[Effects of penehyclidine hydrochloride on Nrf2/ARE signaling pathway during endotoxin-induced acute lung injury in neonate rats].

Objective: To evaluate the effects of penehyclidine hydrochloride on the nuclear factor erythroid 2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathway during endotoxin-induced acute lung injury(ALI) in neonate rats. Methods: Forty 7-day-old Wistar rats weighing 12-18 g were randomly divided into 4 groups (n=10) using a random number table: normal saline group(NS group), acute lung injury(ALI group), penehyclidine hydrochloride group(PHC group) and penehyclidine hydrochloride+ Nrf2 siRNA plasmid group(PNS group). The ALI model was induced with intraperitoneal endotoxin (5.0 mg/kg) in groups ALI, PHC and PNS. In groups PHC and PNS, penehyclidine hydrochloride (2.0 mg/kg) was injected intraperitoneally at 1 h before ALI respectively, while the equal volume of normal saline was administered in groups NS and ALI. The animal of PNS group were inhaled adenovirus packaging of Nrf2-siRNA three times (one time a day) before modeling. At 4 h after endotoxin injection, the rats were sacrificed. The lungs were collected to determine the wet/dry(W/D) lung weight ratio. The expression of Nrf2 and heme oxygen and enzyme 1(HO-1) were determined by Western blotting, contents of tumor necrosis factor-alpha(TNF-α),interleukin10 (IL-10)were determined by enzyme-linked immunosorbent assay(ELISA). The cell apoptosis were determined by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling(TUNEL),and the apoptotic index was calculated. Results: The W/D ratio in NS, ALI, PHC and PNS groups were (4.2±0.1), (9.6±0.7), (6.5±0.6), (8.3±1.3) respectively. The apoptotic index were (3.7±0.5)%, (31.5±3.2)%, (17.6±4.2)%, (28.1±3.5)%respectively.The contents of TNF-α were (10.3±1.6), (98.5±8.5), (68.5±6.7), (89.9±8.5) pg/ml respectively. The contents of IL-10 were (7.9±0.6), (102.8±9.3), (72.5±5.8), (97.7±9.1) pg/ml respectively.The expression of Nrf2 were (23.2±7.6), (79.8±13.0), (155.5±16.7), (12.0±3.3) respectively. The expression of HO-1 were (31.7±8.6), (90.8±10.3), (147.6±22.5), (61.4±9.7) respectively. There were statistically significant differences among different groups (F=86.013, 154.897, 328.810, 374.198, 333.965, 125.274, all P<0.05). Compared with group NS, the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 increased, the expression of Nrf2 and HO-1 up-regulated in group ALI and group PHC (all P<0.05). Compared with group ALI, the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 decreased, the expression of Nrf2 and HO-1 up-regulated in group PHC (all P<0.05). Compared with group ALI, no significant differences were found in the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 in group PNS(all P>0.05), while the expression of Nrf2 and HO-1 down-regulated in group PNS (all P<0.05). Compared with group PHC, the W/D ratio,apoptotic index and the contents of TNF-α,IL-10 increased, the expression of Nrf2 and HO-1 down-regulated in group PNS (all P<0.05). Conclusion: Nrf2/ARE signaling pathway is involved in the reduction of ALI by penehyclidine hydrochloride in neonate rats.

Synergistic and simultaneous biosorption of phenanthrene and iodine from aqueous solutions by soil indigenous bacterial biomass as a low-cost biosorbent.

The removal of phenanthrene and iodine from aqueous solutions in single and binary systems by inactivated soil indigenous bacterial biomass (SIBB), as well as affecting factors, were evaluated. Sorption kinetic and isotherm studies were carried out to investigate the synergistic effects of phenanthrene and iodine. Optimal parameters for the biosorption process included a solution pH of 6.0 and biosorbent dosage of 0.75 g L-1. The ionic strength significantly decreased the biosorption of both phenanthrene and iodine in single conditions, while no obvious influences were found in the binary conditions. A pseudo-second-order model was well fitted to the kinetic biosorption data for both phenanthrene and iodine. The results showed that the presence of co-solute accelerated the biosorption processes and the pseudo-second-order biosorption rates (k 2) for phenanthrene and iodine increased from 0.005441 to 0.009825 g mg-1 min-1 and from 0.000114 to 0.000223 g mg-1 min-1, respectively. The SIBB showed strong affinity with both phenanthrene and iodine, with a partition coefficient K d (Linear model) of 6892.4 L kg-1 for phenanthrene and affinity parameter K L (Langmuir model) of 232 500 L kg-1 for iodine. The presence of co-solute illustrated a synergistic effect on the biosorption of phenanthrene and iodine due to intermolecular forces between phenanthrene and iodine, enhancing the K d of 34.7% for phenanthrene and K L of 107.0% for iodine, respectively. The results suggested that SIBB was an effective material for the simultaneous biosorption of phenanthrene and iodine from aqueous solutions.

