Conservative treatment of fragility fracture of the pelvis: A retrospective study

BACKGROUND

Although an increasing number of studies have reported the usefulness of early minimally invasive surgery (MIS) or fragility fracture of the pelvis (FFP), MIS is difficult to perform in every hospital, partly because of equipment problems. Moreover, different opinions exist on FFP treatment methods and the indication for surgery is usually determined by the fracture type. Since our hospital follows a conservative approach as the basic treatment, this study examined the outcomes of such an FFP approach.

HYPOTHESIS

FFP outcomes are influenced by the fracture type and walking ability before the injury.

PATIENTS AND METHODS

We investigated the bone fusion rate, bone fusion duration, unloading duration, walking ability trends, and outcomes in 76 patients with FFP treated conservatively at our hospital.

RESULTS

The union rate, mean period until union, and follow-up period were 93.4%, 3.3 months, and 14.3 months, respectively. Walking ability significantly decreased from 5.1 points before the injury to 4.4 points during the last follow-up (p<0.01). The average unloading period was 12.8 days, and FFPs showed a high bone fusion rate, even with conservative treatment.

DISCUSSION

Most patients eventually returned to their pre-injury status despite slightly decreased walking ability. Given the invasive nature of surgery, the indications for surgery should be carefully assessed after considering the risk-benefit ratio.

LEVEL OF EVIDENCE

III; retrospective study.

Ensemble dynamics and information flow deduction from whole-brain imaging data

The recent advancements in large-scale activity imaging of neuronal ensembles offer valuable opportunities to comprehend the process involved in generating brain activity patterns and understanding how information is transmitted between neurons or neuronal ensembles. However, existing methodologies for extracting the underlying properties that generate overall dynamics are still limited. In this study, we applied previously unexplored methodologies to analyze time-lapse 3D imaging (4D imaging) data of head neurons of the nematode Caenorhabditis elegans. By combining time-delay embedding with the independent component analysis, we successfully decomposed whole-brain activities into a small number of component dynamics. Through the integration of results from multiple samples, we extracted common dynamics from neuronal activities that exhibit apparent divergence across different animals. Notably, while several components show common cooperativity across samples, some component pairs exhibited distinct relationships between individual samples. We further developed time series prediction models of synaptic communications. By combining dimension reduction using the general framework, gradient kernel dimension reduction, and probabilistic modeling, the overall relationships of neural activities were incorporated. By this approach, the stochastic but coordinated dynamics were reproduced in the simulated whole-brain neural network. We found that noise in the nervous system is crucial for generating realistic whole-brain dynamics. Furthermore, by evaluating synaptic interaction properties in the models, strong interactions within the core neural circuit, variable sensory transmission and importance of gap junctions were inferred. Virtual optogenetics can be also performed using the model. These analyses provide a solid foundation for understanding information flow in real neural networks.

Post-marketing surveillance of zinc acetate dihydrate for hypozincemia in Japan

Zinc is an essential microelement, and its deficit causes various diseases and symptoms. In adults, especially in elderly individuals, zinc shortage can cause symptoms such as taste disorder, dermatitis, and susceptibility to infection. In children, zinc deficiency can lead to growth retardation. In 2017, the indication for zinc acetate dihydrate (NOBELZIN®) was expanded from Wilson's disease to include hypozincemia, leading to wider use of zinc acetate dihydrate. At five years after this broadening of use, we conducted a post-marketing study (PMS) to investigate the utilization, safety, and effectiveness of zinc acetate dihydrate. Over 52 weeks, the overall incidence of adverse drug reactions (ADRs) was 9.4% (87/928). The most common ADR was copper deficiency (2.4%), followed by nausea (1.4%). Among 928 patients, 19 (2%) developed serious ADRs. Of the patients with copper deficiency, 92% were >65 years of age, and all had comorbidities at baseline. Physicians evaluated the effectiveness of zinc acetate dihydrate using three categories: "effective", "not effective", and "indeterminate". The overall efficacy rate was 83.0%. The average serum zinc levels were elevated from 50-60 μg/dL to >90 μg/dL within 12 weeks, and were maintained up to 52 weeks after administration. Among the symptomatic sub-categories, the efficacy rate was highest in pressure ulcer (96.2%; 25/26), followed by in stomatitis (87.5%; 42/48), and taste disorder (87.4%; 181/207). Among pediatric patients with developmental symptoms, an efficacy rate of 66% was achieved. In conclusion, zinc acetate dihydrate has been safely used, and has produced beneficial effects on various diseases and symptoms.

Development of artificial intelligence-based slow-motion echocardiography and clinical usefulness for evaluating regional wall motion abnormalities

The diagnostic accuracy of exercise stress echocardiography (ESE) for myocardial ischemia requires improvement, given that it currently depends on the physicians' experience and image quality. To address this issue, we aimed to develop artificial intelligence (AI)-based slow-motion echocardiography using inter-image interpolation. The clinical usefulness of this method was evaluated for detecting regional wall-motion abnormalities (RWMAs). In this study, an AI-based echocardiographic image-interpolation pipeline was developed using optical flow calculation and prediction for in-between images. The accuracy for detecting RWMAs and image readability among 25 patients with RWMA and 25 healthy volunteers was compared between four cardiologists using slow-motion and conventional ESE. Slow-motion echocardiography was successfully developed for arbitrary time-steps (e.g., 0.125×, and 0.5×) using 1,334 videos. The RWMA detection accuracy showed a numerical improvement, but it was not statistically significant (87.5% in slow-motion echocardiography vs. 81.0% in conventional ESE; odds ratio: 1.43 [95% CI: 0.78-2.62], p = 0.25). Interreader agreement analysis (Fleiss's Kappa) for detecting RWMAs among the four cardiologists were 0.66 (95%CI: 0.55-0.77) for slow-motion ESE and 0.53 (95%CI: 0.42-0.65) for conventional ESE. Additionally, subjective evaluations of image readability using a four-point scale showed a significant improvement for slow-motion echocardiography (2.11 ± 0.73 vs. 1.70 ± 0.78, p < 0.001).In conclusion, we successfully developed slow-motion echocardiography using in-between echocardiographic image interpolation. Although the accuracy for detecting RWMAs did not show a significant improvement with this method, we observed enhanced image readability and interreader agreement. This AI-based approach holds promise in supporting physicians' evaluations.

