Electrophysiological effects of melatonin on rat trigeminal ganglion neurons that participate in nociception in vitro

OBJECTIVE

Melatonin (MT) is a hormone mainly produced by the pineal gland. It may be involved in the regulation of nociception, the mechanisms of which remain unclear. In the present study, electrophysiological effects of MT on neurons were studied.

MATERIALS AND METHODS

The cultured neurons were isolated from Sprague-Dawley rats trigeminal ganglia (TG). The neuron was voltage clamped using the whole cell patch clamp technique. We recorded resting membrane potential, action potential threshold and number, action potential duration and GABA-activated inward currents in the presence of 0.01 μM, 10 μM MT, and in the absence of MT.

RESULTS

In the presence of high concentration of MT, the spontaneous action potential disappeared and action potential threshold was significantly increased. GABA-activated inward currents were recorded and blocked by GABAA receptor antagonist, bicuculline, in the majority of TG neurons (91% 40/44). Continuous perfusion of MT could cause a decrease of GABA-activated currents. The inhibiting effect was dose-dependent and irreversible.

CONCLUSIONS

The results suggest that MT has several electrophysiological effects on TG neurons, which may be involved in the peripheral mechanisms of orofacial pain.

P886Exercise left ventricular outflow track obstruction in hypertrophic cardiomyopathy: peak exercise or post-exercise pressure gradients?

Background

Left ventricular outflow track obstruction (LVOTO) is a key feature of hypertrophic cardiomyopathy (HCM), associated with poor prognosis and requiring specific management in symptomatic patients. Furthermore, new drugs targeting LVOTO are under investigation. Exercise echocardiography is the more relevant test to unmask latent obstruction in patients with HCM and to link obstruction to symptoms during physical activity. However, little is known about the role and impact of obstruction according to the precise time of occurrence during exercise or immediate recovery.

Objective

We hypothesized that LVOT pressure gradients could be enhanced during immediate recovery after exercise compared to peak exercise in patients with HCM.

Methods

We conducted an observational, single center and retrospective study and included all the patients with HCM referred to our department between 2010 and 2018 for an exercise echocardiography. All exercises were performed on a bicycle in a semi-supine position and LVOT pressure gradient were recorded continuously during and immediately after exercise in the same position.

Results

121 patients with HCM were included (age 49±16 y, 64% male, 59% NYHA 2 and 3, LV ejection fraction 66±7%, max LV wall thickness 19±5 mm, 69% receiving betablockers). Exercise was performed until exhaustion at a mean workload of 118±58 Watts. Overall, the maximal LVOT gradients increased from rest, to peak exercise and recovery (respectively 17±18, 39±43 and 55±60 mmHg, p<0,0001). More than half of the patients (52%) had a gradient ≥30 mmHg at least in one phase, but a maximal gradient ≥50 mmHg (threshold for invasive treatment in symptomatic patients) was observed in only 7% of the population at rest, 25% at peak exercise and 37% at recovery (p<0.001). Finally, a maximal gradient ≥50 mmHg was recorded only during immediate recovery (69±25 mmHg) and not during exercise in 16 patients (13%). None of them experienced post-exercise syncope.

Conclusion

The time course of significant LVOTO during exercise in HCM should be evaluated carefully. LVOTO is more severe and more prevalent during immediate recovery. Some patients exhibit only significant post-exercise LVOT pressure gradients, which therefore cannot explain limitation during exercise.

Anti-α-enolase antibody combined with β2 microglobulin evaluated the incidence of nephritis in systemic lupus erythematosus patients

OBJECTIVE

Anti-α-enolase antibody (Ab) combined with β2 microglobulin (β2-MG) were investigated to predict the incidence of nephritis in systemic lupus erythematosus (SLE) patients.

METHODS

Levels of serum anti-α-enolase Ab and urinary β2-MG were detected in 115 SLE patients, 29 SLE patients with nephritis and 70 healthy controls by ELISA and immunoturbidimetry, respectively. Furthermore, the correlation between anti-α-enolase Ab combined with β2-MG and the incidence of nephritis in SLE patients was evaluated by correlation analysis.

RESULTS

The optical density value of serum anti-α-enolase Ab in SLE patients with nephritis (0.84) was greatly increased compared with SLE patients (0.76) or healthy controls (0.54). Moreover, the levels of urinary β2-MG in SLE patients with nephritis (6.75 mg/L) were increased compared with SLE patients (3.45 mg/L) or healthy controls (1.48 mg/L). There was a positive correlation between the level of anti-α-enolase Ab and β2-MG ( r = 0.754). Furthermore, anti-α-enolase Ab combined with β2-MG for evaluating the incidence of nephritis in SLE patients had the best assessment of the effectiveness (area under the receiver operating characteristic curve (AUC): 92.7%) compared with only anti-α-enolase Ab (AUC: 80.9%) or β2-MG (AUC: 84.5%).