[Effect of single lumen endobronchial tube and double lumen endobronchial tube on ventilation and lung injury in patients with esophageal cancer undergoing combined thoracoscopic and laparoscopic esophagectomy].

Objective: To investigate the effect of the single lumen endobronchial tube and the double lumen endobronchial tube on ventilation and lung injury in patients with esophageal cancer undergoing combined thoracoscopic and laparoscopic esophagectomy. Methods: Sixty patients with esophageal cancer undergoing combined thoracoscopic and laparoscopic esophagectomy were divided into single lumen endobronchial tube group (D group, n=30) and double lumen endobronchial tube group (S, n=30) according to the random number table. Blood samples were harvested at the moment of tracheal intubation (T(0)), after artificial pneumothorax (one lung ventilation) 30 min (T(1)), after artificial pneumothorax (one lung ventilation) 90 min (T(2)), artificial pneumothorax over (double lung ventilation) 30 min (T(3)) and after extubation 30 min (T(4)) for arterial blood gas analysis. Heart rate (HR), mean arterial pressure (MAP), pulse oxygen saturation (SpO(2)), oxygen tension (PaO(2)), carbon dioxide partial pressure (PaCO(2)) and airway pressure (PAW) were recorded at T(0)-T(4). The incidences of pneumonia of two groups were record at 3 days after operation. Results: There were no obvious differences in HR, MAP, SpO(2), PaO(2), PaCO(2) between two groups at T(0)-T(4) (P>0.05). Compared with T(0), the levels of HR and PaO(2) were increased remarkably at T(1)-T(3) (P<0.05), the levels of PaCO(2) were increased remarkably at T(1)-T(4) (P<0.01), and the levels of Paw were increased remarkably at T(1)-T(3) (P<0.01). Compared with S group, the levels of Paw were decreased remarkably at T(1)-T(2) (29.5±3.7 vs 21.3±2.1, P=0.001; 30.7±4.8 vs 20.3±2.3, P=0.001). There were no obvious differences in the levels of TNF-α, IL-6, IL-8 in Bronchoalveolar Lavage Fluid (BALF) between two groups at T(0) (P>0.05). Compared with T(0), the levels of TNF-α, IL-6, IL-8 in BALF were increased remarkably at T(3), T(5) (P<0.05). Compared with S group, the levels of TNF-α, IL-6, IL-8 in D group in BALF were decreased remarkably at T(3), T(5) (P<0.05). Compared with S group, the incidence of pneumonia in D group were decreased remarkably at 3 days after operation (4(13.3%) vs 11(36.7%), P=0.017). Conclusion: The ventilation effect of the single lumen endobronchial tube on lung injury for patients with esophageal cancer undergoing combined thoracoscopic and laparoscopic esophagectomy is the same as that of the double lumen endobronchial tube, however the single lumen endobronchial tube has less injury on the lung.

Large Displacement in Relaxor Ferroelectric Terpolymer Blend Derived Actuators Using Al Electrode for Braille Displays.

Poly(vinylidene fluoride) (PVDF) based polymers are attractive for applications for artificial muscles, high energy density storage devices etc. Recently these polymers have been found great potential for being used as actuators for refreshable full-page Braille displays for visually impaired people in terms of light weight, miniaturized size, and larger displacement, compared with currently used lead zirconate titanate ceramic actuators. The applied voltages of published polymer actuators, however, cannot be reduced to meet the requirements of using city power. Here, we report the polymer actuator generating quite large displacement and blocking force at a voltage close to the city power. Our embodiments also show good self-healing performance and disuse of lead-containing material, which makes the Braille device safer, more reliable and more environment-friendly.

Persistent inflammation increases GABA-induced depolarization of rat cutaneous dorsal root ganglion neurons in vitro.

