Sound velocity of CaSiO3 perovskite suggests the presence of basaltic crust in the Earth's lower mantle.

Laboratory measurements of sound velocities of high-pressure minerals provide crucial information on the composition and constitution of the deep mantle via comparisons with observed seismic velocities. Calcium silicate (CaSiO3) perovskite (CaPv) is a high-pressure phase that occurs at depths greater than about 560 kilometres in the mantle1 and in the subducting oceanic crust2. However, measurements of the sound velocity of CaPv under the pressure and temperature conditions that are present at such depths have not previously been performed, because this phase is unquenchable (that is, it cannot be physically recovered to room conditions) at atmospheric pressure and adequate samples for such measurements are unavailable. Here we report in situ X-ray diffraction and ultrasonic-interferometry sound-velocity measurements at pressures of up to 23 gigapascals and temperatures of up to 1,700 kelvin (similar to the conditions at the bottom of the mantle transition region) using sintered polycrystalline samples of cubic CaPv converted from bulk glass and a multianvil apparatus. We find that cubic CaPv has a shear modulus of 126 ± 1 gigapascals (uncertainty of one standard deviation), which is about 26 per cent lower than theoretical predictions3,4 (about 171 gigapascals). This value leads to substantially lower sound velocities of basaltic compositions than those predicted for the pressure and temperature conditions at depths between 660 and 770 kilometres. This suggests accumulation of basaltic crust in the uppermost lower mantle, which is consistent with the observation of low-seismic-velocity signatures below 660 kilometres5,6 and the discovery of CaPv in natural diamond of super-deep origin7. These results could contribute to our understanding of the existence and behaviour of subducted crust materials in the deep mantle.

Effects of inflammation on the properties of Nav1.8-ChR2-positive and Nav1.8-ChR2-negative afferent mechanoreceptors in the hindpaw glabrous skin of mice.

We recently used Nav1.8-ChR2 mice in which Nav1.8-expressing afferents were optogenetically tagged to classify mechanosensitive afferents into Nav1.8-ChR2-positive and Nav1.8-ChR2-negative mechanoreceptors. We found that the former were mainly high threshold mechanoreceptors (HTMRs), while the latter were low threshold mechanoreceptors (LTMRs). In the present study, we further investigated whether the properties of these mechanoreceptors were altered following tissue inflammation. Nav1.8-ChR2 mice received a subcutaneous injection of saline or Complete Freund's Adjuvant (CFA) in the hindpaws. Using the hind paw glabrous skin-tibial nerve preparation and the pressure-clamped single-fiber recordings, we found that CFA-induced hind paw inflammation lowered the mechanical threshold of many Nav1.8-ChR2-positive Aß-fiber mechanoreceptors but heightened the mechanical threshold of many Nav1.8-ChR2-negative Aß-fiber mechanoreceptors. Spontaneous action potential impulses were not observed in Nav1.8-ChR2-positive Aß-fiber mechanoreceptors but occurred in Nav1.8-ChR2-negative Aß-fiber mechanoreceptors with a lower mechanical threshold in the saline goup, and a higher mechanical threshold in the CFA group. No significant change was observed in the mechanical sensitivity of Nav1.8-ChR2-positive and Nav1.8-ChR2-negative Aδ-fiber mechanoreceptors and Nav1.8-ChR2-positive C-fiber mechanoreceptors following hind paw inflammation. Collectively, inflammation significantly altered the functional properties of both Nav1.8-ChR2-positive and Nav1.8-ChR2-negative Aß-fiber mechanoreceptors, which may contribute to mechanical allodynia during inflammation.

Species-specific formation of paraspeckles in intestinal epithelium revealed by characterization of NEAT1 in naked mole-rat.

Paraspeckles are mammalian-specific nuclear bodies built on the long noncoding RNA NEAT1_2 The molecular mechanisms of paraspeckle formation have been mainly studied using human or mouse cells, and it is not known if the same molecular components are involved in the formation of paraspeckles in other mammalian species. We thus investigated the expression pattern of NEAT1_2 in naked mole-rats (nNEAT1_2), which exhibit extreme longevity and lower susceptibility to cancer. In the intestine, nNEAT1_2 is widely expressed along the entire intestinal epithelium, which is different from the expression of mNeat1_2 that is restricted to the cells of the distal tip in mice. Notably, the expression of FUS, a FET family RNA binding protein, essential for the formation of paraspeckles both in humans and mice, was absent in the distal part of the intestinal epithelium in naked mole-rats. Instead, mRNAs of other FET family proteins EWSR1 and TAF15 were expressed in the distal region. Exogenous expression of these proteins in Fus-deficient murine embryonic fibroblast cells rescued the formation of paraspeckles. These observations suggest that nNEAT1_2 recruits a different set of RNA binding proteins in a cell type-specific manner during the formation of paraspeckles in different organisms.

