Target deconvolution studies of (2R,6R)-hydroxynorketamine: an elusive search

The off-label use of racemic ketamine and the FDA approval of (S)-ketamine are promising developments for the treatment of depression. Nevertheless, racemic ketamine and (S)-ketamine are controlled substances with known abuse potential and their use is associated with undesirable side effects. For these reasons, research efforts have focused on identifying alternatives. One candidate is (2R,6R)-hydroxynorketamine ((2R,6R)-HNK), a ketamine metabolite that in preclinical models lacks the dissociative and abuse properties of ketamine while retaining its antidepressant-like behavioral efficacy. (2R,6R)-HNK's mechanism of action however is unclear. The main goals of this study were to perform an in-depth pharmacological characterization of (2R,6R)-HNK at known ketamine targets, to use target deconvolution approaches to discover novel proteins that bind to (2R,6R)-HNK, and to characterize the biodistribution and behavioral effects of (2R,6R)-HNK across several procedures related to substance use disorder liability. We found that unlike (S)- or (R)-ketamine, (2R,6R)-HNK did not directly bind to any known or proposed ketamine targets. Extensive screening and target deconvolution experiments at thousands of human proteins did not identify any other direct (2R,6R)-HNK-protein interactions. Biodistribution studies using radiolabeled (2R,6R)-HNK revealed non-selective brain regional enrichment, and no specific binding in any organ other than the liver. (2R,6R)-HNK was inactive in conditioned place preference, open-field locomotor activity, and intravenous self-administration procedures. Despite these negative findings, (2R,6R)-HNK produced a reduction in immobility time in the forced swim test and a small but significant increase in metabolic activity across a network of brain regions, and this metabolic signature differed from the brain metabolic profile induced by ketamine enantiomers. In sum, our results indicate that (2R,6R)-HNK does not share pharmacological or behavioral profile similarities with ketamine or its enantiomers. However, it could still be possible that both ketamine and (2R,6R)-HNK exert antidepressant-like efficacy through a common and previously unidentified mechanism. Given its pharmacological profile, we predict that (2R,6R)-HNK will exhibit a favorable safety profile in clinical trials, and we must wait for clinical studies to determine its antidepressant efficacy.

The role of 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma after radioimmunotherapy using 131I-rituximab as consolidation therapy

Purpose

To evaluate the prognostic value of pretreatment ¹⁸F-FDG PET/CT after consolidation therapy of ¹³¹I-rituximab in patients with diffuse large B-cell lymphoma (DLBCL) who had acquired complete remission after receiving chemotherapy.

Methods

Patients who were diagnosed with DLBCL via histologic confirmation were retrospectively reviewed. All patients had achieved complete remission after 6 to 8 cycles of R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisolone) chemotherapy after which they underwent consolidation treatment with ¹³¹I-rituximab. ¹⁸F-FDG PET/CT scans were performed before R-CHOP for initial staging. The largest diameter of tumor, maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained from pretreatment ¹⁸F-FDG PET/CT scans. Receiver-operating characteristic curves analysis was introduced for assessing the optimal criteria. Kaplan-Meier curve survival analysis was performed to evaluate both relapse free survival (RFS) and overall survival (OS).

Results

A total of 15 patients (12 males and 3 females) with a mean age of 56 (range, 30–73) years were enrolled. The median follow-up period of these patients was 73 months (range, 11–108 months). Four (27%) patients relapsed. Of them, three died during follow-up. Median values of the largest tumor size, highest SUVmax, MTV, and TLG were 5.3 cm (range, 2.0–16.4 cm), 20.2 (range, 11.1–67.4), 231.51 (range, 15–38.34), and 1277.95 (range, 238.37–10341.04), respectively. Patients with SUVmax less than or equal to 16.9 showed significantly worse RFS than patients with SUVmax greater than 16.9 (5-year RFS rate: 60% vs. 100%, p = 0.008). Patients with SUVmax less than or equal to 16.9 showed significantly worse OS than patients with SUVmax greater than 16.9 (5-year OS rate: 80% vs. 100% p = 0.042).

Conclusion

Higher SUVmax at pretreatment ¹⁸F-FDG PET/CT was associated with better relapse free survival and overall survival in DLBCL patients after consolidation therapy with ¹³¹I-rituximab. However, because this study has a small number of patients, a phase 3 study with a larger number of patients is needed for clinical application in the future.

Application of real-time MRI-guided linear accelerator in stereotactic ablative body radiotherapy for non-small cell lung cancer: one step forward to precise targeting

PURPOSE

Tumor motion is a major challenge in stereotactic ablative body radiotherapy (SABR) for non-small cell lung cancer (NSCLC), causing excessive irradiation to compensate for this motion. Real-time tumor tracking with a magnetic resonance imaging-guided linear accelerator (MR-Linac) could address this problem. This study aimed to assess the effects and advantages of MR-Linac in SABR for the treatment of lung tumors.

