Low-tube-voltage whole-body CT angiography with extremely low iodine dose: a comparison between hybrid-iterative reconstruction and deep-learning image-reconstruction algorithms

AIM

To evaluate arterial enhancement, its depiction, and image quality in low-tube potential whole-body computed tomography (CT) angiography (CTA) with extremely low iodine dose and compare the results with those obtained by hybrid-iterative reconstruction (IR) and deep-learning image-reconstruction (DLIR) methods.

MATERIALS AND METHODS

This prospective study included 34 consecutive participants (27 men; mean age, 74.2 years) who underwent whole-body CTA at 80 kVp for evaluating aortic diseases between January and July 2020. Contrast material (240 mg iodine/ml) with simultaneous administration of its quarter volume of saline, which corresponded to 192 mg iodine/ml, was administered. CT raw data were reconstructed using adaptive statistical IR-Veo of 40% (hybrid-IR), DLIR with medium- (DLIR-M), and high-strength level (DLIR-H). A radiologist measured CT attenuation of the arteries and background noise, and the signal-to-noise ratio (SNR) was then calculated. Two reviewers qualitatively evaluated the arterial depictions and diagnostic acceptability on axial, multiplanar-reformatted (MPR), and volume-rendered (VR) images.

RESULTS

Mean contrast material volume and iodine weight administered were 64.1 ml and 15.4 g, respectively. The SNRs of the arteries were significantly higher in the following order of the DLIR-H, DLIR-M, and hybrid-IR (p<0.001). Depictions of six arteries on axial, three arteries on MPR, and four arteries on VR images were significantly superior in the DLIR-M or hybrid-IR than in the DLIR-H (p≤0.009 for each). Diagnostic acceptability was significantly better in the DLIR-M and DLIR-H than in the hybrid-IR (p<0.001-0.005).

CONCLUSION

DLIR-M showed well-balanced arterial depictions and image quality compared with the hybrid-IR and DLIR-H.

Radiologic-histopathologic correlation of fatty island sign with fat necrosis in atypical lipomatous tumor and lipoma

AIM

This study aimed to assess the imaging features of atypical lipomatous tumors (ALTs) and lipoma with fat necrosis.

METHODS

This study included patients with histopathologically proven fat necrosis within adipocytic tumors who underwent preoperative imaging. Magnetic resonance imaging (MRI) and/or computer tomography (CT) findings of fat necrosis associated with lipomatous tumors were retrospectively reviewed, emphasizing the "fatty island sign (FIS)." FISs were defined as well-demarcated, focal fat-containing areas surrounded by more thickened septa compared with other intratumoral septa. Imaging findings of FIS were compared between ALT and lipoma.

RESULTS

Fat necrosis was histopathologically confirmed in 17 patients (6 ALTs and 11 lipomas). Among them, 18 FISs were observed in 10 lesions (59%). Multiple FISs within a lesion were observed in 4 (40%) patients. The median maximum diameter of the FISs was 37 mm. Hypointense areas within FISs relative to the subcutaneous fat on T1- and T2-weighted images were observed in 8 (80%) and 9 (90%), respectively, whereas hyperintense areas within FISs on fat-suppressed T2-weighted images were observed in 2 (20%). Nonfatty solid components within FISs were observed in 2 (20%). On CT, increased fat attenuation and pure fat attenuation within FISs were observed in 6 (86%) and 1 (14%), respectively. The imaging findings of FIS were not significantly different between ALT and lipoma.

CONCLUSION

FISs were observed in 59% of the histologically proven ALT and lipoma patients with fat necrosis. The hypointense areas relative to the subcutaneous fat on T1- and T2-weighted images and increased fat attenuation on CT were usually observed within FISs.

Duloxetine improves chronic orofacial pain and comorbid depressive symptoms in association with reduction of serotonin transporter protein through upregulation of ubiquitinated serotonin transporter protein

ABSTRACT

Chronic orofacial pain (COP) is relieved by duloxetine (DLX) and frequently causes depressive symptoms. The aim of this study was to confirm effects of DLX on pain and depressive symptoms, and to associate with their effectiveness in platelet serotonin transporter (SERT) expression, which is a target molecule of DLX and plasma serotonin concentration in COP patients with depressive symptoms. We assessed for the severity of pain and depressive symptoms using the Visual Analog Scale (VAS) and 17-item Hamilton Depression Rating Scale (HDRS), respectively. Chronic orofacial pain patients were classified into 2 groups based on their HDRS before DLX-treatment: COP patients with (COP-D) and without (COP-ND) depressive symptoms. We found that the VAS and HDRS scores of both groups were significantly decreased after DLX treatment compared with those before DLX treatment. Upregulation of total SERT and downregulation of ubiquitinated SERT were observed before DLX treatment in both groups compared with healthy controls. After DLX treatment, there were no differences in total SERT of both groups and in ubiquitinated SERT of COP-D patients compared with healthy controls; whereas, ubiquitinated SERT of COP-ND patients remained downregulated. There were positive correlations between changes of serotonin concentrations and of VAS or HDRS scores in only COP-D patients. Our findings indicate that DLX improves not only pain but also comorbid depressive symptoms of COP-D patients. Duloxetine also reduces platelet SERT through upregulation of ubiquitinated SERT. As the result, decrease of plasma serotonin concentrations may be related to the efficacy of DLX in relieving pain and depression in COP patients.

Effect of X-ray tube on image quality and pancreatic ductal adenocarcinoma conspicuity in pancreatic protocol dual-energy CT

AIM

To compare the radiation dose, image quality, and conspicuity of pancreatic ductal adenocarcinoma (PDAC) in pancreatic protocol dual-energy computed tomography (CT) between two X-ray tubes mounted in the same CT machine.

MATERIAL AND METHODS

This retrospective study comprised 80 patients (median age, 73 years; 45 men) who underwent pancreatic protocol dual-energy CT from January 2019 to March 2022 using either old (Group A, n=41) or new (Group B, n=39) X-ray tubes mounted in the same CT machine. The imaging parameters were completely matched between the two groups, and CT data were reconstructed at 70 and 40 keV. The CT dose-index volume (CTDIvol); CT attenuation of the abdominal aorta, pancreas, and PDAC; background noise; and qualitative scores for the image noise, overall image quality, and PDAC conspicuity were compared between the two groups.

RESULTS

The CTDIvol was lower in Group B than Group A (7.9 versus 9.2 mGy; p<0.001). The CT attenuation of all anatomical structures at 70 and 40 keV was comparable between the two groups (p=0.06-0.78). The background noise was lower in Group B than Group A (12 versus 14 HU at 70 keV, p=0.046; and 26 versus 30 HU at 40 keV, p<0.001). Qualitative scores for image noise and overall image quality at 70 and 40 keV and PDAC conspicuity at 40 keV were higher in Group B than Group A (p<0.001-0.045).