FBXO2/SCF ubiquitin ligase complex directs xenophagy through recognizing bacterial surface glycan.

Xenophagy, also known as antibacterial selective autophagy, degrades invading bacterial pathogens such as group A Streptococcus (GAS) to defend cells. Although invading bacteria are known to be marked with ubiquitin and selectively targeted by xenophagy, how ubiquitin ligases recognize invading bacteria is poorly understood. Here, we show that FBXO2, a glycoprotein-specific receptor for substrate in the SKP1/CUL1/F-box protein (SCF) ubiquitin ligase complex, mediates recognition of GlcNAc side chains of the GAS surface carbohydrate structure and promotes ubiquitin-mediated xenophagy against GAS. FBXO2 targets cytosolic GAS through its sugar-binding motif and GlcNAc expression on the GAS surface. FBXO2 knockout resulted in decreased ubiquitin accumulation on intracellular GAS and xenophagic degradation of bacteria. Furthermore, SCF components such as SKP1, CUL1, and ROC1 are required for ubiquitin-mediated xenophagy against GAS. Thus, SCFFBXO2 recognizes GlcNAc residues of GAS surface carbohydrates and functions in ubiquitination during xenophagy.

Kv4.3 Channel Dysfunction Contributes to Trigeminal Neuropathic Pain Manifested with Orofacial Cold Hypersensitivity in Rats.

Trigeminal neuropathic pain is the most debilitating pain disorder but current treatments including opiates are not effective. A common symptom of trigeminal neuropathic pain is cold allodynia/hyperalgesia or cold hypersensitivity in orofacial area, a region where exposure to cooling temperatures are inevitable in daily life. Mechanisms underlying trigeminal neuropathic pain manifested with cold hypersensitivity are not fully understood. In this study, we investigated trigeminal neuropathic pain in male rats following infraorbital nerve chronic constrictive injury (ION-CCI). Assessed by the orofacial operant behavioral test, ION-CCI animals displayed orofacial cold hypersensitivity. The cold hypersensitivity was associated with the hyperexcitability of small-sized trigeminal ganglion (TG) neurons that innervated orofacial regions. Furthermore, ION-CCI resulted in a reduction of A-type voltage-gated K+ currents (IA currents) in these TG neurons. We further showed that these small-sized TG neurons expressed Kv4.3 voltage-gated K+ channels, and Kv4.3 expression in these cells was significantly downregulated following ION-CCI. Pharmacological inhibition of Kv4.3 channels with phrixotoxin-2 inhibited IA-currents in these TG neurons and induced orofacial cold hypersensitivity. On the other hand, pharmacological potentiation of Kv4.3 channels amplified IA currents in these TG neurons and alleviated orofacial cold hypersensitivity in ION-CCI rats. Collectively, Kv4.3 downregulation in nociceptive trigeminal afferent fibers may contribute to peripheral cold hypersensitivity following trigeminal nerve injury, and Kv4.3 activators may be clinically useful to alleviate trigeminal neuropathic pain.SIGNIFICANCE STATEMENT Trigeminal neuropathic pain, the most debilitating pain disorder, is often triggered and exacerbated by cooling temperatures. Here, we created infraorbital nerve chronic constrictive injury (ION-CCI) in rats, an animal model of trigeminal neuropathic pain to show that dysfunction of Kv4.3 voltage-gated K+ channels in nociceptive-like trigeminal ganglion (TG) neurons underlies the trigeminal neuropathic pain manifested with cold hypersensitivity in orofacial regions. Furthermore, we demonstrate that pharmacological potentiation of Kv4.3 channels can alleviate orofacial cold hypersensitivity in ION-CCI rats. Our results may have clinical implications in trigeminal neuropathic pain in human patients, and Kv4.3 channels may be an effective therapeutic target for this devastating pain disorder.

