The role of pineal microRNA-325 in regulating circadian rhythms after neonatal hypoxic-ischemic brain damage.

Circadian rhythm disorder is a common, but often neglected, consequence of neonatal hypoxic-ischemic brain damage (HIBD). However, the underlying molecular mechanisms remain largely unknown. We previously showed that, in a rat model of HIBD, up-regulation of microRNA-325 (miR-325) in the pineal gland is responsible for the suppression of Aanat, a key enzyme involved in melatonin synthesis and circadian rhythm regulation. To better understand the mechanism by which miR-325 affects circadian rhythms in neonates with HIBD, we compared clinical samples from neonates with HIBD and samples from healthy neonates recruited from the First Affiliated Hospital of Soochow University (Dushuhu Branch) in 2019. We found that circulating miR-325 levels correlated positively with the severity of sleep and circadian rhythm disorders in neonates with HIBD. Furthermore, a luciferase reporter gene assay revealed that LIM homeobox 3 (LHX3) is a novel downstream target of miR-325. In addition, in miR-325 knock-down mice, the transcription factor LHX3 exhibited an miR-325-dependent circadian pattern of expression in the pineal gland. We established a neonatal mouse model of HIBD by performing double-layer ligation of the left common carotid artery and exposing the pups to a low-oxygen environment for 2 hours. Lhx3 mRNA expression was significantly down-regulated in these mice and partially rescued in miR-325 knockout mice subjected to the same conditions. Finally, we showed that improvement in circadian rhythm-related behaviors in animals with HIBD was dependent on both miR-325 and LHX3. Taken together, our findings suggest that the miR-325-LHX3 axis is responsible for regulating circadian rhythms and provide novel insights into the identification of potential therapeutic targets for circadian rhythm disorders in patients with neonatal HIBD. The clinical trial was approved by Institutional Review Board of Children's Hospital of Soochow University (approval No. 2015028) on July 20, 2015. Animal experiments were approved by Animal Care and Use Committee, School of Medicine, Soochow University, China (approval No. XD-2016-1) on January 15, 2016.

The role of a lncRNA (TCONS_00044595) in regulating pineal CLOCK expression after neonatal hypoxia-ischemia brain injury.

A common, yet often neglectable, feature of neonatal hypoxic-ischemic brain damage (HIBD) is circadian rhythm disorders resulted from pineal gland dysfunction. Our previous work demonstrated that miRNAs play an important role in regulating key circadian genes in the pineal gland post HIBD [5,21]. In current study, we sought out to extend our investigation by profiling expression changes of pineal long non-coding RNAs (lncRNAs) upon neonatal HIBD using RNA-Seq. After validating lncRNA changes, we showed that one lncRNA: TCONS_00044595 is highly enriched in the pineal gland and exhibits a circadian expression pattern. Next, we performed bioinformatic analysis to predict the lncRNA-miRNA regulatory network and identified 168 miRNAs that potentially targetlncRNA TCONS_00044595. We further validated the bona fide interaction between one candidate miRNA: miR-182, a known factor to regulate pineal Clock expression, and lncRNA TCONS_00044595. Finally, we showed that suppression of lncRNA TCONS_00044595 alleviated the CLOCK activation both in the cultured pinealocytes under OGD conditions and in the pineal gland post HIBD in vivo. Our study thus shed light into novel mechanisms of pathophysiology of pineal dysfunction post neonatal HIBD.

A review of the design and clinical evaluation of the ShefStim array-based functional electrical stimulation system.

Functional electrical stimulation has been shown to be a safe and effective means of correcting foot drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible for selecting the correct stimulation level each time the system is donned. Researchers have investigated different approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, through modelling of the array geometry and interface layer to array search algorithm development. Finally, the paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim system with automated setup produces results which are comparable with clinician setup of conventional systems. Further, the final study demonstrated that patients can use the system without clinical supervision. When used unsupervised, setup time was 14min (9min for automated search plus 5min for donning the equipment), although this figure could be reduced significantly with relatively minor changes to the design.

The detection of YMDD mutation of hepatitis B virus by allele-specific PCR and a cross-contamination proofed device.

