Short-term outcomes of laparoscopic and robotic distal gastrectomy for gastric cancer: Real-world evidence from a large-scale inpatient database in Japan.

BACKGROUND AND OBJECTIVES: Robotic distal gastrectomy (RDG) has been widely performed throughout Japan since it became insured in 2018. This study aimed to evaluate the short-term outcomes of RDG and laparoscopic distal gastrectomy (LDG) for gastric cancer using real-world data. METHODS: A total of 4161 patients who underwent LDG (n = 3173) or RDG (n = 988) for gastric cancer between April 2018 and October 2022 were identified through the Japanese Diagnosis Procedure Combination Database, which covers 42 national university hospitals. The primary outcome was postoperative in-hospital mortality rate. The secondary outcomes were postoperative complication rates, time to diet resumption, and postoperative length of stay (LOS). RESULTS: In-hospital mortality and postoperative complication rates in the RDG group were comparable with those in the LDG group (0.1% vs. 0.0%, p = 1.000, and 8.7% vs. 8.2%, p = 0.693, respectively). RDG was associated with a longer duration of anesthesia (325 vs. 262 min, p < 0.001), similar time to diet resumption (3 vs. 3 days, p < 0.001), and shorter postoperative LOS (10 vs. 11 days, p < 0.001) compared with LDG. CONCLUSIONS: RDG was performed safely and provided shorter postoperative LOS, since it became covered by insurance in Japan.

Impact of Oophorectomy on Survival and Improving Nutritional Status in Ovarian Metastasis from Colorectal Adenocarcinoma.

INTRODUCTION: Ovarian metastasis of colorectal cancer is known to have a poor prognosis. This study aimed to elucidate the characteristics of patients who underwent oophorectomy for ovarian metastasis from colorectal cancer. METHODS: This retrospective study included 16 patients who underwent oophorectomy for colorectal cancer metastasis to the ovary from January 2004 to December 2017. Improvement in patient's symptoms and pre- and postoperative changes in various nutritional and inflammatory indicators were assessed. Survival analysis and identification of prognostic factors were conducted with a median follow-up of 40.7 (5-109) months. RESULTS: Of 16 patients, 12 had (75%) synchronous and 4 (25%) had metachronous metastasis. Fourteen patients were symptomatic but symptoms resolved postoperatively. Thirteen patients (81.3%) had ascites and 5 (31.3%) had pleural effusion on preoperative computed tomography that disappeared after surgery in all cases. The median value of prognostic nutritional factor was significantly increased postoperatively (36.0 [preoperatively] vs. 47.5, p < 0.0001). The median (interquartile range) values for lymphocyte-C-reactive protein ratio were 715.2 (110-2,607) preoperatively and 6,095.2 (1,612.3-14,431.8) postoperatively (p = 0.0214). The median survival of the entire cohort was 60.4 months. The 3-year survival rates for R0 + R1 and R2 cases were 83% and 24% (p = 0.018), respectively. Univariate analysis showed that R2 resection and low postoperative lymphocyte-C-reactive protein ratio were associated with poor prognosis. CONCLUSIONS: Oophorectomy for ovarian metastasis from colorectal cancers was safely performed. It improved the patients' symptoms and nutritional status and may result in improved prognosis.

[A Case of Conversion Surgery after Nivolumab Monotherapy as Third-Line Therapy for Advanced Gastric Cancer].

A 79-year-old man with unresectable advanced gastric cancer due to invasion to the pancreas and positive lavage cytology( T4b, N+, M1, CY1, cStage ⅣB; Japanese classification of gastric carcinoma, 15th edition)received standard chemotherapy, including 6 courses of S-1 plus cisplatin as first-line therapy and 2 courses of paclitaxel plus ramucirumab followed by 6 courses of paclitaxel monotherapy as second-line therapy. The primary lesion became PD with these treatments. Subsequently, nivolumab monotherapy was introduced as third-line therapy. After 9 courses, the primary tumor shrunk, and lavage cytology turned to negative on diagnostic laparoscopy. We judged that the tumor was resectable, and the patient underwent radical total gastrectomy and D2 lymphadenectomy as conversion surgery. The pathological stage was ypT3(SS), N0, M0, CY0, and the therapeutic effect was Grade 1b. R0 resection was accomplished. He has been alive without recurrence for 18 months after resection without adjuvant chemotherapy.