Risk of Colorectal Cancer in Serrated Polyposis Syndrome: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Serrated polyposis syndrome (SPS) is characterized by development of numerous serrated lesions throughout the colorectum and increased risk of colorectal cancer (CRC). However, SPS has been an underrecognized CRC predisposition syndrome, and the true risk of CRC in SPS, both overall and in surveillance, is not known. The aim of this systematic review and meta-analysis is to describe the risk of CRC in patients with SPS. METHODS: Electronic databases were searched on March 25, 2021, for studies describing CRC risk in SPS. Random-effects meta-analysis was performed to assess pooled risk of CRC among SPS patients. Primary outcomes were risk of CRC at time of SPS diagnosis and during surveillance following diagnosis of SPS. Secondary outcomes included risk of CRC prior to diagnosis of SPS and effect of World Health Organization subtype on CRC risk. RESULTS: Thirty-six studies including 2788 patients with SPS were included in the analysis. Overall risk of CRC in SPS was 19.9% (95% confidence interval [CI], 15.3%-24.5%). CRC risk at the time of diagnosis was 14.7% (95% CI, 11.4%-18.8%), while risk during surveillance was 2.8% (95% CI, 1.8%-4.4%), or 7 cases per 1000 person-years. SPS patients also had a high incidence of history of CRC prior to SPS diagnosis (7.0%; 95% CI, 4.6%-11.7). Subgroup analysis did not reveal any significant differences based on World Health Organization subtype. CONCLUSIONS: Our meta-analysis demonstrated that patients with SPS have an elevated risk of CRC, which is highest at the time of diagnosis and suggests the importance of early SPS recognition and screening to modify CRC risk. The persistently elevated CRC risk during surveillance supports current guidelines recommending heightened surveillance protocols.

Single- and multiple-dose safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of ASP0367, or bocidelpar sulfate, a novel modulator of peroxisome proliferator-activated receptor delta in healthy adults: Results from a phase 1 study.

INTRODUCTION/AIMS: ASP0367, or bocidelpar sulfate, is an orally administered small molecule that potently and selectively modulates peroxisome proliferator-activated receptor δ (PPARδ) to address mitochondrial dysfunction occurring in diseases including primary mitochondrial myopathy and Duchenne muscular dystrophy. The objectives of this first-in-human trial were to evaluate the safety/tolerability, pharmacokinetics, and pharmacodynamics of ASP0367 in healthy participants. METHODS: In this double-blind phase 1 study, adult participants were randomized to single or multiple ascending oral doses of ASP0367 or placebo. The study duration was 1 and 14 days, respectively. Pharmacokinetic parameters under fed conditions were also evaluated. RESULTS: A total of 64 (single-dose cohort) and 37 (multiple-dose cohort) participants were included in the study. After single doses of 1 to 120 mg, ASP0367 was rapidly absorbed, with median time to maximum plasma concentration (tmax ) of 1.50 to 2.24 hours under fasting conditions; ASP0367 concentrations declined in a multiphasic manner after reaching maximum plasma concentration. Under fed conditions, tmax was delayed 1.7 hours. After multiple once-daily doses, mean half-life of ASP0367 10 to 75 mg ranged from 14.1 to 17.5 hours; steady state was reached after 4 days. Negligible accumulation was observed after repeated dosing. No participants receiving ASP0367 discontinued treatment, and all treatment-emergent adverse events were mild to moderate in severity; none were considered drug-related. No clinically significant changes were observed on laboratory or electrocardiographic evaluation. Treatment- and dose-dependent upregulation of six PPARδ target genes was observed with single and multiple doses of ASP0367. DISCUSSION: ASP0367, or bocidelpar sulfate, was well tolerated; rapid absorption, roughly dose-proportional bioavailability, and effects on PPARδ target genes were demonstrated in healthy adult participants.

Electrophysiological properties of maxillary trigeminal Aß-afferent neurons of rats.

Aß-afferents in maxillary or V2 trigeminal ganglion (TG) neurons are somatosensory neurons that may be involved in both non-nociceptive and nociceptive functions in orofacial regions. However, electrophysiological properties of these V2 trigeminal Aß-afferent neurons have not been well characterized so far. Here, we used rat ex vivo trigeminal nerve preparations and applied patch-clamp recordings to large-sized V2 TG neurons to characterize their electrophysiological properties. All the cells recorded had afferent conduction velocities in the range of Aß-afferent conduction speeds. However, these V2 trigeminal Aß-afferent neurons displayed different action potential (AP) properties. APs showed fast kinetics in some cells but slow kinetics with shoulders in repolarization phases in other cells. Based on the derivatives of voltages in AP repolarization with time (dV/dt), we classified V2 trigeminal Aß-afferent neurons into four types: type I, type II, type IIIa and type IIIb. Type I V2 trigeminal Aß-afferent neurons had the largest dV/dt of repolarization, the fastest AP conduction velocities, the shortest AP and afterhyperpolarization (AHP) durations, and the highest AP success rates. In contrast, type IIIb V2 trigeminal Aß-afferent neurons had the smallest dV/dt of AP repolarization, the slowest AP conduction velocities, the longest AP and AHP durations, and the lowest AP success rates. The type IIIb cells also had significantly lower voltage-activated K+ currents. For type II and type IIIa V2 trigeminal Aß-afferent neurons, AP parameters were in the range between those of type I and type IIIb V2 trigeminal Aß-afferent neurons. Our electrophysiological classification of V2 trigeminal Aß-afferent neurons may be useful in future to study their non-nociceptive and nociceptive functions in orofacial regions.