METHODS

Overall, 41 patients with NSCLC treated with SABR using MR-Linac between March 2019 and December 2021 were included. For comparison, 40 patients treated with SABR using computed tomography-based modalities were also enrolled. The SABR dose ranged from 48 to 60 Gy in 3-5 fractions. The primary endpoint was a lower radiation volume compared to CT-based SABR. The secondary endpoint was the local control rate of SABR using the MR-Linac.

RESULTS

The median follow-up time was 19 months (range: 3-105 months). There was no significant difference in the gross tumor volume between the MR and CT groups (7.1 ± 9.3 cm³ vs 8.0 ± 6.8 cm³, p = 0.643), but the planning target volume was significantly smaller in the MR group (20.8 ± 18.8 cm³ vs 34.1 ± 22.9 cm³, p = 0.005). The 1-year local control rates for the MR and CT groups were 92.1 and 75.4%, respectively (p = 0.07), and the 1-year overall survival rates were 87.4 and 87.0%, respectively (p = 0.30).

CONCLUSION

Lung SABR with MR-Linac can reduce the radiation field without compromising the local control rate. Further follow-up is needed to assess the long-term effects.

Design, Synthesis, and Characterization of [18F]mG2P026 as a High-Contrast PET Imaging Ligand for Metabotropic Glutamate Receptor 2

An array of triazolopyridines based on JNJ-46356479 (6) were synthesized as potential positron emission tomography radiotracers for metabotropic glutamate receptor 2 (mGluR2). The selected candidates 8-10 featured enhanced positive allosteric modulator (PAM) activity (20-fold max.) and mGluR2 agonist activity (25-fold max.) compared to compound 6 in the cAMP GloSensor assays. Radiolabeling of compounds 8 and 9 (mG2P026) was achieved via Cu-mediated radiofluorination with satisfactory radiochemical yield, >5% (non-decay-corrected); high molar activity, >180 GBq/μmol; and excellent radiochemical purity, >98%. Preliminary characterization of [¹⁸F]8 and [¹⁸F]9 in rats confirmed their excellent brain permeability and binding kinetics. Further evaluation of [¹⁸F]9 in a non-human primate confirmed its superior brain heterogeneity in mapping mGluR2 and higher affinity than [¹⁸F]6. Pretreatment with different classes of PAMs in rats and a primate led to similarly enhanced brain uptake of [¹⁸F]9. As a selective ligand, [¹⁸F]9 has the potential to be developed for translational studies.

Correlation of Animal-based parameters with environment-based parameters in an on-farm welfare assessment of growing pigs

Nine pig farms were evaluated for the welfare quality in Korea using animal- and environment-based parameters (particularly air quality parameters) during the winter of 2013. The Welfare Quality^® (WQ^®) protocol consists of 12 criteria within four principles. The WQ^® protocol classifies farms into four categories ranging from ‘excellent’ to ‘not classified’. Each of these criteria has specific measures for calculating scores. Calculations for the welfare scores were conducted online using the calculation model in the WQ^® protocol. Environment-based parameters like microclimate (i.e., temperature, relative humidity, air speed, and particulate matter), bacteria (total airborne bacteria, airborne total coliform, and airborne total Escherichia coli), concentration of gases (carbon dioxide, ammonia, and hydrogen sulfide) were measured to investigate the relationship between animal- and environment-based parameters. Correlations between the results of animal- and environment-based parameters were estimated using spearman correlation coefficient. The overall assessments found that five out of nine farms were ‘acceptable’, and four farms were ‘enhanced’; no farm was ‘not classified’. The average score for the four principles across the nine farms, in decreasing order, were ‘good feeding’ (63.13 points) > ‘good housing’ (59.26 points) > ‘good health’ (33.47 points) > ‘appropriate behaviors’ (25.48 points). In the result of the environment aspect, the relative humidity of farms 2 (93.4%), 3 (100%), and 9 (98%) was much higher than the recommended maximum relative humidity of 80%, and four out of the nine farms had ammonia concentrations greater than 40 ppm. Ammonia had negative correlations with ‘positive social behaviors’ and positive emotional states: content, enjoying, sociable, playful, lively, happy and it had positive correlations with negative emotional states: aimless, distressed. The concentration of carbon dioxide had negative correlations with positive emotional states; calm, sociable, playful, happy and it had a positive correlation with negative emotional state; aimless. Our results indicate that the control of the environment for growing pigs can help improve their welfare, particularly via good air quality (carbon dioxide, ammonia, hydrogen sulfide).

