Stereochemical properties of quazepam and its affinity for the GABAA receptor.

C9-methylated quazepam 1 was prepared, and its physicochemical properties were investigated. The atropisomers of 1 were isolated as (a1R, a2S) and (a1S, a2R) isomers. Their absolute configurations were determined based on ECD spectra in comparison with those calculated using the time-dependent density functional theory. Preliminary examination of affinity for the GABAA receptor revealed that the (a1R, a2S) isomer of 1 possessed higher activity than its antipode (a1S, a2R) isomer. The active configuration of C9-methylated quazepam 1 is the same as that of 1,4-benzodiazepin-2-ones.

Fentanyl-Type Antagonist of the µ-Opioid Receptor: Important Role of Axial Chirality in the Active Conformation.

In recent years, synthetic opioids have emerged as a predominant cause of drug-overdose-related fatalities, causing the "opioid crisis." To design safer therapeutic agents, we accidentally discovered µ-opioid receptor (MOR) antagonists based on fentanyl with a relatively uncomplicated chemical composition that potentiates structural modifications. Here, we showed the development of novel atropisomeric fentanyl analogues that exhibit more potent antagonistic activity against MOR than naloxone, a morphinan MOR antagonist. Derivatives displaying stable axial chirality were synthesized based on the amide structure of fentanyl. The aS- and aR-enantiomers exerted antagonistic and agonistic effects on the MOR, respectively, and each atropisomer interacted with the MOR by assuming a distinct binding mode through molecular docking. These findings suggest that introducing atropisomerism into fentanyl may serve as a key feature in the molecular design of future MOR antagonists to help mitigate the opioid crisis.

Safety and efficacy of neoadjuvant chemotherapy with paclitaxel, carboplatin, and cetuximab for locally advanced head and neck squamous cell carcinoma.

BACKGROUND: As a substantial waiting time is usually required for radical surgery, safe and effective preoperative neoadjuvant chemotherapy (NAC) is desired for the treatment of locally advanced head and neck squamous cell carcinoma (HNSCC). However, the significance of NAC in advanced HNSCC is still unclear. This study aimed to assess the safety and efficacy of NAC using the paclitaxel, carboplatin, and cetuximab (PCE) regimen. METHODS: We retrospectively evaluated the background characteristics, incidence of adverse events, overall response rate (ORR), pathological response, recurrence-free survival (RFS), and overall survival (OS) in 26 patients. Patients receiving the PCE regimen were further divided into two groups based on the number of chemotherapy cycles (one cycle or more) and eligibility for cisplatin. Patients aged ≥ 75 years and those with an estimated glomerular filtration rate (eGFR) < 60 mL/min were classified as ineligible for cisplatin. RESULTS: The median age was 70 (27-81) years. The median eGFR at treatment initiation was 63.2 (41.1-89.7) mL/min. Fourteen (53.8%) patients were ineligible for cisplatin. Grade 3 or higher neutropenia was observed in 11 of 25 (42.3%) patients. No delay in or withdrawal from surgery was observed. The ORR was 65.4%. The 2-year RFS and OS were 61.5% and 76.7%, respectively. No significant differences in safety and efficacy between the number of chemotherapy cycles and cisplatin eligibility were observed. CONCLUSION: NAC using the PCE regimen for patients with locally advanced HNSCC, including cisplatin-ineligible patients, has acceptable toxicity and favorable efficacy.

Treatment Outcome in Head and Neck Cancer With Distant Metastasis at Initial Diagnosis.

OBJECTIVE: Recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) treatment has changed dramatically with the introduction of immune checkpoint inhibitors (ICIs). However, there are few reports of treatment outcomes on HNSCC with distant metastasis (M1) at initial diagnosis, and its treatment strategy has not been standardized. We aimed to analyze the treatment outcome and prognostic factors of patients with HNSCC with initial M1 disease. METHODS: In this multi-institutional retrospective study, 98 patients with HNSCC were initially diagnosed with M1 disease between 2007 and 2021. The patients were divided into the non-palliative (received any systemic chemotherapy, n = 60) and palliative (did not receive systemic chemotherapy, n = 38) groups. Overall survival (OS) was compared between the groups. In the non-palliative group, predictors of OS were explored based on patient characteristics and treatment details. RESULTS: The median OS in the non-palliative group was 15 months (95% confidence interval [CI], 10-20), which was significantly longer than that in the palliative group (3 months, 95% CI, 2-5) (p < 0.001). Multivariate analysis revealed that administration of locoregional radiation therapy (RT) (hazard ratio [HR] 0.407 [95% CI 0.197-0.844]; p = 0.016), ICIs (HR 0.216 [95% CI 0.088-0.532]; p < 0.001) and RT/surgery for distant metastasis (HR 0.373 [95% CI 0.150-0.932]; p = 0.034) were the independent prognostic factors of OS. CONCLUSION: An intensive treatment strategy combining systemic therapy using ICIs with RT/surgery for locoregional or distant metastasis may yield a survival benefit for patients with HNSCC with M1 disease. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1679-1686, 2024.