Mice Recognise Mice in Neighbouring Rearing Cages and Change Their Social Behaviour

Mice are social animals that change their behaviour primarily in response to visual, olfactory, and auditory information from conspecifics. Rearing conditions such as cage size and colour are important factors influencing mouse behaviour. In recent years, transparent plastic cages have become standard breeding cages. The advantage of using a transparent cage is that the experimenter can observe the mouse from outside the cage without touching the cage. However, mice may recognise the environment outside the cage and change their behaviour. We speculated that mice housed in transparent cages might recognise mice in neighbouring cages. We used only male mice in this experiment. C57BL/6 mice were kept in transparent rearing cages with open lids, and the cage positions were maintained for 3 weeks. Subsequently, we examined how mice behaved toward cagemate mice, mice from neighbouring cages, and mice from distant cages. We compared the level of interest in mice using a social preference test. Similar to previous reports, subject mice showed a high degree of interest in unfamiliar mice from distant cages. By contrast, subject mice reacted to mice from neighbouring cages as familiar mice, similar to cagemate mice. This suggests that mice housed in transparent cages with open lids perceive the external environment and identify mice in neighbouring cages. Researchers should pay attention to the environment outside the mouse cage, especially for the social preference test.

Effects of home-cage elevation on behavioral tests in mice

BACKGROUND

Research reproducibility is a common problem in preclinical behavioral science. Mice are an important animal model for studying human behavioral disorders. Experimenters, processing methods, and rearing environments are the main causes of data variability in behavioral neuroscience. It is likely that mice adapt their behavior according to the environment outside the breeding cage. We speculated that mice housed on elevated shelves and mice housed on low shelves might have differently altered anxiety-like behavior toward heights.

PURPOSE

The purpose of this study was to investigate potential behavioral changes in mice raised at different heights for 3 weeks. Changes in behavior were examined using various experimental tests.

RESULTS

Mice housed on elevated shelves showed reduced anxiety-like behavior in a light/dark traffic test compared with mice housed on low shelves. There were no significant differences between the two groups in terms of activity, exploratory behavior, muscle strength, or depression-like behavior.

CONCLUSIONS

Our results indicate that different cage heights and corresponding light exposure may alter the anxiety-like behavior of mice in response to brightness. Researchers need to carefully control the cage height and light intensity experienced by the mice to produce reproducible test results.

Minimally invasive surgery technique for unstable pelvic ring fractures with severe vertical shear displacement: A retrospective study

BACKGROUND

Unstable pelvic fractures, especially vertical shear fractures, require surgery for correct reduction, rigid fixation, and improved postoperative outcomes. Herein, we assess the effectiveness of our minimally invasive procedure for the management of unstable pelvic fractures.

HYPOTHESIS

We hypothesized that this procedure would be useful for the management of unstable pelvic fractures.

PATIENTS AND METHODS

This study included 28 patients with unstable pelvic fractures (vertical shear injuries; AO types C1-3) treated using minimally invasive surgery for spinopelvic fixation (MIS-SP) between 2014 and 2020 (mean follow-up time, 15 months). The MIS-SP requires four percutaneous pedicle screws and four iliac screw insertions. Subsequently, reduction and fixation are performed.

RESULTS

The mean preoperative displacement of the posterior pelvic elements in craniocaudal correction was 17.6 (range, 9.0-32.2) mm. The mean length of the craniocaudal reduction was 16.5 (8.1-30.1) mm, with a mean reduction rate of 93.5% (78%-100%). The mean length of the mediolateral reduction was 11.3 (3.9-19.6) mm, with a mean reduction rate of 87.3% (76%-100%).

DISCUSSION

Our novel reduction and fixation procedure is a powerful, minimally invasive option for the treatment of unstable pelvic ring fractures.

LEVEL OF EVIDENCE

III.

Delayed surgery after hip fracture affects the incidence of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is one of the most common complications of hip fracture surgeries, and it is unclear whether delayed surgery affects the incidence of VTE. This study aimed to examine the association between delayed surgery and VTE incidence by statistically adjusting for factors that may influence VTE incidence.

METHODS

We included 862 patients ≥ 65 years with hip fractures who underwent surgery between October 2010 and December 2020. We examined the effect of surgical delay 48 h after injury on postoperative VTE. Patients with and without VTE were assigned to groups V and NV, respectively. Those with and without proximal deep venous thrombosis (DVT) were assigned to PD and NPD groups, respectively. Univariate analysis was performed to identify factors that might influence DVT development. Risk factors for developing VTE and proximal DVT were analyzed using logistic regression analysis to determine whether delayed surgery was a risk factor.

RESULTS

VTE was observed in 436 patients (40%) and proximal DVT in 48 patients (5.6%). Univariate analysis showed significant differences in the time from trauma to surgery between the V and NV groups and between the PD and NPD groups. In multivariate analysis, surgery 48 h later was also a risk factor for developing VTE and proximal DVT.

CONCLUSION

A delay in surgery beyond 48 h after a hip fracture injury is a risk factor for developing VTE and proximal DVT.

Cell Tracking in C. elegans with Cell Position Heatmap-Based Alignment and Pairwise Detection

3D cell tracking in a living organism has a crucial role in live cell image analysis. Cell tracking in C. elegans has two difficulties. First, cell migration in a consecutive frame is large since they move their head during scanning. Second, cell detection is often inconsistent in consecutive frames due to touching cells and low-contrast images, and these inconsistent detections affect the tracking performance worse. In this paper, we propose a cell tracking method to address these issues, which has two main contributions. First, we introduce cell position heatmap-based non-rigid alignment with test-time fine-tuning, which can warp the detected points to near the positions at the next frame. Second, we propose a pairwise detection method, which uses the information of detection results at the previous frame for detecting cells at the current frame. The experimental results demonstrate the effectiveness of each module, and the proposed method achieved the best performance in comparison.

WormTensor: a clustering method for time-series whole-brain activity data from C. elegans

BACKGROUND

In the field of neuroscience, neural modules and circuits that control biological functions have been found throughout entire neural networks. Correlations in neural activity can be used to identify such neural modules. Recent technological advances enable us to measure whole-brain neural activity with single-cell resolution in several species including [Formula: see text]. Because current neural activity data in C. elegans contain many missing data points, it is necessary to merge results from as many animals as possible to obtain more reliable functional modules.

