Stabilization of sp-Hybridized Nitrogen Cation by Lewis Acid-Base Complex Formation with Intramolecular Iodine.

Here we show that the sp-hybridized nitrogen cation is strongly stabilized by a peri-iodine substituent in the tetralone system. The cation is captured by anionic species such as CF3 CO2 - , affording hypervalent iodine(III) compounds with a short nitrogen-iodine (N-I) bond, in which the cation serves as a Lewis acid. Notably, the O-I bond of the O-trifluoroacetate or O-acetate is intrinsically weaker than the N-I bond due to its more ionic character and is further weakened by protonation in trifluoroacetic acid. As a result, the oxygen ligand can dissociate in the presence of a Brønsted acid, affording a I+ cation intermediate that retains the N-I bond. We isolated the cation as the tetrafluoroborate, and characterized it experimentally by 1 H NMR spectroscopy and X-ray structure analysis, and theoretically by means of DFT calculation. The results suggest that the N-I bonded cation is intrinsically stable, and is weakly coordinated with water and the BF4 counter anion or trifluoroacetate anion. This cation can be employed as a reagent for α-oxidation of ketones.

Preoperative and Postoperative C-Reactive Protein to Albumin Ratio (CAR) as a Prognostic Marker for Survival of Esophageal Squamous Cell Carcinoma Patients After Surgery.

BACKGROUND/AIM: Recent studies have reported that the C-reactive protein (CRP) to albumin ratio (CAR) may be a useful prognostic biomarker in various types of cancer patients. However, the mechanism underlying this observation is unclear. The present study aimed to clarify why the CAR can predict post-esophagectomy prognosis, the relationship between pre- and postoperative CAR, and whether postoperative CAR can predict the prognosis of esophageal cancer patients. PATIENTS AND METHODS: We investigated 158 esophagectomy patients with esophageal squamous cell carcinoma. Hematological examinations were performed on postoperative days (POD) 1, 3, 5, 7, 10, and 14. RESULTS: Preoperative CAR was a significant independent prognostic factor of overall survival (OS) [hazard ratio (HR)=2.247; p=0.0005], and there was a strong correlation between preoperative CAR and tumor depth. The preoperative high-CAR (pre-high-CAR) group had significantly higher CAR on all postoperative days (POD). We then divided the patients as follows: those with at least two low-CAR days on POD 5, 7, and 10 were assigned to the modified post-low-CAR (mPost-low-CAR) group, and others were assigned to the modified post-high-CAR (mPost-high-CAR) group. The 5-year OS rate was significantly higher in the mPost-low-CAR group than in the mPost-high-CAR group, which predicted a more accurate prognosis (p<0.0001, HR=2.769). CONCLUSION: Preoperative CAR was associated with tumor depth and diameter, and patients in the pre-high-CAR group continued to have significantly higher CAR postoperatively. These factors were presumed to reflect disease prognosis. Furthermore, grouping by CAR on POD 5, 7, and 10 reflected patient prognosis more accurately than preoperative CAR.

The Impact of Pretransplant Use of Tyrosine Kinase Inhibitors on Allogeneic Stem Cell Transplantation in Patients with Chronic Myeloid Leukemia-A Single-institution Retrospective Study.

Objective Chronic myeloid leukemia (CML) is a malignant hematological disorder, and allogeneic stem cell transplantation (allo-SCT) was its only curative treatment until the introduction of tyrosine kinase inhibitors (TKIs). Allo-SCT is still considered for CML patients who are resistant to TKIs and in an advanced phase. Currently, second- and third-generation (2/3 G) TKIs are typically incorporated into the first-line treatment of CML. However, the impact of 2/3 G TKIs on subsequent allo-SCT remains unclear. We therefore evaluated the effect of 2/3 G TKIs on allo-SCT. Methods We retrospectively evaluated the effect of pretransplant therapy with TKIs on the outcome of allo-SCT for CML using clinical data at our institution. Patients or Materials Thirty-two CML patients who received their first allo-SCT procedure at our institute from 2001 to 2020 were included. We divided the patients into three subgroups based on TKI treatment before allo-SCT. Patients receiving no TKIs, only imatinib (IM), and 2/3 G TKIs were classified into the Non-TKI, IM, and 2/3 G TKI groups, respectively. Results In a univariate analysis, the pretransplant use of 2/3 G TKIs was significantly associated with a higher 5-year overall survival (91.7%) and relapse-free survival (75.0%) than the use of IM (37.5% and 12.5%) in patients presenting with or progressing to the advanced phase. In addition, pretransplant use of 2/3 G TKIs did not increase the incidence of graft-versus-host disease (GVHD). Conclusions We demonstrated that the pretransplant use of 2/3 G TKIs was safe and improved the outcome of CML patients who presented with or progressed to the advanced phase without increasing the frequency of GVHD.

