The Correlation of Inflammation, Oxidative Stress, and Hippocampal Perfusion in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) is closely related to abnormal cerebral blood flow. Inflammation and oxidative stress have always been important factors in the pathophysiology of AF. It remains unknown whether inflammation and oxidative stress are correlated to hippocampal perfusion in patients with AF.Sixty-three patients with AF with normal hippocampal blood perfusion (NHBP) were compared to 71 patients with AF with abnormal hippocampal blood perfusion (AHBP) using a case-control study design. The serum levels of inflammation and oxidative stress were measured. The hippocampal perfusion was detected. (1) The serum levels of high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and oxidized low-density lipoprotein (ox-LDL) were statistically higher in the AHBP group than in the NHBP group. In the AHBP subgroup analysis, the serum levels of hs-CRP and IL-6 were statistically higher in patients with persistent AF than those with paroxysmal AF. (2) The relative cerebral blood volume (rCBV), mean transit time (MTT), and the time-to-peak (TTP) were statistically higher in the AHBP group than in the NHBP group. Moreover, cerebral blood flow (rCBF) was statistically lower in the AHBP group than in the NHBP group. (3) relative cerebral blood volume (rCBV), rCBF, MTT, and TTP were passively associated with serum hs-CRP and IL-6; rCBV, rCBF, and MTT were positively associated with ox-LDL. The serum levels of hs-CRP, IL-6, and ox-LDL were associated with AHBP in patients with AF after multivariate logistic regression analysis.Oxidative stress and inflammatory biomarkers were increased in patients with AF with AHBP, in which the serum levels of hs-CRP and IL-6 in the persistent AF group were statistically higher than those in the paroxysmal AF group. The serum levels of hs-CRP, IL-6, and ox-LDL were associated with AHBP in patients with AF.

Enhancing wheat regeneration and genetic transformation through overexpression of TaLAX1.

In the realm of genetically transformed crops, the process of plant regeneration holds utmost significance. However, the low regeneration efficiency of several wheat varieties currently restricts the use of genetic transformation for gene functional analysis and improved crop production. This research explores overexpression of TaLAX PANICLE1 (TaLAX1), which markedly enhances regeneration efficiency, thereby boosting genetic transformation and genome editing in wheat. Particularly noteworthy is the substantial increase in regeneration efficiency of common wheat varieties previously regarded as recalcitrant to genetic transformation. Our study shows that increased expression of TaGROWTH-REGULATING FACTOR (TaGRF) genes, alongside that of their co-factor, TaGRF-INTERACTING FACTOR 1 (TaGIF1), enhances cytokinin accumulation and auxin response, which may play pivotal roles in the improved regeneration and transformation of TaLAX1-overexpressing wheat plants. Overexpression of TaLAX1 homologs also significantly increases the regeneration efficiency of maize and soybean, suggesting that both monocot and dicot crops can benefit from this enhancement. Our findings shed light on a gene that enhances wheat genetic transformation and elucidate molecular mechanisms that potentially underlie wheat regeneration.

Solvent Effects on the 1 H-NMR Chemical Shifts of Imidazolium-Based Ionic Liquids.

The 1 H nuclear magnetic resonance (1 H-NMR) spectrum is a useful tool for characterizing the hydrogen bonding (H-bonding) interactions in ionic liquids (ILs). As the main hydrogen bond (H-bond) donor of imidazolium-based ILs, the chemical shift (δH2 ) of the proton in the 2-position of the imidazolium ring (H2) exhibits significant and complex solvents, concentrations and anions dependence. In the present work, based on the dielectric constants (ϵ) and Kamlet-Taft (KT) parameters of solvents, we identified that the δH2 are dominated by the solvents polarity and the competitive H-bonding interactions between cations and anions or solvents. Besides, the solvents effects on δH2 are understood by the structure of ILs in solvents: 1) In diluted solutions of inoizable solvents, ILs exist as free ions and the cations will form H-bond with solvents, resulting in δH2 being independent with anions but positively correlated with ßS . 2) In diluted solutions of non-ionzable solvents, ILs exist as contact ion-pairs (CIPs) and H2 will form H-bond with anions. Since non-ionizable solvents hardly influence the H-bonding interactions between H2 and anions, the δH2 are not related to ßS but positively correlated with ßIL .