Multicenter prospective phase II trial of concurrent chemoradiotherapy with weekly low-dose carboplatin for cisplatin-ineligible patients with advanced head and neck squamous cell carcinoma.

BACKGROUND: The optimal chemotherapy regimen in concurrent chemoradiotherapy (CCRT) for cisplatin-ineligible head and neck squamous cell carcinoma (HNSCC) has not been established. We aimed to evaluate the feasibility, efficacy, and safety of CCRT with weekly low-dose carboplatin for the treatment of advanced HNSCC in patients who are cisplatin-ineligible. METHODS: This prospective phase II study enrolled adult patients (age ≥ 20 years) with HNSCC receiving whole-neck irradiation including bilateral levels II-IV and who were aged (≥ 75-year-old patients with 40 mL/min estimated glomerular filtration rate [eGFR] or better) or had renal dysfunction (< 75-year-old patients with 30-60 mL/min eGFR). Carboplatin was administered weekly (area under the plasma concentration-time curve = 2.0) for up to seven cycles during concurrent radiotherapy (70 Gy/35 Fr). The primary endpoint was the completion rate of CCRT. Secondary endpoints included overall response rate and incidence of adverse events. RESULTS: Among the 30 patients enrolled, 28 were men. The median age was 73.5 years. Seventeen patients were < 75 years whereas 13 were ≥ 75 years old. The completion rate of CCRT was 90%. The overall response rate was 90%. Grade 3 adverse events that occurred in 10% or more patients were oral/pharyngeal mucositis (47%), leukocytopenia (20%), and neutropenia (10%). Grade 4 adverse events occurred in one patient (elevation of alanine aminotransferase level). No treatment-related deaths occurred. CONCLUSION: CCRT with weekly low-dose carboplatin is a promising treatment option, with favorable feasibility, efficacy, and acceptable toxicity, for patients who are cisplatin-ineligible with advanced HNSCC. CLINICAL TRIAL REGISTRATION NUMBER: jRCTs031190028.

Stereochemistry of N-Acyl-5H-dibenzo[b,d]azepin-7(6H)-ones.

The stereochemical properties of N-acyl-5H-dibenzo[b,d]azepin-7(6H)-ones (2a-c), which inhibit potassium channels in T cells, were examined by freezing their conformational change due to 4-methyl substitution. N-Acyl-5H-dibenzo[b,d]azepin-7(6H)-ones exist as pairs of enantiomers [(a1R, a2R), (a1S, a2S)], and each atropisomer is separable at room temperature. An alternate procedure for preparing 5H-dibenzo[b,d]azepin-7(6H)-ones involves the intramolecular Friedel-Crafts cyclization of N-benzyloxycarbonylated biaryl amino acids. Consequently, the N-benzyloxy group was removed during the cyclization reaction to produce 5H-dibenzo[b,d]azepin-7(6H)-ones suitable for the subsequent N-acylation reaction.

Head and neck small-cell carcinoma: A multicenter study of 39 cases from 10 institutions.

Objective: Basal information of head and neck small-cell carcinoma (HNSmCC) including epidemiology, primary site, treatment, and prognosis remains sparse due to its rarity. We report here a multicenter retrospective study on the diagnosis, treatment, and outcomes of patients with HNSmCC. Materials and methods: This study involved 47 patients with HNSmCC from 10 participating institutions. Eight patients were excluded for whom no pathological specimens were available (n = 2) and for discrepant central pathological judgements (n = 6). The remaining 39 patients were processed for data analysis. Results: As pretreatment examinations, computed tomography (CT) was performed for the brain (n = 8), neck (n = 39), and chest (n = 32), magnetic resonance imaging (MRI) for the brain (n = 4) and neck (n = 23), positron emission tomography-CT (PET-CT) in 23 patients, bone scintigraphy in 4, neck ultrasonography in 9, and tumor markers in 25. Primary sites were oral cavity (n = 1), nasal cavity/paranasal sinuses (n = 16), nasopharynx (n = 2), oropharynx (n = 4), hypopharynx (n = 2), larynx (n = 6), salivary gland (n = 3), thyroid (n = 2), and others (n = 3). Stages were II/III/IV-A/IV-B/IV-C/Not determined = 3/5/16/6/5/4; stage IV comprised 69%. No patient had brain metastases. First-line treatments were divided into 3 groups: the chemoradiotherapy (CRT) group (n = 27), non-CRT group (n = 8), and best supportive care group (n = 4). The CRT group included concurrent CRT (CCRT) (n = 17), chemotherapy (Chemo) followed by radiotherapy (RT) (n = 5), and surgery (Surg) followed by CCRT (n = 5). The non-CRT group included Surg followed by RT (n = 2), Surg followed by Chemo (n = 1), RT alone (n = 2), and Chemo alone (n = 3). The 1-year/2-year overall survival (OS) of all 39 patients was 65.3/53.3%. The 1-year OS of the CRT group (77.6%) was significantly better compared with the non-CRT group (31.3%). There were no significant differences in adverse events between the CCRT group (n = 22) and the Chemo without concurrent RT group (n = 9). Conclusion: Neck and chest CT, neck MRI, and PET-CT would be necessary and sufficient examinations in the diagnostic set up for HNSmCC. CCRT may be recommended as the first-line treatment. The 1-year/2-year OS was 65.3%/53.3%. This study would provide basal data for a proposing the diagnostic and treatment algorithms for HNSmCC.

