OBJECTIVETo study the effects of companion fungus on hyphal growth and polysaccharide content of Polyporus umbellata.

METHODThe mycelia and culture filtrate of companion fungus were added to the liquid culture system, and the biomass yield and polysaccharide of P. umbellatus were measured.

RESULTMycelia and appropriate unsterilized culture filtrate of companion fungus could enhance the biomass yield of P. umbellatus significantly, while sterilized culture filtrate of companion fungus could decrease the biomass yield of P. umbellatus significantly. Either mycelia or culture filtrate of companion fungus could increase the intracellular polysaccharide content of P. umbellatus significantly. At the same time, they also could decrease extracellular polysaccharide content of P. umbellatus evidently.

CONCLUSIONThe mycelia and culture filtrate of companion fungus could be used in further fermentation of P. umbellatus.

Biomass ; Extracellular Space ; metabolism ; Hyphae ; growth & development ; Intracellular Space ; metabolism ; Polyporus ; cytology ; growth & development ; metabolism ; Polysaccharides ; metabolism ; Symbiosis

Volume transmission (VT) is a widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with VT signals moving from source to target cells via energy gradients leading to diffusion and convection (flow). The VT channels are diffuse forming a plexus in the extracellular space, while in wiring transmission (WT) the channels (axons, terminals) are private. The speed is slow (seconds-minutes) in VT while rapid in the millisecond range in WT. The extracellular space is the substrate for VT, which is modulated by the extracellular matrix. Extrasynaptic VT is linked to synaptic transmission and likely often takes place due to incomplete diffusion barriers with the synaptic transmitter reaching extrasynaptic domains of the pre-and post-synaptic membrane of the synapse, the astroglia, and even adjacent synapses. Indications exist for the existence of striatal D2-like receptor-mediated extrasynaptic form of dopamine (DA) VT at the local circuit level in vivo in the human striatum. Synaptic glutamate via extrasynaptic VT can act on extrasynaptic metabotropic glutamate receptors located on the astroglia leading to Ca(2+) mediated astrocytic glutamate release into the extracellular space (ECS). Long distance peptide VT and CSF VT is the major long distance VT with distances more than 1 mm and flow in the CSF. Indications for long distance VT of beta-endorphin and oxytocin are obtained. We propose that monogamy in the female prairie vole may take place through an increase in oxytocin VT, especially in nucleus accumbens. Release of extracellular vesicles containing receptors, proteins, RNAs and mtDNA from cellular networks in the central nervous system (CNS) into the ECF and CSF may be a fundamental communication in the CNS. It represents a special form of volume transmission, the Roamer subtype of VT. It may greatly contribute to dynamic events of synaptic plasticity but also to spread of pathological proteins in protein conformational disorders. VT also occurs in the peripheral nervous system and associated cells. Short and long distance VT may take place in meridian channels via diffusion and flow in the interstitial fluid. Acupuncture can produce VT signals by releasing transmitters and modulators from nerve terminals and mast cells.
Animals ; Cell Communication ; Central Nervous System ; cytology ; Extracellular Space ; metabolism ; Humans ; Synapses ; metabolism

OBJECTIVETo investigate the changes in the distribution and chemical states of the hepatic intra- and extra-cellular sodium ion in the rats with severe burns, so as to provide guidance for fluid resuscitation at early postburn stage.

METHODSNineteen adult male Sprague-Dawley (SD) rats were employed in the study and were randomly divided into control (n = 12) and burn (n = 7) groups. The changes in the longitudinal (T1) and transverse (T2) relaxation times of hepatic intra-cellular and extra-cellular sodium in the two groups were studied with 23Na NMR spectroscopy and a shift reagent.

RESULTSAfter infusion of the shift reagent,the extra-cellular sodium content in rat liver decreased by 17%, with obvious increase in fast T2 component (P < 0.01), indicating an increase in the fraction of Na+ binding sites in the extra-cellular space. The characteristics of relaxation of intra-cellular sodium remained unchanged despite a 57% increment in intra-cellular sodium content.

CONCLUSIONThe deficiency of sodium as a permeable molecule might be related to the postburn movement of hypertonic sodium from extra-cellular to intra-cellular space. The results indicated that it is reasonable to administer high concentration of sodium in fluid resuscitation during the first 24 postburn hours.