Glutamate-Sensing Genes Are Conserved among Populations Compared to Glutamate Metabolism Genes.

INTRODUCTION: Glutamate is a representative taste molecule with an umami flavor and is a major nutrient found abundantly in nature. Furthermore, it plays a significant role in the human body as a key metabolic intermediate and neurotransmitter. Therefore, the divergence of glutamate functions among populations during their evolution is of particular interest with a hypothesis that the genetic variation can lead to understanding divergence in taste perception. To elucidate variation in glutamate applications and to deepen our understanding of taste perception, we examined the nucleotide diversity of genes associated with glutamate sensing and metabolism among human populations. METHODS: We first established 67 genes related to glutamate sensing and metabolism based on the database and literature survey. Then, for those genes, we used a population genomics approach based on ten populations over 76,156 human genomes in the gnomAD database. RESULTS: Statistical tests of means and medians of the minor allele frequencies did not show any significant difference among populations. However, we observed substantial differences between two functional groups, glutamate sensing and glutamate metabolism, in populations of Latino/admixed American, Ashkenazi Jewish, and Others. Interestingly, we could find significant differences between the African population and the East Asian population at the single nucleotide polymorphism level of glutamate metabolism genes, but no clear differences were noted in glutamate-sensing genes. These suggest that glutamate-sensing genes are under the functional constraint compared to glutamate metabolism genes. CONCLUSION: Thus, glutamate-sensing genes and metabolism genes have a contrasting mode of the evolution, and glutamate-sensing genes are conservatively evolved, indicating its functional importance.

Cetuximab Enhances the Efficacy of MRTX1133, a Novel KRASG12D Inhibitor, in Colorectal Cancer Treatment.

BACKGROUND/AIM: Kirsten Rat Sarcoma viral oncogene homolog (KRAS) has remained undruggable for decades. KRAS has predominantly been used to evaluate the applicability of anti-Epidermal Growth Factor Receptor (EGFR) antibody drugs. However, various KRAS inhibitors have recently emerged. Unfortunately, KRAS inhibitors have not been effective against colorectal cancer. Therefore, this study aimed to determine the effects of MRTX1133, a novel KRASG12D inhibitor, in combination with an anti-EGFR antibody, cetuximab, on signal transduction and cell proliferation. MATERIALS AND METHODS: The KRASG12D-mutated LS513 and KRAS wild-type CACO-2 human colon cancer cell lines were utilized. The KRASG12D mutation was stably transduced into the CACO-2 cells using a retrovirus. We evaluated the effects of the drugs using the CCK-8 assay and assessed the activity of proteins related to the MAPK pathway using western blotting. RESULTS: We demonstrated that the administration of MRTX1133, a novel KRASG12D inhibitor, to KRASG12D-mutated colorectal cancer cells led to feedback activation of the ERK pathway via EGFR activation, inducing drug resistance. Intriguingly, when MRTX1133 was used in combination with cetuximab, KRASG12D-mutant colorectal cancer growth was effectively inhibited, both in vitro and in vivo. CONCLUSION: The combination of MRTX1133 and cetuximab serves as a potential and promising therapeutic approach for colorectal cancer with KRASG12D mutation. KRASG12D is a frequent genetic mutation not only in colorectal cancer, but also in pancreatic and lung cancer, and the results of this study open new avenues for potential treatment of many cancer patients.

Increased mitochondria are responsible for the acquisition of gemcitabine resistance in pancreatic cancer cell lines.