CONCLUSION

The latest X-ray tube could reduce the radiation dose and improve image quality in pancreatic protocol dual-energy CT.

Inhalation adherence for asthma and COPD improved during the COVID-19 pandemic: a questionnaire survey at a university hospital in Japan

Background: Good adherence to an inhaled medication protocol is necessary for the management of asthma and chronic obstructive pulmonary disease (COPD), and several interventions to improve adherence have been reported. However, the impact of patient life changes and psychological aspects on treatment motivation is obscure. Here, we investigated changes in inhaler adherence during the COVID-19 pandemic and how lifestyle and psychological changes affected it.Methods: Seven-hundred sixteen adult patients with asthma and COPD who had visited Nagoya University Hospital between 2015 and 2020 were selected. Among them, 311 patients had received instruction at a pharmacist-managed clinic (PMC). We distributed one-time cross-sectional questionnaires from January 12 to March 31, 2021. The questionnaire covered the status of hospital visits, inhalation adherence before and during the COVID-19 pandemic, lifestyles, medical conditions, and psychological stress. The Adherence Starts with Knowledge-12 (ASK-12) was used to assess adherence barriers.Results: Four-hundred thirty-three patients answered the questionnaire. Inhalation adherence was significantly improved in both diseases during the COVID-19 pandemic. The most common reason for improved adherence was fear of infection. Patients with improved adherence were more likely to believe that controller inhalers could prevent COVID-19 from becoming more severe. Improved adherence was more common in patients with asthma, those not receiving counseling at PMC, and those with poor baseline adherence.Conclusions: Inhalation adherence for asthma and COPD improved in the COVID-19 pandemic. The patients seemed to realize the necessity and benefits of the medication more strongly than before the pandemic, which motivated them to improve adherence.

Early Assessment of Radiation Treatment at Clinical Field Strength by D2O Administration and Deuterium MRI

PURPOSE/OBJECTIVE(S)

An accurate and non-invasive assessment of tumor response following treatment is essential. Traditional anatomical imaging techniques are insufficient before a significant morphological change can be observed. Metabolic imaging of molecular processes in the living body is also used. In recent years, deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field (4-11T) MRI using deuterium-labeled molecules as a contrast agent. The study aim was to evaluate the feasibility of using deuterium MRI 1.5T for tumor visualization and early assessment of the efficacy of three anticancer treatment strategies (radiation and anticancer drugs) in pancreatic cancer model mice given heavy water (D2O) to induce deuterium (2H)-tissue labeling.

MATERIALS/METHODS

A MIA PaCa-2 pancreatic cancer model of six BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days after starting free drinking of 30% D2O. We also evaluated 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration of other 20 mice. Additional confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS and histopathology were performed.

RESULTS

The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H in the tumor decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments.

CONCLUSION

Deuterium MRI at 1.5T proved feasibility to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for early assessment of radiotherapy and chemotherapy of pancreatic cancer.

Computed Tomography and 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Imaging Biomarkers of Lung Invasive Non-mucinous Adenocarcinoma: Prediction of Grade 3 Tumour Based on World Health Organization Grading System

AIMS

To evaluate computed tomography (CT) and 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) findings of invasive non-mucinous adenocarcinoma (INMA) of the lung as a predictor of histological tumour grade according to 2021 World Health Organization (WHO) classification.

MATERIALS AND METHODS

This retrospective study included consecutive patients with surgically resected INMA who underwent both preoperative CT and 18F-FDG-PET/CT. A three-tiered tumour grade was performed based on the fifth edition of the WHO classification of lung tumours. CT imaging features and the maximum standardised uptake value (SUVmax) were compared among the three tumour grades.

RESULTS

In total, 214 patients with INMA (median age 70 years; interquartile range 65-76 years; 123 men) were histologically categorised: 36 (17%) as grade 1, 102 (48%) as grade 2 and 76 (35%) as grade 3. Pure solid appearance was more frequent in grade 3 (83%) than in grades 1 (0%) and 2 (26%) (P < 0.001). The SUVmax of the entire tumour was higher in grade 3 than in grades 1 and 2 (P < 0.001). Multivariable analysis revealed that pure solid appearance (odds ratio = 94.0; P < 0.001), round/oval shape (odds ratio = 4.01; P = 0.001), spiculation (odds ratio = 2.13; P = 0.04), air bronchogram (odds ratio = 0.40; P = 0.03) and SUVmax (odds ratio = 1.45; P < 0.001) were significant predictors for grade 3 INMAs.

CONCLUSION

Pure solid appearance, round/oval shape, spiculation, absence of air bronchogram and high SUVmax were associated with grade 3 INMAs. CT and 18F-FDG-PET/CT were potentially useful non-invasive imaging methods to predict the histological grade of INMAs.

Astrotactin 2 (ASTN2) regulates emotional and cognitive functions by affecting neuronal morphogenesis and monoaminergic systems

Astrotactin2 (ASTN2) regulates neuronal migration and synaptic strength through the trafficking and degradation of surface proteins. Deletion of ASTN2 in copy number variants has been identified in patients with schizophrenia, bipolar disorder, and autism spectrum disorder in copy number variant (CNV) analysis. Disruption of ASTN2 is a risk factor for these neurodevelopmental disorders, including schizophrenia, bipolar disorder, autism spectrum disorder, and attention deficit hyperactivity disorder. However, the importance of ASTN2 in physiological functions remains poorly understood. To elucidate the physiological functions of ASTN2, we investigated whether deficiency of ASTN2 affects cognitive and/or emotional behaviors and neurotransmissions using ASTN2-deficient mice. Astn2 knockout (KO) mice produced by CRISPR/Cas9 technique showed no obvious differences in physical characteristics and circadian rhythm. Astn2 KO mice showed increased exploratory activity in a novel environment, social behavior and impulsivity, or decreased despair-, anxiety-like behaviors and exploratory preference for the novel object. Some behavioral abnormalities, such as increased exploratory activity and impulsivity, or decreased exploratory preference were specifically attenuated by risperidone, but not by haloperidol. While, the both drugs did not affect any emotion-related behavioral abnormalities in Astn2 KO mice. Dopamine contents were decreased in the striatum, and serotonin or dopamine turnover were increased in the striatum, nucleus accumbens, and amygdala of Astn2 KO mice. In morphological analyses, thinning of neural cell layers in the hippocampus, reduction of neural cell bodies in the prefrontal cortex, and decrease in spine density and PSD95 protein in both tissues were observed in Astn2 KO mice. The present findings suggest that ASTN2 deficiency develops some emotional or cognitive impairments related to monoaminergic dysfunctions and abnormal neuronal morphogenesis with shrinkage of neuronal soma. ASTN2 protein may contribute to the pathogenic mechanism and symptom onset of mental disorders.