Lamivudine (LAM) is commonly used to treat Hepatitis B virus (HBV) infection, but its use frequently induces drug resistance. Therefore, rapid and correct detection of drug-resistant HBV is important for effective treatment of HBV infection. In this study, we aimed to develop a novel, simple, and user-friendly method for the detection of LAM resistant HBV. Samples were collected from 60 HBV infected patients for the analysis by allele-specific polymerase chain reaction (AS-PCR), nucleic acid detection strip (NADS) and a cross-contamination proofed device. HBV YMDD mutations were detected by AS-PCR, restriction fragment length polymorphism (RFLP) and DNA sequencing. A 91.7% concordance between all three methods was obtained. Compared to sequencing and RFLP, AS-PCR detected more samples with mutant variants and was more sensitive. This novel method had a detection limit of approximately 103 copies/ml and detected a variant of only 5% of total HBV population. In conclusion, we develop a new assay which could be useful for the detection of HBV LAM resistance, especially in resource-poor settings.

[N-terminal pro-B-type natriuretic peptide value for prediction of mortality among critically ill patients in different age groups in intensive care unit].

OBJECTIVE: To investigate N-terminal pro-B-type natriuretic peptide (NT-proBNP) cutoff value for the mortality in different age groups in critically ill patients. METHODS: A retrospective study was conducted. 295 patients admitted to the intensive care unit (ICU) of 401st Hospital of PLA from January 2011 to October 2012 were divided into two groups according to age [group with age<65 years old (n=105) and group with age≥ 65 years old (n=190)]. The concentrations of serum NT-proBNP, hematocrit (HCT), procalcitonin (PCT), C-reactive protein(CRP), serum creatinine(SCr), estimated glomerular filtration rate (eGFR), acute physiology and chronic health evaluationII (APACHEII) score and probability of survival (PS) were recorded within 24 hours. The primary outcome was ICU mortality. Receiver operator characteristic curve (ROC curve) was used to evaluate the value of NT-proBNP for predicting the mortality. RESULTS: (1) There were no significant differences in the length of stay in ICU, mechanical ventilation rate, the mortality, the incidence of cardiovascular disease, digestive disease, neurologic disease, and the number of patients having received operation, HCT, PCT and CRP between the two groups (all P>0.05). The percentage of the male, the APACHEII score, the percentage of respiratory disease, and NT-proBNP in group with age≥65 years old were higher than those of the group with age<65 years old [the percentage of the male: 51.6% vs. 33.0%, χ (2)=9.093, P=0.003; APACHEII score: 22.94±8.10 vs. 19.44±8.51, Z=-3.259, P=0.001; the percentage of respiratory disease: 29.47% vs. 17.14%, χ(2)=5.472, P=0.024; NT-proBNP: 5 859.00 (2 050.75, 23 802.75) ng/L vs. 2 882.00 (275.15, 6 236.00) ng/L, Z=-5.514, P=0.000]; PS, the percentage of patients having multiple injuries and other diseases and eGFR in group with age≥65 years old were lower than those of the group with age <65 years old [PS: 59.0 (31.5,79.0)% vs. 70.0 (40.0, 84.0)%, Z=-3.431, P=0.001; the percentage of multiple injuries: 0.53% vs. 17.14%, χ(2)=30.987, P=0.000; the percentage of other disease: 5.79% vs. 13.33%, χ(2)=4.962, P=0.030; eGFR (ml×min(-1)×1.73 m(-2)): 81.07 (45.77, 131.80) vs. 95.54 (33.64, 165.55), Z=-2.214, P=0.027]. (2) The area under the ROC curve (AUC) [95% confidence interval (95%CI)] of NT-proBNP in patients with age<65 years old was significantly higher than that of group with age≥65 years old and the entire group [0.825 (0.738-0.892) vs. 0.664 (0.592-0.731) and 0.725 (0.670-0.775), Z1=-2.835, P1=0.005; Z2=-1.995, P2=0.046]. (3) The sensitivity (76.10% vs. 64.10%), specificity (82.35% vs. 67.12%), positive predictive value (90.0% vs. 75.8%), and negative predictive value (62.2% vs. 53.8%) with cutoff value of NT-proBNP (2 882 ng/L) in group with age<65 years old were significantly higher than those with NT-proBNP cutoff value (6 062 ng/L) in group with age≥65 years old. CONCLUSIONS: NT-proBNP cutoff value in different age groups for the prediction of mortality in the critically ill patients maybe more objective and accurate.