Pancreatic ductal adenocarcinoma has a particularly poor prognosis as it is often detected at an advanced stage and acquires resistance to chemotherapy early during its course. Stress adaptations by mitochondria, such as metabolic plasticity and regulation of apoptosis, promote cancer cell survival; however, the relationship between mitochondrial dynamics and chemoresistance in pancreatic ductal adenocarcinoma remains unclear. We here established human pancreatic cancer cell lines resistant to gemcitabine from MIA PaCa-2 and Panc1 cells. We compared the cells before and after the acquisition of gemcitabine resistance to investigate the mitochondrial dynamics and protein expression that contribute to this resistance. The mitochondrial number increased in gemcitabine-resistant cells after resistance acquisition, accompanied by a decrease in mitochondrial fission 1 protein, which induces peripheral mitosis, leading to mitophagy. An increase in the number of mitochondria promoted oxidative phosphorylation and increased anti-apoptotic protein expression. Additionally, enhanced oxidative phosphorylation decreased the AMP/ATP ratio and suppressed AMPK activity, resulting in the activation of the HSF1-heat shock protein pathway, which is required for environmental stress tolerance. Synergistic effects observed with BCL2 family or HSF1 inhibition in combination with gemcitabine suggested that the upregulated expression of apoptosis-related proteins caused by the mitochondrial increase may contribute to gemcitabine resistance. The combination of gemcitabine with BCL2 or HSF1 inhibitors may represent a new therapeutic strategy for the treatment of acquired gemcitabine resistance in pancreatic ductal adenocarcinoma.

High SLC20A1 Expression Indicates Poor Prognosis in Prostate Cancer.

BACKGROUND/AIM: High expression of solute carrier family 20 member 1 (SLC20A1) indicates poor clinical outcomes for patients with breast cancer subtypes treated with endocrine therapy and radiotherapy. However, the association between SLC20A1 expression and clinical outcomes in prostate cancer remains to be determined. MATERIALS AND METHODS: Open-source datasets (The Cancer Genome Atlas prostate, Stand Up to Cancer-Prostate Cancer Foundation Dream Team, and The Cancer Genome Atlas PanCancer Atlas) were downloaded and analyzed. SLC20A1 expression was analyzed in prostate cancer and normal prostate tissue. Survival analysis using Kaplan-Meier curves and Cox regression analysis were performed to examine patient prognosis, as well as the effects of endocrine therapy and radiotherapy on high SLC20A1 expression in patients with prostate cancer. RESULTS: SLC20A1 was higher in prostate cancer than in normal prostate tissues. High SLC20A1 expression predicted poor disease-free and progression-free survival. Following endocrine therapy, no significant difference in prognosis was observed between patients with high SLC20A1 and those with low SLC20A1 expression. However, following radiotherapy, high SLC20A1 expression tended to be associated with a poor clinical outcome. CONCLUSION: SLC20A1 may serve as a prognostic biomarker for prostate cancer, and the recommended treatment for patients with high SLC20A1 expression is endocrine therapy.

MEK inhibitor and anti-EGFR antibody overcome sotorasib resistance signals and enhance its antitumor effect in colorectal cancer cells.

The Kirsten rat sarcoma (KRAS) oncogene was "undruggable" until sotorasib, a KRASG12C selective inhibitor, was developed with promising efficacy. However, inhibition of mutant KRAS in colorectal cancer cells (CRC) is ineffective due to feedback activation of MEK/ERK downstream of KRAS. In this study, we screened for combination therapies of simultaneous inhibition to overcome sotorasib resistance using our previously developed Mix Culture Assay. We evaluated whether there was an additive effect of sotorasib administered alone and in combination with two or three drugs: trametinib, a MEK inhibitor, and cetuximab, an anti-epidermal growth factor receptor (EGFR) antibody. The MAPK pathway was reactivated in KRASG12C-mutated cell lines treated with sotorasib alone. Treatment with KRAS and MEK inhibitors suppressed the reactivation of the MAPK pathway, but upregulated EGFR expression. However, the addition of cetuximab to this combination suppressed EGFR reactivation. This three-drug combination therapy resulted in significant growth inhibition in vitro and in vivo. Our data suggest that reactive feedback may play a key role in the resistance signal in CRC. Simultaneously inhibiting KRAS, MEK, and EGFR is a potentially promising strategy for patients with KRASG12C-mutated CRC.

Optimal Administration of Glycyrrhizin Avoids Pharmacokinetic Interactions With High-dose Methotrexate and Exerts a Hepatoprotective Effect.