[Promoting Appropriate Use of Medications by "Lectures and Practices Regarding Medicine" for the Regional Community Residents]

We held lectures and practices for the regional community residents with the aim of promoting appropriate use of medications. To evaluate the usefulness of our activity, we conducted medicine-related questionnaire surveys (pre- and post-questionnaires) before and after the lectures and practices, and satisfaction with the activity questionnaire surveys (post-questionnaires) after them. We also evaluated the effect of age difference on the results by dividing the participants into elderly (age ≥65) and non-elderly (age <65), before the analysis. In the both (elderly and non-elderly) groups, the ratio of positive answers in several items of post-questionnaire regarding appropriate use of medications was higher than that of pre-questionnaire. These results suggest that the basic medicine-related knowledge improved by attending the lectures and practices, and indicate that the knowledge of the regional community residents is higher than we imagined. Furthermore, there was no difference in the ratio of positive answers between the both groups, suggesting that our activity is applicable to a wide range of age groups. Our activity benefitted the participants, and not only provided education to the regional community residents regarding appropriate drug use, but also lead to the development of regional community activity, by the coming together of the regional community residents of various age.

Memantine ameliorates the impairment of social behaviors induced by a single social defeat stress as juveniles

Clinically, juveniles are more sensitive to stress than adults, and exposure to stress as juveniles prolongs psychiatric symptoms and causes treatment resistance. However, the efficacy of antidepressants for juveniles with psychiatric disorders is unknown. In the present study, we investigated whether the expression or development of impaired social behavior was attenuated by memantine, a NMDA receptor antagonist. In addition, we clarified the molecular mechanisms related to intracellular signal transduction through NMDA receptors and the ameliorating effect of memantine in mice with impaired social behavior. Acute administration of memantine before the social interaction test, but not before exposure to social defeat stress, attenuated social behavioral impairment. A single social defeat stress increased the phosphorylation of NMDA receptor subunit GluN2A and extracellular-signal-related kinase 1/2 (ERK1/2). Memantine inhibited the increase of phosphorylated GluN2A and ERK1/2 resulting from social interaction behavior. In both GluN2A deficient and pharmacological blockaded mice, social behavioral impairment was not observed in the social interaction test through regulation of ERK1/2 phosphorylation. These findings suggest that memantine ameliorates social behavioral impairment in mice exposed to a single social defeat stress as juveniles by regulating the NMDA receptor and subsequent ERK1/2 signaling activation. Memantine may constitute a novel therapeutic drug for stress-related psychiatric disorders in juveniles with adverse juvenile experiences.

Duloxetine attenuates pain in association with downregulation of platelet serotonin transporter in patients with burning mouth syndrome and atypical odontalgia

OBJECTIVE

The aim of this study was evaluation of the association between severity of pain and expression of total or ubiquitinated serotonin transporter (SERT) protein in patients with burning mouth syndrome and atypical odontalgia (BMS/AO), who were treated by duloxetine.

METHODS

Patients with BMS/AO were assessed for severity of pain using the visual analog scale (VAS), and expression of total and ubiquitinated SERT protein in platelets before (baseline) and 12 weeks after duloxetine-treatment.

RESULTS

The expression of total and ubiquitinated SERT protein at baseline in all patients (n = 33) were higher and lower, respectively, compared to those in healthy controls. 12 weeks after duloxetine-treatment, there was no difference in the total SERT protein levels between patients (n = 21) and healthy controls. In the 16 patients who could be measured, mean VAS scores and total SERT protein levels were significantly decreased after the treatment, compared to those at baseline. There was tendency for a positive correlation between total SERT protein levels and VAS scores in these patients.

CONCLUSIONS

Our findings indicate that duloxetine relieves pain in association with downregulation of platelet SERT expression in patients with BMS/AO.

Subcapsular hepatic hematoma as a complicating cardiac surgery

An 80-year-old woman was hospitalized for aortic valve insufficiency, paroxysmal atrial fibrillation, and ascending aortic aneurysm. She underwent aortic valve replacement, pulmonary vein isolation, left atrium appendectomy, and ascending aorta replacement. She developed a subcapsular hepatic hematoma during the surgery. The patient was managed conservatively and discharged successfully.

Deep-learning image-reconstruction algorithm for dual-energy CT angiography with reduced iodine dose: preliminary results

AIM

To evaluate the computed tomography (CT) attenuation values, background noise, arterial depiction, and image quality in whole-body dual-energy CT angiography (DECTA) at 40 keV with a reduced iodine dose using deep-learning image reconstruction (DLIR) and compare them with hybrid iterative reconstruction (IR).

MATERIAL AND METHODS

Whole-body DECTA with a reduced iodine dose (200 mg iodine/kg) was performed in 22 patients, and DECTA data at 1.25-mm section thickness with 50% overlap were reconstructed at 40 keV using 40% adaptive statistical iterative reconstruction with Veo (hybrid-IR group), and DLIR at medium and high levels (DLIR-M and DLIR-H groups). The CT attenuation values of the thoracic and abdominal aortas and iliac artery and background noise were measured. Arterial depiction and image quality on axial, multiplanar reformatted (MPR), and volume-rendered (VR) images were assessed by two readers. Quantitative and qualitative parameters were compared between the hybrid-IR, DLIR-M, and DLIR-H groups.

RESULTS

The vascular CT attenuation values were almost comparable between the three groups (p=0.013-0.97), but the background noise was significantly lower in the DLIR-H group than in the hybrid-IR and DLIR-M groups (p<0.001). The arterial depictions on axial and MPR images and in almost all arteries on VR images were comparable (p=0.14-1). The image quality of axial, MPR, and VR images was significantly better in the DLIR-H group (p<0.001-0.015).

CONCLUSION

DLIR significantly reduced background noise and improved image quality in DECTA at 40 keV compared with hybrid-IR, while maintaining the arterial depiction in almost all arteries.

Intraoperative angiography for visceral arteries originating from false lumen

A 70-year-old man had an acute type B aortic dissection 9 years before his admission. The last enhanced computed tomography that was performed revealed an aneurysm that extended from the ascending aorta to the aortic arch, associated with a chronic aortic dissection, which extended from the aortic arch to the left external iliac artery. His visceral arteries originated from the false lumen. We performed a total arch replacement with a frozen elephant trunk in the hybrid operating room. Immediately after the circulatory arrest termination, using intraoperative angiography, we verified that the blood supply to the visceral arteries was patent.

Early postnatal inhibition of GLAST causes abnormalities of psychobehaviors and neuronal morphology in adult mice

The importance of glutamate transporters in learning, memory, and emotion remains poorly understood; hence, in the present study, we investigated whether deficiency of pharmacological GLAST in neurodevelopmental processes affects cognitive and/or emotional behaviors in mice. The mice were injected with a glutamate transporter inhibitor, dl-threo-β-benzyloxyaspartate (dl-TBOA), during the early postnatal period. At 8 weeks of age, they showed impairments in cognitive or emotional behaviors; dysfunction of glutamatergic neurotransmission (increased expressions of GLAST, GLT-1, or GFAP protein, and decreased ability of glutamate release) in the cortex or hippocampus; morphological changes (decreased cell size in the cortex and thickness of the pyramidal neuronal layer of the CA1 area in the hippocampus). Such behavioral and morphological changes were not observed in adult mice injected with dl-TBOA. These results suggest that GLAST plays an important role in the regulation of cognitive and emotional behaviors. Early postnatal glutamatergic facilitation by GLAST dysfunction leads to cognitive and emotional abnormalities due to neurodevelopmental abnormalities such as morphological changes.