RESULTS

In this work, we developed a new time-series clustering method, WormTensor, to identify functional modules using whole-brain activity data from C. elegans. WormTensor uses a distance measure, modified shape-based distance to account for the lags and the mutual inhibition of cell-cell interactions and applies the tensor decomposition algorithm multi-view clustering based on matrix integration using the higher orthogonal iteration of tensors (HOOI) algorithm (MC-MI-HOOI), which can estimate both the weight to account for the reliability of data from each animal and the clusters that are common across animals.

CONCLUSION

We applied the method to 24 individual C. elegans and successfully found some known functional modules. Compared with a widely used consensus clustering method to aggregate multiple clustering results, WormTensor showed higher silhouette coefficients. Our simulation also showed that WormTensor is robust to contamination from noisy data. WormTensor is freely available as an R/CRAN package https://cran.r-project.org/web/packages/WormTensor .

Pneumocephalus After Anterior Lumbar Spinal Surgery Due to Trauma: A Case Report

Pneumocephalus as a complication of anterior lumbar spinal surgery is extremely rare. A 53-year-old male patient presented with L4 fracture. Posterior fixation from L3 to L5 was conducted one day after the trauma. As the patient's neurological deficit persisted, additional anterior surgery by L4 vertebral body replacement was performed on the 19th day. Both surgeries were completed without obvious intraoperative complications. Two weeks after the anterior lumbar surgery, the patient complained of severe headaches, and computed tomography scan revealed pneumocephalus and massive fluid retention in the abdomen. The symptoms improved with conservative treatment, including bed rest, spinal drainage, intravenous drip infusion, and prophylactic administration of antibiotics. Due to the lack of tamponade effect in the soft tissues, a large amount of cerebrospinal fluid leakage may induce and cause progression of pneumocephalus in anterior dural injury.

Comprehensive behavioral study of C57BL/6.KOR-ApoEshl mice

Background

Apolipoprotein E (ApoE) is associated with Alzheimer's disease (AD) and cognitive dysfunction in elderly individuals. There have been extensive studies on behavioral abnormalities in ApoE-deficient (Apoe^shl) mice, which have been described as AD mouse models. Spontaneously hyperlipidemic mice were discovered in 1999 as ApoE-deficient mice due to ApoE gene mutations. However, behavioral abnormalities in commercially available Apoe^shl mice remain unclear. Accordingly, we aimed to investigate the behavioral abnormalities of Apoe^shl mice.

Results

Apoe^shl mice showed decreased motor skill learning and increased anxiety-like behavior toward heights. Apoe^shl mice did not show abnormal behavior in the Y-maze test, open-field test, light/dark transition test, and passive avoidance test.

Conclusion

Our findings suggest the utility of Apoe^shl mice in investigating the function of ApoE in the central nervous system.

Fingolimod increases parvalbumin-positive neurons in adult mice

In recent years, it has been shown that central nervous system agents, such as antidepressants and antiepileptic drugs, reopen a critical period in mature animals. Fingolimod, which is used for the treatment of multiple sclerosis, also restores neuroplasticity. In this study, we investigated the effects of parvalbumin (PV)-positive neurons and perineuronal nets (PNN) on fingolimod administration with respect to neuroplasticity. Fingolimod was chronically administered intraperitoneally to mature mice. PV-positive neurons and PNN in the hippocampus, prefrontal cortex, and somatosensory cortex were analyzed. An increase in PV-positive neurons was observed in the hippocampus, prefrontal cortex, and somatosensory cortex of the fingolimod-treated mice. An increase in Wisteria floribunda agglutinin-positive PNN was confirmed in mice treated with fingolimod in the somatosensory cortex only. Fingolimod increased the density of PV-positive neurons in the brains of mature mice. The results indicate that fingolimod may change the critical period in mature animals.

Effect of simultaneous testing of two mice in the tail suspension test and forced swim test

In mouse studies, the results of behavioural experiments are greatly affected by differences in the experimental environment and handling methods. The Porsolt forced swim test and tail suspension test are widely used to evaluate predictive models of depression-like behaviour in mice. It has not been clarified how the results of these tests are affected by testing single or multiple mice simultaneously. Therefore, this study evaluated the differences between testing two mice simultaneously or separately. To investigate the effect of testing multiple mice simultaneously, the Porsolt forced swim test and tail suspension test were performed in three patterns: (1) testing with an opaque partition between two mice, (2) testing without a partition between two mice, and (3) testing a single mouse. In the Porsolt forced swim test, the mice tested simultaneously without a partition demonstrated increased immobility time as compared to mice tested alone. No difference in immobility time was observed between the three groups in the tail suspension test. Our results showed that the environment of behavioural experiments investigating depression-like behaviour in mice can cause a difference in depression-like behaviour. The results of this experiment indicated that it is necessary to describe the method used for behavioural testing in detail.

Mice can recognise water depths and will avoid entering deep water

Rodents are averse to bodies of water, and this aversion has been exploited in experiments designed to study stress in mice. However, a few studies have elucidated the characteristics of murine water aversion. In this study, we investigated how mice behave in and around areas filled with water. Using variants of the open field test that contained pools of water at corners or sides of the field, we recorded the movements of mice throughout the field under various conditions. When the water was 8 mm deep, the mice explored the water pool regardless of whether an object was placed within it, but when the water was 20 mm deep, the mice were less willing to enter it. When the mice were placed on a dry area surrounded by 3 mm-deep water, they explored the water, but when they were surrounded by 8 mm-deep water, they stayed within the dry area. Our results indicate that mice exhibit exploratory behaviours around water, they can recognise water depths and avoid unacceptably deep water, and their willingness to enter water may be reduced by situational anxiety. Our experimental method could be used to investigate water-related anxiety-like behaviours in mice.

Ultrastructural observation of filtration membrane in cell-free and concentrated ascites reinfusion therapy for malignant ascites

INTRODUCTION

Cell-free and concentrated ascites reinfusion therapy (CART) is used for the treatment of diuretic-resistant ascites. An increase in circuit pressure and clogging of the filtration membrane often occur in CART for malignant ascites.

METHODS

To clarify the precise mechanism of filter clogging, we performed an ultrastructural observation study of the filtration membrane after the filtration of malignant ascites.

RESULTS

The deposition on the filtration membrane was composed of blood cells, fibrin, or both. Cellular deposition was associated with a greater number of blood cells in the original ascites fluid. In contrast, fibrin deposition was associated with higher levels of interleukin-6, α1-antitrypsin, haptoglobin, and fibrinogen/fibrin degradation products.

