Portalsystemic hemodynamic changes in chronic severe hepatitis B: An ultrasonographic study

AIM:To evaluate portalsystemic hemodynamic changes in chronic severe hepatitis B. METHODS:Hemodynamic parameters included portal vein diameter (PVD), portal vein peak velocity (PVPV), portal vein volume (PVV), spleen length (SPL), spleen vein diameter (SPVD), spleen vein volume (SPVV) and umbilical vein recanalization. They were measured by Color Doppler ultrasonography in 36 patients with chronic severe hepatitis B, compared with 51 normal controls, 61 patients with chronic hepatitis B, 46 patients with compensable cirrhosis, and 36 patients with decompensable cirrhosis. RESULTS:In the group of chronic severe hepatitis B, PVD (12.38 ± 1.23 mm) was significantly different from the normal control, compensable cirrhosis and decompensable cirrhosis groups (P = 0.000-0.026), but not significantly different from the chronic hepatitis group. PVPV (16.15 ± 3.82 cm/s) dropped more significantly in the chronic severe hepatitis B group than the normal control, chronic hepatitis B and compensable cirrhosis groups (P = 0.000-0.011). PVV (667.53 ± 192.83 mL/min) dropped significantly as compared with the four comparison groups (P = 0.000-0.004). SPL (120.42 ± 18.36 mm) and SPVD (7.52 ± 1.52 mm) were longer in the normal control and chronic hepatitis B groups (P = 0.000-0.009), yet they were significantly shorter than those in the decompensable cirrhosis group (P = 0.000). SPVV (242.51 ± 137.70 mL/min) was also lower than the decompensable cirrhosis group (P = 0.000). The umbilical vein recanalization rate (75%) was higher than the chronic hepatitis B and compensable cirrhosis groups. In the course of progression from chronic hepatitis to decompensable cirrhosis, PVD, SPL and SPVD gradually increased and showed significant differences between every two groups (P = 0.000-0.002). CONCLUSION:Patients with chronic severe hepatitis B have a tendency to develop acute portal hypertension, resulting in significantly reduced portal vein perfusion. Observation of the portalsystemic hemodynamic changes may be contributed to the disease progression of chronic liver disease.

Pertussis toxin modulation of sodium channels in the central neurons of cyhalothrin-resistant and cyhalothrinsusceptible cotton bollworm, Helicoverpa armigera

Pertussis toxin （FIX） inhibits the activation of the α-subunit of the inhibitory heterotrimeric G-proteins （Cαi/o） and modulates voltage-gated sodium channels, which may be one of the primary targets of pyrethroids. To investigate the potential mechanisms of agricultural pests resistance to pyrethroid insecticides, we examined the modulations by PTX on sodium channels in the central neurons of the 3rd-4th instar larvae of cyhalothrin-resistant （Cy-R） and cyhaiothrin-susceptible （Cy-S） Helicoverpa armigera by the whole-cell patch-clamp technique. The isolated neurons were cultured for 12-16 h in an improved L15 insect culture medium with or without PTX （400 ng/mL）. The results showed that both the Cy-R and Cy-S sodium channels exhibited fast kinetics and tetrodotoxin （TTX） sensitivity. The Cy-R sodium channels exhibited not only altered gating properties, including a 8.88-mV right shift in voltage-dependent activation （V0.5act） and a 6.54-mV right shift in voltage-dependent inactivation （V0.5inact）, but also a reduced peak in sodium channel density （Ⅰdensity） （55.2% of that in Cy-S neurons）. Cy-R sodium channels also showed low excitability, as evidenced by right shift of activation potential （Ⅴacti） by 5-10 mV and peak potential （Ⅴpcak） by 20 mV. FIX exerted significant effects on Cy-S sodium channels, reducing sodium channel density by 70.04%, right shifting V0.5act by 14.41 mV and V0.5inact by 9. 38 mV. It did not cause any significant changes of the parameters mentioned above in the Cy-R sodium channels. The activation time （Tpeak） from latency to peak at peak voltage and the fast inactivation time constant （τinact） in both Cy-S and Cy-R neurons were not affected. The results suggest that cotton bollworm resistant to pyrethroid insecticides involves not only mutations and allosteric alterations of voltage-gated sodium channels, but also might implicate perturbation of PTX-sensitive Gαi/o-COupled signaling Wansduction pathways.