Survey of chemotherapy-induced nausea and vomiting in patients with urothelial carcinoma

Chemotherapy-induced nausea and vomiting (CINV) can cause anorexia, weight loss and deterioration of patient quality of life. It is one of the most unpleasant adverse effects of chemotherapy treatment regimens. For the optimal treatment of gastrointestinal symptoms during urothelial carcinoma chemotherapy, the present study investigated the association between gastrointestinal symptoms and therapeutic effects of gemcitabine plus platinum [cisplatin (GC) or carboplatin (GCa)] therapies. The incidence and frequency of nausea/vomiting with GC split therapy (gemcitabine, 1,000 mg/m² on days 1 and 8; split-dose cisplatin, 35 mg/m² on days 1 and 8; 21-day schedule) and GCa therapy [gemcitabine, 750-1,000 mg/m² on days 1, 8 and 15; carboplatin, area under the blood concentration-time curve=5 mg min/ml (Calvert formula) on day 2; 28-day schedule] were lower compared with those of GC therapy (gemcitabine, 1,000 mg/m² on days 1, 8 and 15; single-dose cisplatin 70 mg/m² on day 2; 28-day schedule). However, no differences in therapeutic outcomes were observed among therapies. GCa therapy, regardless of renal function, and GC split therapy demonstrated significant increases compared with GC therapy in alleviating gastrointestinal symptoms associated with cancer chemotherapy in patients with urothelial carcinoma. Overall, these results suggested that split-dose cisplatin administration or the use of carboplatin instead of cisplatin may be useful in patients who experience CINV without compromising treatment effectiveness.

[Endovascular Therapy for Kinking of an Open Stent Graft after Stanford Type A Acute Aortic Dissection Repair:Report of a Case]

This is the case of 50s female with Stanford type A acute aortic dissection who underwent emergent total arch replacement. The aortic arch was transected just distal to the left subclavian artery, followed by the insertion of J Graft Frozenix into the descending aorta. No blood pressure gradient was observed between the radial and femoral arteries immediately after the operation. Nevertheless, intermittent claudication was observed after a week. Ankle-brachial index( ABI) measurement was calculated at 0.7 in both legs. Computed tomography (CT) revealed a kinking of the non-stented part of the endograft. Subsequently, thoracic endovascular aortic repair( TEVAR) was performed. As a result, ABI measurement normalized and lower limb pain disappeared. Three years after, CT showed that the endograft expanded satisfactorily. In deployment of J Graft Frozenix, the non-stented part should be kept as short as possible. For kinking, TEVAR should be considered the initial treatment option.

Deep-learning-based image reconstruction in dynamic contrast-enhanced abdominal CT: image quality and lesion detection among reconstruction strength levels

AIM

To evaluate the use of deep-learning-based image reconstruction (DLIR) algorithms in dynamic contrast-enhanced computed tomography (CT) of the abdomen, and to compare the image quality and lesion conspicuity among the reconstruction strength levels.

MATERIALS AND METHODS

This prospective study included 59 patients with 373 hepatic lesions who underwent dynamic contrast-enhanced CT of the abdomen. All images were reconstructed using four reconstruction algorithms, including 40% adaptive statistical iterative reconstruction-Veo (ASiR-V) and DLIR at low, medium, and high-strength levels (DLIR-L, DLIR-M, and DLIR-H, respectively). The signal-to-noise ratio (SNR) of the abdominal aorta, portal vein, liver, pancreas, and spleen and the lesion-to-liver contrast-to-noise ratio (CNR) were calculated and compared among the four reconstruction algorithms. The diagnostic acceptability was qualitatively assessed and compared among the four reconstruction algorithms and the conspicuity of hepatic lesions was compared between <5 and ≥5 mm lesions.

RESULTS

The SNR of each anatomical structure (p<0.0001) and CNR (p<0.0001) were significantly higher in DLIR-H than the other reconstruction algorithms. Diagnostic acceptability was significantly better in DLIR-M than the other reconstruction algorithms (p<0.0001). The conspicuity of hepatic lesions was highest when using 40% ASiR-V and tended to lessen as the reconstruction strength level was getting higher in DLIR, especially in <5 mm lesions; however, all hepatic lesions could be detected.

CONCLUSIONS

DLIR improved the SNR, CNR, and image quality compared with 40% ASiR-V, while making it possible to decrease lesion conspicuity using higher reconstruction strength.

Multiple nicotinic acetylcholine receptor subtypes regulate social or cognitive behaviors in mice repeatedly administered phencyclidine

Habitual smoking in patients with schizophrenia (SCZ) is considered to improve their own psychoses or to develop a vulnerability to psychological dependence on (-)-nicotine ([-]-NIC) by stimulating nicotinic acetylcholine receptors (nAChRs) in the central nervous system. In the present study, we investigated whether habitual smoking is due to get therapeutic effect or to psychological dependence and which nAChR subunits are associated with them using mice that were repeatedly administered phencyclidine (PCP: 10 mg/kg/day, s.c. for 14 days) as SCZ-like model mice. Mice that were repeatedly administered PCP showed impairments in social or cognitive behaviors; decreased expression of α7 and/or α4 nAChR subunits in the prefrontal cortex (PFC); and increased expression of α7, α4, and β2 nAChR subunits in the nucleus accumbens (NAc). These changes were attenuated by repeated administration of (-)-NIC. The attenuating effects on behavioral impairments were prevented by a selective α7 nAChR antagonist and a selective α4β2 nAChR antagonist. At non- or weak effective dose by themselves, co-administration of (-)-NIC (0.03 mg/kg) and risperidone (0.03 mg/kg) showed synergistic effects on behavioral impairments in PCP-administered mice. Repeated (-)-NIC administration did not affect the performance of conditioned place preference, while it showed behavioral sensitization to (-)-NIC in the PCP-administered mice. Repeated (-)-NIC administration did not affect the performance of conditioned place preference, while it showed behavioral sensitization to (-)-NIC and attenuating effect on haloperidol-induced catalepsy in the PCP-administered mice. Our findings suggest that habitual smoking in SCZ might be attributed to get therapeutic and reduce side effects mediated by α7 and α4β2 nAChR activation by (-)-NIC.