Omnidirectional light absorption enhancement of perovskite solar cells by an antireflection film with holographic lithography microstructures.

We report an omnidirectional light absorption enhancement of a perovskite solar cell (PSC) using antireflection (AR) film with soft imprinted microstructures from master molds via holographic lithography technology, which has high throughput and repeatability. The PSC's omnidirectional power conversion efficiency (PCE) enhancement is achieved by reducing Fresnel surface reflections and enhancing the optical path length. The maximum PCE of PSCs with AR film is up to 20.27%, corresponding to an absolute increase of 0.93% compared to 19.34% of control devices. Significantly, the enhancements of PCE increase with incident angle enlargement, which attributes to more effective Fresnel surface reflection suppression. Moreover, AR films exhibit water and dust repellent properties due to hydrophobicity, which is beneficial for PSC's long-term stability and light harvesting.

Impulse-dependent extracellular resting dopamine concentration in rat striatum in vivo.

The ambient resting dopamine (DA) concentration in brain regulates cognition and motivation. Despite its importance, resting DA level in vivo remains elusive. Here, by high-frequency stimulation of the medial forebrain bundle and immediately following the stimulus-induced DA overflow, we recorded a DA "undershoot" which is a temporal reduction of DA concentration to a level below the baseline. Based on the DA undershoot, we predicted a resting DA concentration of ∼73nM in rat striatum in vivo. Simulation studies suggested that removing basal DA by DAT during the post-stimulation inhibition of tonic DA release caused the DA undershoot, and the resting concentration of DA modulated the kinetics of the evoked DA transient. The DA undershoot was eliminated by either blocking D2 receptors with haloperidol or blocking the DA transporter (DAT) with cocaine. Therefore, the impulse-dependent resting DA concentration is in the tens of nanomolar range and is modulated by the presynaptic D2 receptors and the DAT in vivo.

Nicotine dynamically modulates dopamine clearance in rat striatum in vivo.

Nicotine binds to nicotinic acetylcholine receptors on dopaminergic terminals to evoke dopamine (DA) release. The clearance of released DA occurs rapidly through reuptake into nerve terminals through the DA transporter (DAT). However, whether nicotine modulates DAT function in vivo is still not well understood. In the present study, we determined the effect of nicotine on DA clearance using in vivo amperometric recording in the striatum of urethane-anesthetized rats. Stable DA release was evoked by electrical stimulation of the medial forebrain bundle (MFB). Subsequently, nicotine or saline was administered with MFB stimulation at 10-min intervals for 60 min. Kinetic analysis revealed that nicotine decreased the amplitude of DA overflow and the maximal DA clearance rate (V(max)) in response to stimulation of 96 pulses at 80 Hz. Surprisingly, nicotine enhanced the maximal DA clearance rate (V(max)) by stimulation of 768 pulses at 80 Hz. Furthermore, we found that this paradoxical effect of nicotine on V(max) depended on the stimulation pattern. These results suggest that nicotine may exert its addictive role by dynamically modulating DAT function in vivo.

Role of vesicle pools in action potential pattern-dependent dopamine overflow in rat striatum in vivo.

Action potential (AP) patterns and dopamine (DA) release are known to correlate with rewarding behaviors, but how codes of AP bursts translate into DA release in vivo remains elusive. Here, a given AP pattern was defined by four codes, termed total AP number, frequency, number of AP bursts, and interburst time [N, f, b, i].. The 'burst effect' was calculated by the ratio (γ) of DA overflow by multiple bursts to that of a single burst when total AP number was fixed. By stimulating the medial forebrain bundle using AP codes at either physiological (20 Hz) or supraphysiological (80 Hz) frequencies, we found that DA was released from two kinetically distinct vesicle pools, the fast-releasable pool (FRP) and prolonged-releasable pool (PRP), in striatal dopaminergic terminals in vivo. We examined the effects of vesicle pools on AP-pattern dependent DA overflow and found, with given 'burst codes' [b=8, i=0.5 s], a large total AP number [N = 768, f = 80 Hz] produced a facilitating burst-effect (γ[b8/b1] = 126 ± 3%), while a small total AP number [N=96, 80 Hz] triggered a depressing-burst-effect (γ[b8/b1] = 29 ± 4%). Furthermore, we found that the PRP (but not the FRP) predominantly contributed to the facilitating-burst-effect and the FRP played an important role in the depressing-burst effect. Thus, our results suggest that striatal DA release captures pre-synaptic AP pattern information through different releasable pools.