CONCLUSION

Our results suggest that the specific pathophysiologies of malignancy (such as inflammation or coagulation/fibrinolysis) and characteristics of malignant ascites (highly concentrated and cell-rich) are associated with clogging of the filtration membrane during CART.

EGL-4/PKG regulates the role of an interneuron in a chemotaxis circuit of C. elegans through mediating integration of sensory signals

Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.

3DeeCellTracker, a deep learning-based pipeline for segmenting and tracking cells in 3D time lapse images

Despite recent improvements in microscope technologies, segmenting and tracking cells in three-dimensional time-lapse images (3D + T images) to extract their dynamic positions and activities remains a considerable bottleneck in the field. We developed a deep learning-based software pipeline, 3DeeCellTracker, by integrating multiple existing and new techniques including deep learning for tracking. With only one volume of training data, one initial correction, and a few parameter changes, 3DeeCellTracker successfully segmented and tracked ~100 cells in both semi-immobilized and 'straightened' freely moving worm's brain, in a naturally beating zebrafish heart, and ~1000 cells in a 3D cultured tumor spheroid. While these datasets were imaged with highly divergent optical systems, our method tracked 90-100% of the cells in most cases, which is comparable or superior to previous results. These results suggest that 3DeeCellTracker could pave the way for revealing dynamic cell activities in image datasets that have been difficult to analyze.

Alpha-pinene and dizocilpine (MK-801) attenuate kindling development and astrocytosis in an experimental mouse model of epilepsy

Understanding the molecular and cellular mechanisms involved during the onset of epilepsy is crucial for elucidating the overall mechanism of epileptogenesis and therapeutic strategies. Previous studies, using a pentylenetetrazole (PTZ)-induced kindling mouse model, showed that astrocyte activation and an increase in perineuronal nets (PNNs) and extracellular matrix (ECM) molecules occurred within the hippocampus. However, the mechanisms of initiation and suppression of these changes, remain unclear. Herein, we analyzed the attenuation of astrocyte activation caused by dizocilpine (MK-801) administration, as well as the anticonvulsant effect of α-pinene on seizures and production of ECM molecules. Our results showed that MK-801 significantly reduced kindling acquisition, while α-pinene treatment prevented an increase in seizures incidences. Both MK-801 and α-pinene administration attenuated astrocyte activation by PTZ and significantly attenuated the increase in ECM molecules. Our results indicate that astrocyte activation and an increase in ECM may contribute to epileptogenesis and suggest that MK-801 and α-pinene may prevent epileptic seizures by suppressing astrocyte activation and ECM molecule production.

Increased anxiety-related behavior in mice following β-citronellol inhalation

β-Citronellol is a monoterpene alcohol found in essential oils of various aromatic plant species. The physiological effects of β-citronellol inhalation on the central nervous system remain unclear. We investigated the effects of β-citronellol inhalation on mouse behavior. First, we examined whether the odor of β-citronellol was attractive or repellent to mice. Then, following 30 minutes of β-citronellol inhalation, a series of behavioral tests (elevated plus maze, open field, Y-maze, tail suspension, and forced swim tests) were performed. Mice were neither attracted to nor repelled by β-citronellol. Mice that inhaled β-citronellol showed an increase in anxiety-like behavior in the elevated plus maze and open field tests. Performance in the Y-maze and forced swim tests was not affected. These results indicate that β-citronellol acts on the central nervous system of mice following inhalation and increases anxiety. Essential oils and cosmetics containing β-citronellol should be used with caution.

Hexanal inhalation affects cognition and anxiety-like behavior in mice

Hexanal is a 6-carbon aldehyde that smells like green leaves and urine to mammals. However, its physiological effects remain unclear. In particular, the effects of hexanal inhalation on the central nervous system have not been clarified. We investigated hexanal inhalation in mice and conducted a series of behavioral experiments to examine the neuropsychological effects of hexanal. After inhaling hexanal emissions for 30 min, mice were subjected to an open field test, a hot plate test, a grip strength test, an elevated plus maze test, a Y-maze test, a tail suspension test, and a forced swim test to examine the effects of hexanal odor on mouse behavior. Compared to controls, mice that inhaled hexanal exhibited reduced anxiety-like behavior in the elevated plus maze test. In addition, mice that inhaled hexanal displayed significantly improved spatial cognitive ability in the Y-maze test. However, in some behavioral experiments there was no significant difference between control mice and mice that inhaled hexanal. The results of this study suggest that hexanal inhalation causes anxiolytic effects and improves cognitive function in mice. These findings may have implications for safety management procedures and determining the effective use of household goods containing hexanal, though further work is required.

Impact of diabetes mellitus on the early phase arterial healing after drug-eluting stent implantation: a multicenter coronary angioscopic study

Background

Diabetes mellitus (DM) is a strong risk factor for major cardiac and cerebrovascular events. In particular, coronary artery disease with DM is often complicated with complex lesions. Drug-eluting stents (DES) are mainly used for these lesions, and dual-antiplatelet therapy (DAPT) has been used to prevent stent thrombosis. Early arterial healing after DES implantation may enable short DAPT strategy. However, the impact of DM on the arterial healing in the early phase has not been elucidated to date.

Purpose

We evaluated the arterial healing in the early phase after DES implantation using coronary angioscopy (CAS) and compared the findings between DM and non-DM patients.

Methods

This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients which were evaluated 3 to 5 months after DES implantation. Patients were divided into two groups: DM (149 lesions in 118 patients) versus non-DM groups (188 lesions in 152 patients). We assessed neointimal coverage (NIC) grades (maximum, minimum and dominant), thrombus adhesion and maximum yellow color of plaque underneath the stent. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

Results

Minimum NIC coverage grade was lower in DM group than in non-DM group (P=0.002, Figure), while maximum and dominant NIC coverage grades were similar between them (P=0.94 and P=0.59, respectively). Thrombus adhesion (44.3% versus 38.8%, P=0.32) and maximum yellow color grade (P=0.78) were also similar between DM and non-DM groups. Even after the adjustment by the confounding factors such as follow-up duration and primary disease of acute coronary syndrome, DM was an independent factor predicting grade 0 of minimum NIC (odds ratio [OR] 1.83 [95% confidence interval 1.11–3.03], P=0.019).

Conclusion

DM patients showed less covered struts than non-DM patients 3 to 5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applicable to DM patients.