Mice with cleavage-resistant N-cadherin exhibit synapse anomaly in the hippocampus and outperformance in spatial learning tasks

N-cadherin is a homophilic cell adhesion molecule that stabilizes excitatory synapses, by connecting pre- and post-synaptic termini. Upon NMDA receptor (NMDAR) activation by glutamate, membrane-proximal domains of N-cadherin are cleaved serially by a-disintegrin-and-metalloprotease 10 (ADAM10) and then presenilin 1(PS1, catalytic subunit of the γ-secretase complex). To assess the physiological significance of the initial N-cadherin cleavage, we engineer the mouse genome to create a knock-in allele with tandem missense mutations in the mouse N-cadherin/Cadherin-2 gene (Cdh2 R714G, I715D, or GD) that confers resistance on proteolysis by ADAM10 (GD mice). GD mice showed a better performance in the radial maze test, with significantly less revisiting errors after intervals of 30 and 300 s than WT, and a tendency for enhanced freezing in fear conditioning. Interestingly, GD mice reveal higher complexity in the tufts of thorny excrescence in the CA3 region of the hippocampus. Fine morphometry with serial section transmission electron microscopy (ssTEM) and three-dimensional (3D) reconstruction reveals significantly higher synaptic density, significantly smaller PSD area, and normal dendritic spine volume in GD mice. This knock-in mouse has provided in vivo evidence that ADAM10-mediated cleavage is a critical step in N-cadherin shedding and degradation and involved in the structure and function of glutamatergic synapses, which affect the memory function.

Involvement of PKCβI-SERT activity in stress vulnerability of mice exposed to twice-swim stress

Stress vulnerability and pathogenic mechanisms in stress-related disorders are strongly associated with the functions of serotonin transporter (SERT). SERT phosphorylation induces a reduction of the serotonin (5-HT, 5-hydroxytryptamine) transport properties, its phosphorylation regulated by protein kinase C (PKC). However, the functional relationship between regulated SERT activity by PKC and stress vulnerability remains unclear. Here, we investigated whether the functional regulation of SERT by PKC was involved in stress vulnerability using mice exposed to twice-swim stress that exhibited the impairment of social behaviors. The mild-swim stress (6 min) given just before the social interaction test did not affect the social behaviors of mice. However, mice exposed to strong-swim stress (15 min) became vulnerable to the mild-swim stress, and subsequent social behaviors were impaired. Chelerythrine, a PKC inhibitor, exacerbated decreased sociality in mice exposed to acute mild-swim stress. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, ameliorated the impairment of social behaviors in mice exposed to twice-swim stress. Phosphorylated PKCβI or SERT and 5-HT levels were decreased in the prefrontal cortex of twice-stressed mice. These decreases were attenuated by PMA. Our findings demonstrate that mice exposed to twice-swim stress developed stress vulnerability, which may be involved in the regulation of SERT phosphorylation and 5-HT levels accompanying PKCβI activity.

Immunological inflammatory biomarkers as prognostic predictors for advanced hepatocellular carcinoma

Background

The immunological inflammatory biomarkers for advanced hepatocellular carcinoma are unclear. We aimed to investigate the association of immunity and inflammatory status with treatment outcomes in patients with advanced hepatocellular carcinoma who received molecular-targeted agents as primary treatment.

Patients and methods

We enrolled 728 consecutive patients with advanced hepatocellular carcinoma who received sorafenib (n = 554) or lenvatinib (n = 174) as primary treatment in Japan between May 2009 and June 2020. Changes in the neutrophil-to-lymphocyte ratio before and 1 month after treatment and their impact on survival were evaluated. The cut-off values of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio for predicting overall and progression-free survival were calculated using receiver operating characteristic curves.

Results

The neutrophil-to-lymphocyte ratio, but not the platelet-to-lymphocyte ratio, was an independent prognostic factor. Patients with decreased neutrophil-to-lymphocyte ratio survived significantly longer than patients with increased neutrophil-to-lymphocyte ratio (median overall survival: 14.7 versus 10.4 months, P = 0.0110). Among patients with a low pre-treatment neutrophil-to-lymphocyte ratio, the overall survival did not differ significantly between those with decreased and those with increased neutrophil-to-lymphocyte ratio after 1 month (median: 19.0 versus 14.8 months, P = 0.1498). However, among patients with high pre-treatment neutrophil-to-lymphocyte ratio, those whose neutrophil-to-lymphocyte ratio decreased after 1 month showed significantly longer survival than those whose neutrophil-to-lymphocyte ratio increased (median: 12.7 versus 5.5 months, P < 0.0001). The therapeutic effect was not correlated with pre-treatment neutrophil-to-lymphocyte ratio or platelet-to-lymphocyte ratio.

Conclusions

The neutrophil-to-lymphocyte ratio is a prognostic factor, along with liver function and tumor markers, in patients with advanced hepatocellular carcinoma who received molecular-targeted agents as primary treatment. Thus, the neutrophil-to-lymphocyte ratio could be a prognostic biomarker for advanced hepatocellular carcinoma primarily treated with immunotherapy.

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NLR was an independent prognostic factor with advanced HCC, along with liver function and tumor markers.

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Patients with decreased NLR 1 month after treatment survived significantly longer than patients with increased NLR.

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The therapeutic effect was not correlated with pre-treatment NLR or PLR.

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NLR is a prognostic factor in patients with advanced HCC who received molecular-targeted agents as primary treatment.

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Thus, NLR could be a prognostic biomarker for advanced HCC treated with immunotherapy.

Involvement of nicotinic acetylcholine receptors in behavioral abnormalities and psychological dependence in schizophrenia-like model mice

The smoking incentive in patients with schizophrenia (SCZ) depends on stimulation of nicotinic acetylcholine receptors (nAChRs) in the central nervous system. To detect potential predictor genes for nicotine responses in SCZ, we explored common factor using research data in human and animal samples. In lymphoblastoid cell lines from SCZ, the mRNA expression level of α7 nAChR subunit was decreased. In SCZ-like model mice of phencyclidine (PCP; 10 mg/kg/day, subcutaneously for 14 days)-administered mice, the mRNA expression level of α7 nAChR subunit and protein expression level of α7 or α4 nAChR subunit were significantly decreased in the prefrontal cortex during PCP withdrawal. Protein, but not mRNA, expression levels of α7, α4, and β2 nAChR subunits were significantly increased in the nucleus accumbens. Acute (-)-nicotine [(-)-NIC: 0.3 mg/kg, s.c.] treatment attenuated impairments of social behaviors and visual recognition memory. These effects of (-)-NIC were completely blocked by both methyllycaconitine, a selective α7 nAChR antagonist, and dihydro-β-erythroidine (DHβE), a selective α4β2 nAChR antagonist. (-)-NIC did not induce conditioned place preference, but enhanced sensitivity to methamphetamine-induced hyperactivity. These findings suggest that α7 nAChR is associated with development of disease and is implicated in the therapeutic effect of nicotine in SCZ. The smoking incentive in SCZ might be attributed to treat their own symptoms, rather than a result of (-)-NIC dependence, by stimulating α7 and/or α4β2 nAChRs.

