Nerve Regeneration and Gait Function Recovery with Implantation of Glucose/Mannose Conduits Using a Rat Model: Efficacy of Glucose/Mannose as a New Neurological Guidance Material

Therapy with clinical nerve guidance conduits often causes functional incompleteness in patients. With the aim of better therapeutic efficacy, nerve regeneration and gait function were investigated in this study using a novel nerve guidance conduit consisting of glucose/mannose. The glucose/mannose nerve guidance conduits were prepared by filling the conduits with the glucose/mannose aqueous solutions for different kinematic viscosity, which were applied to sciatic nerve defects (6 mm gap) in a rat model. The nerve regeneration effect and the gait function recovery with the fabricated nerve guidance conduits were examined. From the results of the XRD measurement, the glucose/mannose conduits were identified as crystal structures of cellulose type II. Young's modulus and the maximum tensile strength of the crystalline glucose/mannose conduits demonstrated good strength and softness for the human nerve. Above 4 weeks postoperative, macroscopic observation revealed that the nerve was regenerated in the defective area. In various staining results of the nerve tissue removed at 4 weeks postoperative, myelinated nerves contributing to gait function could not be observed in the proximal and distal sites to the central nerve. At 8-12 weeks postoperative, myelinated nerves were found at the proximal and distal sites in hematoxylin/eosin staining. Glia cells were confirmed by phosphotungstic acid-hematoxylin staining. Continuous nerve fibers were observed clearly in the sections of the regenerated nerves towards the longitudinal direction at 12 weeks postoperative. The angle between the metatarsophalangeal joint and the ground plane was approximately 93° in intact rats. At 4 weeks postoperative, walking was not possible, but at 8 weeks postoperative, the rats were able to walk, with an angle of 53°. At 12 weeks postoperative, the angle increased further, reaching 65°, confirming that the rats were able to walk more quickly than at 8 weeks postoperative. These results demonstrated that gait function in rats treated with glucose/mannose nerve guidance conduits was rapidly recovered after 8 weeks postoperative. The glucose/mannose nerve guidance conduit could be applied as a new promising candidate material for peripheral nerve regeneration.

Dynamic changes and importance of plasma concentrations of ether phospholipids, of which the majority are plasmalogens, in postpartum Holstein dairy cows

CONTEXT

Ethanolamine plasmalogens (EPls) and choline plasmalogens (CPls) are classes of ethanolamine ether phospholipids (ePE) and choline ether phospholipids (ePC), respectively. EPls play crucial roles in maternal and breastfed infant bodies and stimulate gonadotropin secretion by gonadotrophs.

AIMS

To estimate changes in and importance of plasma concentrations of EPls and CPls, utilising newly developed enzymatic fluorometric assays for ePE and ePC in postpartum Holstein cows.

METHODS

Plasma samples were collected from 3weeks before expected parturition until approximately 8weeks after parturition (16 primiparous and 38 multiparous cows) for analysis.

KEY RESULTS

Plasma concentrations of ePE and ePC, most of which are plasmalogens, declined before and increased after parturition and stabilised near the day of the first postpartum ovulation (1stOV). From weeks 2 to 3 after parturition, third-parity cows exhibited ePE concentrations that were higher than those of other parity cows. The days from parturition to 1stOV correlated with days from parturition to conception. On the day of 1stOV, milk yield correlated with plasma concentration of both ePE and ePC, while ePC concentration correlated negatively with milk fat percentage. At the early luteal phase after 1stOV, plasma ePE concentration correlated with plasma anti-Müllerian hormone concentration (r=0.39, P<0.01), and plasma ePC concentration correlated with plasma follicle-stimulating hormone concentration (r=0.43, P<0.01).

CONCLUSION

The concentrations of ePE and ePC changed dramatically around parturition and 1stOV, and the concentrations correlated with important parameters for milk production and reproduction.

IMPLICATIONS

The blood plasmalogen may play important roles in postpartum dairy cows.