Synthesis and Characterization of 5-(2-Fluoro-4-[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2

Metabotropic glutamate receptor 2 (mGluR2) is a therapeutic target for several neuropsychiatric disorders. An mGluR2 function in etiology could be unveiled by positron emission tomography (PET). In this regard, 5-(2-fluoro-4-[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridine-7-carboxamide ([11C]13, [11C]mG2N001), a potent negative allosteric modulator (NAM), was developed to support this endeavor. [11C]13 was synthesized via the O-[11C]methylation of phenol 24 with a high molar activity of 212 ± 76 GBq/μmol (n = 5) and excellent radiochemical purity (>99%). PET imaging of [11C]13 in rats demonstrated its superior brain heterogeneity and reduced accumulation with pretreatment of mGluR2 NAMs, VU6001966 (9) and MNI-137 (26), the extent of which revealed a time-dependent drug effect of the blocking agents. In a nonhuman primate, [11C]13 selectively accumulated in mGluR2-rich regions and resulted in high-contrast brain images. Therefore, [11C]13 is a potential candidate for translational PET imaging of the mGluR2 function.

Association of EGFR mutations in second primary lung cancer and HER2 expression in breast cancer survivors

Background

The incidence of second primary lung cancer (SPLC) is increasing with longer survival rates from breast cancer. Despite of studies to suggest the mutual exclusivity of epidermal growth factor receptor (EGFR) and human epidermal growth receptor 2 (HER2) in several cancers, the effect of HER2 expression in breast cancer on EGFR mutations in SPLC is unclear. Therefore, this study aimed to determine the association between HER2 expression and EGFR mutations.

Methods

We conducted a retrospective cohort study of breast cancer survivors diagnosed with SPLC after breast cancer treatment between 1997 and 2018. We investigated the association between HER2 expression in breast cancer and EGFR mutations in SPLC, specifically focusing on negative correlations by using logistic regression analysis.

Results

EGFR mutations in SPLC were detected in 19 of 38 patients. Analysis for HER2 revealed a statistically significant difference in the proportion of EGFR mutations between patients with SPLC and previous HER2 positive breast cancer (43.5%) and those with SPLC and previous HER2 negative breast cancer (90.0%; P=0.021). The ratio of EGFR mutations decreased with the degree of HER2 expression in patients with previous breast cancer (90.0%: for no HER2 expression, 62.5% for HER2 1+, 0.0% for HER2 2+, and 41.7% for HER2 3+; P=0.018). Multivariate logistic analyses revealed that EGFR mutations in SPLC were significantly associated with age [odds ratio (OR): 1.11, 95% confidence interval (CI): 1.01-0.23, P=0.039] and HER2 positive status (OR: 0.04, 95% CI: 0.01-0.56, P=0.017).

Conclusions

This study suggests that the frequency of EGFR mutations in SPLC may be associated with low HER2 expression in previous breast cancer.

Real-world experience of safety and effectiveness of regorafenib for treatment of metastatic colorectal cancer, advanced gastrointestinal stromal tumors, and hepatocellular carcinoma: a post-marketing surveillance study in Korea

Purpose: This regulatory post-marketing surveillance (PMS) study was performed to evaluate the safety and effectiveness of regorafenib on Korean patients with colorectal cancer (CRC), gastrointestinal stromal tumors (GIST), and hepatocellular carcinoma (HCC) in a real-world clinical setting.

Methods: This PMS was conducted as a multi-center, prospective, observational study at 34 centers in Korea from August 2013 to August 2019. The primary objective was to evaluate the safety of regorafenib in real-world practice, with the secondary objective to investigate its effectiveness, including its overall response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results: In total, 301 patients were included in the analysis (254 patients with CRC, 14 patients with GIST, and 33 patients with HCC). The incidence rates of adverse events (AEs) were 85.0%, 78.6%, and 81.8% in patients with CRC, GIST, and HCC, respectively. The most frequent AE related to regorafenib in the three cancer types was palmar-plantar erythrodysesthesia syndrome (PPES). The ORRs of patients with CRC, GIST, and HCC were 4.7%, 0%, and 41.4%, respectively. The median PFS and OS were 2.1 and 6.1 months for CRC, respectively; 9.2 and 16.4 months for GIST, respectively; and 5.5 months and not estimated (NE) for HCC, respectively. Patients who experienced a dose modification or discontinuation of regorafenib showed significantly shorter median PFS and OS (2.2 vs. 2.6 months, respectively, P = 0.0335 for PFS; 5.3 vs. 8.5 months, respectively, P = 0.0010 for OS).

Conclusion: This PMS study, which is the largest surveillance study of CRC in Korea, found no newly identified safety concerns for patients who received regorafenib in the real-world setting. Additionally, the results of this study were consisted with those previously reported in phase III trials.