Minimum neointimal coverage grade

Funding Acknowledgement

Type of funding source: None

Heparan sulfate deficiency leads to hypertrophic chondrocytes by increasing bone morphogenetic protein signaling

OBJECTIVE

Exostosin-1 (EXT1) and EXT2 are the major genetic etiologies of multiple hereditary exostoses and are essential for heparan sulfate (HS) biosynthesis. Previous studies investigating HS in several mouse models of multiple hereditary exostoses have reported that aberrant bone morphogenetic protein (BMP) signaling promotes osteochondroma formation in Ext1-deficient mice. This study examined the mechanism underlying the effects of HS deficiency on BMP/Smad signaling in articular cartilage in a cartilage-specific Ext^-/- mouse model.

METHOD

We generated mice with a conditional Ext1 knockout in cartilage tissue (Ext1-cKO mice) using Prg4-Cre transgenic mice. Structural cartilage alterations were histologically evaluated and phospho-Smad1/5/9 (pSmad1/5/9) expression in mouse chondrocytes was analyzed. The effect of pharmacological intervention of BMP signaling using a specific inhibitor was assessed in the articular cartilage of Ext1-cKO mice.

RESULTS

Hypertrophic chondrocytes were significantly more abundant (P = 0.021) and cartilage thickness was greater in Ext1-cKO mice at 3 months postnatal than in control littermates (P = 0.036 for femur; and P < 0.001 for tibia). However, osteoarthritis did not spontaneously occur before the 1-year follow-up. matrix metalloproteinase (MMP)-13 and adamalysin-like metalloproteinases with thrombospondin motifs(ADAMTS)-5 were upregulated in hypertrophic chondrocytes of transgenic mice. Immunostaining and western blotting revealed that pSmad1/5/9-positive chondrocytes were more abundant in the articular cartilage of Ext1-cKO mice than in control littermates. Furthermore, the BMP inhibitor significantly decreased the number of hypertrophic chondrocytes in Ext1-cKO mice (P = 0.007).

CONCLUSIONS

HS deficiency in articular chondrocytes causes chondrocyte hypertrophy, wherein upregulated BMP/Smad signaling partially contributes to this phenotype. HS might play an important role in maintaining the cartilaginous matrix by regulating BMP signaling.

Pentylenetetrazol kindling induces cortical astrocytosis and increased expression of extracellular matrix molecules in mice

Although epilepsy is one of the most common chronic neurological disorders with a prevalence of approximately 1.0 %, the underlying pathophysiology remains to be elucidated. Understanding the molecular and cellular mechanisms involved in the development of epilepsy is important for the development of appropriate therapeutic strategy. In this study, we investigated the effects of status epilepticus on astrocytes, microglia, and extracellular matrix (ECM) molecules in the somatosensory cortex and piriform cortex of mice. Activation of astrocytes was observed in many cortices except the retrosplenial granular cortex after pentylenetetrazol (PTZ)-induced kindling in mice. Activated astrocytes in the cortex were found in layers 1-3 but not in layers 4-6. In the somatosensory and piriform cortices, no change was observed in the number of parvalbumin (PV)-positive neurons and PV-positive neurons covered with perineuronal nets. However, the amount of ECM in the extracellular space increased. The expression of VGLUT1- and GAD67-positive synapses also increased. Thus, in the PTZ-kindling epilepsy mice model, an increase in the number of ECM molecules and activation of astrocytes were observed in the somatosensory cortex and piriform cortex. These results indicate that PTZ-induced seizures affect not only the hippocampus but also other cortical areas. Our study findings may help to develop new therapeutic approaches to prevent seizures or their sequelae.

Factors associated with development and distribution of granular/fuzzy astrocytes in neurodegenerative diseases

Granular/fuzzy astrocytes (GFAs), a subtype of “aging‐related tau astrogliopathy,” are noted in cases bearing various neurodegenerative diseases. However, the pathogenic significance of GFAs remains unclear. We immunohistochemically examined the frontal cortex, caudate nucleus, putamen and amygdala in 105 cases composed of argyrophilic grain disease cases (AGD, N = 26), and progressive supranuclear palsy (PSP, N = 10), Alzheimer’s disease (AD, N = 20) and primary age‐related tauopathy cases (PART, N = 18) lacking AGD, as well as 31 cases bearing other various neurodegenerative diseases to clarify (i) the distribution patterns of GFAs in AGD, and PSP, AD and PART lacking AGD, (ii) the impacts of major pathological factors and age on GFA formation and (iii) immunohistochemical features useful to understand the formation process of GFAs. In AGD cases, GFAs consistently occurred in the amygdala (100%), followed by the putamen (69.2%) and caudate nucleus and frontal cortex (57.7%, respectively). In PSP cases without AGD, GFAs were almost consistently noted in all regions examined (90–100%). In AD cases without AGD, GFAs were less frequent, developing preferably in the putamen (35.0%) and caudate nucleus (30.0%). PART cases without AGD had GFAs most frequently in the amygdala (35.3%), being more similar to AGD than to AD cases. Ordered logistic regression analyses using all cases demonstrated that the strongest independent factor of GFA formation in the frontal cortex and striatum was the diagnosis of PSP, while that in the amygdala was AGD. The age was not significantly associated with GFA formation in any region. In GFAs in AGD cases, phosphorylation and conformational change of tau, Gallyas‐positive glial threads indistinguishable from those in tufted astrocytes, and the activation of autophagy occurred sequentially. Given these findings, AGD, PSP, AD and PART cases may show distinct distributions of GFAs, which may provide clues to predict the underlying processes of primary tauopathies.

Caffeine inhalation effects on locomotor activity in mice

It is estimated that 80% of the world's population consumes caffeine from beverages and food every day. The traditional form of caffeine intake is oral, but more recently people have been inhaling caffeine using nasal sprays. However, the effects of caffeine inhalation are not well understood. The purpose of this study was to determine whether caffeine inhalation affects mouse behavior. To test this, we compared spontaneous activity of mice following inhalation and intraperitoneal administration of caffeine. Next, we investigated whether spontaneous activity changed with the time and/or concentration of caffeine inhaled. We found that mice that inhaled caffeine increased their spontaneous activity similar to mice that were administered caffeine intraperitoneally. Furthermore, spontaneous activity increased in an inhalation time-dependent and concentration-dependent manner. These results show that caffeine-induced stimulation also occurs by inhalation in mice, which suggests that caffeine can reach the brain even by inhalation. This study is useful not only for creating new administration methods of caffeine but also for adjusting caffeine storage and management.