BACKGROUND/AIM: Glycyrrhizin (GZ) is widely used to treat high-dose methotrexate (MTX)-induced liver dysfunction. However, in a previous in vivo study, we showed that simultaneous administration of both drugs increased the plasma concentration of MTX and exacerbated hepatic injuries. In this study, we investigated the optimal dosing interval in rats to avoid the interaction between high-dose MTX and GZ and to demonstrate the inherent hepatoprotective effect of GZ. MATERIALS AND METHODS: Male Wistar rats were treated with high-dose MTX (2,000 mg/kg) alone, with concomitant administration of 100 mg/kg GZ or GZ administered 3, 6, and 24 h before MTX administration. Plasma concentrations of MTX, alanine aminotransferase, aspartate aminotransferase, and total bilirubin were measured. RESULTS: The plasma concentration and half-life of methotrexate were significantly increased after concomitant administration of GZ, or when GZ was administered 3 h before MTX administration, compared with MTX alone, increasing hepatic enzyme levels. However, when GZ was administered 6 and 24 h before MTX administration, the levels were not significantly different from those of MTX alone and showed a tendency to decrease MTX-induced liver injury. These results suggest that the pharmacokinetic interaction between GZ and MTX could be avoided and the hepatoprotective effect of GZ could be achieved by an optimal dosing regimen, using the half-life of GZ as an indicator. CONCLUSION: When using high-dose MTX in combination with GZ, the administration intervals should be considered to avoid unwanted interactions and to achieve the GZ hepatoprotective effect.

Importance of intraoperative indocyanine green imaging in the management of non-occlusive mesenteric ischemia: a case report.

BACKGROUND: Non-obstructive intestinal ischemia (NOMI) is caused by intestinal vascular spasm and has a poor prognosis if not diagnosed and treated early. Indocyanine green (ICG) fluorescence imaging has been reported to be useful for the intraoperative assessment of the extent of intestinal resection required for NOMI. Few reports have described massive intestinal bleeding after conservative management of NOMI. We report a case of NOMI with massive postoperative bleeding from the site of an ICG contrast defect found before the initial surgery. CASE PRESENTATION: A 47-year-old woman with hemodialysis-dependent chronic kidney disease presented complaining of severe abdominal pain. A computed tomography scan showed portal gas and dilation of the small intestine, leading to a diagnosis of NOMI and subsequent emergency surgery. At the time of initial surgery, the contrast effect of ICG was slightly reduced, showing a granular distribution in the ascending colon to cecum (fine grain pattern) and significantly reduced in parts of the terminal ileum except around blood vessels (perivascular pattern). However, there was no obvious gross necrosis of the serosal surface, and the intestinal tract was not resected. The acute postoperative course was uneventful; however, the patient went into shock on the 24th postoperative day due to massive, small intestinal bleeding, and emergency surgery was performed. The bleeding originated from the section of the ileum that had complete loss of ICG contrast effect before the initial surgery. A right hemicolectomy with the terminal ileum resection was performed, and an ileo-transverse anastomosis was performed. The second post-operative course was uneventful. CONCLUSIONS: We report a case of delayed hemorrhage of the ileum shown to have poor blood flow on ICG imaging at the initial surgery. Intraoperative ICG fluorescence imaging is useful in assessing the degree of intestinal ischemia for NOMI. When patients with NOMI are followed up without surgery, complications such as bleeding should be noted.

RhoA G17E/Vav1 Signaling Induces Cancer Invasion via Matrix Metalloproteinase-9 in Gastric Cancer.

BACKGROUND: RAS homolog family member A (RhoA), a member of the Rho family of small GTPases, and Vav1, a guanine nucleotide exchange factor for Rho family GTPases, have been reported to activate pathways related to the actin cytoskeleton and regulation of cell shape, attachment, and motility. The interaction between these molecules in lymphoma is involved in malignant signaling, but its function in epithelial malignancy is unknown. Here, we investigated the malignant signal of mutant RhoA in gastric cancer and demonstrated the potential of RhoA G17E/Vav1 as a therapeutic target for diffuse gastric cancer. METHODS: The RhoA mutants R5W, G17E, and Y42C were retrovirally transduced into the gastric cancer cell line MKN74. The stably transduced cells were used for morphology, proliferation, and migration/invasion assays in vitro. MKN74 cells stably transduced with ectopic wild-type RhoA and mutant RhoA (G17E) were used in a peritoneal xenograft assay. RESULTS: The RhoA mutations G17E and Y42C induced morphological changes in MKN74. G17E induced Vav1 expression at the mRNA and protein levels and promoted the migration and invasion of MKN74. An RNA interference assay of Vav1 revealed that RhoA G17E enhanced cancer cell invasion via Vav1. Furthermore, immunoprecipitation revealed that Vav1 and RhoA G17E specifically bind and function together through matrix metalloproteinase -9. In a peritoneal xenograft model of nude mice, RhoA G17E promoted peritoneal dissemination, whereas Vav1 knockdown suppressed it. CONCLUSION: Overall, our findings indicate that RhoA G17E is associated with Vav1 and promoted cancer invasion via matrix metalloproteinase -9 in gastric cancer cells. Thus, RhoA G17E/Vav1 signaling in diffuse gastric cancer may be a useful therapeutic target.