Pegfilgrastim Prophylaxis is Effective in the Prevention of Febrile Neutropenia and Reduces Mortality in Patients Aged ≥75 Years with Diffuse Large B-Cell Lymphoma Treated with R-CHOP: A Prospective Cohort Study

Purpose

Febrile neutropenia (FN) can cause suboptimal treatment and treatment-related mortality (TRM) in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP).

Materials and Methods

We conducted a prospective cohort study to evaluate the effectiveness of pegfilgrastim prophylaxis in DLBCL patients receiving R-CHOP, and we compared them with the PROCESS cohort (n=485).

Results

Since January 2015, 986 patients with DLBCL were enrolled. Pegfilgrastim was administered at least once in 930 patients (94.3%), covering 90.3% of all cycles. FN developed in 137 patients (13.9%) in this cohort (23.7% in the PROCESS cohort, p < 0.001), and 4.2% of all cycles (10.2% in the PROCESS cohort, p < 0.001). Dose delay was less common (≥ 3 days: 18.1% vs. 23.7%, p=0.015; ≥ 5 days: 12.0% vs. 18.3%, p=0.023) in this cohort than in the PROCESS cohort. The incidence of TRM (3.2% vs. 5.6%, p=0.047) and infection-related death (1.8% vs. 4.5%, p=0.004) was lower in this cohort than in the PROCESS cohort. The 4-year overall survival (OS) and progression-free survival (PFS) rates of the two cohorts were not different (OS: 73.0% vs. 71.9%, p=0.545; PFS: 69.5% vs. 68.8%, p=0.616). However, in patients aged ≥ 75 years, the 4-year OS and PFS rates were higher in this cohort than in the PROCESS cohort (OS: 49.6% vs. 33.7%, p=0.032; PFS: 44.2% vs. 30.3% p=0.047).

Conclusion

Pegfilgrastim prophylaxis is effective in the prevention of FN and infection-related death in DLBCL patients receiving R-CHOP, and it also improves OS in patients aged ≥ 75 years.

Structure, function and pharmacology of human itch GPCRs

The MRGPRX family of receptors (MRGPRX1-4) is a family of mas-related G-protein-coupled receptors that have evolved relatively recently1. Of these, MRGPRX2 and MRGPRX4 are key physiological and pathological mediators of itch and related mast cell-mediated hypersensitivity reactions2-5. MRGPRX2 couples to both Gi and Gq in mast cells6. Here we describe agonist-stabilized structures of MRGPRX2 coupled to Gi1 and Gq in ternary complexes with the endogenous peptide cortistatin-14 and with a synthetic agonist probe, respectively, and the development of potent antagonist probes for MRGPRX2. We also describe a specific MRGPRX4 agonist and the structure of this agonist in a complex with MRGPRX4 and Gq. Together, these findings should accelerate the structure-guided discovery of therapeutic agents for pain, itch and mast cell-mediated hypersensitivity.

A novel index reflecting both anatomical and physiologic parameters in coronary artery disease, the FFR adjusted SYNTAX score (FaSs)

Background

Various physiology-based indices have been proposed to predict adverse clinical events in patients with coronary artery disease (CAD), such as the sum of three vessel-fractional flow reserve (3v-FFR), and the functional SYNTAX score (fSS). However, these values could not fully reflect the anatomical factors, which remains as a barrier for clinical application of these indices.

Purpose

To propose a novel index which can reflect both anatomical and physiologic features in CAD patients, and evaluate the additional predictive value for cardiovascular adverse events compared to previous indices.

Methods

For an index which can reflect both anatomical and physiologic features, we proposed the FFR adjusted SYNTAX score (FaSs). The FaSs is calculated by adding the product of the SYNTAX score and `1-FFR', for all three major coronary arteries. Among the 1136 patients who enrolled at 3V FFR-FRIENDS study, we investigated 866 patients, after excluding those who had missing variables. The 3v-FFR, fSS and FaSs were calculated, derived from the baseline FFR and SYNTAX score. Patients were divided into two groups according to the median value of each index. The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischemia-driven revascularization) at 2 years follow-up.

Results

Among the total population, MACE occurred in 35 (4.04%) patients. Using the median value in a multivariable COX regression model, only FaSs was associated with an increased risk of MACE, (Hazard Ratio [HR] 5.256, 95% confidence interval [CI] 2.014–13.720), while 3v-FFR (HR 1.383, 95% CI 0.685–2.790) and fSS (HR 1.640, 95% CI 0.830–3.243) were not significantly associated with a higher risk of MACE. This was also observed in the Kaplan Meier survival curve analysis (log-rank p value: p&lt;0.001 for FaSs, 0.153 for 3v-FFR, and 0.061 for fSS; Figure 1) The sensitivity and specificity of the FaSs was 85.7% and 51.6%, which was higher compared to the 3v-FFR (62.9% and 49.3%, respectively) and fSS (57.1% and 58.5%, respectively). When these indices were combined with clinical risk factors (age, sex, hypertension, diabetes, hyperlipidemia, chronic renal failure, LVEF&lt;40%), FaSs was superior compared with 3v-FFR and fSS assessed in regards of the predictive accuracy for MACE (Figure 2).