CONCLUSION

These data suggested that anti-α-enolase Ab may be a potential indicator for the prediction of nephritis in SLE patients.

[The effect of arthroscopic synovectomy on refractory knee arthritis with popliteal cyst in 153 patients]

Objective: To investigate the efficacy of arthroscopic synovectomy on refractory knee arthritis complicated with popliteal cyst. Methods: Patients diagnosed as rheumatoid arthritis (RA) or spondyloarthritis (SpA) with refractory knee arthritis who underwent knee arthroscopic synovectomy in our hospital from 2010 to 2017 were enrolled, including 20 patients (16 RA, 4 SpA) with popliteal cyst. Clinical data, RA disease activity score (DAS28), SpA back pain score, etc, were collected to evaluate the efficacy of knee surgery. Results: Erythrocyte sedimentation rate (ESR) [58(17, 79)mm/1h vs. 19(9, 30)mm/1h, P< 0.001],C reactive protein (CRP) [3.72(0.92,8.14) mg/L vs. 0.85(0.10,3.08) mg/L,P<0.001], rheumatoid factor [64.6(20.2,193.3) vs. 20.5(10.0,58.4),P<0.001], DAS28 score(4.67±1.25 vs. 2.81±1.23,P<0.001), knee joint discomfort score [5(4,6) vs. 2(1,3),P<0.001] and the volume of knee joint effusion by ultrasound (P<0.05) in 95 RA patients were significantly decreased compared to those before operation. ESR [27(12,54)mm/1h vs. 20 (16,28) mm/1 h,P<0.001], CRP [3.27(1.06,6.95) mg/L vs. 1.41(0.34,3.03)mg/L,P<0.001],knee discomfort score [2(0,5) vs. 1(0,3),P<0.05], back pain visual analogue score (VAS) [5(4,5) vs. 2(1,3), P<0.001], and the volume of knee joint effusion by ultrasound (P<0.001) in 58 SpA patients were significantly lower than those before the operation.The rate [16.84%(16/95) vs. 6.32%(6/95),P=0.023] and grading (P=0.007) of popliteal cyst in RA were decreased after the operation. No statistically difference was observed in the rate [6.90% (4/58) vs. 5.17%(3/58), P=0.697] of popliteal cyst in patients with SpA, yet with a trend of decrease in 4 patients. Conclusion: This study provide evidence that knee arthroscopic synovectomy has a good effect for refractory knee arthritis, which can reduce disease activity, improve joint symptoms and decrease the grading of popliteal cyst.

Association of benign thyroid diseases with thyroid cancer risk: a meta-analysis of prospective observational studies

PURPOSE

Evidence showed that benign thyroid disease was one of the risk factors for thyroid cancer. However, the results of some studies were inconsistent and were previously meta-analyses of case-control studies. Therefore, we performed a meta-analysis of prospective studies to investigate the relationship between benign thyroid diseases and thyroid cancer risk.

METHODS

All eligible studies were identified via systematic searches of multiple literature databases. The combined RR (relative risk)/HR (hazard ratio) or SIR (standardized incidence ratio) with 95% confidence interval was calculated. Heterogeneity was assessed with the I² test. Publication bias and subgroup analyses were also performed.

RESULTS

Twelve studies were eligible for inclusion in the meta-analysis. The pooled RR/HR of thyroid carcinoma in benign thyroid diseases was 4.39 (95% CI 3.22-5.55). The pooled SIR of thyroid carcinoma in benign thyroid diseases was 5.98 (95% CI 4.09-7.86). Subgroup analysis was performed using the type of benign thyroid diseases. Effect value was RR/HR: hyperthyroidism (RR/HR = 3.89, 95% CI = 1.69-6.08), hypothyroidism (RR/HR = 2.72, 95% CI = 1.04-4.41), and goiter (RR/HR = 22.18, 95% CI = 12.09-32.28). Effect value was SIR: hyperthyroidism (RR/HR = 5.96, 95% CI = 1.88-10.03), goiter (RR/HR = 7.65, 95% CI = 6.94-8.37), and thyroiditis (RR/HR = 3.25, 95% CI = 1.62-4.89).

CONCLUSIONS

Our study has shown that benign thyroid diseases might be associated with increased risk of thyroid cancer, especially in hyperthyroidism, hypothyroidism, and goiter. However, further investigation is needed to better understand the underlying biological mechanisms.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N^{*} Resonance Region

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Application of dexmedetomidine-remifentanil in high-intensity ultrasound ablation of uterine fibroids: a randomised study

OBJECTIVE

To compare the effects of dexmedetomidine-remifentanil with the traditional analgesia and sedation regimen midazolam-remifentanil during HIFU treatment of uterine fibroids.