Hypocretin-1 potentiates NMDA receptor-mediated somatodendritic secretion from locus ceruleus neurons.

Our previous observations showed that several stimuli, including high-K(+) solution, glutamate, and voltage pulses, induce somatic noradrenaline (NA) secretion from locus ceruleus (LC) neurons. Hypocretin (orexin), a hypothalamic peptide critical for normal wakefulness, has been shown to evoke NA release from the axon terminals of LC neurons. Here, we used amperometry to test the effect of hypocretin-1 (HCRT) on NMDA receptor-mediated somatodendritic release in LC neurons. Either HCRT or NMDA applied alone dose-dependently induced somatodendritic secretion. Bath application of HCRT notably potentiated NMDA receptor-mediated somatodendritic NA release. This potentiation was blocked by SB 334867, a selective HCRT receptor (Hcrtr 1) antagonist, or bisindolylmaleimide, a specific protein kinase C (PKC) inhibitor, indicating the involvement of Hcrtr 1 and PKC. Consistent with this, phorbol 12-myristate 13-acetate, a PKC activator, mimicked the HCRT-induced potentiation. Furthermore, HCRT enhanced NMDA-induced intracellular Ca(2+) elevation via activation of Hcrtr 1 and PKC, which may contribute to HCRT-potentiated somatodendritic secretion. These results suggest that HCRT modulates LC activity not only by regulating noradrenergic input to its targets, but also by affecting noradrenergic communication in the soma and dendrites.

IL-1beta inhibits IK and increases [Ca2+]i in the carotid body glomus cells and increases carotid sinus nerve firings in the rat.

Increasing evidence indicates that there exists a reciprocal communication between the immune system and the brain. Interleukin 1beta (IL-1beta), a proinflammatory cytokine produced during immune challenge, is believed to be one of the mediators of immune-to-brain communication, but how it gets into the brain is unknown because of its large molecular weight and difficulty in crossing the blood-brain barrier. Our previous work has demonstrated that IL-1 receptor type I is strongly expressed in the glomus cells of rat carotid body (CB), a well characterized polymodal chemoreceptive organ which serves not only for the detection of hypoxia, hypercapnia and acidity, but also for low temperature and blood glucose. The present study was designed to test whether IL-1beta could stimulate the CB glomus cells and alter the discharge properties in the carotid sinus nerve, the afferent nerve innervating the organ. The results from whole-cell patch-clamp recordings and calcium imaging showed that extracellular application of IL-1beta significantly decreased the outward potassium current and triggered a transient rise in [Ca(2+)](i) in the cultured glomus cells of rat CB. Furthermore, by using extracellular recordings and pharmacological intervention, it was found that IL-1beta stimulation of the CB in the anaesthetized rat in vivo significantly increased the discharge rate in the carotid sinus nerve, most probably mediated by ATP release. This experiment provides evidence that the CB responds to cytokine stimulation and proposes the possibility that the CB might play a role in immune-to-brain communication.

[A comparative study of various diagnostic procedures in macular edema].

