH···π interactions between complex cations, and CH···X (X = O, N, and F) hydrogen bonding interactions between cations and inherently frustrated NTf2 anions. Variable-temperature structural studies unveil a variety of stepped SCO behaviors of 2-4 and deactivation of SCO in 1 are governed by the regulation of ordering of NTf2 counteranions through the subtle modification of terminal substituents of complex cations. Quantitative light-induced excited spin-state trapping (LIESST) effect was observed for 2-4 via green light irradiation (532 nm) at 10 K. This study opens up a new way for systematic control of magnetic response from no SCO to half-, two-step, and finally three-step SCO with hysteresis by precise tuning of the ordering of flexible NTf2 anions included in the supramolecular network with potentially SCO-active complex cations.

[Left Atrial Myxoma with Ossification;Report of a Case].

A 69-year-old female with left atrial tumor was refered to our hospital for surgical treatment. The tumor was attached to the interatrial septum and resected completely. Histopathological analysis confirmed a myxoma with ossification(mature bone). These findings may support the hypothesis that the undifferentiated mesenchymal cells are the origin of cardiac myxoma.

[Mobilization of the Liver for Farther Incision of the Diaphragm in Transdiaphragmatic Re-do Coronary Artery Bypass Grafting].

Re-do coronary artery bypass grafting to the right coronary artery via the diaphragm is useful, especially when re-sternotomy may injure a patent internal thoracic artery graft under the sternum. When the target vessel is located on the posterior wall of the heart, however, anastomosis becomes difficult. In our case, we mobilized the liver from the diaphragm and divided the diaphragm more posteriorly. The gastroepiploic artery was successfully anastomosed to the target vessel.

Impact of flexible hexyl chain ordering in a mononuclear spin crossover iron(III) complex.

A novel FeIII complex [Fe(Hex-tnal)2]BPh4 (1) with a tridentate N2O ligand having an n-hexyl chain, Hex-Htnal (=1-((((1-hexyl-1H-1,2,3-triazol-4-yl)methyl)imino)methyl)naphthalen-2-ol), is reported. Temperature-dependent magnetic susceptibility measurements revealed that 1 exhibits a two-step spin crossover (SCO) transition in the 400-10 K temperature range, including an unusual gradual χMT change above RT (300-345 K) and a hysteretic χMT jump in a narrow temperature range of 345-357 K. These behaviors were also characterized by differential scanning calorimetry. Variable-temperature single-crystal X-ray diffraction studies revealed that the order-disorder transition and conformational change of the hexyl chains and the symmetry change associated with the re-entrant structural phase transition, namely triclinic P1̄ (100-275 K) ↔ monoclinic C2/c (296-340 K) ↔ triclinic P1̄ (360 K), are coupled to variations in intermolecular interactions and the N4O2 coordination environment, resulting in the occurrence of the unusual two-step SCO transition of 1. This study demonstrates that the flexible motion of alkyl substituents in the supramolecular lattice influences the occurrence of anomalous magnetic switching properties.

Negative Pressure Pneumomediastinum: A Novel Concept of Spontaneous Pneumomediastinum Without Mediastinal Widening Following Weight Loss.

Purpose: Spontaneous pneumomediastinum, supposedly attributed to air leakage from the respiratory tract, is a common complication of interstitial lung disease often resulting in mediastinal widening. However, several cases of pneumomediastinum without mediastinal widening have been observed. This study aimed to investigate the cause of pneumomediastinum in patients without mediastinal widening. Patients and Methods: This study included 41 patients diagnosed with pneumomediastinum using computed tomography (CT) between July 2011 and September 2021 at Yokohama Minamikyosai Hospital; patients had undergone previous CT showing no gas density. Based on a comparison with previous CT images, the patients were classified into two groups: without mediastinal widening and with mediastinal widening. Results: Of the 41 patients, 13 and 28 had pneumomediastinum without and with mediastinal widening, respectively. There were no significant differences in the sex, age, body mass index, or pneumomediastinum distribution between the groups. However, the rate of weight loss per month was significantly greater in the group without mediastinal widening than in that with mediastinal widening. No significant differences were observed in the respiratory function test results between the two groups; that said, 10 of the 13 patients without mediastinal widening had restrictive disorders. Pulmonary disease in this group included idiopathic pulmonary fibrosis (n = 6), interstitial lung disease with collagen disease (n = 4), and other disease (n = 1). Pneumomediastinum occurred during periods of weight loss in all patients without widening, excluding two patients without data. Conclusion: Pneumomediastinum without mediastinal widening occurs during rapid weight loss and is often associated with restrictive lung disorders. The negative pressure attributed to the decreased plasticity of the lungs, which complements the space where the mediastinal fat has disappeared, is presumably the cause of pneumomediastinum. This pathophysiology is different from that of conventional pneumomediastinum attributed to increased intrapleural space pressure; thus, we propose to name the abovementioned pathophysiology "negative pressure pneumomediastinum".