Animals ; Burns ; metabolism ; physiopathology ; Cations ; metabolism ; Extracellular Space ; metabolism ; Hepatocytes ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Sodium ; metabolism

The synthetic characteristic of extracellular polysaccharide (EPS) of Ganoderma lucidum performed in batch fermentation was studied. The result showed that the production EPS was partially growth-associated. The cell dry weight (CDW) and EPS reached 15.56 g x L(-1), 3.02 g x L(-1) respectively. The yield of EPS to cell dry weight ( Y(p/x)) was 0.19. Based on the test result of batch fermentation, a kinetic model was proposed by using the Logistic equation for cell growth, the Luedeking Piret equation for EPS production and the Luedeking-piret-like equation for consumption of glucose as substrate. The calculated results of models were compared satisfactorily with experimental data under various glucose concentrations, the average relative error was no more than 5%. The kinetic model had practically guiding producing PES in fermentation of Ganoderma lucidum.
Culture Techniques ; methods ; Extracellular Space ; metabolism ; Fermentation ; Kinetics ; Models, Biological ; Polysaccharides ; biosynthesis ; Reishi ; chemistry ; growth & development

A new class of RNA regulatory genes known as microRNAs (miRNAs) has been found to introduce a whole new layer of gene regulation in eukaryotes. The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly, but are also detectable outside cells, including in various body fluids (e.g. serum, plasma, saliva, urine and milk). This phenomenon raises questions about the biological function of such extracellular miRNAs. Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles (e.g. exosomes, shedding vesicles and apoptotic bodies) or packaged with RNA-binding proteins (e.g. high-density lipoprotein, Argonaute 2 and nucleophosmin 1). These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes. Furthermore, secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease. Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases. In this review, we summarize what is known about the mechanism of miRNA secretion. In addition, we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs. We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.
Animals ; Diagnosis ; Extracellular Space ; genetics ; Gene Transfer, Horizontal ; Humans ; MicroRNAs ; genetics ; metabolism ; Therapeutics

Extracellular ATP (exATP) has been known to be a critical ligand regulating skeletal muscle differentiation and contractibility. ExATP synthesis was greatly increased with the high level of adenylate kinase 1 (AK1) and ATP synthase beta during C2C12 myogenesis. The exATP synthesis was abolished by the knock-down of AK1 but not by that of ATP synthase beta in C2C12 myotubes, suggesting that AK1 is required for exATP synthesis in myotubes. However, membrane-bound AK1beta was not involved in exATP synthesis because its expression level was decreased during myogenesis in spite of its localization in the lipid rafts that contain various kinds of receptors and mediate cell signal transduction, cell migration, and differentiation. Interestingly, cytoplasmic AK1 was secreted from C2C12 myotubes but not from C2C12 myoblasts. Taken together all these data, we can conclude that AK1 secretion is required for the exATP generation in myotubes.
Adenosine Triphosphate/*biosynthesis ; Adenylate Kinase/*metabolism ; Animals ; Cell Line ; Extracellular Space/metabolism ; Isoenzymes/*metabolism ; Mice ; Muscles/cytology/*metabolism

In order to explore the reason why hypokalemia could increase the vulnerable window (VW) for unidirectional conduction block in Long QT Syndromes (LQTS), we observed the effect of hypokalemia on the spatial gradients of Na channel conductance (G(Na)) and gating factors by using the LR91 1-dimensional heterogeneous virtual cardiac ventricular tissue model quatitively. The computer simulation experiments were divided into two groups, namely control and LQTS groups. The action potential was elicited after the basic stimulus S1 (-70 microA/microF, 1.5 ms) was given 10 times with basic cycle length (BCL) 500, 1000 and 2000 ms. To test the VW in unit of time (VWtime), the S1-S2 programmed stimuli were used with shortening S1S2 interval at the decrement of 1 ms. At the same time, the spatial gradients of Na channel conductance (G(Na)) and gating factors, m, h, j, were investigated. The APD and ionic channel currents were also detected under the conditions of normal and lower concentration of K+ outside of cell. We found that hypokalemia, LQTS and slow pacing rate enhanced the spatial gradient of G(Na) by increasing the spatial gradient of inactive gating factors h x j. The results also showed that hypokalemia deduced the peak values of I(K) and I(K1), which prolonged the action potential duration and enlarged the repolarization dispersion in this 1-D tissue cable model. Possibly these are the important factors to cause the spatial gradient of h x j and G(Na). enlargement. These changes increase the incidence of unidirectional conduction block of VW, and are vital reasons to increase the possibility of ventricular arrhythmia generation.
Computer Simulation ; Extracellular Space ; metabolism ; Humans ; Hypokalemia ; metabolism ; Long QT Syndrome ; etiology ; metabolism ; physiopathology ; Models, Biological ; Myocardium ; metabolism ; Sodium Channels ; metabolism

