The developments of domestic and foreign researches on mutagenesis of sulfur dioxide were briefly reviewed in this paper from different aspects: microbiological experiments, the experiments of cultured mammalian cells in vitro,experiments on mammal and population in vivo.

Objective To study the genetic effects of lead on root tip cell of Vicia faba. Methods Micronucleus tests were conducted on root tip cell of Vicia faba treated with Pb2+ of concentrations of 0.1, 1.0, 5.0, 25.0, 50.0 mg/L for 12-36 h. Results The results indicated that the rates of micronucleus of lead-treated tip cell were significantly higher than that of the control (P

No abstract available.
Leprosy*

No abstract available.
Humans ; Internship and Residency*

No abstract available.
Impetigo*

Two-dimensional Doppler echocardiographic velocity profiles of four cardiac valves in a group of 85 infants and children with left to right shunt lesions(VSD, ASD and PDA) are presented. Velocities were obtained before operation and 10 days afterward. The results were as follows ; 1) VSD(type 2) Peak velocities of mitral valve were significantly decreased when compared preop. with postop. echocardiogram(n=37, preop 132+/-24, postop 98+/-16 cm/sec, p<0.0005). Peak velocities of tricuspid valve were also significantly decreased(n=30, perop 60+/-21, postop 50+/-17cm/sec, p<0.01). Peak velocities of aortic valve were decreased(n=18, perop 120+/-20, postop 108+/-26cm/sec, 0.010.05). Peak velocities of pulmonic valve were significantly decreased(n=17, perop 168+/-46, postop 104+/-51cm/sec, p<0.0005). 3) PDA Peak velocities of mitral valve were significantly decreased when compared perop. with postop. echocardiogram(n=29, perop 138+/-28, postop 111+/-19cm/sec, p<0.0005). Tricuspid valve velocities showed no significant changes between preop. and postop. echocardiogram (n=15, perop 47+/-12, postop 44+/-10cm/sec, p>0.05). Aortic valve velocities showed no significant changes (n=10, perop 134+/-23, postop 121+/-25cm/sec, p>0.05). Peak velocities of pulmonic valve were significantly decreased(n=28, perop 138+/-37, postop 107+/-27cm/sec, p<0.005). This study demonstrates that Doppler echocardiographic assessment of velovity changes are correlated with known hemodynamic data and also will be a good index in the evaluation of operation.
Aortic Valve ; Child ; Echocardiography* ; Echocardiography, Doppler ; Heart Valves* ; Hemodynamics ; Humans ; Infant ; Mitral Valve ; Tricuspid Valve

AIMTo study the effect of magnesium sulfate on transient outward K+ current (IA) and delayed rectifier K+ current (IK) in freshly dissociated hippocampal neurons of rats.

METHODSThe whole-cell patch clamp techniques were used.

RESULTSMagnesium sulfate reversibly reduced the amplitudes of IA and IK in a concentration-dependent and voltage-dependent, but not frequency-dependent manner. Half-blocking concentration (IC50) on IA and IK were 6.30 mmol.L-1 and 7.60 mmol.L-1, respectively. Magnesium sulfate (6 mmol.L-1) affected the activation process of IA and IK. Before and after application of the drug, the half-activation voltages of IA were (7 +/- 6) mV and (-7 +/- 11) mV (n = 10, P < 0.01), and the half-activation voltages of IK were (20 +/- 6) mV and (28 +/- 4) mV (n = 10, P < 0.01), but the slope factors were not changed. In addition, magnesium sulfate (6 mmol.L-1) also affected the inactivation process of IA. Before and after application of the drug, the half-inactivation voltages of IA were (-65 +/- 5) mV and (-89 +/- 6) mV (n = 10, P < 0.01).

CONCLUSIONMagnesium sulfate inhibited IA and IK in freshly dissociated hippocampal neurons of rats, which might contribute to protect the central neuronal system (CNS) against damages induced by ischemia and oxygen deprivation.

Animals ; Cell Separation ; Delayed Rectifier Potassium Channels ; Female ; Hippocampus ; cytology ; Magnesium Sulfate ; pharmacology ; Male ; Neurons ; drug effects ; physiology ; Neuroprotective Agents ; pharmacology ; Patch-Clamp Techniques ; Potassium Channels ; drug effects ; metabolism ; Potassium Channels, Voltage-Gated ; Rats ; Rats, Wistar

The effect of SO2 derivatives on Na(+) currents was studied in freshly dissociated hippocampal CA1 neurons of rat using the whole-cell patch-clamp technique. The results indicated that SO2 derivatives caused a dose-dependent and voltage-dependent increase in the voltage-activated Na+ currents. The amplitudes of Na(+) currents were increased by 50.59 19.08% and 82.06 18.51% (n=15)by SO2 derivatives at 10 and 100 micromol/L, respectively. The action was frequency-independent. The results also showed that SO2 derivatives did not affect the activation process, but changed the inactivation process significantly. Before and after application of 10 micromol/L SO2 derivatives, the half-inactivation voltage was -69.71+/-4.67 and -53.27+/-4.95 mV (n=10, P<0.01), respectively, but the slope factor was not changed. These results imply that SO2 derivatives have neurotoxic effects and that SO2 pollution is probably related to some diseases of central neuronal system.
Animals ; Dose-Response Relationship, Drug ; Female ; Hippocampus ; cytology ; drug effects ; Male ; Membrane Potentials ; drug effects ; Neurons ; drug effects ; physiology ; Patch-Clamp Techniques ; Rats ; Rats, Wistar ; Sodium Channels ; drug effects ; physiology ; Sulfites ; toxicity

The effects of magnesium sulfate (MgSO4) on sodium currents (Na(+) currents) were studied in freshly dissociated hippocampal CA(1) neurons of rat using the whole-cell patch-clamp technique. The results indicated that MgSO4 caused a concentration-dependent and voltage-dependent decrease in Na(+) currents. The half-inhibitory concentration (IC(50)) was 4.05 mmol/L. This action was frequency-independent. The results also showed that 4 mmol/L MgSO4 shifted the steady state activation curve of Na(+) currents towards positive potential (control V(h)=-55.8+/-6.8 mV, MgSO4 V(h)=-34.2+/-6.2 mV, n=8, P<0.01) without changing the slope factor. However, the steady state inactivation curve was not affected. These results suggest that blockade of Na(+) currents by MgSO4 might be an interpretation for its neuroprotection against damages induced by ischemia and oxygen deprivation.
Animals ; Hippocampus ; cytology ; drug effects ; physiology ; Magnesium Sulfate ; pharmacology ; Neurons ; drug effects ; physiology ; Patch-Clamp Techniques ; Rats ; Rats, Wistar ; Sodium Channel Blockers ; pharmacology ; Sodium Channels ; physiology

Objective To study the effects of asiaticoside on the growth of melanoma B16 cell cultures in vitro. Methods Melanoma B16 cells were subcultured and the inhibition of cellular growth was investigated. The morphology of the cells was observed after inhibition. The induction of apoptosis by asiaticoside was determined by flow cytometry. Results It was found that asiaticoside could significantly inhibit the growth of B16 cell cultures in vitro in a dose-dependent manner. The annexin-v positive cells were increased, along with that cells intaking R123 marked mitochondria were decreased, and PI positive cells increased, which indicated that cellular apoptosis was induced. Conclusion Asiaticoside plays an inhibitory role in the growth of melanoma B16 cells.