Atropisomeric Properties of N-Alkyl/Aryl 5H-Dibenz[b,f]azepines.

The atropisomeric properties of N-alkyl and N-aryl 4-substituted 5H-dibenz[b,f]azepines were investigated. The N-alkylation and N-arylation of 4-Cl or 4-Me substituted compounds was performed; however, none of the atropisomers produced were separated by chiral HPLC. Notably, we observed that the rotation of the four axes (ax. 1-4) in the 4-substituted 5H-dibenz[b,f]azepine structure is so rapid that N-alkylation or N-arylation is not sufficient to freeze it at room temperature. Additionally, the X-ray crystal structures of N-aryl compounds 13b and 14a indicated that the N atom in the triphenyl amine moiety in their structures shows sp2-like property.

Axial chirality and affinity at the GABAA receptor of triazolobenzodiazepines.

Triazolobenzodiazepines substituted with a methyl group at the C1- and C10-positions and chloro group at C2' of pendant-phenyl were prepared and their physicochemical properties were investigated. The atropisomers of 1,10-disubstituted triazolobenzodiazepines, 1d and 1f, were isolated as (a1R, a2S) and (a1S, a2R) isomers. Their absolute configurations were determined on the basis of CD spectra in comparison with those of stereochemically defined 9-methyl-1,4-benzodiazepin-2-ones. Examination of the affinity at the human GABAA receptors revealed that each (a1R, a2S) isomer of 1d and 1f possessed higher activity than its antipode (a1S, a2R) isomer. It was also found that 1a, which behaves achirally due to the rapid conformational change, had the highest GABAA affinity, equal to that of triazolam. Considering that each eutomer of 1d and 1f is (a1R, a2S), the conformation of 1a at the binding site of the GABAA receptor is expected to be (a1R, a2S).

Chemoradiotherapy with 3-weekly CDDP 80†mg/m2 for head and neck squamous cell carcinoma: 5-year survival data from a phase 2 study.

Objective: The global standard for chemoradiation therapy (CCRT) for head and neck squamous cell carcinoma is cisplatin 100 mg/m2 administered once every three weeks, although cisplatin 80 mg/m2 is also widely used as an alternative treatment to reduce adverse events in Japan. We aimed to assess the long-term survival outcomes and late adverse events associated with CCRT with a 3-weekly cisplatin dose of 80 mg/m2. Methods: A phase 2 study on CCRT with a 3-weekly cisplatin dose of 80 mg/m2 was performed in 47 patients between April 2015 and December 2016 at four centers in Japan. Survival outcomes and late adverse events at 5 years after this phase 2 trial were investigated. Results: The median follow-up period was 61 months. The 5-year progression-free survival/overall survival of all 47 patients was 66.0%/76.6%, while that of patients with stage III, IV disease (UICC) was 65.6%/71.9%. Seventeen patients (36%) experienced dysphagia as a late adverse event. Univariate and multivariate analyses revealed a significant association between acute mucositis/low body mass index (BMI) during CCRT and late dysphagia. Conclusion: The survival outcomes of CCRT with a 3-weekly cisplatin dose of 80 mg/m2 may be comparable to the previously reported dose of 100 mg/m2. Acute mucositis and low BMI at CCRT were risk factors for late dysphagia, indicating the importance of managing these conditions during CCRT to prevent late adverse events. Caution and care for acute mucositis and swallowing training in patients with low BMI may be important for preventing late-stage dysphagia.

Treatment Outcome of External Auditory Canal Carcinoma: The Utility of Lateral Temporal Bone Resection.