Risk of Cancers in Patients with Pediatric Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis.

OBJECTIVES: We performed a systematic review and meta-analysis to evaluate the risk of the development of cancers in patients with pediatric-onset inflammatory bowel disease (IBD). STUDY DESIGN: A computerized literature search was performed. The primary outcome was the pooled incidence of cancer in studies reporting the risk as a standardized incidence ratio. The secondary outcomes were the pooled incidence rates of all cancers and site-specific cancers including colorectal cancer and hematologic cancers. RESULTS: Sixty-six studies reporting outcomes in 38 092 patients were included. The pooled standardized incidence ratio for cancer was 2.39 (P < .0001, 95% CI 2.00-2.86) in IBD. The pooled incidence rates for cancer in patients with Crohn's disease (CD) and ulcerative colitis (UC) were 0.014 (95% CI 0.0087-0.021) and 0.031 (95% CI 0.018-0.052), respectively. The pooled incidence rate of colorectal cancer in CD and UC were 0.0075 (95% CI 0.0049-0.011) and 0.020 (95% CI 0.012-0.034), respectively. The pooled rates of hematologic cancers in CD and UC were 0.0061 (95% CI 0.0040-0.0090) and 0.0045 (95% CI 0.0026-0.0079), respectively. Cumulative meta-analyses showed a decreasing trend in the incidence of these cancers in both CD and UC. CONCLUSIONS: Patients with pediatric-onset IBD had an increased risk of cancer development compared with the general population, however, incidence appeared to be decreasing in recent years.

Efficacy and Safety of Monoclonal Antibodies Against Clostridioides difficile Toxins for Prevention of Recurrent Clostridioides difficile Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Clostridioides difficile infection is one of the most common health care-associated infections. To reduce the recurrent Clostridioides difficile infection (rCDI), monoclonal antibodies against Clostridioides difficile toxin A (actoxumab) and toxin B (bezlotoxumab) were developed. In the present study, we performed a systematic review and meta-analysis to assess their efficacy and safety. MATERIALS AND METHODS: An electronic database was searched for relevant randomized controlled trials assessing bezlotoxumab and/or actoxumab. Outcomes included rate of rCDI and adverse events including cardiovascular and gastrointestinal events. RESULTS: Four randomized controlled trials comparing antitoxin antibodies (n=1916) versus placebo (n=889) were identified. rCDI was significantly reduced by bezlotoxumab plus actoxumab (risk ratio=0.54, 95% confidence interval=0.41-0.70, P<0.001) and bezlotoxumab monotherapy (risk ratio=0.62, 95% confidence interval=0.51-0.76, P<0.001) compared with placebo. Subgroup analysis showed that bezlotoxumab plus actoxumab was remarkably preventive for patients with the following high-risk features: inpatients, vancomycin treatment, and BI/NAP/027 strain. Regarding safety, there was no difference in cardiovascular and gastrointestinal events as well as all-cause mortality between bezlotoxumab-treated patients and placebo. CONCLUSIONS: The results of our meta-analysis demonstrated the effectiveness and safety of bezlotoxumab for the prevention of rCDI. Bezlotoxumab may be a good therapeutic option for severe C. difficile infection rather than mild cases.

The risk of respiratory tract infections and interstitial lung disease with interleukin 12/23 and interleukin 23 antagonists in patients with autoimmune diseases: A systematic review and meta-analysis.