Gastric glomus tumor resection using laparoscopic endoscopic cooperative surgery: A case report.

Gastric glomus tumors are rare submucosal mesenchymal neoplasms that are difficult to diagnose preoperatively. We present a case of a 60-year-old woman who was diagnosed with a gastric glomus tumor using endoscopic ultrasonography-guided fine-needle aspiration biopsy. The tumor was successfully resected with laparoscopic endoscopic cooperative surgery (LECS). LECS could be an effective method for the resection of gastric glomus tumors.

Risk factors for umbilical incisional hernia after laparoscopic colorectal surgery.

BACKGROUND: Laparoscopic colorectal surgery (LCRS) requires a small laparotomy at the umbilicus. The wound is small and inconspicuous, but if the patient develops an umbilical incisional hernia (UIH), the wound is visible and the patient suffers from symptoms of discomfort. However, the incidence of UIH after LCRS and its risk factors are not well understood. The purpose of this study was to investigate the risk factors for UIH after LCRS for colorectal cancer. METHODS: This was a single-centre retrospective study of 135 patients with colorectal cancer, conducted at our hospital from April 2013 to March 2019. The diagnosis of UIH was based on computed tomography and physical examination findings. Preoperative patient data such as enlargement of the umbilical orifice (EUO), subcutaneous fat thickness (SFT) and intraperitoneal thickness (IPT) were collected and analysed using univariate and multivariate analyses for the presence of risk factors for UIH. RESULTS: A total of 135 patients who underwent LCRS were analysed. The incidence of UIH was 20.7%. Univariate analysis revealed significantly high body mass index (BMI) ≥ 25 (P = 0.032), EUO (P < 0.001), SFT ≥18 mm (P = 0.011), and IPT ≥61 mm (P < 0.01) in the UIH group. Multivariate analysis revealed significant differences in EUO (P < 0.001), SFT ≥18 mm (P = 0.046) and IPT ≥61 mm (P = 0.022). CONCLUSION: EUO was the most important risk factor for UIH, followed by IPT and SFT. These findings are predictive indicators of the development of UIH after LCRS and can be assessed objectively and easily with preoperative computed tomography.

High SLC20A1 Expression Is Associated With Poor Prognosis for Radiotherapy of Estrogen Receptor-positive Breast Cancer.

BACKGROUND/AIM: Radiotherapy is one of the main treatments for estrogen receptor-positive (ER+) breast cancer. However, in some ER+ breast cancer cases, radiotherapy is insufficient to inhibit progression and there is a lack of markers to predict radiotherapy insensitivity. Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been proposed to be a viable prognostic marker for luminal A and B types of ER+ breast cancer. The present study examined the possibility of SLC20A1 as a novel biomarker for the prediction of radiotherapy efficiency. PATIENTS AND METHODS: The Molecular Taxonomy of Breast Cancer International Consortium dataset was downloaded from cBioportal and the prognosis of patients with high SLC20A1 expression (SLC20A1 high ) was compared with that of patients with low SLC20A1 expression, without or with radiotherapy and tumor stages I, II, and III, using the Kaplan-Meier method and multivariate Cox regression analyses of disease-specific and relapse-free survival. RESULTS: Patients in the SLC20A1 high group with radiotherapy showed poor clinical outcomes in both luminal A and luminal B breast cancers. Furthermore, in luminal A breast cancer at tumor stage I, patients in the SLC20A1 high  group with radiotherapy also showed poor clinical outcomes. Therefore, these results suggest that radiotherapy is insufficient for patients in the SLC20A1 high group for both luminal A and B types, and especially for the luminal A type at tumor stage I. CONCLUSION: SLC20A1 can be used as a prognostic marker for the prediction of the efficacy of radiotherapy for luminal A and luminal B breast cancers.