Ethanolamine plasmalogens derived from whale brain stimulate both follicle-stimulating hormone and luteinizing hormone secretion by bovine gonadotrophs

Ethanolamine plasmalogens (EPls) are the only known ligands of a novel receptor, G protein-coupled receptor 61, and bovine brain EPls stimulate follicle-stimulating hormone (FSH) but not luteinizing hormone (LH), secreted by bovine gonadotrophs. We hypothesized that the brain EPls of whales (Balaenoptera edeni), another Cetartiodactyla with at least twice the lifespan of bovines, could stimulate FSH secretion by gonadotrophs. To test this hypothesis, bovine gonadotrophs (from approximately 2-year-old Japanese Black heifers) were cultured for 3.5 days and treated with increasing concentrations of brain EP1s from whales (approximately 22 years old). FSH and LH secretion was stimulated by all tested concentrations of whale EPls (p < 0.05). To clarify the important differences between bovine and whale EPls, we utilized two-dimensional liquid chromatography-mass spectrometry, which revealed 35 peaks. Among them, we observed significant differences between 12 EPl molecular species. Additionally, we identified differentially expressed genes for enzymes involved in EPl synthesis or degradation in the hypothalamus of young heifers and old cows (approximately 10 years old) as compared to whales (approximately 28 years old) via deep sequencing of the transcriptome. We conclude that whale brains contain unique EPls that stimulate both FSH and LH secretion by bovine gonadotrophs.

Involvement of the Thalamus, Hippocampus, and Brainstem in Hypsarrhythmia of West Syndrome: Simultaneous Recordings of Electroencephalography and fMRI Study

BACKGROUND AND PURPOSE

West syndrome is a developmental and epileptic encephalopathy characterized by epileptic spasms, neurodevelopmental regression, and a specific EEG pattern called hypsarrhythmia. Our aim was to investigate the brain activities related to hypsarrhythmia at onset and focal epileptiform discharges in the remote period in children with West syndrome using simultaneous electroencephalography and fMRI recordings.

MATERIALS AND METHODS

Fourteen children with West syndrome underwent simultaneous electroencephalography and fMRI at the onset of West syndrome. Statistically significant blood oxygen level-dependent responses related to hypsarrhythmia were analyzed using an event-related design of 4 hemodynamic response functions with peaks at 3, 5, 7, and 9 seconds after the onset of each event. Six of 14 children had focal epileptiform discharges after treatment and underwent simultaneous electroencephalography and fMRI from 12 to 25 months of age.

RESULTS

At onset, positive blood oxygen level-dependent responses were seen in the brainstem (14/14 patients), thalami (13/14), basal ganglia (13/14), and hippocampi (13/14), in addition to multiple cerebral cortices. Group analysis using hemodynamic response functions with peaks at 3, 5, and 7 seconds showed positive blood oxygen level-dependent responses in the brainstem, thalamus, and hippocampus, while positive blood oxygen level-dependent responses in multiple cerebral cortices were seen using hemodynamic response functions with peaks at 5 and 7 seconds. In the remote period, 3 of 6 children had focal epileptiform discharge-related positive blood oxygen level-dependent responses in the thalamus, hippocampus, and brainstem.

CONCLUSIONS

Positive blood oxygen level-dependent responses with hypsarrhythmia appeared in the brainstem, thalamus, and hippocampus on earlier hemodynamic response functions than the cerebral cortices, suggesting the propagation of epileptogenic activities from the deep brain structures to the neocortices. Activation of the hippocampus, thalamus, and brainstem was still seen in half of the patients with focal epileptiform discharges after adrenocorticotropic hormone therapy.

Treadmill Training for Common Marmoset to Strengthen Corticospinal Connections After Thoracic Contusion Spinal Cord Injury

Spinal cord injury (SCI) leads to locomotor dysfunction. Locomotor rehabilitation promotes the recovery of stepping ability in lower mammals, but it has limited efficacy in humans with a severe SCI. To explain this discrepancy between different species, a nonhuman primate rehabilitation model with a severe SCI would be useful. In this study, we developed a rehabilitation model of paraplegia caused by a severe traumatic SCI in a nonhuman primate, common marmoset (Callithrix jacchus). The locomotor rating scale for marmosets was developed to accurately assess the recovery of locomotor functions in marmosets. All animals showed flaccid paralysis of the hindlimb after a thoracic contusive SCI, but the trained group showed significant locomotor recovery. Kinematic analysis revealed significantly improved hindlimb stepping patterns in trained marmosets. Furthermore, intracortical microstimulation (ICMS) of the motor cortex evoked the hindlimb muscles in the trained group, suggesting the reconnection between supraspinal input and the lumbosacral network. Because rehabilitation may be combined with regenerative interventions such as medicine or cell therapy, this primate model can be used as a preclinical test of therapies that can be used in human clinical trials.