BACKGROUND: Respiratory tract infections (RTIs) and interstitial lung disease (ILD) secondary to interleukin (IL) 12/23 or IL-23 antagonists have been reported in autoimmune diseases. OBJECTIVE: To assess the risk of RTIs and noninfectious ILD with these drugs. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials. Risk of RTIs and noninfectious ILD was compared to placebo by Mantel-Haenszel risk difference. We divided RTIs into upper RTIs (URTI), viral URTIs, and lower RTIs (LRTIs) including infectious pneumonia. Noninfectious ILD included ILD, eosinophilic pneumonia, and pneumonitis. RESULTS: We identified 54 randomized controlled trials including 10,907 patients with 6 IL-12/23 or IL-23 antagonists and 5175 patients with placebo. These drugs significantly increased the risk of RTIs (Mantel-Haenszel risk difference, 0.019; 95% confidence interval, 0.005-0.033; P = .007), which was attributed to URTIs, but not viral URTIs or LRTIs. There was no significant difference in infectious pneumonia and noninfectious ILD between 2 groups. LIMITATIONS: Because of the rarity of infectious pneumonia and ILD, sensitivity analysis was required. CONCLUSIONS: The use of IL-12/23 or IL-23 antagonists for autoimmune diseases increased the risk of URTIs, but not viral URTIs, LRTIs, and noninfectious ILD.

Predictability of simple endoscopic score for Crohn's disease for postoperative outcomes in Crohn's disease.

BACKGROUND AND AIM: Approximately half of patients with Crohn's disease (CD) who have surgery will experience clinical recurrence within 10 years of their surgery. This study aimed to assess the postoperative outcomes according to disease location and validated the simple endoscopic score for CD (SES-CD) to predict disease-related outcomes. METHODS: We retrospectively assessed medical records of CD patients who underwent ileocolonoscopy within 12 months after surgery at the University of Chicago between 2005 and 2016. We defined patients with postoperative colonic inflammation at the first postoperative ileocolonoscopy or had Montreal classification L2 as colon-dominant disease and patients without colonic involvement or who had L1 as small intestine (SI)-dominant disease. The outcomes included clinical and surgical recurrence. RESULTS: Among 207 CD patients, 51 (24.6%) and 156 (75.4%) patients had colon-dominant and SI-dominant disease, respectively. Patients with colon-dominant disease had a greater risk of postoperative clinical recurrence compared with those with SI-dominant disease (P = 0.018). Colon-dominant disease was a risk of earlier surgical recurrence compared with SI-dominant disease, although there were no significant differences in the recurrence-free survivals. SES-CD > 2 at the first postoperative ileocolonoscopy was a significant risk of clinical recurrence on log-rank test (P < 0.001) and Cox proportional hazards model (hazard ratio = 2.25; 95% confidence interval = 1.14-4.47; P = 0.020). An SES-CD of 1 was an appropriate cut-off to predict the clinical recurrence of SI-dominant disease, but a higher SES-CD cut-off value of 5 was required for colon-dominant disease. CONCLUSIONS: We demonstrated that SES-CD predicts postoperative clinical recurrence of CD, regardless of disease location.

The Correlation between Vitamin D Levels and the Risk of Postoperative Recurrence in Crohn's Disease.

BACKGROUND AND AIMS: Vitamin D deficiency has been associated with disease activity in Crohn's disease (CD). We assessed whether there is a correlation between vitamin D levels and the risk of postoperative recurrence in CD. METHODS: CD patients who underwent surgery were identified from a prospectively maintained database at the University of Chicago. The primary endpoint was the correlation of serum 25-hydroxy vitamin D levels measured at 6-12 months after surgery and the proportion of patients in endoscopic remission, defined as a simple endoscopic score for CD of 0. Clinical, biological (C-reactive protein), and histologic recurrences were also studied. RESULTS: Among a total of 89 patients, 17, 46, and 26 patients had vitamin D levels of <15, 15-30, and >30 ng/mL, respectively. Patients with higher vitamin D levels were significantly more likely to be in endoscopic remission compared to those with lower levels (23, 42, and 67% in ascending tertile order; p = 0.028). On multivariate analysis, vitamin D >30 ng/mL (odds ratio [OR] 0.22, 95% confidence interval [CI] 0.07-0.66, p = 0.006) and anti-tumor necrosis factor agent treatment (OR 0.25, 95% CI 0.08-0.83, p = 0.01) were associated with reduced risk of endoscopic recurrence. Rates of clinical, biological, and histologic remission trended to be higher in patients with higher vitamin D levels (p = 0.17, 0.55, 0.062, respectively). CONCLUSION: In the present study, higher vitamin D level was associated with lower risk of postoperative endoscopic CD recurrence. Further, studies are warranted to assess the role of vitamin D in postoperative CD recurrence.

Hemolysis and von Willebrand factor degradation in mechanical shuttle shear flow tester.