Neuron ID dataset facilitates neuronal annotation for whole-brain activity imaging of C. elegans

BACKGROUND

Annotation of cell identity is an essential process in neuroscience that allows comparison of cells, including that of neural activities across different animals. In Caenorhabditis elegans, although unique identities have been assigned to all neurons, the number of annotatable neurons in an intact animal has been limited due to the lack of quantitative information on the location and identity of neurons.

RESULTS

Here, we present a dataset that facilitates the annotation of neuronal identities, and demonstrate its application in a comprehensive analysis of whole-brain imaging. We systematically identified neurons in the head region of 311 adult worms using 35 cell-specific promoters and created a dataset of the expression patterns and the positions of the neurons. We found large positional variations that illustrated the difficulty of the annotation task. We investigated multiple combinations of cell-specific promoters driving distinct fluorescence and generated optimal strains for the annotation of most head neurons in an animal. We also developed an automatic annotation method with human interaction functionality that facilitates annotations needed for whole-brain imaging.

CONCLUSION

Our neuron ID dataset and optimal fluorescent strains enable the annotation of most neurons in the head region of adult C. elegans, both in full-automated fashion and a semi-automated version that includes human interaction functionalities. Our method can potentially be applied to model species used in research other than C. elegans, where the number of available cell-type-specific promoters and their variety will be an important consideration.

Effects of repetitive gentle handling of male C57BL/6NCrl mice on comparative behavioural test results

Mice are the most commonly used laboratory animals for studying diseases, behaviour, and pharmacology. Behavioural experiment battery aids in evaluating abnormal behaviour in mice. During behavioural experiments, mice frequently experience human contact. However, the effects of repeated handling on mice behaviour remains unclear. To minimise mice stress, methods of moving mice using transparent tunnels or cups have been recommended but are impractical in behavioural tests. To investigate these effects, we used a behavioural test battery to assess differences between mice accustomed to the experimenter’s handling versus control mice. Repeatedly handled mice gained slightly more weight than control mice. In behavioural tests, repeatedly handled mice showed improved spatial cognition in the Y-maze test and reduced anxiety-like behaviour in the elevated plus-maze test. However, there was no change in anxiety-like behaviour in the light/dark transition test or open-field test. Grip strength, rotarod, sociability, tail suspension, Porsolt forced swim, and passive avoidance tests revealed no significant differences between repeatedly handled and control mice. Our findings demonstrated that mice repeatedly handled by the experimenter before behavioural tests showed reduced anxiety about high altitudes and improved spatial cognition, suggesting that repeated contact can affect the results of some behavioural tests.

P4711The prognostic impact of infrapopliteal arterial calcification on wound healing in patients with critical limb ischemia

Background

Critical limb ischemia (CLI) is the most progressed manifestation of peripheral artery disease. Although patients with CLI commonly complicate with severely calcified lesions in infrapopliteal lesions, the prognostic impact of infrapopliteal arterial calcification on wound healing in patients with CLI has not been systematically studied.

Purpose

The aim of current study was to elucidate the prognostic impact of infrapopliteal arterial calcification on wound healing in CLI undergoing endovascular therapy (EVT).

Methods

This study enrolled 639 CLI patients with tissue loss (age 74±10 years, male 62%, diabetes 69%, hemodialysis 57%, Rutherford class 5 77%, class 6 23%) primarily treated with EVT for the infrapopliteal lesions between April 2010 and December 2015. Arterial calcification was assessed by high intensity fluoroscopy and classified into 3 groups as follows; 1) none, 2) unilateral and 3) bilateral calcification. The primary outcome measure was complete wound healing. The predictors of the outcome were evaluated by Cox proportional hazards regression analysis.

Results

During a mean follow-up period of 22±19 months, 1-year wound healing rate were 59.0%. In Kaplan-Meier analysis, 1-year wound healing rate was worse in patients with bilateral calcification than in those with unilateral or none calcification (Figure, 46.2% versus 55.1% versus 67.8%, P<0.001). After multivariate analysis, the predictors of wound healing were non-ambulatory status (hazard ratio (HR) 0.67 [95% confidential interval (CI) 0.53–0.85], P=0.001) and bilateral calcification (HR 0.75 [95% CI 0.47–0.98], versus none or unilateral calcification, P=0.036).

Figure 1

Conclusion

Infrapopliteal Arterial calcification as well as non-ambulatory status was associated with wound healing in patients with CLI.

P2810Clinical outcomes 1 year after filter protection during percutaneous coronary intervention in patients with attenuated plaque identified by intravascular ultrasound

Background

In the VAMPIRE 3 (VAcuuM asPIration thrombus REemoval 3) trial, we have previously shown that selective use of distal filter protection during percutaneous coronary intervention (PCI) decreased the incidence of no-reflow phenomenon and was associated with fewer in-hospital serious adverse cardiac events than conventional PCI in patients with attenuated plaque ≥5mm. However, whether the early efficacy of distal embolic protection translate into long term clinical benefit is unknown.

Methods

Patients with acute coronary syndrome (ACS) with attenuated plaque ≥5mm were assigned to distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The primary end point of the incidence of no-reflow phenomenon during PCI and the secondary end point of in-hospital serious adverse cardiac events has been reported previously. The rate of a major adverse events, a composite of death from any cause, non-fatal myocardial infarction, or unplanned target vessel revascularization (TVR) at 1 year was the prespecified secondary end point of the trial. All clinical endpoint events were adjudicated by an independent Clinical Event Committee.

Results

Major adverse events at 1 year occurred in 12 patients (12.2%) in the DP group and in 3 patients (3.1%) in the CT group (P=0.029). The difference was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], p=0.018) in the DP group compared with the CT group. In patients treated with bare metal stents (n=42), major adverse events occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug eluting stents (n=152), rates of major adverse events were similar between the groups (8.1% vs. 3.9%, p=0.32). Rates of cardiac death were not significantly different (1.0% vs. 1.0%, p=1.00). No definite stent thrombosis was observed in either group.

Conclusions

In the VAMPIRE 3 trial of patients with ACS with attenuated plaque ≥5mm, the 1-year rates of major adverse events in the distal protection group were higher than in the conventional treatment group. This effect could be mitigated by the use of drug eluting stents.

Acknowledgement/Funding

This work was supported in part by a grant from Nipro, Boston Scientific Corporation, and Japan Lifeline.

P3386Angioscopic comparison between polymer-free biolimus A9-coated stent and durable polymer drug-eluting stent 10 months after the implantation

Background

Polymer-free biolimus A9-coated stent (DCS) has currently emerged as expected better arterial healing compared to durable polymer drug-eluting stent (DP-DES). However, superiority of DCS on arterial healing over DP-DES has not been well elucidated using intracoronary images.