The current status of robotic surgery for endometrial cancer in Japan

The da Vinci^® surgical system (Intuitive Surgical Inc., Sunnyvale, CA, USA) was approved in 2009 by the Japanese Ministry of Health, Labor, and Welfare. In gynecology, robotic surgery for hysterectomy for benign indications and early-stage endometrial cancer has been covered by National Health Insurance since 2018. In a context where the da Vinci surgical system has prevailed in urology departments in Japan, gynecological robotic surgery has spread rapidly once it was covered by insurance. Although minimally invasive gynecologic surgery (minimally invasive surgery, or MIS) in Japan has a specific context, there are several problems with its safety, surgeon education, and cost in Japan. To maximize the many advantages of robotic surgery, its effectiveness needs to be carefully evaluated and this new technology needs to be safely incorporated in practice.

Spike protein of SARS-CoV-2 suppresses gonadotrophin secretion from bovine anterior pituitaries

Coronavirus disease (COVID-19), the ongoing global pandemic, is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Recent evidence shows that the virus utilizes angiotensin-converting enzyme 2 (ACE2) as a spike protein receptor for entry into target host cells. The bovine ACE2 contains key residues for binding to the spike protein receptor-binding domain. This study evaluated the hypothesis that bovine gonadotroph expresses ACE2, and spike protein suppresses luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion from cultured bovine anterior pituitary (AP) cells. ACE2 mRNA expression and ACE2 protein expression were detected in the bovine AP cells using reverse transcription PCR and western blot analysis. Immunofluorescence microscopy analysis with the anti-ACE2 antibody revealed the co-localization of ACE2 and gonadotropin-releasing hormone (GnRH) receptor on the gonadotroph plasma membrane. Approximately 90% of GnRH receptor-positive cells expressed ACE2, and approximately 46% of ACE2-positive cells expressed the GnRH receptor. We cultured bovine AP cells for 3.5 days and treated them with increasing concentrations (0, 0.07, 0.7, or 7 pM) of recombinant spike protein having both S1 and S2 regions. The spike protein (0.07-7 pM) suppressed both basal and GnRH-induced LH secretion (P < 0.05). Spike protein (0.7-7 pM) suppressed GnRH-induced (P < 0.05), but not basal FSH secretion. In contrast, pre-treatment with ERK 1/2/5 inhibitor (U0126) partially restored the GnRH-induced LH and FSH secretion from the spike protein suppression. Collectively, the results indicate that gonadotrophs express ACE2, a receptor for coronavirus 2 spike protein, which in turn suppresses LH and FSH secretion from AP cells.

Identification of Functional Domains of CXCL14 Involved in High-Affinity Binding and Intracellular Transport of CpG DNA

Some CXC chemokines, including CXCL14, transport CpG oligodeoxynucleotides (ODNs) into dendritic cells (DCs), thereby activating TLR9. The molecular basis of this noncanonical function of CXC chemokines is not well understood. In this study, we investigated the CpG ODN binding and intracellular transport activities of various CXC chemokines and partial peptides of CXCL14 in mouse bone marrow-derived dendritic cells. CXCL14, CXCL4, and CXCL12 specifically bound CpG ODN, but CXCL12 failed to transport it into cells at low dose. CXCL14 N-terminal peptides 1-47, but not 1-40, was capable of transporting CpG ODN into the cell, resulting in an increase in cytokine production. However, both the 1-47 and 1-40 peptides bound CpG ODN. By contrast, CXCL14 peptides 13-50 did not possess CpG ODN binding capacity or transport activity. The chimeric peptides CXCL12 (1-22)-CXCL14 (13-47) bound CpG ODN but failed to transport it. These results suggest that amino acids 1-12 and 41-47 of CXCL14 are required for binding and intracellular transport of CpG ODN, respectively. We found that an anti-CXCL14 Ab blocked cell-surface binding and internalization of the CpG ODN/CXCL14 complex. On the basis of these findings, we propose that CXCL14 has two functional domains, one involved in DNA recognition and the other in internalization of CXCL14-CpG DNA complex via an unidentified CXCL14 receptor, which together are responsible for eliciting the CXCL14/CpG ODN-mediated TLR9 activation. These domains could play roles in CXCL14-related diseases such as arthritis, obesity-induced diabetes, and various types of carcinoma.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Calcium Transient Dynamics of Neural Ensembles in the Primary Motor Cortex of Naturally Behaving Monkeys