Chronic blood trauma caused by the shear stresses generated by mechanical circulatory support (MCS) systems is one of the major concerns to be considered during the development of ventricular assist devices. Large multimers with high-molecular-weight von Willebrand factor (VWF) are extended by the fluid forces in a shear flow and are cleaved by ADAMTS13. Since the mechanical revolving motions in artificial MCSs induce cleavage in large VWF multimers, nonsurgical bleeding associated with the MCS is likely to occur after mechanical hemodynamic support. In this study, the shear stress (~ 600 Pa) and exposure time related to hemolysis and VWF degradation were investigated using a newly designed mechanical shuttle shear flow tester. The device consisted of a pair of cylinders facing the test section of a small-sized pipe; both the cylinders were connected to composite mechanical heads with a sliding-sleeve structure for axial separation during the withdrawing motion. The influence of exposure time, in terms of the number of stress cycles, on hemolysis and VWF degradation was confirmed using fresh goat blood, and the differences in the rates of dissipation of the multimers were established. The plasma-free hemoglobin levels showed a logarithmic increase corresponding to the number of cycles, and the dissipation of large VWF multimers occurred within a few seconds under high shear stress flow conditions.

Pressure-induced variation of persistent luminescence characteristics in Y3Al5-xGaxO12:Ce3+-M3+ (M = Yb, and Cr) phosphors: opposite trend of trap depth for 4f and 3d metal ions.

Changing the electronic structure of materials by pressure and the accompanying changes in optical properties have attracted scientific interest. We have reported that the energy position of the conduction band (CB) bottom and the crystal field splitting of the Ce3+:5d excited level in Y3Al5-xGaxO12:Ce3+ are changed by applying pressure, which results in the red shifting of the Ce3+:5d → 4f luminescence and the increase of the quenching temperature. We also reported dramatic improvement of the persistent luminescence performance by either Cr3+ or Yb3+ codoping into the Y3Al5-xGaxO12:Ce3+ phosphors. The different trap depths formed by Cr3+ and Yb3+ affect the initial persistent luminescence intensity and the persistent luminescence duration. In this study, the effect of pressure on the persistent luminescence performance was investigated. For the Y3AlGa4O12:Ce3+-Yb3+ phosphor, the slope of persistent luminescence decay curve becomes more gentle with increasing pressure, while for the Y3AlGa4O12:Ce3+-Cr3+ phosphor the slope becomes steeper. These results indicate that the trap depth of Yb3+ becomes deeper and that of Cr3+ becomes shallower with increasing pressure. Based on the pressure-dependence of the luminescence quenching and the trap depth change estimated from the decay slopes, the relative electronic energies of the CB bottom and the Yb2+ (4f14) or Cr2+ (3d4) levels are discussed. The CB bottom energy is increased relative to the ground 1S0 state of Yb2+ with increasing pressure, which results in deepening of the electron trap depth of the Yb2+ state. The opposite tendency of the Cr3+ codoped sample was described by a decreasing tendency of the energy gap between the CB bottom and the Cr2+:eg level, the relative energy level of which is increased by the increase of the crystal field with increasing pressure in the garnet host material, where the electron-trapping Cr2+ ions take the high spin state (t32ge1g) rather than the low-spin state (t42g).

Roles of the noradrenergic nucleus locus coeruleus and dopaminergic nucleus A11 region as supraspinal defecation centers in rats.

We previously demonstrated that administration of norepinephrine, dopamine, and serotonin into the lumbosacral defecation center caused propulsive contractions of the colorectum. It is known that the monoamines in the spinal cord are released mainly from descending neurons in the brainstem. In fact, stimulation of the medullary raphe nuclei, the origin of descending serotonergic neurons, enhances colorectal motility via the lumbosacral defecation center. Therefore, the purpose of this study was to examine the roles of the noradrenergic nucleus locus coeruleus (LC) and dopaminergic nucleus A11 region in the defecation reflex. Colorectal motility was measured with a balloon in anesthetized rats. Electrical stimulation of the LC and A11 region increased colorectal pressure only when a GABAA receptor antagonist was injected into the lumbosacral spinal cord. The effects of the LC stimulation and A11 region stimulation on colorectal motility were inhibited by antagonists of α1-adrenoceptors and D2-like dopamine receptors injected into the lumbosacral spinal cord, respectively. Spinal injection of a norepinephrine-dopamine reuptake inhibitor augmented the colokinetic effect of LC stimulation. The effect of stimulation of each nucleus was abolished by surgical severing of the parasympathetic pelvic nerves. Our findings demonstrate that activation of descending noradrenergic neurons from the LC and descending dopaminergic neurons from the A11 region causes enhancement of colorectal motility via the lumbosacral defecation center. The present study provides a novel concept that the brainstem monoaminergic nuclei play a role as supraspinal defecation centers.NEW & NOTEWORTHY The present study demonstrates that electrical and chemical stimulations of the locus coeruleus or A11 region augment contractions of the colorectum. The effects of locus coeruleus and A11 stimulations on colorectal motility are due to activation of α1-adrenoceptors and D2-like dopamine receptors in the lumbosacral defecation center, respectively. The present study provides a novel concept that the brainstem monoaminergic nuclei play a role as supraspinal defecation centers.