Imperceptible magnetic sensor matrix system integrated with organic driver and amplifier circuits

Artificial electronic skins (e-skins) comprise an integrated matrix of flexible devices arranged on a soft, reconfigurable surface. These sensors must perceive physical interaction spaces between external objects and robots or humans. Among various types of sensors, flexible magnetic sensors and the matrix configuration are preferable for such position sensing. However, sensor matrices must efficiently map the magnetic field with real-time encoding of the positions and motions of magnetic objects. This paper reports an ultrathin magnetic sensor matrix system comprising a 2 × 4 array of magnetoresistance sensors, a bootstrap organic shift register driving the sensor matrix, and organic signal amplifiers integrated within a single imperceptible platform. The system demonstrates high magnetic sensitivity owing to the use of organic amplifiers. Moreover, the shift register enabled real-time mapping of 2D magnetic field distribution.

Mice deficient in protein tyrosine phosphatase receptor type Z (PTPRZ) show reduced responsivity to methamphetamine despite an enhanced response to novelty

Methamphetamine (METH), a commonly abused drug, elevates extracellular dopamine (DA) levels by inducing DA efflux through the DA transporter (DAT). Emerging evidence in rodent models suggests that locomotor responses to a novel inescapable open field may predict behavioral responses to abused drugs; METH produces more potent stimulant effects in high responders to novelty than in low responders. We herein found that mice deficient in protein tyrosine phosphatase receptor type Z (Ptprz-KO) exhibited an enhanced behavioral response to novelty; however, METH-induced hyperlocomotion was significantly lower in Ptprz-KO than in wild-type mice when METH was administered at a non-toxic dose of 1 mg per kg body weight (bdw). Single-cell RT-PCR revealed that the majority of midbrain DA neurons expressed PTPRZ. No histological alterations were observed in the mesolimbic or nigrostriatal dopaminergic pathways in Ptprz-KO brains; however, a significant decrease was noted in brain DA turnover, suggesting functional alterations. In vivo microdialysis experiments revealed that METH-evoked DA release in the nucleus accumbens was significantly lower in Ptprz-KO mice than in wild-type mice. Consistent with this result, Ptprz-KO mice showed significantly fewer cell surface DAT as well as weaker DA uptake activity in striatal synaptosomes prepared 1 hr after the administration of METH than wild-type mice, while no significant differences were observed in the two groups treated with saline. These results indicate that the high response phenotype of Ptprz-KO mice to novelty may not be simply attributed to hyper-dopaminergic activity, and that deficits in PTPRZ reduce the effects of METH by reducing DAT activity.

Functional roles of the glial glutamate transporter (GLAST) in emotional and cognitive abnormalities of mice after repeated phencyclidine administration

Alterations of the glutamatergic system components, including N-methyl-d-aspartate (NMDA) receptors are relevant to the pathophysiology of schizophrenia. Repeated phencyclidine (PCP) administration induces several schizophrenia-like psychobehavioral abnormalities and decreases extracellular glutamate levels, which are associated with increased levels of glial glutamate and aspartate transporter (GLAST) in the prefrontal cortex (PFC) of mice. In the present study, we investigated the functional roles of GLAST in the emotional and cognitive abnormalities in mice following repeated PCP administration by using GLAST heterozygous (+/-) mice, since GLAST mutant mice are a useful tool for elucidating the contribution of glutamate dysfunction to the pathophysiology of schizophrenia. PCP-administered GLAST wild-type (+/+) mice showed enhancement of immobility in a forced swimming test, impairments of visual recognition memory in a novel object recognition test, decrease in high potassium (K⁺)-induced extracellular glutamate release, and overexpression of GLAST and S100 proteins in the PFC, compared to saline-administered GLAST^+/+ mice. Such behavioral and neurochemical abnormalities were not observed in PCP-administered GLAST^+/- mice. In conclusion, these results clearly suggest that genetic GLAST dysfunction and glial activation play important roles in the development of emotional and cognitive abnormalities in PCP-administered GLAST^+/+ mice.

Author Correction: Proteomic analysis of lymphoblastoid cell lines from schizophrenic patients

The original Article required a few updates; one co-author name, which was given as Hiroki Kiumura, has been updated to Hiroki Kimura. Furthermore, supplementary information has been updated, and grant numbers have been added. These updates have been made to both the PDF and HTML versions of this Article.

Proteomic analysis of lymphoblastoid cell lines from schizophrenic patients

Although a number of studies have identified several convincing candidate genes or molecules, the pathophysiology of schizophrenia (SCZ) has not been completely elucidated. Therapeutic optimization based on pathophysiology should be performed as early as possible to improve functional outcomes and prognosis; to detect useful biomarkers for SCZ, which reflect pathophysiology and can be utilized for timely diagnosis and effective therapy. To explore biomarkers for SCZ, we employed fluorescence two-dimensional differential gel electrophoresis (2D-DIGE) of lymphoblastoid cell lines (LCLs) (1st sample set: 30 SCZ and 30 CON). Differentially expressed proteins were sequenced by liquid chromatography tandem-mass spectrometry (LC-MS/MS) and identified proteins were confirmed by western blotting (WB) (1st and 2nd sample set: 60 SCZ and 60 CON). Multivariate logistic regression analysis was performed to identify an optimal combination of biomarkers to create a prediction model for SCZ. Twenty protein spots were differentially expressed between SCZ and CON in 2D-DIGE analysis and 22 unique proteins were identified by LC-MS/MS. Differential expression of eight of 22 proteins was confirmed by WB. Among the eight candidate proteins (HSPA4L, MX1, GLRX3, UROD, MAPRE1, TBCB, IGHM, and GART), we successfully constructed logistic regression models comprised of 4- and 6-markers with good discriminative ability between SCZ and CON. In both WB and gene expression analysis of LCL, MX1 showed reproducibly significant associations. Moreover, Mx1 and its related proinflamatory genes (Mx2, Il1b, and Tnf) were also up-regulated in poly I:C-treated mice. Differentially expressed proteins might be associated with molecular pathophysiology of SCZ, including dysregulation of immunological reactions and potentially provide diagnostic and prognostic biomarkers.