Detection of homogentisic acid by electrospray ionization mass spectrometry.

OBJECTIVE: Homogentisic acid (HGA) is excreted in excessive amounts in the urine of patients with alkaptonuria, which is a hereditary metabolic disorder of phenylalanine and tyrosine. Therefore, the detection of HGA in urine is useful for the diagnosis of alkaptonuria. To evaluate the detection of HGA, we confirmed the color shift of HGA solutions and analyzed them by electrospray ionization mass spectrometry (ESI-MS). METHODS: We observed the color change of the HGA solutions under different pH conditions (pH 6.0, 7.0, and 8.0) and examined the influences of adding potassium hydroxide (KOH) and ascorbic acid (AA) to the HGA solutions. Then, we analyzed the chemical reaction in HGA solutions using ESI-MS. RESULTS: The HGA solution at pH 8.0 became brown after incubation at room temperature for 24 h and became darker brown with the addition of KOH; however, HGA solutions at pH 6.0 and 7.0 showed no color changes. The brown color change of the HGA solution at pH 8.0 was also inhibited by AA. Moreover, all HGA sample solutions showed the deprotonated molecular ion peak at m/z 167.035 in the negative ion mode after incubation at room temperature for 24 h and with the addition of KOH and AA. CONCLUSION: We identified the molecular ion of HGA in all sample solutions by ESI-MS, regardless of different pH conditions, color changes, or the presence of AA. These results suggest that spectral analysis by ESI-MS is suitable for the detection of HGA and the diagnosis of alkaptonuria.

Synthesis of Dimethyldisilabicycloalkanes: Cage-Size Effects on the Relative Stabilities between In,Out and Twist-Out,Out Forms.

In large bicycloalkanes, several in/out forms exist, wherein substituents on the bridgehead atoms are oriented either outside or inside the cage. The relative stability between the in,out and twist-out,out forms, which can interconvert through homeomorphic conversion, was found to depend upon the cage size. The in,out form demonstrated thermodynamic stability in the smaller C10 derivative, whereas the twist-out,out form prevailed in the larger derivatives of C14 and C18 plausibly as a result of dispersion forces among the chains.

Predictive postoperative inflammatory response indicators of infectious complications following gastrectomy for gastric cancer.

Background Perioperative factors are useful for predicting postoperative infectious complications (PIC) in gastric cancer. Specifically, postoperative inflammatory response indicators (PIRI), [C-reactive protein (CRP) level, body temperature (BT), and white blood cell (WBC) count], are widely used in clinical practice. We investigated predictive factors for PIC, including PIRI, to establish a simple and practical indicator of postoperative complications after gastrectomy.Methods We retrospectively collected clinical data from 200 patients with fStage I-III gastric cancer. Univariate/multivariate analysis was performed to evaluate the relationship of predictive factors [host factors, clinicopathological factors, and PIRI (BT, WBC count, and CRP level on postoperative day (POD) 1 and 3) ]. Cut-off values of the predictive factors were analyzed using receiver operating characteristic (ROC) curve modulated by the presence/absence of PIC Grade II, III (Clavien-Dindo classification).Results Age [Odds ratio (OR): 5.67], smoking history (OR: 3.51), and CRP level (OR: 5.65), WBC count (OR: 8.96), and BT (OR: 3.37) on POD3 were selected as independent factors from multivariate analysis. Cut-off values were 77 years, 14.8 mg/dL, 116.0×102 /µL, and 37.4°C, respectively.Conclusions Predictive factors relative to PIC in gastric cancer were CRP level ≥ 14.8mg/dL, WBC count ≥ 116.0×102 /µL, and BT ≥ 37.4°C all on POD3. Age ≥ 77 years, and history of smoking were relative to PIC, suggesting a simple and practical indicator applicable in clinical practice.