High-frequency ultrasound exposure improves depressive-like behavior in an olfactory bulbectomized rat model of depression.

OBJECTIVES: According to previous studies, ultrasound exposure appears to be a noninvasive method for modulating brain activity related to cognition and consciousness; however, its effects on emotional states remain unclear. Therefore, an animal model is required in which the effects and effect mechanisms of ultrasound exposure can be investigated. Thus, we used olfactory bulbectomized rats as an animal model of depression and investigated their emotional state following ultrasound exposure. METHODS: In male Wistar/ST olfactory bulbectomized rats, hyperemotionality was evaluated according to hyperemotionality scoring and the scores before and after 24-h ultrasound exposure were compared. Elevated plus maze (EPM) tests were also conducted after 24-h ultrasound exposure, and blood samples were collected in which plasma corticosterone concentrations were measured. RESULTS: Following exposure to high-frequency (~50 kHz) ultrasound vocalizations (USVs) associated with the pleasant emotions of rats, the hyperemotionality scores of olfactory bulbectomized rats were significantly reduced. Additionally, the latency of the first entry into the open arm of the EPM was significantly decreased in USV-exposed olfactory bulbectomized rats, as were their plasma corticosterone levels. Furthermore, artificial ultrasound (50 kHz) at a similar frequency to that of USV also significantly decreased the hyperemotionality score of olfactory bulbectomized rats. CONCLUSIONS: Ultrasound exposure improved depressive-like behavior in olfactory bulbectomized rats and reduced their plasma corticosterone levels. Thus, we recommend the use of olfactory bulbectomized rats as an animal model for investigating the effects and effect mechanisms of ultrasound exposure.

Alfaxalone improved in acute stress-induced tactile hypersensitivity and anxiety-like behavior in mice.

Stress has been shown to affect brain activity and exert potent and complex modulatory effects on pain. Several behavioral tests have shown that acute stress produces hyperalgesia, depending on the stress conditions. In the present study, we investigated the effects of single restraint stress on the tactile threshold and anxiety sensitivity in mice. Mice were evaluated for the tactile threshold using von Frey filaments and for anxiety sensitivity using the elevated plus maze (EPM) test. Tactile thresholds were lowered by both 2 and 4 hour of restraint stress, but anxiety-like behaviors were observed only after 4 hour of restraint stress in the EPM test. In addition, we found that alfaxalone, which is a positive allosteric modulator of the γ-aminobutyric acid (GABA)A receptor, prevented restraint stress-induced hyperalgesia-like and anxiety-like behaviors. These results indicate that GABAergic function appears to be critical in the regulation of physical stress-induced hyperalgesia and anxiety.

The function of SARS-CoV-2 spike protein is impaired by disulfide-bond disruption with mutation at cysteine-488 and by thiol-reactive N-acetyl-cysteine and glutathione.

Viral spike proteins play important roles in the viral entry process, facilitating attachment to cellular receptors and fusion of the viral envelope with the cell membrane. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to the cellular receptor angiotensin converting enzyme-2 (ACE2) via its receptor-binding domain (RBD). The cysteine residue at position 488, consisting of a disulfide bridge with cysteine 480 is located in an important structural loop at ACE2-binding surface of RBD, and is highly conserved among SARS-related coronaviruses. We showed that the substitution of Cys-488 with alanine impaired pseudotyped SARS-CoV-2 infection, syncytium formation, and cell-cell fusion triggered by SARS-CoV-2 spike expression. Consistently, in vitro binding of RBD and ACE2, spike-mediated cell-cell fusion, and pseudotyped viral infection of VeroE6/TMPRSS2 cells were inhibited by the thiol-reactive compounds N-acetylcysteine (NAC) and a reduced form of glutathione (GSH). Furthermore, we demonstrated that the activity of variant spikes from the SARS-CoV-2 alpha and delta strains were also suppressed by NAC and GSH. Taken together, these data indicate that Cys-488 in spike RBD is required for SARS-CoV-2 spike functions and infectivity, and could be a target of anti-SARS-CoV-2 therapeutics.