DESIGN

A randomised controlled trial.

SETTING

Department of Anesthesia in a single hospital.

POPULATION

Patients with uterine fibroids.

METHODS

A total of 80 patients diagnosed with uterine fibroids and scheduled for selective HIFU treatment were randomly divided into the dexmedetomidine group (the D group) and midazolam group (the M group). At 20 minutes before the HIFU procedure, patients in the D group received a loading dose of 0.8 μg/kg dexmedetomidine, followed by a continuous intravenous infusion of 0.2 μg/kg/hour until the end of the operation. Patients in the M group were given a corresponding amount of 0.9% saline. Patients in the M group received a slow intravenous infusion of 0.03 mg/kg midazolam before the procedure, an intravenous injection of 0.02 mg/kg 30 minutes later, another 0.02 mg/kg 60 minutes later, followed by 0.02 mg/kg at 40-minutes intervals. Patients in the D group were given a corresponding amount of 0.9% saline. During the HIFU procedure, patients in both groups were administered remifentanil at an effect site concentration of 1.0 ng/ml. Sedation and analgesia were rated using the Ramsay Sedation Scale (RSS) and Visual Analogue Scale (VAS) before drug administration (T1), after drug administration but before HIFU (T2), at the beginning of HIFU (T3), 15 minutes later (T4), 45 minutes later (T5), 75 minutes later (T6), and at the end of HIFU (T7). Patient satisfaction score and Steward recovery score survey were conducted 30 minutes after surgery.

MAIN OUTCOME MEASURES

Different effects of the traditional midazolam-remifentanil regimen and dexmedetomidine-remifentanil.

RESULTS

All patients in both groups underwent a successful HIFU procedure without developing serious complications during the postoperative period. However, the D group reported significantly fewer cases of respiratory depression than the M group during HIFU treatment (P < 0.05). The pause during HIFU ablation in the D group was significantly shorter than that in the M group. HIFU ablation intensity, the number of patients with an RSS of 3 or 4 measured at different time points, and the number of patients with an RSS of 3 or 4 measured at arousal were significantly greater in the D than the M group (P < 0.05). Likewise, the D group scored significantly higher in the evaluation of patient satisfaction, recovery score, and surgeon satisfaction (P < 0.05).

CONCLUSIONS

Both dexmedetomidine-remifentanil and midazolam-remifentanil met the requirements and ensured the safety of HIFU treatment of uterine fibroids. However, compared with the traditional midazolam-remifentanil regimen, dexmedetomidine-remifentanil was associated with more stable sedation in patients, more efficient HIFU treatment and higher degree of patient comfort.

TWEETABLE ABSTRACT

Dexmedetomidine-remifentanil is associated with more stable sedation in patients, more efficient HIFU treatment and higher degree of patient comfort than is midazolam-remifentanil.

Constraints on Minute-Scale Transient Astrophysical Neutrino Sources

High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5}  erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52}  erg. A hypothetical population of transient sources has to be more common than 10^{-5}  Mpc^{-3}  yr^{-1} (5×10^{-8}  Mpc^{-3}  yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.

Potential involvement of S1PR1/STAT3 signaling pathway in cardiac valve damage due to rheumatic heart disease

Rheumatic heart disease (RHD) is a public health burden in developing countries. Th17 cell-associated cytokines might play a role in the pathogenesis and development of RHD, but the specific molecular mechanism is not completely understood. We investigated the potential role of sphingosine-1-phosphate receptor 1 (S1PR1)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in cardiac valve damage in a rat model of RHD. We used 20 Lewis rats divided randomly into control and RHD groups. The RHD model was constructed by injecting inactivated group A Streptococci and complete Freund's adjuvant (CFA). The rats in the control group were injected with normal saline and CFA. Th17 cell-related cytokines were measured by ELISA. Fibrosis was assessed by histological examination. RT-qPCR and western blot were used to detect the expression of S1PR1 and STAT3/phosphorylated STAT3 (p-STAT3). The S1PR1/STAT3 signaling pathway was activated in the RHD model. Compared to the control group, serum levels of IL-17 and IL-21 cytokines associated with Th17 cells were increased significantly in the RHD group; the collagen volume fraction also was substantially increased. The S1PR1/STAT3 signaling pathway might be involved in RHD induced cardiac valve damage by regulating Th17 cells.

Understandingd*(2380) in a chiral quark model

We review our recent progresses made in the study of the structure and decay properties of the newly observedd*(2380) within a chiral constituent quark model. It is found that thed*(2380) can be explained as a compact hexaquark-dominated exotic state with a fraction of hidden color components of about 2/3 in its configuration. Based on this scenario the single- and double- pionic partial decay widths are calculated and the corresponding numerical results are in good agreement with the experimental data.