Search

The differences in the chemical composition of Morus nigra (M. nigra) extracts from four different extraction methods, ultrasound-assisted extraction with pure water (WU), pure water decoction extraction (WD), ultrasonic-assisted extraction with formic acid water (FAU), and pure water heat reflux extraction (WHR), were identified using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) technology.

Titanium isotopic compositions have been used to elucidate geochemical and cosmochemical processes. Until now, no Ti isotopic reference material has been reported worldwide, which imposes restriction upon analytical method establishment and laboratory quality control. In this paper, a newly prepared Ti isotopic standard solution is introduced. Ti element standard solution offered by the Alfa Company from U.S.A. was chosen as the starting material, based on the comparison of Ti isotopic measurement results of 3 commercially available Ti element standard solutions. The preparation of the new standard solution was strictly followed using the stipulation on reference material of the metrological technical standard of state, including homogeneity and stability tests, and certification analyses. 150 bottles of the solution were prepared, among which 15 bottles were selected randomly for homogeneity test and no detectable heterogeneity was found by F test. The stability inspection through 30 months indicated no significant changes on δTi values. The certified values and uncertainty at the 95% confidence level were shown to be: δ50Ti=-2.23‰±0.14‰, δ49Ti=-1.67‰±0.09‰,δ48Ti=-1.13‰±0.06‰ andδ47Ti=-0.57‰±0.05‰. This newly certified standard solution can be used to calibrate instruments and verify analytical quality in Ti isotope measurements, and compare inter-laboratory data.

Abstract Loss of a sensory input causes the hypersensitivity in other modalities. In addition to cross-modal plasticity, the sensory cortices without receiving inputs undergo the plastic changes. It is not clear how the different types of neurons and synapses in the sensory cortex coordinately change after input deficits in order to prevent loss of their functions and to be used for other modalities. We studied this subject in the barrel cortices from whiskers-trimmed mice vs. controls. After whisker trimming for a week, the intrinsic properties of pyramidal neurons and the transmission of excitatory synapses were upregulated in the barrel cortex, but inhibitory neurons and GABAergic synapses were downregulated. The morphological analyses indicated that the number of processes and spines in pyramidal neurons increased, whereas the processes of GABAergic neurons decreased in the barrel cortex. The upregulation of excitatory neurons and the downregulation of inhibitory neurons boost the activity of network neurons in the barrel cortex to be high levels, which prevent the loss of their functions and enhances their sensitivity to sensory inputs. These changes may prepare for attracting the innervations from sensory cortices and/or peripheral nerves for other modalities during cross-modal plasticity.

Abstract Background Gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine tumors accounting for 65–75% of neuroendocrine neoplasms (NENs). Given the fact that there are few studies on GEP-NENs among Chinese patients, we performed a retrospective study in South China. Methods Totally 178 patients with GEP-NENs treated at the First Affiliated Hospital of Sun Yat-sen University between January 1995 and May 2012 were analyzed retrospectively. Results Pancreas was found the most common site of involvement (34.8%). 149 patients (83.7%) presented as non-functional tumors with non-specific symptoms such as abdominal pain (33.7%); carcinoid syndrome was not found in this study. Several methods are useful for localization of GEP-NENs, yielding varied detection rates from 77.8% to 98.7%. Positive rates of chromogranin A (CgA) and synaptophysin (Syn) immunhistochemically were 69.1% and 90.2%, respectively. 87 patients (51.5%) had G1 tumors, 31(18.3%) G2 tumors and 51 (30.2%) G3 tumors. Neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) were 69.8%, 27.2% and 3.0%, respectively. 28.1% of patients presented with distant disease. Surgery was performed in 152 (85.4%) patients, and overall 5-year survival rate was 54.5%. Functionality, G1 grading and NET classification were associated with favorable prognosis in univariate analysis. Distant metastasis contributed to unfavorable prognosis of these tumors. Conclusions Nonfunctional tumors with non-specific symptoms account for the majority of GEP-NENs. Diagnosis depends on pathological classification. Multidisciplinary treatments could help improve the outcome.