Conclusion

The FaSs, which is a novel index calculated by a formula using the SYNTAX score and FFR, showed a superior predictive value for MACE compared to previous indices. Our results confirm the importance of considering both anatomical and physiologic parameters in evaluating the patient's risk for cardiovascular adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

A promising chemical series of positive allosteric modulators of the μ-opioid receptor that enhance the antinociceptive efficacy of opioids but not their adverse effects

Positive allosteric modulators (PAMs) of the μ-opioid receptor (MOR) have been proposed to exhibit therapeutic potential by maximizing the analgesic properties of clinically used opioid drugs while limiting their adverse effects or risk of overdose as a result of using lower drug doses. We herein report in vitro and in vivo characterization of two small molecules from a chemical series of MOR PAMs that exhibit: (i) MOR PAM activity and receptor subtype selectivity in vitro, (ii) a differential potentiation of the antinociceptive effect of oxycodone, morphine, and methadone in mouse models of pain that roughly correlates with in vitro activity, and (iii) a lack of potentiation of adverse effects associated with opioid administration, such as somatic withdrawal, respiratory depression, and analgesic tolerance. This series of MOR PAMs holds promise for the development of adjuncts to opioid therapy to mitigate against overdose and opioid use disorders.

Multicenter, phase II study of response-adapted lenalidomide-based therapy for transplant-ineligible patients with newly diagnosed multiple myeloma without high-risk features

Lenalidomide and low-dose dexamethasone (Rd) are a standard treatment for older adults with multiple myeloma (MM). Lenalidomide monotherapy has rarely been evaluated for newly diagnosed transplant-ineligible MM patients. This multicenter phase II trial evaluated a response-adapted strategy for elderly patients with newly diagnosed MM without high-risk features. Patients were administered single-agent lenalidomide for the first 21 days of two 28-day cycles. Patients with progressive disease received Rd. The primary endpoint was progression-free survival using the uniform response assessment from the International Myeloma Working Group . Of the 34 enrolled patients, 28 were included in the efficacy analysis. The overall response rate (ORR, ≥ partial response [PR]) to single-agent lenalidomide or lenalidomide plus prednisone was 64.3%. Ten patients received Rd after disease progression, with an Rd ORR of 70%. The ORR of response-adapted lenalidomide-based therapy was 75%. After the median follow-up of 35.6 months, the median progression-free survival was 33.5 months (95% confidence interval [CI], 16.9-50.2), and the median overall survival was 51.8 months (95% CI, 22.0-81.6). The most common adverse event was neutropenia (46.7%), and 17 patients (56.7%) experienced infection including pneumonia. Response-adapted lenalidomide-based therapy was feasible in newly diagnosed, transplant-ineligible MM patients without high-risk features.

Autologous EBV-specific T cell treatment results in sustained responses in patients with advanced extranodal NK/T lymphoma: results of a multicenter study

We conducted a phase II clinical trial to develop an autologous EBV-specific T cell product (baltaleucel T) for advanced, relapsed ENKTL. Among 47 patients who provided whole blood starting material for manufacturing the product, 15 patients received a median of 4 doses of baltaleucel T. Thirty-two (68%) patients did not receive baltaleucel-T due to manufacturing failure, rapid disease progression, and death. Of the 15 patients, 10 patients had measurable disease at baseline (salvage cohort), and 5 patients had no disease at baseline assessment (adjuvant cohort). In the 15 patients, the median follow-up duration was 10.2 months (range 2.0-23.5 months), median progression-free survival (PFS) was 3.9 months, and the median overall survival (OS) was not reached. Patients in the salvage cohort achieved a 30% complete response (CR) and a 50% overall response rate (ORR). In the adjuvant cohort, disease progression was reported in three patients and two patients did not relapse during study follow-up. When we compared survival outcomes of seven responders and eight non-responders, the PFS (P = 0.001) and OS (P = 0.014) of responders proved statistically superior to that of non-responders. Baltaleucel-T was well tolerated. We have performed a phase II clinical trial of autologous EBV-specific T cell treatment (baltaleucel-T) in R/R ENKTL. Autologous EBV-specific T cells were well tolerated and demonstrated single-agent activity in R/R ENTKL.

Incidence and risk factors of urinary tract infections in hospitalised patients with spinal cord injury

AIMS AND OBJECTIVES

To investigate the incidence of urinary tract infection and analyse its risk factors among hospitalised patients with spinal cord injury.