Blonanserin ameliorates social deficit through dopamine-D3 receptor antagonism in mice administered phencyclidine as an animal model of schizophrenia

Blonanserin differs from other antipsychotic drugs, such as risperidone and olanzapine, and exhibits a higher affinity for dopamine-D_2/3 receptors than for serotonin 5-HT_2A receptors. We investigated the involvement of dopamine-D₃ receptors in the effect of blonanserin on the social deficit observed in an animal model of schizophrenia and sought to elucidate the molecular mechanism underlying its action. Mice received phencyclidine (PCP: 10 mg/kg/day, s.c.), a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, once a day for 14 consecutive days. We then evaluated the sociability, using a social interaction test, and the expression of GluN1 subunit, an essential subunit of the NMDA receptors, in these mice. Blonanserin significantly ameliorated the PCP-induced social deficit, whereas olanzapine and haloperidol did not. This effect of blonanserin was antagonized by 7-OH-DPAT, a dopamine-D₃ receptor agonist, and SCH23390, a dopamine-D₁ receptor antagonist. However, the ameliorating effect of blonanserin was not inhibited by DOI, a serotonin 5-HT_2A receptor agonist. The PCP-induced social deficit was also ameliorated by U99194, a dopamine-D₃ receptor antagonist and SKF38393, a dopamine-D₁ receptor agonist, being effects antagonized by 7-OH-DPAT or SCH23390. Blonanserin significantly inhibited the decrease in the phosphorylation levels of GluN1 at Ser⁸⁹⁷ by protein kinase A (PKA) in the prefrontal cortex (PFC) in PCPadministered mice. These results suggest that activation of NMDA receptors due to Ser⁸⁹⁷-phosphorylation of GluN1 subunit, which is a step linked to dopamine-D₁ receptor-PKA signaling through dopamine-D₃ receptor antagonism in the PFC, is required for the ameliorating effect of blonanserin on the PCP-induced social deficit. These findings also provide in vivo evidence that blonanserin antagonism of the dopamine-D₃ receptors may be useful as a novel treatment strategy and that the dopamine-D₃ receptors can be a novel therapeutic target molecule for the social deficit observed in schizophrenia.

Pancreatic MRI associated with pancreatic fibrosis and postoperative fistula: comparison between pancreatic cancer and non-pancreatic cancer tissue

AIM

To evaluate the potential value of magnetic resonance imaging (MRI) for predicting postoperative pancreatic fistula (POPF) in patients with pancreatic cancer (PC) and non-pancreatic cancer (non-PC).

MATERIAL AND METHODS

This retrospective study was approved by the institutional review board and written informed consent was waived. Forty patients underwent pancreatoduodenectomy due to PC (n=31) and non-PC (n=9). The pancreas-to-muscle signal intensity ratio (SIR) on three-dimensional (3D)- fast field echo (FFE) T1-, in- and opposed-phase T1-, and T2-weighted images, as well as the apparent diffusion coefficient (ADC) value of the pancreas were measured. The frequency of POPF and MRI measurements were compared between patients with PC and non-PC. The MRI measurements were also compared with the grade of pancreatic fibrosis on pathological findings, fat deposition, and interstitial oedema.

RESULTS

The frequency of POPF was significantly higher in patients with non-PC than in those with PC (p=0.0067), with an odds ratio of 10.4. The SIR on 3D-FFE T1-weighted images was significantly higher in patients with non-PC (p=0.0001) and those with POPF (p=0.017) than in those with PC and those without POPF, respectively. Multiple regression analysis demonstrated that the SIR on 3D-FFE T1-weighted image was independently associated with the grade of pancreatic fibrosis (p<0.0001).

CONCLUSION

The frequency of POPF was significantly higher in patients with non-PC than in those with PC was inversely related to the grade of pancreatic fibrosis. The SIR on 3D-FFE T1-weighted image might be a potential imaging biomarker for predicting POPF.

Neuropeptide VGF-Derived Peptide LQEQ-19 has Neuroprotective Effects in an In Vitro Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease caused by the loss of upper and lower motor neurons resulting in muscle weakness and paralysis. Recently, VGF, a neuropeptide that is a precursor of bioactive polypeptides, was found to be decreased in ALS patients, and its inducer exerted protective effects in models of ALS. These findings suggested that VGF was involved in the pathology of ALS. Here, we investigated the neuroprotective effects of various VGF-derived peptides in an in vitro ALS model. We applied seven VGF-derived peptides (TLQP-21, AQEE-30, AQEE-11, LQEQ-19, QEEL-16, LENY-13, and HVLL-7) to the motor neuron-derived cell line, NSC-34, expressing SOD1^G93A, which is one of the mutated proteins responsible for familial ALS. Nuclear staining revealed that AQEE-30 and LQEQ-19, which are derived from the C-terminal polypeptide of the VGF precursor protein, attenuated neuronal cell death. Furthermore, immunoblot analysis demonstrated that LQEQ-19 promoted the phosphorylation of Akt and extracellular signal-regulated kinase (ERK) 1/2, and inhibiting these mitogen-activated MAP kinases (MAPKs) with phosphoinositide 3-kinase or MEK/ERK inhibitors, eliminated the neuroprotective effects of LQEQ-19. In conclusion, these results suggest that VGF C-terminal peptides exert their neuroprotective effects via activation of MAPKs such as Akt and ERK1/2. Furthermore, these findings indicate that VGF-derived peptides have potential application in ALS therapy.

Effects of hypnotics on prefrontal cortex activity during a verbal fluency task in healthy male subjects: A near-infrared spectroscopy study

OBJECTIVE

To assess the effects of hypnotics on prefrontal cortex activity in healthy subjects using near-infrared spectroscopy (NIRS) in a double-blind, placebo-controlled crossover trial.

METHODS

Eighteen healthy males received acute doses of ramelteon (8 mg), triazolam (0.125 mg), or placebo in a predetermined randomization schedule, with a washout period of more than 1 week. All subjects performed a verbal fluency task during NIRS assessments at baseline and at 1 and 4 hr post-dose. The number of words correctly generated during the task (behavioral performance) and scores on the Stanford Sleepiness Scale (SSS) were also recorded at each test time.

RESULTS

Compared with the placebo, triazolam (0.125 mg) significantly decreased oxyhemoglobin (oxy-Hb) concentration change in NIRS during the posttask period and significantly increased behavioral performance, whereas triazolam (0.125 mg) and ramelteon (8 mg) significantly increased SSS scores.

CONCLUSIONS

The differential effects of two types of hypnotics on oxy-Hb change measured by NIRS were observed in acute dosing, suggesting that when assessing brain activity of patients with psychiatric disorders, researchers should consider how certain types of hypnotics can influence brain function. This would also provide useful information to clinicians when prescribing hypnotics suitable for their patients' conditions.