Isolation and Reactions of Imidoyl Fluorides Generated from Oxime Using the Diethylaminosulfur Trifluoride/Tetrahydrofuran (DAST-THF) System.

Fluorination of oximes with the relatively mild diethylaminosulfur trifluoride/tetrahydrofuran (DAST-THF) system affords imidoyl fluorides. These compounds were isolated, and their structures were confirmed by X-ray single-crystal structure analysis. Reaction of imidoyl fluorides with various nucleophiles efficiently afforded amides, amidines, thioamides, and amine derivatives in high yields. Furthermore, one-pot reaction of in situ generated imidoyl fluorides from oximes was also applicable to efficient synthesis of these products. The oxime stereochemistry and acid-labile protecting group remained intact in this system.

Sex-inducing effects toward planarians widely present among parasitic flatworms.

Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.

A spectrophotometric method for the determination of tryptophan following oxidation by the addition of sodium hypochlorite pentahydrate.

Tryptophan (Trp) is an essential amino acid that functions in various biological processes and human daily health. As the significant functions of Trp become more apparent, its measurement is becoming increasingly important in various situations. Herein, we improved the Trp color reaction based on the Hopkins-Cole reaction and established a simple colorimetric method for Trp determination using several different reagents, including sodium hypochlorite pentahydrate and monosodium glutamate. The detection method can be performed using safe materials, rather than conventional toxic substances, and induces a crimson color change with an absorption peak at 525 nm, enabling the quantification of Trp by simple spectrophotometry in just 10 min. This assay exhibited a linear detection range from 10 to 100 mg/L (R2 = 0.9996). The average recoveries in the spiked cerebrospinal fluid ranged from 90.5% to 104.3%, with a relative standard deviation of 0.27% (n = 3, 29.40 mg/L Trp) to 1.19% (n = 3, 72.90 mg/L Trp). This novel spectrophotometric method may enable many researchers and laboratory technicians to detect Trp in various sample solutions without expensive analytical instruments or complicated operations.

Synthesis and rotational dynamics of diazamacrocycles having bridged 1,4-naphthylene as framed molecular rotors.

The rotation of a part of a molecule has attracted attention because of its possible role in the development of an artificial molecular rotor. In this study, 1,4-naphthylene bridged diazamacrocycles, in which the 1,4-diaminonaphthalene moiety is bridged by two long alkyl chains, were designed as novel framed molecular rotors, and the dependence of the rotation on the frame size were investigated. Framed rotors CnNp (n = 12, 14, 16, 18), where the number in the compound name indicates the length of a side chain, were synthesized by direct cyclization of 1,4-naphthalenediamine with α,ω-dihaloalkane in the presence of Na2CO3 as the base. The rotation of the naphthylene rotor in C12Np, C14Np, and C16Np was nearly suppressed in solution, whereas the rotor in C18Np showed rotation, as confirmed by the temperature-dependent coalescence of the NMR signals of the α-CH2.

Neighboring Group Participation of Nitrogen Cation to Form an Unusual Six-Membered Ring Intermediate During Oxime Rearrangement.

Neighboring group participation involving a 6-membered ring structure is rare, despite the privilege of 6-membered ring transition structures in organic chemistry. We examined the putative role of a 6-membered cyclic intermediate with neighboring group participation of nitrogen cation in syn-migration of peri-ester indanone oximes. Direct observation of a peri-methyl ester-iminylium intermediate in solution by means of 1H NMR supported the existence of the 6-membered cation intermediate. Density functional theory (DFT) calculations also supported the intervention of this intermediate in the rearrangement and indicated that it has a planar structure stabilized by electron delocalization.