BACKGROUND

While the incidence of urinary tract infection varies widely according to the healthcare setting and patients' clinical characteristics, formal reports are limited in quantity. There has been no consensus regarding the risk factors for urinary tract infection.

DESIGN

A retrospective descriptive study.

METHODS

Electronic medical records of 964 subjects between 2010-2017 were reviewed. Urinary tract infection status was examined to identify newly occurred cases. Data included demographic and clinical characteristics, hydration status and length of hospitalisation. The reporting of the study followed the EQUATOR Network's STROBE checklist.

RESULTS

Of the sample, 31.7% had urinary tract infection (95% confidence interval: 1.288 to 1.347, p < .001). Sex, completeness of injury, type of bladder emptying, detrusor function and urethral pressure were significant factors affecting urinary tract infection. Patients who were male and those with injury classifications A, B and C had higher risk of urinary tract infection. Patients with urinary or suprapubic indwelling catheters, as well as those with areflexic detrusor combined with normotonic urethral pressure or overactive detrusor combined with normotonic urethral pressure, showed higher risk. Length of hospitalisation in patients with urinary tract infection was greater than that in uninfected patients, which implies the importance of prevention of urinary tract infection.

CONCLUSIONS

Nurses should carefully assess risk factors to prevent urinary tract infection in patients with spinal cord injury in the acute and sub-acute stages of the disease trajectory and provide individualised nursing care.

RELEVANCE TO CLINICAL PRACTICE

This study contributes evidence for up-to-date clinical nursing practice for the comprehensive management of urinary tract infection. This can lead to improvements in nursing care quality and patient outcomes, including length of hospitalisation.

Assessment of postoperative acromial and subacromial morphology after arthroscopic acromioplasty using magnetic resonance imaging

OBJECTIVE

To identify the morphological characteristics of the acromion and subacromial bursal space after arthroscopic acromioplasty using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

One hundred patients who received arthroscopic rotator cuff repair and acromioplasty each received at least three MRI examinations (preoperative, first immediate postoperative, and second follow-up imaging between 8 months and 1 year postoperatively). Changes over time in the thickness and morphology of the postoperative acromion as well as the subacromial bursal space were assessed. Clinical and radiological parameters were also analyzed to identify any association with changes in acromial morphology.

RESULTS

Despite minimal acromial thinning observed at the first immediate postoperative state, the acromions showed significant thinning at the second postoperative MRI, with a mean reduction of 32%. Along with acromial thinning, an exaggerated concave contour of the acromial undersurface was observed in some patients. In the subacromial space, a loculated fluid collection developed in 91% of the patients at the second postoperative follow-up. No statistically significant association was noted between postoperative acromial thickness change and clinical or radiological factors (P value > 0.05).

CONCLUSION

A significant delayed reduction in acromial thickness within approximately 1 year of arthroscopic acromioplasty is thought to be a normal postoperative feature. The simultaneous collection of a loculated, cyst-like fluid in the subacromial bursal space may be an important associated factor of postoperative acromial thinning.

Synthesis and Characterization of [18F]JNJ-46356479 as the First 18F-Labeled PET Imaging Ligand for Metabotropic Glutamate Receptor 2

PURPOSE

Metabotropic glutamate receptor 2 (mGluR2) has been implicated in various psychiatric and neurological disorders, such as schizophrenia and Alzheimer's disease. We have previously developed [¹¹C]7 as a PET radioligand for imaging mGluR2. Herein, [¹⁸F]JNJ-46356479 ([¹⁸F]8) was synthesized and characterized as the first ¹⁸F-labeled mGluR2 imaging ligand to enhance diagnostic approaches for mGluR2-related disorders.

PROCEDURES

JNJ-46356479 (8) was radiolabeled via the copper (I)-mediated radiofluorination of organoborane 9. In vivo PET imaging experiments with [¹⁸F]8 were conducted first in C57BL/6 J mice and Sprague-Dawley rats to obtain whole body biodistribution and brain uptake profile. Subsequent PET studies were done in a cynomolgus monkey (Macaca fascicularis) to investigate the uptake of [¹⁸F]8 in the brain, its metabolic stability, as well as pharmacokinetic properties.

RESULTS

JNJ-46356479 (8) exhibited excellent selectivity against other mGluRs. In vivo PET imaging studies showed reversible and specific binding characteristic of [¹⁸F]8 in rodents. In the non-human primate, [¹⁸F]8 displayed good in vivo metabolic stability, excellent brain permeability, fast and reversible kinetics with moderate heterogeneity across brain regions. Pre-treatment studies with compound 7 revealed time-dependent decrease of [¹⁸F]8 accumulation in mGluR2 rich regions based on SUV values with the highest decrease in the nucleus accumbens (18.7 ± 5.9%) followed by the cerebellum (18.0 ± 7.9%), the parietal cortex (16.9 ± 7.8%), and the hippocampus (16.8 ± 6.9%), similar to results obtained in the rat studies. However, the volume of distribution (V_T) results derived from 2T4k model showed enhanced V_T from a blocking study with compound 7. This is probably because of the potentiating effect of compound 7 as an mGluR2 PAM as well as related non-specific binding in the tissue data.