Abstract Action potentials at the neurons and graded signals at the synapses are primary codes in the brain. In terms of their functional interaction, the studies were focused on the influence of presynaptic spike patterns on synaptic activities. How the synapse dynamics quantitatively regulates the encoding of postsynaptic digital spikes remains unclear. We investigated this question at unitary glutamatergic synapses on cortical GABAergic neurons, especially the quantitative influences of release probability on synapse dynamics and neuronal encoding. Glutamate release probability and synaptic strength are proportionally upregulated by presynaptic sequential spikes. The upregulation of release probability and the efficiency of probability-driven synaptic facilitation are strengthened by elevating presynaptic spike frequency and Ca2+. The upregulation of release probability improves spike capacity and timing precision at postsynaptic neuron. These results suggest that the upregulation of presynaptic glutamate release facilitates a conversion of synaptic analogue signals into digital spikes in postsynaptic neurons, i.e., a functional compatibility between presynaptic and postsynaptic partners.

Abstract Anxiety is a prevalent psychological disorder, in which the atypical expression of certain genes and the abnormality of amygdala are involved. Intermediate processes between genetic defects and anxiety, pathophysiological characteristics of neural network, remain unclear. Using behavioral task, two-photon cellular imaging and electrophysiology, we studied the characteristics of neural networks in basolateral amygdala and the influences of metabotropic glutamate receptor (mGluR) on their dynamics in DBA/2 mice showing anxiety-related genetic defects. Amygdala neurons in DBA/2 high anxiety mice express asynchronous activity and diverse excitability, and their GABAergic synapses demonstrate weak transmission, compared to those in low anxiety FVB/N mice. mGluR1,5 activation improves the anxiety-like behaviors of DBA/2 mice, synchronizes the activity of amygdala neurons and strengthens the transmission of GABAergic synapses. The activity asynchrony of amygdala neurons and the weakness of GABA synaptic transmission are associated with anxiety-like behavior.

Abstract The aim of this study was to investigate the hepatoprotective effect of Matrine salvianolic acid B salt on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats. Salvianolic acid B and Matrine has long been used to treat liver fibrosis. Matrine salvianolic acid B salt is a new compound containing Salvianolic acid B and Matrine. Hepatic fibrosis induced by CCl4 was studied in animal models using Wistar rats. Organ coefficient, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), hexadecenoic acid (HA), laminin (LN), hydroxyproline (Hyp), and glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD) in liver tissues were measured, respectively. Histopathological changes in the livers were studied by hematoxylin-eosin (H&E) staining and Masson Trichrome (MT) examination. The expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) was observed by immunohistochemical analysis. A significant reduction in serum levels of AST, ALT, HA, LN and Hyp was observed in the Matrine salvianolic acid B salt treated groups, suggesting that the salt had hepatoprotective effects. The depletion of GSH and SOD, as well as MDA accumulation in liver tissues was suppressed by Matrine salvianolic acid B salt too. The expression of TGF-β1 and α-SMA measured by immunohistology was significantly reduced by Matrine salvianolic acid B salt in a dose-dependent manner. Matrine salvianolic acid B salt treatment attenuated the necro-inflammation and fibrogenesis induced by CCl4 injection, and thus it is promising as a therapeutic anti-fibrotic agent against hepatic fibrosis.

Abstract Background Nerve cells program the brain codes to manage well-organized cognitions and behaviors. It remains unclear how a population of neurons and astrocytes work coordinately to encode their spatial and temporal activity patterns in response to frequency and intensity signals from sensory inputs. Results With two-photon imaging and electrophysiology to record cellular functions in the barrel cortex in vivo, we analyzed the activity patterns of neurons and astrocytes in response to whisker stimuli with increasing frequency, an environmental stimulus pattern that rodents experience in the accelerated motion. Compared to the resting state, whisker stimulation caused barrel neurons and astrocytes to be activated more synchronously. An increased stimulus frequency up-regulated the activity strength of neurons and astrocytes as well as coordinated their interaction. The coordination among the barrel neurons and astrocytes was fulfilled by increasing their functional connections. Conclusions Our study reveals that the nerve cells in the barrel cortex encode frequency messages in whisker tactile inputs through setting their activity coordination.

Abstract The neurons in the brain produce sequential spikes as the digital codes whose various patterns manage well-organized cognitions and behaviors. A source for the physiologically integrated synaptic signals to initiate digital spikes remains unknown, which we studied at pyramidal neurons of cortical slices. In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels. The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin. Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.

Two novel di-tert-butyl-type structures (1-2), and five known compounds (3-7) were isolated from the chemical investigations of a saline lake actinomycete, Streptomyces sp. XZB42. The structures of the new compounds were elucidated by extensive NMR spectroscopic analysis, HRESIMS data, GIAO (gauge-including atomic orbitals) NMR and specific optical rotation (SOR). [ABSTRACT FROM AUTHOR]