Cold-Restraint Stress-Induced Ultrasonic Vocalization as a Novel Tool to Measure Anxiety in Mice.

Ultrasonic vocalization (USVs) is a promising tool to measure behavioral anxiety in rodents as USV recording is noninvasive, behaviorally relevant, ethological, and reproducible. Studies reporting the effects of stress-induced USVs in adult mice remain limited and debated. We investigated the conditions under which mice emit aversive USVs and evaluated the effects of psychiatric drugs on stress-induced USVs. Male C57BL/6J mice were used. USVs during entire stress sessions were recorded according to their frequency. To investigate the effect of psychiatric drugs on USVs, the number of USVs under cold-restraint stress conditions before and after drug administration was compared. Immediately after stress exposure, blood samples were collected and plasma corticosterone levels were measured. The combination of cold and restraint stress conditions significantly increased the USV numbers and plasma corticosterone levels compared with each stress alone. A benzodiazepine anxiolytic (midazolam) and δ-opioid receptor agonist putative anxiolytic (KNT-127) significantly reduced the stress-induced USV number and plasma corticosterone levels; however, a monoaminergic antidepressant (duloxetine) and N-methyl-D-aspartic acid receptor antagonist antidepressant (ketamine) did not reduce the USV numbers. No changes were noted in the USV numbers after repeated exposure to cold-restraint stress on days 1 and 3. The suppressive effect of midazolam on day 3 was comparable to that on day 1. Stress-induced USV may be used as a quantitative measure of anxiety to systematically assess the effects of anxiolytics. Therefore, cold-restraint stress-induced USVs may be used as a novel tool to measure rodent anxiety and as a useful anxiolytic-screening system.

Risk Factors for Hepatic Toxicity of High-dose Methotrexate in Patients With Osteosarcoma.

BACKGROUND/AIM: High-dose methotrexate (HD-MTX) is widely used to treat osteosarcoma. However, some patients develop hepatic toxicity, leading to dose modification and delays in the scheduled chemotherapy. The present study aimed to identify the risk factors of hepatotoxicity in patients with osteosarcoma. PATIENTS AND METHODS: We conducted a retrospective study of patients with osteosarcoma treated with HD-MTX between January 2014 and June 2020 at the National Cancer Center Hospital, Japan. The risk factors for MTX-induced hepatotoxicity (≥grade 3) were identified using multivariate logistic regression analysis. RESULTS: The final analysis included 88 courses of 36 patients. Hepatotoxicity occurred in 51 (58.0%) of the 88 courses. Female sex, MTX dose (>10.2 g/m2), and serum calcium concentration (>9.3 mg/dl) were identified as risk factors for HD-MTX-induced hepatotoxicity. CONCLUSION: Identifying the risk factors of HD-MTX-induced hepatotoxicity may contribute to improvements in the safety and management of HD-MTX therapy.

Direct Inhibition of SARS-CoV-2 Spike Protein by Peracetic Acid.

Peracetic acid (PAA) disinfectants are effective against a wide range of pathogenic microorganisms, including bacteria, fungi, and viruses. Several studies have shown the efficacy of PAA against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, its efficacy in SARS-CoV-2 variants and the molecular mechanism of action of PAA against SARS-CoV-2 have not been investigated. SARS-CoV-2 infection depends on the recognition and binding of the cell receptor angiotensin-converting enzyme 2 (ACE2) via the receptor-binding domain (RBD) of the spike protein. Here, we demonstrated that PAA effectively suppressed pseudotyped virus infection in the Wuhan type and variants, including Delta and Omicron. Similarly, PAA reduced the authentic viral load of SARS-CoV-2. Computational analysis suggested that the hydroxyl radicals produced by PAA cleave the disulfide bridges in the RBD. Additionally, the PAA treatment decreased the abundance of the Wuhan- and variant-type spike proteins. Enzyme-linked immunosorbent assay showed direct inhibition of RBD-ACE2 interactions by PAA. In conclusion, the PAA treatment suppressed SARS-CoV-2 infection, which was dependent on the inhibition of the interaction between the spike RBD and ACE2 by inducing spike protein destabilization. Our findings provide evidence of a potent disinfection strategy against SARS-CoV-2.