Diaphragmatic hernia post coronary artery bypass with gastroepiploic artery.

An 86-year-old man, with a medical history of coronary artery bypass grafting with the right gastroepiploic artery 20 years prior, was admitted to our hospital for right-sided heart failure. Computed tomography findings revealed an intrapericardial diaphragmatic hernia of the transverse colon compressing the right ventricle. The hernia was successfully repaired, and the patient recovered without any complications. Diaphragmatic hernia is rare but may be a lethal complication following coronary artery bypass grafting. We should be aware of the possibility of this condition.

[Acute massive pulmonary thromboembolism with cardiac arrest].

Acute massive pulmonary thromboembolism (APE) is still associated with a high mortality rate. Furthermore, significantly higher mortality rates are observed in patients who underwent cardiopulmonary resuscitation (CPR) because of severe brain damage or multiple organ failure. We present successfully treated 4 patients who were transferred from outside hospitals under continuous CPR. Three of 4 patients required percutaneous cardiopulmonary support (PCPS). Preoperatively, all 4 patients had no brain damage despite of CPR for a maximum of 40 minutes. Open pulmonary thrombectomy was successfully performed under on pump beating cardiopulmonary support. All patients dramatically improved and were discharged without any complication. When hemodynamic instability or cardiac arrest occurs in patients with APE, rapid CPR, rapid diagnosis with echocardiography, and quick PCPS establishment are keys in our management strategy.

Detecting ligand-protein interactions inside cells using reactive peptide tags and split luciferase.

We report a method for detecting ligand-protein interactions occurring within cells using short peptide reactive tags appended to ligands and proteins, along with a split NanoLuc luciferase. This method can be applied to estimate the binding affinities of ligand-protein interactions and to detect the interactions of proteins with unstable synthetic ligands inside the cells.

Gastric cancer mortality related to direct radiographic and endoscopic screening: A retrospective study.

BACKGROUND: Despite its decreased incidence in Japan, gastric cancer continues among the leading causes of cancer-related deaths in both men and women. Accordingly, efforts are still required to lower the mortality rate of gastric cancer in Japan. Maebashi City introduced endoscopic gastric cancer screening in 2004, and participants are able to choose between direct radiography and endoscopy. Hence, we expected to see a decrease in mortality rate from gastric cancer after introducing endoscopic screening and a difference in mortality rate reduction between screening methods. AIM: To evaluate the impact on gastric cancer mortality rate of two types of gastric cancer screening in Maebashi City, Japan. METHODS: Participants aged 40 to 79 years of the Maebashi City gastric cancer screening program in 2006 who were screened by direct radiography (n = 11155) or endoscopy (n = 10747) were included. Participants were followed until March 31, 2012, by cross-referencing their data against the Gunma Prefecture cancer registry data. We compared the detection rate of gastric cancers. Then, we compared the mortality rate between the two groups. The Cox proportional hazards model was used to estimate the hazard ratio (HR) of gastric cancer death. Finally, the reduction in gastric cancer mortality rate associated with each screening method was evaluated. RESULTS: Gastric cancer was detected in 22 participants undergoing direct radiography (detection rate, 0.20%) and in 52 participants undergoing endoscopy (detection rate, 0.48%). However, most gastric cancers detected by endoscopic screening were early cancers that may not have resulted in death. We found no significant difference in gastric cancer mortality rate between participants receiving annual screening and those who do not. When the number of gastric cancer deaths in the direct radiography group was set as 1 in the Cox proportional hazard analysis, the HR of gastric cancer death was 1.368 (95%CI: 0.7308-2.562) in the overall group of participants. The results showed no significant difference between the two screening methods in any of the analysis groups. CONCLUSION: Although endoscopic screening detected more gastric cancer than direct radiographic screening, no significant difference in the reduction of gastric cancer mortality rate between the two screening methods was found.