We examined the role of lateral temporal bone resection (LTBR) in the treatment of external ear canal (EAC) carcinoma between 2007 and 2018. The estimated 3-year disease-free survival (DFS) and disease-specific survival (DSS) according to the tumor stage and treatments were investigated in 36 patients with EAC squamous cell carcinoma. T stage classification according to the University of Pittsburgh staging system was as follows: 14 patients in T1, four patients in T2, nine patients in T3, and nine patients in T4. The 3-year DFS rate was 77.4% for T1 tumors, 100% for T2, 44.4% for T3 tumors, and 11.1% for T4 tumors (p < 001). The 3-year DSS rate was 100% for T1/T2 tumors, 87.5% for T3 tumors, and 11.1% for T4 tumors (p < 0.01). T1/T2 patients received mostly LTBR. Among nine T3 tumors, five patients (56%) received LTBR combined with preoperative chemotherapy and/or postoperative radiation (RT). Four of them had negative surgical margin and survived with no evidence of disease. The DFS of T3 patients who underwent concurrent chemoradiotherapy and LTBR was 0 and 80%, respectively (p = 0.048). For T1/T2 tumors, surgery achieved an excellent outcome. For T3 tumors, LTBR achieved negative surgical margin and showed good survival when combined with preoperative chemotherapy and/or postoperative RT. In contrast, the prognosis of T3 patients who could not undergo surgery was as poor as that of T4 patients. Therefore, in addition to subtotal temporal bone resection, LTBR-based treatment strategy may be a treatment option for limited cases of T3 patients.

Impaired secretion of carboxyl-terminal truncated factor VII due to an F7 nonsense mutation associated with FVII deficiency.

INTRODUCTION: Factor VII (FVII) is a vitamin K-dependent glycoprotein secreted into the blood circulation from hepatic cells. We investigated the molecular basis of the congenital FVII deficiency found in a Japanese patient. MATERIALS AND METHODS: We analyzed the F7 gene of the patient, who was diagnosed with a FVII deficiency at pregnancy. We expressed a carboxyl-terminal truncated FVII (Arg462X FVII) corresponding to the identified mutation in CHO-K1 cells. To study roles of the carboxyl-terminus in the secretion of FVII, we also expressed a series of recombinant FVIIs deleted of limited numbers of carboxyl-terminal amino acids (462Arg-466Pro). RESULTS: We identified a nonsense mutation (c.1384C>T: p.Arg462X) in F7, leading to a lack of five amino acids in the carboxyl-terminus. In expression experiments, Arg462X FVII was undetectable not only by Western blotting, but also by ELISA. A Western blot analysis of the truncated FVIIs revealed that all mutants were expressed in the cells the same as the wild type, but were secreted into the culture medium in lesser amounts than the wild type depending on the length of the deletion, which was confirmed by ELISA. Arg462X FVII did not colocalize with the Golgi on immunofluorescence staining, suggesting that it might be retained in the ER and degraded in the cell. CONCLUSION: The carboxyl-terminal amino acids of FVII play an important role in its secretion, and the p.Arg462X mutation was likely to have caused the FVII deficiency in this patient.

Quantitative measurements of oxidative stress in mouse skin induced by X-ray irradiation.

To find efficient methods to evaluate oxidative stress in mouse skin caused by X-ray irradiation, several markers and methodologies were examined. Hairless mice were irradiated with 50 Gy X-rays and skin homogenates or skin strips were prepared. Lipid peroxidation was measured using the skin homogenate as the level of thiobarbituric acid reactive substances. The level of lipid peroxidation increased with time after irradiation and was twice that of the control at 78 h. ESR spectra of skin strips showed a clear signal for the ascorbyl radical, which increased with time after irradiation in a manner similar to that of lipid peroxidation. To measure levels of glutathione (GSH) and its oxidized forms (GSSG) simultaneously, two HPLC methods, sample derivatization with 1-fluoro-2,4-dinitrobenzene and detection with a UV detector (method A) and no derivatization and detection with an electrochemical detector (method B), were compared and the latter was found to be better. No significant change was observed within 24 h after irradiation in the levels of GSH and GSSG measured by method B. The GSH/GSSG ratio may be a less sensitive parameter for the evaluation of acute oxidative stress caused by X-ray irradiation in the skin. Monitoring the ascorbyl radical seems to be a good way to evaluate oxidative stress in skin in vivo.

Ultrasonic plastic welding using fundamental and higher resonance frequencies.

Ultrasonic plastic welding using fundamental and higher resonance frequency vibrations simultaneously was studied. Using higher frequency, welding characteristics is improved due to the larger vibration loss of plastic materials. The 26 kHz welding tip vibrates in maximum velocity of over 4.5 m/s (peak-to-zero value) under a fundamental resonance frequency and there are several higher resonance frequencies up to 95 kHz whose vibration velocities are over one-third that of the fundamental frequency. Welding characteristics of 1.0-mm-thick polypropylene sheets are measured in the cases the vibration system are driven under combined driving voltages of fundamental and higher resonance frequencies. Welded area increases as number of driven higher frequencies increases. The welded area by three frequencies is about three to four times that of the case where only the fundamental frequency is driven. The welding characteristics of ultrasonic plastic welding are improved significantly by driving higher resonance frequencies simultaneously.