Persistent inflammation is associated with a shift in spinal GABA(A) signaling from inhibition to excitation such that GABA(A)-receptor activation contributes to inflammatory hyperalgesia. We tested the hypothesis that the primary afferent is the site of the persistent inflammation-induced shift in GABA(A) signaling which is due to a Na(+)-K(+)-Cl(-)-co-transporter (NKCC1)-dependent depolarization of the GABA(A) current equilibrium potential (E(GABA)). Acutely dissociated retrogradely labeled cutaneous dorsal root ganglion (DRG) neurons from naïve and inflamed (3 days after a subcutaneous injection of complete Freund's adjuvant) adult male rats were studied with Ca(2+) imaging, western blot and gramicidin-perforated patch recording. GABA evoked a Ca(2+) transient in a subpopulation of small- to medium-diameter capsaicin-sensitive cutaneous neurons. Inflammation was associated with a significant increase in the magnitude of GABA-induced depolarization as well as the percentage of neurons in which GABA evoked a Ca(2+) transient. There was no detectable change in NKCC1 protein or phosphoprotein at the whole ganglia level. Furthermore, the increase in excitatory response was comparable in both HEPES- and HCO(3)(-)-buffered solutions, but was only associated with a depolarization of E(GABA) in HCO(3)(-)-based solution. In contrast, under both recording conditions, the excitatory response was associated with an increase in GABA(A) current density, a decrease in low threshold K(+) current density, and resting membrane potential depolarization. Our results suggest that increasing K(+) conductance in afferents innervating a site of persistent inflammation may have greater efficacy in the inhibition of inflammatory hyperalgesia than attempting to drive a hyperpolarizing shift in E(GABA).

Enrichment and solubility of trace metals associated with magnetic extracts in industrially derived contaminated soils.

Magnetic fractions (MFs) in industrially derived contaminated soils were extracted with a magnetic separation procedure. Total, soluble, and bioaccessible Cr, Cu, Pb and Zn in the MFs and non-magnetic fractions (NMFs) were analyzed using aqua regia and extraction tests, such as deionized water, toxicity characteristic leaching procedure (TCLP), and gastric juice simulation (GJST) test. Compared with the non-magnetic fractions, soil MFs were enriched with Fe, Mn, Pb, Cd, Cr, Cu, and Ni. Extraction tests indicated that soil MFs contained higher water, TCLP, and GJST-extractable Cr, Cu, Pb, and Zn concentrations than the soil NMFs. The TCLP-extractable Pb concentration in the MFs exceeded the USEPA hazardous waste criteria, suggesting that soil MFs have a potentially environmental pollution risk. Solubility of trace metals was variable in the different extraction tests, which has the order of GJST > TCLP > water. TCLP test showed Cu and Zn were more mobile than Cr and Pb while bioaccessibility of trace metal defined by GJST test showed the order of Cu ≈ Cr ≈ Zn > Pb. These findings suggested that the MFs in the industrially derived contaminated soils had higher possibility of polluting water bodies, and careful environmental impact assessment was necessary.

Mineralogy and heavy metal leachability of magnetic fractions separated from some Chinese coal fly ashes.

Magnetic fractions (MFs) in fly ashes from eight coal-burning power plants were extracted by magnetic separation procedure. Their mineralogy and potential leachability of heavy metals were analyzed using rock magnetism, X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX) and leaching procedures (toxicity characteristics leaching procedure by the United States Environmental Protection Agency, TCLP, and gastric juice simulation test, GJST). Results show that the MFs in the fly ashes range between 2.2 and 16.3wt%, and are generally composed of magnetite, hematite, quartz and mullite. Thermomagnetic analysis and SEM/EDX indicate that the main magnetic carrier magnetite is substituted with small amounts of impure ions, and its structures are featured by rough, dendritic and granular iron spherules. The MFs are found to be rich in Fe, Mn, Cr, Cu, Cd and Pb. Compared with the non-magnetic fractions (NMFs), the MFs have about 5 times higher iron, and 1.6 times higher Mn, Cr, Cu and Cd concentrations. The TCLP test shows that the TCLP-extractable Cr, Cu, and Pb concentrations in the MFs are higher than those in the NMFs, while the TCLP-extractable Cd concentration in the MFs and NMFs is below the detection limit (<0.1mg/L). The GJST-extractable Cd, Cr, Cu, and Pb concentrations in the MFs are higher those in the NMFs. No significant difference in the leachability ratio of Cr, Cu and Pb with TCLP and GJST is found in the MFs and NMFs. However, the GJST test showed that Pb has higher leachability in MFs than that in NMFs. The leachability ratio of heavy metals has an order of Cu>Cr>Pb>Cd. The heavy metals of fly ashes have a great potential to be released into the environment under acid environment.