CONCLUSIONS

[¹⁸F]8 readily crosses the blood-brain barrier and demonstrates fast and reversible kinetics both in rodents and in a non-human primate. Further investigation of [¹⁸F]8 on its binding specificity would warrant translational study in human.

Remarkable variation of visible light photocatalytic activities of M/Sn0.9Sb0.1O2/TiO2 (M=Au, Ag, Pt) heterostructures depending on the loaded metals

Sn_0.9Sb_0.1O₂/TiO₂ (ATO/TiO₂) heterostructure is a potential visible light photocatalysts that function via an inter-semiconductor hole-transport mechanism. Herein we selectively deposited Au, Ag, or Pt onto the ATO surface of ATO/TiO₂ to investigate charge-trapping behaviors of the noble metals and their effects on photocatalytic performance. We observed that Pt deposition greatly enhanced the photocatalytic activity whereas effects of Au or Ag depositions were not significant. The result of spectroscopic analysis also indicates that Pt is the most effective in scavenging the electrons from the ATO CB. Particularly, Pt/ATO/TiO₂ (ATO:TiO₂ = 15:85 in weight) produced CO₂ of 42 ppmv in 2 h, which is 16 times and 4.8 times that of bare ATO/TiO₂ and nitrogen-doped TiO₂, respectively. Pt deposition on the ATO seems to suppress two independent charge recombination pathways, that is, recombination of electron-hole pairs in ATO and electron transport from the ATO CB to TiO₂ VB.

Design, Synthesis, and Characterization of Benzimidazole Derivatives as Positron Emission Tomography Imaging Ligands for Metabotropic Glutamate Receptor 2

Three benzimidazole derivatives (13-15) have been synthetized as potential positron emission tomography (PET) imaging ligands for mGluR2 in the brain. Of these compounds, 13 exhibits potent binding affinity (IC₅₀ = 7.6 ± 0.9 nM), positive allosteric modulator (PAM) activity (EC₅₀ = 51.2 nM), and excellent selectivity against other mGluR subtypes (>100-fold). [¹¹C]13 was synthesized via O-[¹¹C]methylation of its phenol precursor 25 with [¹¹C]methyl iodide. The achieved radiochemical yield was 20 ± 2% (n = 10, decay-corrected) based on [¹¹C]CO₂ with a radiochemical purity of >98% and molar activity of 98 ± 30 GBq/μmol EOS. Ex vivo biodistribution studies revealed reversible accumulation of [¹¹C]13 and hepatobiliary and urinary excretions. PET imaging studies in rats demonstrated that [¹¹C]13 accumulated in the mGluR2-rich brain regions. Pre-administration of mGluR2-selective PAM, 17 reduced the brain uptake of [¹¹C]13, indicating a selective binding. Therefore, [¹¹C]13 is a potential PET imaging ligand for mGluR2 in different central nervous system-related conditions.

Synergistic Effect of Lymphatic Invasion and Venous Invasion on the Risk of Lymph Node Metastasis in Patients with Non-Curative Endoscopic Resection of Early Gastric Cancer

BACKGROUND

Although additive radical surgery is recommended for patients with non-curative endoscopic resection for early gastric cancer (EGC), lymph node (LN) metastasis or remnant tumor is detected in only about 10% of patients. Therefore, we aimed to identify patients who required surgery by identifying significant risk factors for LN metastasis and evaluate long-term outcomes in patients with non-curative endoscopic resection.

METHODS

We retrospectively analyzed the database of Seoul National University Hospital to identify patients who underwent endoscopic resection for EGC from June 2005 to December 2016.

RESULTS

Three hundred and twenty-nine patients did not meet the criteria for curative resection after endoscopic resection. Among them, 140 patients underwent additional surgery and 171 patients refused surgery and regularly received follow-up. In the surgery group, LN metastasis was found in 12.1% of patients. Logistic regression analysis revealed that the rate of LN metastasis was significantly higher in patients with lymphatic invasion (LI) (odds ratio [OR] 5.84, p = 0.014) and venous invasion (VI) (OR 5.66, p = 0.006). We analyzed LN metastasis based on LI and VI in the surgical group. LN metastasis was significantly increased in the positive LI and VI groups compared with the negative LI and VI groups (OR 68.32; 95% confidence interval, 4.74-984.82; p = 0.002).