Methods

This study examined 288 stents in 224 patients with de novo coronary artery lesions. We angioscopically compared 55 DCS from 35 patients with 233 DP-DES from 189 patients 10±2 months after the implantation. We assessed thrombus adhesion, which is a marker of incomplete re-endothelialization. Dominant neointimal coverage (NIC) grade, heterogeneity of NIC and maximum yellow color of plaque underneath the stent were also evaluated. Neointimal coverage was graded as follows: grade 0, stent struts exposed; grade 1, struts bulged into the lumen, although covered; grade 2, struts embedded by the neointima, but translucent; grade 3, struts fully embedded and invisible. NIC was judged as heterogeneous when differences in the NIC grade became apparent. Yellow plaque was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

Results

Thrombus adhesion was similar between DCS and DP-DES (29% versus 23%, P=0.32). Dominant NIC was greater in DCS than in BP-DES (P<0.001), while NIC was more heterogeneous in DCS than in BP-DES (P=0.001, Figure). Maximum yellow color of stented segment was similar between DCS and DP-DES (P=0.09).

Conclusion

DCS provided similar thrombus adhesion to DP-DES, which suggested similar re-endothelialization 10 months after implantation. However, DCS showed thick and heterogeneous NIC compared to DP-DES. The specific feature of polymer-free and Biolimus A9 would cause the difference, and further investigation is necessary to evaluate the longer-term safety and efficacy.

Acknowledgement/Funding

None

P1916A novel echo-guided approach of cryoballoon ablation without using contrast medium

Background

Pulmonary vein isolation (PVI) using cryoballoon requires contrast medium injection for the confirmation of appropriate venous occlusion. However, some patients have contra-indications against contrast use such as allergy for contrast medium, bronchial asthma or renal dysfunction. We hypothesized that intra-cardiac echocardiographic observation of microbubble leakage after saline injection from the cryoballoon lumen can be used as a maker of incomplete venous occlusion.

Purpose

The aim of this study was to assess the effect of echo-guided approach using saline injection on the acute clinical outcomes as well as the amount of contrast medium.

Methods

Twenty consecutive patients with paroxysmal atrial fibrillation (AF) were studied. They had any reason to avoid using contrast medium. Plain CT scan was performed in all cases to understand the anatomical features. Intra-cardiac echocardiography was used in all cases to guide transseptal puncture and to confirm pulmonary-vein occlusion. Procedural results and clinical outcomes were compared with patients who were performed by the conventional method (n=279).

Results

In all study patients, we could perform PVI without using contrast medium. A total of 2 patients required touch-up ablation using radiofrequency ablation catheter. The procedure time (85±23 vs 86±27 min, P=0.84), the dose of radiation exposure (108±78 vs. 140±133 mmGy/m2, P=0.29), and ratio of requiring touch-up ablation (5% vs 4%, P=0.81) were similar between the study group and the reference group. There was no significant difference in the AF-free survival rate (73% vs. 76%, P=0.79) during a follow-up period of 14±6 months.

Images of ICE

Conclusion

Echo-guided approach using saline infusion was effective and less invasive in terms of reduction of contrast use.

P6241Two-year clinical outcomes of biodegradable polymer versus durable polymer drug-eluting stent implantation in hemodialysis patients after percutaneous coronary intervention

Background

Biodegradable polymer drug-eluting stent (BP-DES) has been developed to improve clinical outcomes after percutaneous coronary intervention (PCI) for patients presenting coronary artery disease (CAD). Although BP-DES showed non-inferior safety and efficacy to durable polymer DES (DP-DES) in several randomized clinical trials, hemodialysis (HD) patients, who have been well known as high risk population for adverse events, were excluded in the most of trials. Therefore, there are limited data comparing the clinical outcomes between BP-DES and DP-DES in HD patients with CAD after PCI.

Purpose

The purpose of this study was to investigate clinical outcomes in HD patients after BP-DES implantation compared with those after DP-DES implantation.

Methods

We retrospectively analyzed 234 HD patients (male 74%, mean age 71±10 years) undergoing PCI for 404 lesions with 472 DESs (71 patients for 138 lesions with 170 BP-DESs [91 Ultimaster and 79 Synergy] and 163 HD patients for 266 lesions with 302 DP-DESs [219 Xience, 53 Promus and 30 Resolute]) from 2011 to 2017. Two-year clinical outcomes were compared between BP-DES group and DP-DES group. The primary outcome measure was the incidence of target lesion revascularization (TLR), while the secondary outcome measures were the occurrence of cardiac death (CD), stent thrombosis (ST), myocardial infraction (MI), target vessel revascularization (TVR), non-TVR and major adverse cardiac event (MACE) defined as a composite of CD, MI, and TVR. Outcome measures were estimated by the Kaplan-Meier method and the differences between BP-DES group and DP-DES group were assessed by the log-rank test. We also conducted Cox's proportional hazard model to identify predictors for TLR occurrence.

Results

Baseline patient and lesion characteristics were similar between the two groups. The two-year incidence of TLR was not significantly different between BP-DES group and DP-DES group (14.1% vs. 22.2%, p=0.391). The two-year incidences of CD (17.3% vs. 17.5%, p=0.381), ST (0% vs. 3.9%, p=0.133), MI (4.2% vs. 5.8%, p=0.965), TVR (21.3% vs. 27.5%, p=0.586), non-TVR (26.1% vs. 31.3%, p=0.439) and MACE (41.1% vs. 42.6%, p=0.526) were also not different between the two groups. After multivariate analysis, diabetes mellitus (hazard ratio 1.97; 95% confidence interval 1.03–3.78, p=0.004) was independently associated with TLR occurrence in HD patients.

Two-year clinical outcomes of HD patient

Conclusions

At two-year follow-up after PCI, BP-DES had comparable safety and efficacy profiles to DP-DES in HD patients presenting CAD.