Removal mechanism of phosphate from aqueous solution by fly ash.

This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

Inflammation-induced increase in evoked calcium transients in subpopulations of rat dorsal root ganglion neurons.

The concentration of intracellular Ca(2+) ([Ca(2+)](i)) influences neuronal properties ranging from excitability to neurotransmitter release. Persistent inflammation is associated with changes in the properties of primary afferent neurons ranging from excitability to transmitter release. The purpose of the present study was to determine whether previously described inflammation-induced changes in excitability and transmitter release are associated with changes in the regulation of [Ca(2+)](i). Acutely dissociated dorsal root ganglion (DRG) neurons harvested from adult rats 3 days following a hind-paw injection of complete Freund's adjuvant (CFA) or naïve controls, were stimulated with 30 mM K(+) (High K(+)). High K(+) evoked changes in [Ca(2+)](i) were assessed with fura-2 ratiometric microfluorimetry. Subpopulations of DRG neurons were defined by cell body diameter, isolectin B4 (IB4) binding, capsaicin (CAP) sensitivity and target of innervation (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbo-cyanine perchlorate labeling). Inflammation was associated with significant increases in resting [Ca(2+)](i) and increases in the magnitude and decreases in the decay, of the evoked increase in [Ca(2+)](i). The changes in evoked transients were larger in neurons innervating the site of inflammation. Furthermore, there were differences among subpopulations of DRG neurons with respect to changes in magnitude and/or decay of the evoked transient such that the increase in magnitude was larger in small- and medium-diameter neurons than in large diameter neurons while the decrease in the decay was greater in CAP responsive, IB4 positive, small- and medium-diameter neurons than in CAP unresponsive, IB4 negative and/or large-diameter neurons. These changes in the regulation of [Ca(2+)](i) were not due to inflammation-induced changes in passive or active electrophysiological properties. Importantly, an inflammation-induced increase in evoked Ca(2+) transients in putative nociceptive afferents may contribute to the pain and hyperalgesia associated with persistent inflammation via facilitation of transmitter release from these afferents.

Blue-shift and intensity enhancement of photoluminescence in lead-zirconate-titanate-doped silica nanocomposites.

Transparent PbZr(0.52)Ti(0.48)O(3) (PZT)-doped silica nanocomposites were fabricated via a modified sol-gel process. The nanocomposites were annealed at different temperatures between 740 and 800 °C in order to produce PZT crystallites with different particle sizes. X-ray diffraction analysis indicated that the embedded PZT nanoparticles were crystallized with a perovskite structure while the SiO(2) matrix was still in an amorphous state. Transmission electron microscopy confirmed that the PZT particles were of nanosize with perovskite structure and dispersed within the SiO(2) matrix. Photoluminescence spectra of the samples were measured between 10 and 290 K. The pure silica matrix showed an emission band at 3.20 eV and a weak emission band at 2.65 eV. They were noticeably suppressed in the PZT/SiO(2) nanocomposites. An additional emission band at ∼2.30 eV, due to transition within the PZT crystallites, was identified. This emission band showed a large blue-shift with decreasing PZT crystallite size and a substantially enhanced intensity as compared with that of bulk PZT ceramics. Our studies demonstrate the typical quantum size effect of ferroelectric-doped nanocomposites and the large influence of the silica matrix on the PL intensity of the embedded PZT particles.

Co-expression patterns of the neuropeptides vasoactive intestinal peptide and cholecystokinin with the transduction molecules alpha-gustducin and T1R2 in rat taste receptor cells.