Electrophysiologic characteristics of the Crista terminalis and implications on atrial tachycardia in rabbits.

The objective of this study was to evaluate the electrophysiologic characteristics of Crista terminalis (CT) and their implication in the pathogenesis of atrial tachycardia in rabbits. For this purpose, 27 New Zealand rabbits were used. Using standard glass microelectrode technique, cellular action potentials (APs) of CT and pectinate muscle (PM) were recorded in normal Tyrode's perfusion and Tyrode's perfusion with 4 µM isoproterenol. Longitudinal conduction velocity (V(L)) and transverse conduction velocity (V(T)) of CT were measured. As our data show, CT tissue had a trend of spontaneous phase IV depolarization. Conduction anisotropy (V(L)/V(T)) of CT was 4.53 ± 0.91. The duration of the AP of CT was longer than that of PM cells. APD(20) and APD(90) for CT were 28.1 ± 3.5 and 145.3 ± 7.1 ms; and for PM cells were 21.8 ± 4.1 and 125.3 ± 6.3 ms, respectively (all P values < 0.01). The early and delayed action depolarizations were recorded after isoproterenol perfusion. A fast paroxysmal irregular rhythm was recorded which could be arrested by 0.1 mmol/l Isoptin. It was, therefore, concluded that the latent autorhythmicity, trigger activity, and conduction properties of CT might provide the electrophysiologic basis for the occurrence and sustenance of atrial arrhythmia.

[Evaluation of continuous monitoring of bispectral index in prognosis in patients with acute brain injury].

OBJECTIVE: To discuss the effect of continuous monitoring of bispectral index (BIS) on the prognosis of patients with acute brain injury. METHODS: A retrospective study was carried out, 61 patients with acute brain injury admitted to the intensive care unit (ICU) from March 2009 to July 2010 were divided into survival group (n=25) and death group (n=36). The BIS was continuously monitored for 12 hours within the first 3 days or 24 hours after stoppage of sedative after admission to ICU. The mean value of BIS (BISmean), the maximal value of BIS (BISmax), and the minimal value of BIS (BISmin) were evaluated. At the same time, the acute physiology and chronic health evaluationII (APACHEII) score, probability of survival (PS) and Glasgow coma score (GCS) were evaluated. The values of serum S100 protein and neuron-specific enolase (NSE) were determined. The relationship between BISmean and GCS, S100 protein and NSE were respectively analyzed. RESULTS: (1)There was no significant difference in the sex, age, or duration of mechanical ventilation between two groups. APACHEII score in death group was significantly higher than the survival group (27.36±5.99 vs. 23.28±6.69), PS was significantly lower than the survival group (0.31±0.17 vs. 0.49±0.19), and length of stay in ICU (days) was significantly lower than that of the survival group (6.33±4.48 vs. 27.88±54.46), P<0.05 or P<0.01. (2) BISmean, BISmax, BISmin, GCS in death group were significantly lower than those in the survival group (BISmean: 35.45±28.31 vs. 55.91±17.53, BISmax: 51.92±34.24 vs. 74.84±16.58, BISmin: 22.39±24.83 vs. 39.68±15.72, GCS score: 3.64±1.19 vs. 5.60±2.22), P<0.05 or P<0.01, while serum S100 protein and NSE levels were significantly higher than the survival group [S100 protein (µg/L): 7.54±10.49 vs. 1.18±1.57, NSE (µg/L): 120.74±109.01 vs. 49.83±54.94], both P<0.01. (3) By bivariate analysis, BISmean was positively correlated with GCS (r=0.379, P=0.003), whereas it was found to be negatively correlated with S100 protein and NSE levels (r1=-0.418, P1=0.001; r2=-0.290, P2=0.023). CONCLUSION: BIS monitoring can be applied as an early objective indicator to evaluate the prognosis of the acute brain injured patients with the characteristics of being noninvasive, intuitive, easy-to-manipulate, and non-stop monitoring.

Inertial sensor-based knee flexion/extension angle estimation.