Myoepithelial Carcinoma Occurring on the Ascending Aorta.

Myoepithelial carcinomas are rare malignant tumors that primarily develop in exocrine glands. We present a case of myoepithelial carcinoma located on the aorta of a 39-year-old Japanese woman. Complete resection of the tumor and aorta was performed using cardiopulmonary bypass. Histologic and immunohistochemical analyses confirmed the diagnosis. The patient was symptom-free after the operation, and no tumor recurrence was observed during 7 years of follow-up. We report a rare myoepithelial carcinoma occurring on the aorta.

Extrinsic compression of the left main coronary artery: A rare cause of cardiogenic shock.

A left main coronary artery (LMCA) stenosis due to extrinsic compression by mediastinal tumor is a rare finding. In this case reports, we present a 63-year-old woman, who was transferred to the emergency department with chief complains of persistent chest and back pain. An electrocardiogram revealed diffuse ST-segment depression (elevation in lead aVR). Contrast-enhanced computed tomography (CT) showed a huge cystic mass above the left atrium. After the CT examination, she was temporarily in shock. Compression of the LMCA was evident on the CT angiography and a diagnosis of acute myocardial infarction due to compression of the LMCA by a tumor was made. An emergent resection of the tumor was performed. Histopathological assessment of the resected cyst revealed that it was a schwannoma. She made an uneventful postoperative recovery. A follow-up 3-dimensional CT scan performed after the operation confirmed no evidence of LMCA compression.

Hemilaterally masked arterial spin labeling by intentional magnetic field changes in the labeling area due to placement of material with high susceptibility.

BACKGROUND AND PURPOSE: Arterial spin labeling(ASL)with magnetic resonance imaging (MRI) is an effective method for estimating cerebral blood flow (CBF). Furthermore, assessing perfusion territories of arteries is useful for determining the treatment strategy of patients with carotid artery stenosis. ASL with selective vessel labeling is an effective method to obtain perfusion mapping, however, the application for selective labeling is not installed on all MR scanners. The purpose of this study is to establish a method to selectively mask in the labeling area using material with high susceptibility instead of selectively labeling to obtain a partial perfusion image. MATERIALS AND METHODS: ASL perfusion images were performed in five volunteers. Masking was applied by placing a stainless-steel bolt and nuts on the neck. The area of artifacts extended to the carotid artery was confirmed by the localizer image. In the obtained masked ASL, blood flow of the left and right cerebrum and cerebellum was measured and compared with control ASL without masking. By subtracting masked ASL from the control ASL, the perfusion territory of the carotid artery on the masked side was identified. RESULTS: Mean CBF which was 39.6 ml/(100 g × min) in control ASL decreased to 16.1 ml/(100 g × min) in masked ASL, and the masking ratio was 59.6%. There were no significant differences in the CBF of non-masked areas under the control ASL condition (39.6± 5.2 ml/[100 g × min]) btween that under the masked ASL condition (39.4 ± 7.0 ml/[100 g × min]). By subtracting masked ASL from control ASL, we successfully visualized the hemilateral carotid artery's perfusion territory. CONCLUSION: Intentional susceptibility artifacts with non-magnetic metals on the neck can mask spin labeling of the carotid artery. Furthermore, hemilateral carotid artery perfusion territories can be visualized in hemilaterally masked ASL.

[Curative gastrectomy with reconstruction of a right gastroepiploic artery graft].

We report a case of a 66-year-old man who developed gastric cancer 5 years after coronary artery bypass grafting using right gastroepiploic artery graft (RGEA). Some authors reported successful gastrectomy preserving a functional RGEA, but it carries the risk of injury of the graft or graft spasm. Preoperatively, catheter intervention for target vessels of RGEA (right coronary artery: RCA) was tried but failed. We performed re-do coronary artery bypass grafting (CABG) via right thoracotomy with right internal thoracic artery (RITA)-radial artery (RA) composite graft. The composite graft was drawn into the peritoneal cavity through the diaphragm, and anastomosed to the RGEA on the anterior plane of the liver. After that, partial gastrectomy was performed with resection of the RGEA and dissection of the #6 lymph nodes. We consider this method is safe to treat such cases.

[Ventricular septal defect with right pulmonary agenesis and left bronchial stenosis].