Taste receptor cells are primary sensory receptors utilized by the nervous system to detect the presence of gustatory stimuli in the oral cavity. These cells are particularly heterogeneous and may be divided into various subtypes based on morphological, histochemical, or physiological criteria. One example is the heterogeneous expression of neuropeptides, such as cholecystokinin and vasoactive intestinal polypeptide. These peptides are hypothesized to participate in the transduction processes. To pursue examination of this hypothesis, this study explored the relationship of peptide expression with two important and mostly non-overlapping transductive elements--the taste-specific G protein gustducin, involved in bitter and sweet transduction cascades, and the seven transmembrane taste receptor T1R2, hypothesized to respond to sweet compounds. Double labeling experiments were performed on taste buds of the posterior rat tongue combining immunocytochemistry for peptide expression and in situ hybridization experiments for either gustducin or T1R2 expression. Additionally, vasoactive intestinal peptide (VIP)-expression in posterior taste receptor cells was confirmed using the technique of RT-PCR. More than half (56%) of the CCK-expressing taste receptor cells co-expressed alpha-gustducin mRNA whereas far fewer (15%) co-expressed T1R2 mRNA. A majority of VIP-expressing taste receptor cells co-expressed alpha-gustducin mRNA (60%) whereas only 19% of these cells co-expressed T1R2 mRNA. More remarkable was the observation that these two peptides displayed almost identical expression patterns with these signal transduction molecules, suggesting that peptides are not randomly expressed with relation to signal transduction molecules. This observation supports the hypothesis that peptides may play roles in transduction. Further physiological exploration will be required to elucidate the nature of these roles.

Modeling prediction of membrane bioreactor process with the concept of soluble microbial product.

The existence of soluble microbial products (SMP) produced by microbial cultures involved in biological wastewater treatment process has been widely investigated. This paper aims to establish an available mathematical model by incorporating the SMP concept into the Activated Sludge Model (ASM) No. 3. Prediction of sewage treatment performance in membrane bioreactor process under intermittent aerobic condition by model simulation was presented, and the results provided a more comprehensive image for this process. It was found that SMP could not be ignored and it contributed about 15% of total COD in the reactor under HRT = 12 hr and SRT = 10 days condition. The model also provided reasonable simulation results for nitrogen, biomass concentration, and other treatment behaviors. Furthermore, the treatment performance can be predicted under various operating conditions by this proposed model.

A model for membrane bioreactor process based on the concept of formation and degradation of soluble microbial products.

A mathematical model of soluble microbial products (SMPs) formation-degradation was established based on the activated sludge model no. 1 and was applied to the membrane bioreactor process with high concentration of activated sludge under intermittent aerobic operational condition. The simulation results were in good agreement with the experimental data which indicated that the coefficients used in the model could successfully describe the treatment performance. The most advantage of this modified model over the conventional one was that the significant importance of SMP existence was demonstrated and the model provided an reasonable comprehension for SMP concept. The present study demonstrated that SMPs contributed most to the organic matter in the effluent, and the results coincided well with the observations of many other researchers.

A pilot-scale study of tertiary treatment of Jizhuangzi wastewater treatment plant by continuous preozonation-microflocculation-filtration process.

A pilot-scale study of tertiary wastewater treatment of the JIZHUANGZI Municipal Wastewater Treatment Plant was carried out by preozonation, coagulation and direct filtration process with the aim of producing wastewater suitable for reuse. The proposed treatment scheme could produce a filtered water with lower turbidity, COD(Cr) and colour at lower ozone and coagulant dosages. Ozone was added into the mixing tank with coagulant simultaneously and postozonation was not cost effective. With the increase of ozone dosage, better COD(Cr) and colour removals were observed especially at the ozone dosage between 0.7-1.0 mg l(-1). Similarly, increasing ferric sulphate dosage resulted in better removals of turbidity, COD(Cr) and colour in the filtered water. In contrast, increasing polymer T-80 dosage seemed to improve colour removal rather than turbidity and COD(Cr). To achieve removal efficiency of 70% for turbidity, 45% for COD(Cr) and over 60% for colour, the optimum dosages of ozone, ferric sulphate and polymer T-80 should be 0.7-1.0 mg l(-1), 10.0-12.5 mg l(-1) and 0.7-1.0 mg l(-1), respectively.

Effect of enforced aeration on in-vessel food waste composting.

A laboratory composting was conducted to determine the effect of the continuously enforced aeration on the composting performance. The mixture of dog food, excess sludge, and woodchip was used as raw composting materials. The temperature changes in the decomposition process, and pH, weight loss, ash, and extract composition from the final product after 17 days composting were investigated. The results demonstrated that flow rate of enforced aeration indeed influenced the composting performance. Composting under 0.05-0.1 1 min(-1) condition seemed better than that under 0.2-0.41 min(-1) condition. Higher flow rate of air not only cooled the composting mixture significantly, further adversely affected temperature rise, but also evaporated moisture mostly. Thermophilic composting can occur under 0.05-0.11 min(-1) air flow rate condition, while composting in cases of 0.2-0.4 l min(-1) air flow rate mainly resulted in a mesophilic process. Microbial activity was considered to be significantly inhibited at 0.4 1 min(-1) air flow rate condition based on the analyses of total organic carbon and volatile fatty acids from water extraction of composting products.