Norepinephrine (NE)-containing locus ceruleus (LC) has been known to participate in the regulation of the sleep-wake cycle according to the differential firing rate. The aim of this study was to know the change of extracellular NE level in the rat amygdala, which are reciprocally connected with LC, during sleep-wake-fulness. Extracellular NE levels in the rat amygdala were inrestigated during different stages of the sleep-waking cycle using in vivo microdialysis and polygraphic recording. Dialysates were collected every 5 min and correlated with the results of polygraphic recording. The content of NE was measured by high-performance liquid chromatography with electrochemical detection. NE level was the highest in active waking (AW) and, when compared to AW, NE level was progressively lower in quiet waking (QW; 86%), quiet sleep (QS; 72%), and active sleep (AS or REM sleep; 61%). This result suggests that the rat amygdala also participates in the regulation of the sleep-wake cycle according to the differential NE release.
Amygdala/*metabolism ; Animals ; Arousal/*physiology ; Electroencephalography ; Extracellular Space/metabolism ; Locus Coeruleus/metabolism ; Male ; Microdialysis ; Norepinephrine/*metabolism ; Rats ; Rats, Sprague-Dawley ; Sleep/*physiology

High-mobility group box 1 (HMGB1) protein has been demonstrated to play an important role in chronic inflammatory diseases including rheumatoid arthritis, and systemic lupus erythematosus. This study investigated the association between extracellular HMGB1 expression and disease activity, and clinical features of Behcet's disease (BD). Extracellular HMGB1 expression in the sera of 42 BD patients was measured and was compared to that of 22 age- and sex-matched healthy controls. HMGB1 expression was significantly increased in BD patients compared to healthy controls (78.70 +/- 20.22 vs 10.79 +/- 1.90 ng/mL, P = 0.002). In addition, HMGB1 expression was significantly elevated in BD patients with intestinal involvement compared to those without (179.61 +/- 67.95 vs 61.89 +/- 19.81 ng/mL, P = 0.04). No significant association was observed between HMGB1 concentration and other clinical manifestations, or disease activity. It is suggested that extracellular HMGB1 may play an important role in the pathogenesis of BD.
Adult ; Aged ; Behcet Syndrome/genetics/*metabolism/pathology ; Extracellular Space/metabolism ; Female ; HMGB1 Protein/genetics/*metabolism ; Humans ; Inflammation ; Intestinal Diseases/blood/genetics ; Male ; Middle Aged ; Young Adult

Uridine 5'-triphosphate (UTP) is stored in the granules of cells such as platelets and is released into the extracellular space upon cell stimulation. Extracellular UTP is known to influence many biological processes. We investigated the hemodynamic effects of UTP on the perfused rat liver and characterized its receptors. Liver perfusions were performed in a recirculation system under constant pressure (28 cmH2O). The perfusion flow and oxygen consumption rate were measured at 30 second intervals. UTP decreased the perfusion flow and the oxygen consumption rate, dose-dependently. UTP-induced changes were transient and disappeared in about 10 minutes. Suramin (P2-purinergic antagonist, 100 uM) and indomethacin (cyclooxygenase inhibitor, 20 uM) blocked UTP-induced hemodynamic changes significantly. The effects of UTP were also inhibited when Kupffer cells were damaged with treatment of gadolinium chloride (10 mg/kg iv). L-NAME (1 mM), a potent inhibitor of nitric oxide synthase, markedly enhanced and prolonged the contractile response of UTP in the hepatic vessel. These results suggest that UTP acts mainly on suramin-sensitive UTP receptors on the Kupffer cell through prostanoid synthesis. The nitric oxide systems in the endothelium seem to counteract the vasoconstrictile action of UTP in the hepatic circulation.
Animal ; Extracellular Space/*metabolism ; Hemodynamics ; Liver/*metabolism ; *Liver Circulation ; Perfusion ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't ; Uridine Triphosphate/*metabolism