OBJECTIVE: To compare the results for diagnosis of macular edema between Heidelberg retina tomography (HRT-II macular edema module) and optical coherence tomography (OCT). METHODS: Two hundred and twelve eyes of 106 macular edema patients were diagnosed with fundus fluorescein angiography (FFA). HRT-II was used to obtain Edema Index and OCT was used to measure the retina thickness in the fovea. The results were compared with FFA. RESULTS: As FFA for gold standard, we compared with other diagnosis method. With regard to the diagnosis of macular edema by OCT, the Kappa value was 0.553, the odds ratio (OR) was 8.519. The Kappa value of HRT-II was 0.403 and OR was 3.210. In two groups of patients with and without macular edema, which were diagnosed by FFA, the difference of Macular edema Index P assayed by HRT-II between these two groups was significant (P = 0.00); while the difference of fovea retina thickness P assayed by OCT between these two groups was significant, too (P = 0.00). The best critical value of E was 2.00 and the ROC curve's area was 0.673 in the detection of macular edema by HRT-II. The best critical value of retina thickness for the diagnosis of macular edema was 170 microm and the ROC curve's area was 0.774 in the detection of macular edema by OCT. CONCLUSIONS: In regard to the diagnosis of macular edema, the sensitivity of HRT-II is better than that from OCT, with a lower false-negative result. However, HRT-II has a relatively low specialty with a higher false- positive result. As for the localization of macular edema, HRT-II has its advantage. Compared with FFA, the consistence of OCT for the diagnosis of macular edema is better than that of HRT-II. We can conclude from the OR value that OCT has greater influence than HRT-II in the diagnosis of macular edema. In addition, as for the diagnosis and different diagnosis, the clinical value of OCT is higher than that of HRT-II. Combination of these two different diagnostic methods might provide an accurate quantitative analysis of macular edema.

Ca2+ sparks and Ca2+ glows in superior cervical ganglion neurons.

AIM: Ca2+ release from the endoplasmic reticulum (ER) is an integral component of neuronal Ca2+ signaling. The present study is to investigate properties of local Ca2+ release events in superior cervical ganglion (SCG) neurons. METHODS: Primary cultured SCG neurons were prepared from neonatal rats (P3-P7). Low concentration of caffeine was used to induce Ca2+ release from the ER Ca2+ store, and intracellular Ca2+ was recorded by high-resolution line scan confocal imaging and the Ca2+ indicator Fluo-4. RESULTS: Two populations of local Ca2+ release events with distinct temporal characteristics were evoked by 1.5 mmol/L caffeine near the surface membrane in the soma and the neurites of SCG neurons. Brief events similar to classic Ca2+ sparks lasted a few hundreds of milliseconds, whereas long-lasting events displayed duration up to tens of seconds. Typical somatic and neurite sparks were of 0.3- and 0.52-fold increase in local Fluo-4 fluorescence, respectively. Typical Ca2+ glows were brighter (deltaF/F0 approximately 0.6), but were highly confined in space. The half maximum of full duration of neurite sparks was much longer than those in the soma (685 vs 381 ms). CONCLUSION: Co-existence of Ca2+ sparks and Ca2+ glows in SCG neurons indicates distinctive local regulation of Ca2+ release kinetics. The local Ca2+ signals of variable, site-specific temporal length may bear important implications in encoding a 'memory' of the trigger signal.

[Analysis on the aetiology of influenza in children in Tianjin].

OBJECTIVE: To analyse the pathogen of child patients with influenza in Tianjin area. METHODS: The influenza virus isolation was performed by MDCK cells and embryonated eggs. The identification of the isolates was carried out with hemagglutination (HA) and hemagglutination inhibition (HI) tests. RESULTS: Two hundred and thirty-eight throat swab specimens from children with influenza-like illness were collected in Tianjin area from Oct. 2001 to Mar. 2002 and 64 strains (26.9%) of influenza virus were isolated. Data showed that there were 42 strains (65.6%) of A (H3N2) subtype, 13 strains (20.3%) of A (H1N1) subtype and 9 strains (14.1%) of B type in these positive isolates. All the isolated viruses grew very well in MDCK cells and hemagglutinated with human "O" red blood cells, and most (62/64 strains) of them were able to multiply in embryonated chick eggs. However, there were only 3 isolates with HA positive in inoculating embryonated eggs with the specimens. Meanwhile, it was revealed that out of 55 strains of A type viruses, 53 strains (96.4%) were from O to D phase, 2 strain of A (H3N2) were D phase characters and all B type isolated viruses being D phase properties. CONCLUSION: There were three endemic types of influenza viruses-A (H3N2), A (H1N1) and B type in Tianjin area, with A, the main type.