Risk factor analysis for cytomegalovirus reactivation under prophylaxis with letermovir after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Letermovir has been approved as a novel cytomegalovirus (CMV) prophylactic agent after allogeneic hematopoietic stem cell transplantation (HSCT). However, there are still insufficient data to properly evaluate the real-world role of letermovir, and the risk factors for CMV reactivation under letermovir prophylaxis have not been clarified. METHODS: We performed a single-institution retrospective analysis of patients under prophylaxis with or without letermovir who underwent allogeneic HSCT between March 2012 and December 2019. In August 2018, letermovir was added to the clinical practice at our institution for the prophylaxis of CMV reactivation in allogeneic HSCT recipients. Patients who underwent HSCT without prophylactic letermovir from March 2012 until September 2018 served as a historical control. RESULTS: The cumulative incidence of clinically significant CMV infection (CS-CMVi) was significantly lower in the letermovir group than in the historical control group not receiving letermovir (30.2% vs. 71.6%, p < .05, at 100 days). In addition, the cumulative incidence of non-relapse mortality (NRM) at day 500 was significantly lower in the letermovir group (4.7% vs. 19.8%, p < .05). We then performed a risk factor analysis for developing CS-CMVi in the letermovir group. The only significant factor identified by this multivariable analysis was transplantation from a CMV seronegative donor to a seropositive recipient (Hazard ratio = 2.76, 95% confidence interval 1.14-6.68, p < .05). CONCLUSION: Our study showed that letermovir prophylaxis significantly reduced the incidence of CS-CMVi and NRM in a real-world setting and that the CMV serostatus of the donor remained as a risk factor for CS-CMVi even under letermovir prophylaxis.

Feasibility of augmented rectangle technique in laparoscopic distal gastrectomy: comparison with hemi-double stapling technique in a single-center retrospective cohort study.

PURPOSE: Augmented rectangle technique (ART) anastomosis is a totally intracorporeal anastomosis of laparoscopic distal gastrectomy (LDG), Billroth I (B1) reconstruction for gastric cancer, which secures a wide anastomotic stoma. Since the conventional extracorporeal hemi-double stapling technique (HD) may have a narrow anastomotic stoma, our aim of this study was to evaluate the feasibility and usefulness of ART anastomosis by comparing the surgical outcomes with HD anastomosis. METHODS: Clinical data of 89 patients undergoing LDG with B1 reconstruction were retrospectively collected. Patients were divided into ART group (n = 40) and HD group (n = 49). Surgical outcomes including short-term outcomes, postoperative endoscopic findings, and nutritional factors 1 year after surgery were compared between the groups. RESULTS: Baseline characteristics were similar between the groups. In terms of short-term outcomes, blood loss was less (11.5 mL vs 40 mL, P = 0.011) and postoperative hospital stay was shorter (10 days vs 12 days, P = 0.022) in the ART group. In terms of endoscopic findings, residual food was less (P = 0.032) in the ART group. In terms of nutritional factors, percent decrease of visceral fat area (- 27.6% vs - 40.5%, P = 0.049) and subcutaneous fat area (- 25.7% vs - 39.3%, P = 0.050) 1 year after surgery attenuated in the ART group. CONCLUSIONS: ART anastomosis is superior in perioperative course such as postoperative hospital stay. Moreover, a better nutritional recovery is expected by securing a wide anastomotic stoma leading to a favorable food passage.

Contribution of Solvents to Geometrical Preference in the Z/E Equilibrium of N-Phenylthioacetamide.

We studied the Z/E preference of N-phenylthioacetamide (thioacetanilide) derivatives in various solvents by means of 1H NMR spectroscopy, as well as molecular dynamics (MD) and other computational analyses. Our experimental results indicate that the Z/E isomer preference of secondary (NH)thioamides of N-phenylthioacetamides shows substantial solvent dependency, whereas the corresponding amides do not show solvent dependency of the Z/E isomer ratios. Detailed study of the solvent effects based on molecular dynamics simulations revealed that there are two main modes of hydrogen (H)-bond formation between solvent and (NH)thioacetamide, which influence the Z/E isomer preference of (NH)thioamides. DFT calculations of NH-thioamide in the presence of one or two explicit solvent molecules in the continuum solvent model can effectively mimic the solvation by multiple solvent molecules surrounding the thioamide in MD simulations and shed light on the precise nature of the interactions between thioamide and solvent. Orbital interaction analysis showed that, counterintuitively, the Z/E preference of NH-thioacetamides is mainly determined by steric repulsion, while that of sterically congested N-methylthioacetamides is mainly determined by thioamide conjugation.