A new method for estimating knee joint flexion/extension angles from segment acceleration and angular velocity data is described. The approach uses a combination of Kalman filters and biomechanical constraints based on anatomical knowledge. In contrast to many recently published methods, the proposed approach does not make use of the earth's magnetic field and hence is insensitive to the complex field distortions commonly found in modern buildings. The method was validated experimentally by calculating knee angle from measurements taken from two IMUs placed on adjacent body segments. In contrast to many previous studies which have validated their approach during relatively slow activities or over short durations, the performance of the algorithm was evaluated during both walking and running over 5 minute periods. Seven healthy subjects were tested at various speeds from 1 to 5 mile/h. Errors were estimated by comparing the results against data obtained simultaneously from a 10 camera motion tracking system (Qualysis). The average measurement error ranged from 0.7 degrees for slow walking (1 mph) to 3.4 degrees for running (5 mph). The joint constraint used in the IMU analysis was derived from the Qualysis data. Limitations of the method, its clinical application and its possible extension are discussed.

[The role of coronary sinus musculature on electrical conduction between left atrium and right atrium in isolated canine heart].

OBJECTIVE: To investigate electrophysiological characteristics of the coronary sinus musculature and explore its role on electrical conduction between left atrium and right atrium in isolated canine heart. METHOD: The electrical connections between coronary sinus, left atrium and right atrium were detected by programmed stimulation delivered at coronary sinus ostium, distal coronary sinus and lateral wall of left atrium in a Langendorff model of canine. RESULTS: During stimulation delivered at coronary sinus ostium and distal coronary sinus, posterior wall of left atrium was firstly activated by electronic signal through coronary sinus musculature, the conduct time of coronary sinus ostium stimulation and distal coronary sinus stimulation were (44 +/- 21) ms and (41 +/- 15) ms, respectively. During stimulation delivered at lateral wall of left atrium, electronic signal was firstly observed in coronary sinus. During premature stimulation, conduction blockade of coronary sinus to left atrium was evidenced in parts of hearts, but electronic conduction of left atrium to right atrium remained stable. The ERP at the different stimulation sites of coronary sinus ostium and distal coronary sinus, posterior wall of left atrium were (122 +/- 19) ms, (114 +/- 12) ms (n = 3) and (107 +/- 17) ms (all P > 0.05). CONCLUSION: A conduction way connecting left and right atria exists in coronary sinus which might play an important role on inducing and maintaining atrial arrhythmias under certain pathological conditions.

A finite element model to identify electrode influence on current distribution in the skin.

Discomfort experienced during surface functional electrical stimulation (FES) is thought to be partly a result of localized high current density in the skin underneath the stimulating electrode. This article describes a finite element (FE) model to predict skin current density distribution in the region of the electrode during stimulation and its application to the identification of electrode properties that may act to reduce sensation. The FE model results show that the peak current density was located in an area immediately under the stratum corneum, adjacent to a sweat duct. A simulation of surface FES via a high-resistivity electrode showed a reduction in this peak current density, when compared to that with a low-resistivity electrode.

The role of coronary sinus musculature on electrical conduction between left atrium and right atrium in isolated canine heart / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate electrophysiological characteristics of the coronary sinus musculature and explore its role on electrical conduction between left atrium and right atrium in isolated canine heart.</p><p><b>METHOD</b>The electrical connections between coronary sinus, left atrium and right atrium were detected by programmed stimulation delivered at coronary sinus ostium, distal coronary sinus and lateral wall of left atrium in a Langendorff model of canine.</p><p><b>RESULTS</b>During stimulation delivered at coronary sinus ostium and distal coronary sinus, posterior wall of left atrium was firstly activated by electronic signal through coronary sinus musculature, the conduct time of coronary sinus ostium stimulation and distal coronary sinus stimulation were (44 +/- 21) ms and (41 +/- 15) ms, respectively. During stimulation delivered at lateral wall of left atrium, electronic signal was firstly observed in coronary sinus. During premature stimulation, conduction blockade of coronary sinus to left atrium was evidenced in parts of hearts, but electronic conduction of left atrium to right atrium remained stable. The ERP at the different stimulation sites of coronary sinus ostium and distal coronary sinus, posterior wall of left atrium were (122 +/- 19) ms, (114 +/- 12) ms (n = 3) and (107 +/- 17) ms (all P > 0.05).</p><p><b>CONCLUSION</b>A conduction way connecting left and right atria exists in coronary sinus which might play an important role on inducing and maintaining atrial arrhythmias under certain pathological conditions.</p>