Acknowledgement/Funding

None

Rescue-like Behaviour in Mice is Mediated by Their Interest in the Restraint Tool

Acting without the expectation of compensation is called prosocial behaviour. Since prosocial behaviour requires high cognitive and social abilities, it has been thought to be only shown by primates. Although prosocial behaviour has been recently reported in rats, there are still questions regarding this finding. We demonstrated rescue-like behaviour in mice in a previous report. In this study, we investigated the motives underlying rescue-like behaviour for constrained cage-mates among mice. We prepared either a tube containing a ball of yarn or an opaque tube and assessed whether mice displayed the same rescue-like behaviour shown in the case of tube-restrained cage-mates. Mice did not open the lid of the tube containing the ball of yarn but opened the opaque tube lid. Mice showed a high interest in the tube in which the cage-mate had been restrained and prioritized staying in this tube rather than rescuing additional cage-mates. Oxytocin, which increases empathy, had no effect on the lid-opening behaviour. Thus, the rescue-like behaviour of mice is not based on empathy but is related to social interest in the cage-mate and the tube itself. These results suggest that rodent lid-opening behaviour may not conclusively prove the presence of prosocial behaviour.

Tanycyte-Like Cells Derived From Mouse Embryonic Stem Culture Show Hypothalamic Neural Stem/Progenitor Cell Functions

Tanycytes have recently been accepted as neural stem/progenitor cells in the postnatal hypothalamus. Persistent retina and anterior neural fold homeobox (Rax) expression is characteristic of tanycytes in contrast to its transient expression of whole hypothalamic precursors. In this study, we found that Rax+ residual cells in the maturation phase of hypothalamic differentiation in mouse embryonic stem cell (mESC) cultures had similar characteristics to ventral tanycytes. They expressed typical neural stem/progenitor cell markers, including Sox2, vimentin, and nestin, and differentiated into mature neurons and glial cells. Quantitative RT-PCR analysis showed that Rax+ residual cells expressed Fgf-10, Fgf-18, and Lhx2, which are expressed by ventral tanycytes. They highly expressed tanycyte-specific genes Dio2 and Gpr50 compared with Rax+ early hypothalamic progenitor cells. Therefore, Rax+ residual cells in the maturation phase of hypothalamic differentiation were considered to be more differentiated and similar to late progenitor cells and tanycytes. They self-renewed and formed neurospheres when cultured with exogenous FGF-2. Additionally, these Rax+ neurospheres differentiated into three neuronal lineages (neurons, astrocytes, and oligodendrocytes), including neuropeptide Y+ neuron, that are reported to be differentiated from ventral tanycytes toward the arcuate nuclei. Thus, Rax+ residual cells were multipotent neural stem/progenitor cells. Rax+ neurospheres were stably passaged and retained high Sox2 expression even after multiple passages. These results suggest the successful induction of Rax+ tanycyte-like cells from mESCs [induced tanycyte-like (iTan) cells]. These hypothalamic neural stem/progenitor cells may have potential in regenerative medicine and as a research tool.

Anti-stress effects of the hydroalcoholic extract of Rosa gallica officinalis in mice

Rosa gallica, a plant of the Rosa genus, has been used widely since the 13^th century and is cultivated in many areas as a medicinal plant for the preparation of herbal medicines. However, details of the neuropsychological effects of R. gallica remain unclear; therefore we aimed to investigate the neuropsychological effects of a water-soluble extract of R. gallica in male C57BL/6N mice under normal conditions and under chronic stress. We administered a water-soluble extract of R. gallica to mice and performed a series of behavioral experiments to compare the treated animals with the untreated controls. No significant differences in activity level, anxiety-like behavior, depression-like behavior, body weight, and body temperature were observed between R. gallica-treated mice and control mice. However, in mice subjected to chronic stress, the observed decrease in activity was smaller in the R. gallica-treated mice than in the control mice. The oral administration of R. gallica did not affect the normal behavior of mice. However, when the mice were subjected to stress, R. gallica exerted an anti-stress effect. Therefore, R. gallica has potential as a medicinal plant for the purpose of stress prevention.

Behavioural effects of inhalation exposure to dizocilpine (MK-801) in mice

The complex pathophysiology of brain disorders and the difficulty of delivering therapeutic agents to the brain remain major obstacles in the research and development of new therapeutic methods for brain disorders. Therefore, delivering existing therapeutic agents to the central nervous system is expected to provide benefits in various diseases. In this study, we investigated whether inhaled central nervous system drugs reached the brain and affected mouse behaviour. Dizocilpine (MK-801), which increases locomotor activity in mice, was mainly used to study this hypothesis. First, we administered MK-801, an N-methyl-d-aspartate receptor antagonist, to mice via inhalation and examined whether it induced excessive activity similar to that observed after intraperitoneal administration. We also examined the time- and dose-dependency of drug induced changes in mouse behaviour after MK-801 inhalation. Next, we investigated whether inhalation of scopolamine, pentobarbital, and imipramine also affected mouse behaviour. Mice that inhaled MK-801 showed MK-801-induced hyperactivity similar to that observed following intraperitoneal administration. Furthermore, the extent of activity changed in a time- and dose-dependent manner after MK-801 inhalation. Inhalation of pentobarbital, scopolamine, and imipramine also changed mouse behaviour. These results demonstrate that inhalation of MK-801 exerts effects similar to those achieved with intraperitoneal and oral administration in mice. Thus, central nervous system agonists can reach the brain efficiently via inhalation. This finding may facilitate the development of improved therapies for brain disorders.

Region-specific reduction of parvalbumin neurons and behavioral changes in adult mice following single exposure to cranial irradiation

PURPOSE

Ionizing irradiation has several long-term effects including progressive cognitive impairment. Cognitive deterioration generally appears to be caused by abnormalities in the hippocampal dentate gyrus, with abnormal function of parvalbumin-expressing interneurons (PV neurons) in the cerebral cortex. PV neurons are vulnerable to oxidative stress, which can be caused by ionizing irradiation. We speculated that selective impairment of specific brain regions due to ionizing irradiation may alter the degree of cognitive impairment.

METHODS

We irradiated mature mouse brains with 20 Gy-ionizing irradiation. Subsequently, we analyzed behavioral abnormalities and changes in the number of PV neurons.

RESULTS

PV neuron density was significantly lower in some cortical regions of irradiated mice than in control mice. Within 1 week of irradiation, both body weight and temperature of irradiated mice decreased. In the forced swim test, irradiated mice spent significantly less time immobile than did control mice. However, irradiated mice did not display any abnormalities in the elevated plus maze test, Y-maze test, tail suspension test, and social interaction test between 3 to 6 days after irradiation.

CONCLUSIONS

These results suggest that high-dose irradiation is less likely to cause brain dysfunction in the subacute phase. Moreover, the vulnerability of PV neurons appears to be brain-region specific.