[Genetic studies on lymphoma].

Lymphoma comprises a group of diseases characterized by neoplastic proliferation of mature B, T, and NK cells. This disease entity is widely recognized to be clinically, pathologically, molecularly, and genetically heterogeneous. The classification of lymphomas was classically based on morphology and immunology, but recent dramatic advances in next-generation sequencing technology have revealed various genetic alterations in lymphomas, which influenced the revision of the WHO classification in 2017. Accumulating evidence on genetic alterations has enabled the development of more accurate diagnostic strategies and prognostic markers. Moreover, these findings provide opportunities to exploit new therapeutics that target genetic alterations, which would facilitate the use of precision medicine in lymphomas. Here, we briefly review the fundamental methods of genetic analysis using next-generation sequencing technology and describe the entire scenario of genetic alterations, focusing on the recent major studies that have revealed various genetic alterations in each lymphoma subtype and present a detailed discussion of the results and methods.

Ardisiatetrons A and B: tetronic acid derivatives and triterpenes from the leaves of Ardisia quinquegona and their biological activity.

From the leaves of Ardisia quinquegona, two alkylated tetronic acid derivatives, named ardisiatetrons A and B (1, 2), and four triterpenoids (3-6) were isolated together with one known compound (7) by a combination of various kinds of chromatography. The structure of new methyl migrated triterpene (3) was confirmed by X-ray crystallographic analysis. Compounds 2, 3, and 7 showed moderate anti-Leishmania activity and cytotoxicity towards A549 cells.

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles.

Phosphole-fused π-conjugated acenes have been attracting interest because of the attractive features of the phosphole moiety, such as fluorescence and chemically modifiable properties. Herein, 6-phenyl-6H-benzo[f]naphtho[2,3-b]phosphoindole was prepared by reacting dichlorophenylphosphine with a dilithium intermediate derived from 3,3'-dibromo-2,2'-binaphthyl. Various derivatives, such as a phospholium salt and a borane-phosphole complex with functional groups on the phosphorus atom were synthesized using the obtained phosphole as a common starting material. Single-crystal X-ray analysis of the parent benzo[f]naphtho[2,3-b]phosphoindole revealed that the pentacyclic ring is almost planar. Fluorescence spectroscopy data showed that the phosphole derivatives, such as phosphine oxide and the phospholium salt and borane complex exhibited photoluminescence in chloroform.

First successful case of percutaneous transabdominal thoracic duct embolization (PTTDE) for chylous ascites resulting from laparoscopic gastric cancer surgery.

A 61-year-old woman underwent laparoscopy-assisted distal gastrectomy (LADG) with extragastric lymph node dissection (D2). Two months later, she was readmitted to hospital to be treated for chylous ascites. Oral intake was discontinued and total parenteral nutrition started, but increasing body weight and decreasing serum albumin concentration was not controllable. Percutaneous transabdominal thoracic duct embolization (PTTDE) was performed on the 8th day after the readmission. Five days after PTTDE, oral intake was resumed. Seventeen days after PTTDE, the patient was discharged without recurrence of ascites. She has remained asymptomatic. We describe here the first patient with chylous ascites two months after LADG with D2 dissection for early gastric cancer who was successfully treated by PTTDE.

Structure and Dynamics of Crystalline Molecular Gyrotops with a Difluorophenylene Rotor.

Macrocage molecules with a bridged π-electron system could be assumed as crystalline molecular gyrotops because of the structural similarity and the rotatable π-electron system. In this study, 1,2-difluoro-3,6-phenylene-bridged macrocages were designed and synthesized as crystalline molecular gyrotops with a dipolar rotor. The thermal ring dynamics of the dipolar rotor in the crystal were investigated by solid-state NMR and dielectric spectroscopy. The gyrotop that was surrounded by three C14-alkyl chains exhibited an exchange between two stationary positions in the crystalline state. In contrast, the gyrotop cage consisting of C18 chains exhibited no dynamics in the crystalline state. Although the corresponding phenylene derivatives exhibit a facile rotational motion of the phenylene group in the crystalline state, the dynamics of each derivative was observed to be different. The reason for this difference is ascribed to the difference in the bulkiness between the fluorine and hydrogen atoms in the rotor.