Risk of gastrointestinal cancers in patients with cystic fibrosis: a systematic review and meta-analysis.

BACKGROUND: The management and life expectancy of patients with cystic fibrosis have improved substantially in the past three decades, which has resulted in an increased number of these patients being diagnosed with malignancies. Our aim was to assess the risk of gastrointestinal cancers in patients with cystic fibrosis. METHODS: In this systematic review and meta-analysis, we searched PubMed, MEDLINE, Google Scholar, Scopus, Embase, and Cochrane databases with no language restrictions for studies published from inception of the databases to Aug 1, 2017, assessing the risk of gastrointestinal cancers in patients with cystic fibrosis. We also searched abstracts from scientific meetings and the bibliographies of identified articles for additional references. Studies were included if they reported the standardised incidence ratio (SIR) or incidence ratio per person-years. No exclusion criteria with regard to patient characteristics (age, sex, comorbidities, cystic fibrosis mutation type), study setting (location and time period), or method of reporting cancer diagnoses were applied. The primary outcome was risk of gastrointestinal cancer and site-specific gastrointestinal cancers in patients with cystic fibrosis compared with the general population. Pooled summary estimates were calculated using a random-effects model, and subgroup analyses were done to establish whether risk of gastrointestinal cancer varied according to patient lung transplant status. The study is registered with PROSPERO, number CRD42017075396. FINDINGS: Our search identified 95 681 records, of which six cohort studies including 99 925 patients (544 695 person-years) were eligible for the meta-analysis. The overall risk of gastrointestinal cancer was significantly higher in patients with cystic fibrosis than in the general population (pooled SIR 8·13, 95% CI 6·48-10·21; p<0·0001; log SIR 2·10, 95% CI 1·87-2·32; p<0·0001, I2=93·93%). Subgroup analyses showed that the risk of gastrointestinal cancer among patients with cystic fibrosis who had a lung transplant was increased compared with that of patients who did not receive a transplant (pooled SIR 21·13, 95% CI 14·82-30·14; p<0·0001; log SIR 3·05, 95% CI 2·70-3·41; p<0·0001, I2=28·52% vs pooled SIR 4·18, 3·10-5·62; p<0·0001; log SIR 1·43, 1·13-1·73; p<0·0001, I2=22·66%). The risk for the following site-specific cancers was also significantly increased in patients with cystic fibrosis compared with the general population: small bowel cancer (pooled SIR 18·94, 95% CI 9·37-38·27; p<0·0001; log SIR 2·94, 95% CI 2·24-3·64; p<0·0001, I2=38·61%), colon cancer (10·91, 8·42-14·11; p<0·0001; log SIR 2·39, 2·13-2·65; p<0·0001, I2=88·09%), biliary tract cancer (17·87, 8·55-37·36; p<0·0001; log SIR 2·88, 2·15-3·62; p<0·0001, I2=10·16%), and pancreatic cancer (6·18, 1·31-29·27; p=0·022; log SIR 1·82, 0·27-3·38; p<0·0001, I2=62·57%). INTERPRETATION: Our study suggests that patients with cystic fibrosis had a significantly increased risk of gastrointestinal cancer compared with the general population, including small bowel, colon, biliary tract, and pancreatic cancers. These findings highlight the need to develop individualised screening strategies for site-specific gastrointestinal cancers in patients with cystic fibrosis. FUNDING: None.

Ethanol-induced enhancement of inhibitory synaptic transmission in the rat spinal substantia gelatinosa.