CONCLUSIONS

Both LI and VI were significant predictors of LN metastasis. The risk of LN metastasis was augmented when both LI and VI were positive. Therefore, LI and VI should be evaluated separately in patients with non-curative endoscopic resection. Additive surgery should be recommended for patients with LI and/or VI.

Intravenous busulfan and melphalan versus high-dose melphalan as a conditioning regimen for early autologous stem cell transplantation in patients with multiple myeloma: a propensity score-matched analysis

We compared the efficacy and toxicity of busulfan and melphalan (BUMEL) and those of high-dose melphalan (HDMEL) as conditioning regimens for autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM) through a propensity score-matched analysis. No significant difference in the complete response and overall response rate after ASCT was observed between BUMEL and HDMEL. After a median follow-up of 37.3 months in the BUMEL group and 50.8 months in the HDMEL group, the median progression-free survival was calculated to be 32.9 months and 25.2 months (p = 0.995). With respect to non-hematologic toxicities, infections were more frequently reported in the BUMEL group (p < 0.001). Three patients who received BUMEL developed veno-occlusive disease (VOD), and all of them recovered without administration of defibrotide. In conclusion, BUMEL is an effective alternative conditioning regimen in terms of efficacy, but attention should be paid to toxicities.

Treatment with intravenous busulfan, melphalan, and etoposide followed by autologous stem cell transplantation in patients with non-Hodgkin's lymphoma: a multicenter study from the consortium for improving survival of lymphoma

Several high-dose therapy (HDT) conditioning regimens have been used to treat non-Hodgkin's lymphoma (NHL), such as bis-chloroethylnitrosourea (BCNU)/etoposide/cytosine arabinoside/melphalan (BEAM), BCNU/etoposide/cytosine arabinoside/cyclophosphamide (BEAC), and cyclophosphamide/BCNU/etoposide (CBV). BCNU is an active drug in HDT of NHL, but the supply is limited in some countries, including Korea. Busulfan has been used in allogeneic and autologous stem cell transplantation (ASCT). This phase II study evaluated the efficacy of busulfan/melphalan/etoposide (BuME) as a conditioning regimen for HDT in relapsed or high-risk NHL. The regimen consisted of intravenous busulfan (3.2 mg/kg/day) on days -8, -7, and -6, etoposide (400 mg/m² /day) on days -5 and -4, and melphalan (50 mg/m² /day) on days -3 and -2. A total of 46 patients were included in the study, with 36 (78.3%) achieving a complete response after ASCT. The 2-year progression-free survival (PFS) and overall survival (OS) rates for all patients were 46.7% (95% CI, 31.8-60.4%) and 63.7% (95% CI, 47.7-76.0%), respectively. There was no development of veno-occlusive disease and no treatment-related deaths within 100 days after ASCT. These results indicate that a BuME regimen is well-tolerated and effective for patients with relapsed or high-risk NHL, and may be comparable to some previously used regimens. This regimen may be useful as a substitute for BCNU-containing regimens.

Pomalidomide, cyclophosphamide, and dexamethasone for elderly patients with relapsed and refractory multiple myeloma: A study of the Korean Multiple Myeloma Working Party (KMMWP-164 study)

Patients with transplant‐ineligible relapsed and refractory multiple myeloma (RRMM) have a short life expectancy, especially when they have failed both the proteasome inhibitor and immunomodulator therapies. This study aimed to assess the efficacy and safety of pomalidomide, cyclophosphamide, and dexamethasone (PCd) in elderly patients with RRMM. This phase 2 clinical trial recruited 55 elderly patients with RRMM. The patients underwent a 28‐day treatment cycle: pomalidomide (4 mg/day on days 1‐21, administered orally) and cyclophosphamide (400 mg/day on days 1, 8, and 15; administered orally) plus dexamethasone. The median (range) age of the patients was 73.3 (64‐86) years, and 8 (14.5%) patients who were ≥ 80 years old. Eight (14.5%) and 31 (56.4%) patients exhibited stage III (revised international staging system) and frail status (simplified frailty scale), respectively. The overall response rate (ORR) and clinical benefit rate (CBR) of PCd therapy were 58.2% and 72.7%, respectively. The median PFS and median overall survival (OS) were 6.90 months (95% CI, 4.7‐9.0) and 18.48 months (95% CI, 9.4‐27.6), respectively. The incidence rate of grade ≥ 3 non‐hematological toxicities was 70.8%. In particular, the incidence rate of primary infection was 45.4%, including 21.8% for pneumonia, 9.0% for sepsis, and 14.6% for febrile neutropenia. In conclusion, PCd is an effective regimen for elderly patients with RRMM who had failed both bortezomib and lenalidomide treatments, but in whom the treatment‐associated infection is the main cause of morbidity and mortality.