Involvement of Allosteric Effect and KCa Channels in Crosstalk between β₂-Adrenergic and Muscarinic M₂ Receptors in Airway Smooth Muscle

To advance the development of bronchodilators for asthma and chronic obstructive pulmonary disease (COPD), this study was designed to investigate the mechanism of functional antagonism between β₂-adrenergic and muscarinic M₂ receptors, focusing on allosteric effects and G proteins/ion channels coupling. Muscarinic receptor antagonists (tiotropium, glycopyrronium, atropine) synergistically enhanced the relaxant effects of β₂-adrenergic receptor agonists (procaterol, salbutamol, formoterol) in guinea pig trachealis. This crosstalk was inhibited by iberitoxin, a large-conductance Ca²⁺-activated K⁺ (K_Ca) channel inhibitor, whereas it was increased by verapamil, a L-type voltage-dependent Ca²⁺ (VDC) channel inhibitor; additionally, it was enhanced after tissues were incubated with pertussis or cholera toxin. This synergism converges in the G proteins (G_i, G_s)/K_Ca channel/VDC channel linkages. Muscarinic receptor antagonists competitively suppressed, whereas, β₂-adrenergic receptor agonists noncompetitively suppressed muscarinic contraction. In concentration-inhibition curves for β₂-adrenergic receptor agonists with muscarinic receptor antagonists, EC₅₀ was markedly decreased, and maximal inhibition was markedly increased. Hence, muscarinic receptor antagonists do not bind to allosteric sites on muscarinic receptors. β₂-Adrenergic receptor agonists bind to allosteric sites on these receptors; their intrinsic efficacy is attenuated by allosteric modulation (partial agonism). Muscarinic receptor antagonists enhance affinity and efficacy of β₂-adrenergic action via allosteric sites in β₂-adrenergic receptors (synergism). In conclusion, K_Ca channels and allosterism may be novel targets of bronchodilator therapy for diseases such as asthma and COPD.

Use of Chromogenic Substrate S-2251 for Determination of Plasminogen Activator in Rat Ovaries

A simple, specific and reproducible method for determination of plasminogen activator activity in rat ovaries has been developed by using the chromogenic substrate S-2251. The two steps of enzymatic reactions, i. e. activation of plasminogen and subsequent hydrolysis of the substrate was performed in one step incubation. A linear relationship was observed between the amount of chromogen produced and activator activity in the range of the optical density from 0.05 to 1.20 for 30 min’s incubation. Endogenous activity of non-specific proteases, plasmin or plasmin inhibitors which might be contained in rat ovaries turned out not to interfere with the specificity of a standardized assay procedure. Reproducibility was firmly established with coefficient of variation not exceeding 10%. Using this method, a marked increase followed by a drastic decrease in the activator activity was shown with rat ovaries around the time of ovulation after the injection of human chorionic gonadotropin.

[Effect of Non-alcoholic Beverage Intake in Children on Alcoholic Beverage Drinking and Smoking]

　The early intake of alcohol and/or nicotine in childhood or adolescence is one of risk factors for alcohol and/or nicotine dependence in adult. Recently, non-alcoholic beverages with less than 0.00% alcohol are on sale for adults as substitutes for alcoholic beverages without strict legal limitations. However, it is unclear whether non-alcoholic beverages could be a risk factor in drinking and smoking in childhood or adolescence. The purpose of the present survey is to clarify the effect of non-alcoholic beverage intake in children on alcoholic beverage drinking and smoking. We examined as follows: the experience of alcoholic or non-alcoholic beverage intake, and of smoking in elementary school pupils and/or their family members, and interest in or motivation for drinking and smoking in the pupils. As a result, the percentage of alcoholic or non-alcoholic beverage intake, and of smoking in the pupils were 16.8% or 21.9%, and 0.3%, respectively. The number of family members took the alcoholic or non-alcoholic beverage was larger in the pupils took it compared to the pupils did not take it. In the pupils who experienced the non-alcoholic beverage intake, interest in or motivation for drinking alcoholic beverages and/or smoking is higher than in those who did not. These findings indicate that non-alcoholic beverage intake is related to drinking and smoking. We will introduce drug abuse prevention education on the risk of drug dependence among childhood or adolescents based on the findings of this survey.

Differential effects of physical activity and sleep duration on cognitive function in young adults

PURPOSE

Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy (NIRS).

METHODS

A total of 23 healthy young adults (age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time (TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test (WCST), and the Continuous Performance Test-Identical Pairs (CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.

RESULTS

Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks (r = -0.602, p = 0.002; r = -0.446, p = 0.033, respectively), whereas TST was significantly correlated with % corrects on the 2-back task (r = 0.486, p = 0.019). Multiple regression analysis, including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks (β = -0.634, p = 0.002; β = -0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task (β = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area (r = 0.492, p = 0.017).

CONCLUSION

Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.

Dysfunction of Serotonergic and Dopaminergic Neuronal Systems in the Antidepressant-Resistant Impairment of Social Behaviors Induced by Social Defeat Stress Exposure as Juveniles

BACKGROUND

Extensive studies have been performed on the role of monoaminergic neuronal systems in rodents exposed to social defeat stress as adults. In the present study, we investigated the role of monoaminergic neuronal systems in the impairment of social behaviors induced by social defeat stress exposure as juveniles.

METHODS

Juvenile, male C57BL/6J mice were exposed to social defeat stress for 10 consecutive days. From 1 day after the last stress exposure, desipramine, sertraline, and aripiprazole were administered for 15 days. Social behaviors were assessed at 1 and 15 days after the last stress exposure. Monoamine turnover was determined in specific regions of the brain in the mice exposed to the stress.

RESULTS

Stress exposure as juveniles induced the impairment of social behaviors in adolescent mice. In mice that showed impairment of social behaviors, turnover of serotonin and dopamine, but not noradrenaline, was decreased in specific brain regions. Acute and repeated administration of desipramine, sertraline, and aripiprazole failed to attenuate the impairment of social behaviors, whereas repeated administration of a combination of sertraline and aripiprazole showed additive attenuating effects.

CONCLUSIONS

These findings suggest that social defeat stress exposure as juveniles induces the treatment-resistant impairment of social behaviors in adolescents through dysfunction in the serotonergic and dopaminergic neuronal systems. The combination of sertraline and aripiprazole may be used as a new treatment strategy for treatment-resistant stress-related psychiatric disorders in adolescents with adverse juvenile experiences.

Human neutrophils show decreased survival upon long-term exposure to clozapine

OBJECTIVE

Clozapine is an atypical antipsychotic prescribed for treatment-resistant schizophrenic patients, but treatment with clozapine is strictly limited because it can induce lethal-hematologic side effects. We investigated the effects of short- and long-term exposure of human neutrophils derived from healthy subjects to clozapine and compared them with the effects of reactive metabolite of clozapine, olanzapine, and doxorubicin.

METHODS

Neutrophils were exposed to clozapine and olanzapine (1, 10, 50, or 100 μM), reactive metabolite of clozapine (50 or 100 μM), or doxorubicin (0.2 μM) and cultured for a short (2 hr) or long (24 or 48 hr) duration, and then the survival rate of neutrophils was calculated.

RESULTS

Decreased human neutrophil survival was observed in short-term exposure to clozapine (100 μM) and long-term exposure to clozapine even at a lower concentration (50 μM). A similar phenomenon was observed in reactive metabolite of clozapine and long-term exposure to doxorubicin (0.2 μM), but not to olanzapine (1-100 μM).

CONCLUSIONS

The effect of long-term exposure to clozapine on neutrophil survival is plausibly associated with delayed onset of agranulocytosis after initial exposure. Our results suggest that human neutrophils are vulnerable to clozapine and its reactive metabolite in a concentration- and time-dependent manner.