A PCR-based Rapid Neutralization Assay for GII.4 Norovirus Infection in HIEC6 Cell Culture.

Because of limited viral replication and lack of cytopathic effect in cell culture, a new PCR-based rapid seroneutralization assay for detection of GII.4 norovirus neutralized antibodies was developed with serum samples from acute-phase patients, convalescent-phase patients and healthy controls. According to this study, neutralizing antibodies were detected in 100% of convalescent-phase sera, and in 2.5% of healthy controls sera. However, all of the acute-phase serum samples could not neutralize virus efficiently. Compared to the results from ELISA (96.2% at sensitivity and 80% at specificity), the present in vitro neutralization assay is more specific and more sensitive.

[Role of rennin-angiotensin system in cholinergic agonist carbachol-induced cardiovascular responses in ovine fetus].

To investigate the mechanisms underlying the cholinergic agonist carbachol-induced cardiovascular responses, changes of renin-angiotensin system were examined in fetal hormonal systems. In the ovine fetal model under stressless condition, the cardiovascular function was recorded. Blood samples were collected before (during baseline period) and after the intravenous administration of carbachol. Simultaneously, the levels of angiotensin I (Ang I), angiotensin II (Ang II) and vasopressin in the fetal plasma were detected by immunoradiological method. Also, blood gas, plasma osmolality and electrolyte concentrations were analyzed in blood samples. Results showed that in chronically prepared ovine fetus, intravenous infusion of carbachol led to a significant decrease of heart rate (P < 0.05), and a transient decrease followed by an increase of blood pressure (P < 0.05) within 30 min. After the intravenous infusion of carbachol, blood concentrations of Ang I and Ang II in near-term ovine fetus were both significantly increased (P < 0.05); however, blood concentration of vasopressin, values of blood gas, electrolytes and plasma osmolality in near-term ovine fetus were not significantly changed (P > 0.05). Blood levels of Ang I and Ang II in the atropine (M receptor antagonist) + carbachol intravenous administration group was lower than those in the carbachol group without atropine administration (P < 0.05). In conclusion, this study indicates that the near-term changes of cardiovascular system induced by intravenous administration of carbachol in ovine fetus, such as blood pressure and heart rate, are associated with the changes of hormones of circulatory renin-angiotensin system.

[Expressions of interleukin-15 and osteopontin mRNA in early stage of acute rejection of renal allograft in rats].

OBJECTIVE: To study the expressions of interleukin-15 (IL-15), osteopontin (OPN), granzyme B (GraB) and perforin (PFP) mRNA in early stage of acute rejection (AR) of renal allograft in rats. METHODS: The rat renal transplantation model was established. Male Brown Norway and Lewis rats were used as donors and recipients. Four groups were designated: CsA group (BN-->LEW, n = 10, recipients were treated with CsA i.p.); AB group (BN-->LEW, n = 10, recipients were treated with anti-IL-15 neutralizing antibody i.p.); AR group (BN-->LEW, n = 10, recipients were treated with normal saline i.p.) and control group (LEW-->LEW, n = 6, recipients were treated with normal saline i.p.). The blood samples of recipients were drawn at Days 1, 3, 5 and 7 post-transplantation. The serum expressions of IL-15, OPN, PFP and GraB mRNA of recipients were detected by real-time PCR. Allograft tissues were analyzed by pathological assays. RESULTS: In comparison with other groups, the expressions of OPN, IL-15, PFP and GraB mRNA in AR group were gradually up-regulated and peaked at Day 5. The expressions of IL-15 mRNA in CsA and AB groups were 9685 +/- 1440 and 4346 +/- 741 respectively at Day 5 post-operation. It was significantly lower than that in AR group (17 022 +/- 2153, P < 0.01). The expression of IL-15 mRNA in AB group was significantly lower than that in CsA group (P < 0.01). The expressions of OPN mRNA in CsA and AB groups (13 226 +/- 1565 vs 19 112 +/- 2908) were both significantly lower than that in AR group (24 663 +/- 2449, P < 0.01). But the expression of OPN mRNA in AB group was higher than that in CsA group (P < 0.01). At Day 5 post-transplantation, both the expressions of PFP and GraB mRNA in AB and CsA groups was lower than that in AR group (P < 0.01). The pathological results showed that severe AR occurred at Day 7 post-transplantation in AR group and whereas the extent of rejection sign relieved in AB group. CONCLUSION: In early stage of AR of renal allograft in rats, the expressions of OPN, IL-15, PFP and GraB mRNA are up-regulated. Blocking IL-15/IL-15R pathway in early stage of AR can down-regulate the expressions of PFP and GraB mRNA.