Recent studies have shown that ethanol produces a widespread modulation of neuronal activity in the central nervous system. It is not fully understood, however, how ethanol changes nociceptive transmission. We investigated acute effects of ethanol on synaptic transmission in the substantia gelatinosa (lamina II of the spinal dorsal horn) and mechanical responses in the spinal dorsal horn. In substantia gelatinosa neurons, bath application of ethanol at low concentration (10 mM) did not change the frequency and amplitude of spontaneous inhibitory postsynaptic currents. At medium to high concentrations (20-100 mM), however, ethanol elicited a barrage of large amplitude spontaneous inhibitory postsynaptic currents. In the presence of tetrodotoxin, such enhancement of spontaneous inhibitory postsynaptic currents was not detected. In addition, ethanol (20-100 mM) increased the frequency of spontaneous discharge of vesicular GABA transporter-Venus-labeled neurons and suppressed the mechanical nociceptive response in wide-dynamic range neurons in the spinal dorsal horn. The present results suggest that ethanol may reduce nociceptive information transfer in the spinal dorsal horn by enhancement of inhibitory GABAergic and glycinergic synaptic transmission.

Chronic inflammatory pain induced GABAergic synaptic plasticity in the adult mouse anterior cingulate cortex.

Background Chronic pain is a persistent unpleasant sensation that produces pathological synaptic plasticity in the central nervous system. Both human imaging study and animal studies consistently demonstrate that the anterior cingulate cortex is a critical cortical area for nociceptive and chronic pain processing. Thus far, the mechanisms of excitatory synaptic transmission and plasticity have been well characterized in the anterior cingulate cortex for various models of chronic pain. By contrast, the potential contribution of inhibitory synaptic transmission in the anterior cingulate cortex, in models of chronic pain, is not fully understood. Methods Chronic inflammation was induced by complete Freund adjuvant into the adult mice left hindpaw. We performed in vitro whole-cell patch-clamp recordings from layer II/III pyramidal neurons in two to three days after the complete Freund adjuvant injection and examined if the model could cause plastic changes, including transient and tonic type A γ-aminobutyric acid (GABAA) receptor-mediated inhibitory synaptic transmission, in the anterior cingulate cortex. We analyzed miniature/spontaneous inhibitory postsynaptic currents, GABAA receptor-mediated tonic currents, and evoked inhibitory postsynaptic currents. Finally, we studied if GABAergic transmission-related proteins in the presynapse and postsynapse of the anterior cingulate cortex were altered. Results The complete Freund adjuvant model reduced the frequency of both miniature and spontaneous inhibitory postsynaptic currents compared with control group. By contrast, the average amplitude of these currents was not changed between two groups. Additionally, the complete Freund adjuvant model did not change GABAA receptor-mediated tonic currents nor the set of evoked inhibitory postsynaptic currents when compared with control group. Importantly, protein expression of vesicular GABA transporter was reduced within the presynpase of the anterior cingulate cortex in complete Freund adjuvant model. In contrast, the complete Freund adjuvant model did not change the protein levels of GABAA receptors subunits such as α1, α5, ß2, γ2, and δ. Conclusion Our results suggest that the induction phase of inflammatory pain involves spontaneous GABAergic plasticity at presynaptic terminals of the anterior cingulate cortex.

Impaired peripheral nerve regeneration in type-2 diabetic mouse model.

Peripheral neuropathy is one of the most common and serious complications of type-2 diabetes. Diabetic neuropathy is characterized by a distal symmetrical sensorimotor polyneuropathy, and its incidence increases in patients 40 years of age or older. In spite of extensive research over decades, there are few effective treatments for diabetic neuropathy besides glucose control and improved lifestyle. The earliest changes in diabetic neuropathy occur in sensory nerve fibers, with initial degeneration and regeneration resulting in pain. To seek its effective treatment, here we prepared a type-2 diabetic mouse model by giving mice 2 injections of streptozotocin and nicotinamide and examining the ability for nerve regeneration by using a sciatic nerve transection-regeneration model previously established by us. Seventeen weeks after the last injection, the mice exhibited symptoms of type-2 diabetes, that is, impaired glucose tolerance, decreased insulin level, mechanical hyperalgesia, and impaired sensory nerve fibers in the plantar skin. These mice showed delayed functional recovery and nerve regeneration by 2 weeks compared with young healthy mice and by 1 week compared with age-matched non-diabetic mice after axotomy. Furthermore, type-2 diabetic mice displayed increased expression of PTEN in their DRG neurons. Administration of a PTEN inhibitor at the cutting site of the nerve for 4 weeks promoted the axonal transport and functional recovery remarkably. This study demonstrates that peripheral nerve regeneration was impaired in type-2 diabetic model and that its combination with sciatic nerve transection is suitable for the study of the pathogenesis and treatment of early diabetic neuropathy.