Inhibitory effects of estradiol on inward rectifier and delayed rectifier K+ currents in guinea pig ventricular myocytes.

AIM: To study the effects of estradiol (Est) on inward rectifier K+ (IK1) and delayed rectifier K+ (IK) channels in isolated guinea pig ventricular myocytes. METHODS: Using whole cell patch-clamp recording techniques. RESULTS: Est 10 mumol.L-1 and 100 mumol.L-1 decreased the action potential duration, APD50, from (474 +/- 71) ms to (330 +/- 75) ms and (229 +/- 67) ms (n = 7 cells of 7 guinea pigs, P < 0.05), respectively. Est 100 mumol.L-1 also decreased APD90 from (587 +/- 60) ms to (418 +/- 79) ms (n = 7, P < 0.05). Est inhibited IK tail current (IK.tail) concentration-dependently. IK.tail was depressed 53% (n = 5, P < 0.05) at 10 mumol.L-1 and 80% (n = 5, P < 0.01) at 100 mumol.L-1 compared with control. Est > or = 10 mumol.L-1 blocked IK1. The maximal inhibition of inward current of IK1 occurred at -100 mV test potential was 49% (n = 5, P < 0.01) and outward current of IK1 at -40 mV was 72% (n = 5, P < 0.01). The reverse potential shifted negatively, from -70 to -76 mV. CONCLUSION: Est possessed blocking effects on both IK1 and IK channels in guinea pig ventricular myocytes.

Effects of sex hormones on action potential and contraction of guinea pig papillary muscle.

AIM: To study the effects of sex hormones, estradiol (Est), progesterone (Pro) and testosterone (Tes) on the action potential (AP) and contraction of guinea pig papillary muscle. METHODS: Using conventional glass microelectrode and mechanical recording of myocardial contraction. RESULTS: Est slowed down the maximal rate of rise of phase 0 (Vmax) of AP at low concentration (1 mumol.L-1). At 10 mumol.L-1 and above, Est also prolonged AP duration (APD50 and APD90), effective refractory period (ERP) and decreased the maximal isometric tension (Pmax) and velocity of tension development (dT/dt) of contraction. Tes (100 mumol.L-1 - 1 mmol.L-1) prolonged APD90 and ERP with decreased Pmax and dT/dt. But Pro (1 mumol.L-1 - 1 mmol.L-1) had no effects on both AP and contraction. CONCLUSION: Est prolonged AP and depressed contraction of guinea pig papillary muscle.

Effects of sodium pentobarbital on electric and mechanical activities of guinea pig papillary muscle.

AIM: To study the effects of sodium pentobarbital (SP) on the action potential (AP) and contraction of guinea pig papillary muscle. METHODS: Using conventional glass microelectrode and mechanical recording of myocardium contraction. RESULTS: SP (> or = 10 mumol.L-1) prolonged the AP duration (APD) and effective refractory period (ERP), while amplitude (APA) and Vmax of phase 0 showed no changes. The effects of SP were abolished by pretreatment with cromakalim, an agonist of ATP-sensitive K+ channel. The maximal isometric tension (Pmax) and velocity of tension development (dT/dt) were decreased to 51% and 48% of control, respectively. The first postrest beat (B1) and second postrest beat (B2) were also depressed. CONCLUSION: SP affected the action potential by reducing activities of the K+ channels and reduced the contraction of guinea pig myocardium.

Detection of minimal residual disease in childhood acute lymphoblastic leukemia after termination of therapy.

Using IgH and TCR gamma gene rearrangements as gene markers, we detected minimal residual disease (MRD) by means of the polymerase chain reaction (PCR) and restriction analysis. Of 18 children with acute lymphoblastic leukemia (ALL), MRDs were detected in 9 patients after termination of therapy. All 18 patients had been followed for 1.5 to 102 months after detection. Three of the nine MRD-positive patients relapsed within 3 to 6 months; none of the nine MRD-negative patients relapsed. We suggest that MRD negativity at the end of therapy might be an important factor for long-term disease-free survival, because the negative cases had a very low risk of relapse. Because the outcome for MRD-positive cases is more difficult to evaluate, patients with MRD after termination of therapy should be monitored.