To understand brain circuits of cognitive behaviors under natural conditions, we developed techniques for imaging neuronal activities from large neuronal populations in the deep layer cortex of the naturally behaving common marmoset. Animals retrieved food pellets or climbed ladders as a miniature fluorescence microscope monitored hundreds of calcium indicator-expressing cortical neurons in the right primary motor cortex. This technique, which can be adapted to other brain regions, can deepen our understanding of brain circuits by facilitating longitudinal population analyses of neuronal representation associated with cognitive naturalistic behaviors and their pathophysiological processes.

P3648Plasma glutamate are increased in non-smoker patients with vasospastic angina pectoris and associated with plasma cystine and antioxidant capacity

Background

Endothelial dysfunction of the coronary arteries caused by oxidative stress plays an important role in the pathogenesis of vasospastic angina pectoris (VSAP). Glutamate, a non-essential amino acid, exerts endothelial dysfunction by oxidative stress production through N-methyl-D-aspartate receptor activation. Besides oxidative stress, decrease of antioxidant may be responsible for endothelial dysfunction. Glutathione (GSH), an important antioxidant, is synthesized from imported cystine through the cystine/glutamate antiporter system (XC-) in association with the export of glutamate. Glutamate also competitively inhibits cystine import into the endothelial cells through the XC-leading to GSH depletion. Thus the extracellular glutamate and cystine are crucial for the intracellular redox status. However, it remains unclear whether glutamate and/or cystine are implicated in the pathogenesis of VSAP. As smoking induces powerful oxidant stresses in the whole body, we investigated plasma glutamate, cystine, oxidative stress markers and antioxidant capacity in non-smoker patients with VSAP.

Methods and results

Sixty-two consecutive non-smoker patients suspected having VSAP were performed coronary angiograms (CAG). Forty-nine patients who did not show any significant coronary stenosis (<50%) were performed the intracoronary acetylcholine provocation test. Patients were categorized into the VSAP-positive group (n=27) and the VSAP-negative group (n=22) on the basis of test results. Blood samples were collected from the femoral sheath before the CAG. Plasma glutamate, cystine, nitrotyrosine (NT), reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured. The levels of plasma glutamate and cystine in the VSAP-positive group were significantly higher than those in the VSAP-negative group (59.8±25.7 vs 43.5±18.7 nmol/L, p=0.0054, and 35.3±14.2 nmol/L vs 25.2±9.1 nmol/L, p=0.0018, respectively). The levels of plasma glutamate showed significant and positive association with the levels of plasma cystine (r=0.40, p=0.005). There were no significant differences in the levels of NT and d-ROMs as oxidative stress markers, and BAP as an antioxidant capacity between the two groups, respectively. However, the levels of plasma glutamate showed significant and negative association with BAP values (r=−0.3, p=0.038).

Conclusions

Plasma levels of glutamate were increased in non-smoker patients with VSAP and positively associated with plasma cystine levels and negatively associated with antioxidant capacity, suggesting that plasma glutamate modulate plasma cystine levels and antioxidant capacity through the XC- inhibition, and could be a novel risk factor of VSAP.

Electronic and Optical Properties of Single Wall Carbon Nanotubes

In this article, we overview our recent theoretical works on electronic and optical properties of carbon nanotubes by going from the background to the perspectives. Electronic Raman spectra of metallic carbon nanotubes give a new picture of Raman processes. Thermoelectricity of semiconducting nanotubes gives a general concept of the confinement effect on the thermoelectric power factor. Selective excitation of only a single phonon mode is proposed by the pulsed train technique of coherent phonon spectroscopy. Occurrence of both two and four fold degeneracy in the carbon nanotube quantum dot is explained by difference group velocities and the intra/inter valley scattering near the hexagonal corner of the Brillouin zone.