We report a case of ventricular septal defect (VSD) with right pulmonary agenesis and left bronchial stenosis. Delivery of a male infant was uneventful. Birth weight was 3,050g. At 12 days of age, he presented himself with tachypnea and wheezing. Dextrocardia was noted on a chest X-ray. Computed tomography (CT) of the chest showed right pulmonary agenesis and severe narrowing of the left main bronchus. An echocardiogram showed VSD, patent ductus arteriosus (PDA) and pulmonary hypertension (PH). At 22 days of age, he was put on ventilator. At 1 month of age, pulmonary artery banding and division of PDA were performed through median sternotomy. At 5 months of age, weighing 5.0 kg, the VSD was closed with a Dacron patch through median sternotomy. At 6 months of age, tracheostomy was necessitated. At 1-year-old, he became free from ventilator.

A polymorphism-dependent T(1/2) shift of 100 K in a hysteretic spin-crossover complex related to differences in intermolecular weak CH···X hydrogen bonds (X = S vs. S and N).

A neutral mononuclear iron(II) complex with a 1,2,3-triazole-containing tetradentate ligand has been obtained as two solvent-free polymorphs. Both polymorphs show hysteretic spin crossover with a polymorphism-dependent T(1/2) shift of 100 K that spans room temperature due to differences in intermolecular weak CH···X hydrogen-bonding interactions (X = S vs. S and N).

Synthesis, structure, and spin crossover above room temperature of a mononuclear and related dinuclear double helicate iron(ii) complexes.

A mononuclear iron(ii) complex, [FeII(L1Me)2](PF6)2 (1), and a related dinuclear one, [Fe(L2C2)2](PF6)4·5H2O·MeCN (2), were prepared, where L1Me is a tridentate N3 coordinating Schiff-base ligand, 1-methyl-1,2,3-triazol-4-yl-methylideneamino-2-ethylpyridine, and L2C2 is a dimeric form ligand of L1Me, 1,1'-(1,2-ethanediyl)bis-1,2,3-triazol-4-yl-methylideneamino-2-ethylpyridine, and their magnetostructural relationships were investigated. Mononuclear 1 shows a gradual one-step spin crossover (SCO) from the low-spin (LS) state (S = 0) at room temperature (RT) to the mostly high-spin (HS) state (S = 2) at 470 K spanning a temperature range of more than 170 K, while dinuclear 2 shows an anomalous two-step SCO with a gradual transition in a first step from the LS-LS state at RT to around 432 K and then an abrupt spin transition centred at 432 K with 11 K wide hysteresis in a second step (T1/2↑ = 437 K and T1/2↓ = 426 K) reaching the mostly HS-HS state. Single crystal X-ray structure analyses revealed that the iron(ii) centre of mononuclear 1 has an N6 octahedral coordination environment with two tridentate L1Me ligands, while the complex-cation of 2 has a dinuclear double helicate architecture as though a dimeric form of two complex-cations of 1 replaced their methyl group with a bridging ethylene chain. Both complexes have a cationic two-dimensional (2D) structure in which the 2D layer of mononuclear 1 is constructed of intermolecular CHN hydrogen bonds between adjacent complex-cations, while that of dinuclear 2 is constructed of both intermolecular π-π and CH/π interactions between neighboring helicates.

Mediastinal vacuum phenomenon: atypical pneumomediastinum caused by gas replacement of diminished fat.

We report a case involving an 83-year-old man with interstitial lung disease who developed atypical pneumomediastinum caused by gas replacement of diminished fat. The patient presented with a complaint of worsening symptoms of respiratory difficulty since a diagnosis of chronic eosinophilic pneumonia 5 months back. He had been under observation with no particular treatment for 5 months. Computed tomography performed on admission revealed pneumomediastinum. When the current scan was compared with that obtained 5 months ago, it was evident that the fat surrounding the mediastinum had been replaced by gas density. There was no mediastinal enlargement, pneumothorax, or pneumopericardium. Because the patient was elderly, home oxygen therapy was initiated for the interstitial pneumonia with no steroid therapy. Computed tomography performed 10 months after discharge showed the reappearance of mediastinal fat and no evidence of gas density. This case is unique because the pneumomediastinum was distinct from spontaneous pneumomediastinum caused by alveolar air leaks and resembled the vacuum phenomenon caused by intervertebral disc degeneration.