Identification of two novel poleroviruses and the occurrence of Tobacco bushy top disease causal agents in natural plants.

Tobacco bushy top disease (TBTD) is a devastating tobacco disease in the southwestern region of China. TBTD in the Yunnan Province is often caused by co-infections of several plant viruses: tobacco bushy top virus (TBTV), tobacco vein distorting virus (TVDV), tobacco bushy top virus satellite RNA (TBTVsatRNA) and tobacco vein distorting virus-associated RNA (TVDVaRNA). Through this study, two new poleroviruses were identified in two TBTD symptomatic tobacco plants and these two novel viruses are tentatively named as tobacco polerovirus 1 (TPV1) and tobacco polerovirus 2 (TPV2), respectively. Analyses of 244 tobacco samples collected from tobacco fields in the Yunnan Province through RT-PCR showed that a total of 80 samples were infected with TPV1 and/or TPV2, and the infection rates of TPV1 and TPV2 were 8.61% and 29.51%, respectively. Thirty-three TPV1 and/or TPV2-infected tobacco samples were selected for further test for TBTV, TVDV, TBTVsatRNA and TVDVaRNA infections. The results showed that many TPV1 and/or TPV2-infected plants were also infected with two or more other assayed viruses. In this study, we also surveyed TBTV, TVDV, TBTVsatRNA and TVDVaRNA infections in a total of 1713 leaf samples collected from field plants belonging to 29 plant species in 13 plant families and from 11 provinces/autonomous regions in China. TVDV had the highest infection rates of 37.5%, while TVDVaRNA, TBTV and TBTVsatRNA were found to be at 23.0%, 12.4% and 8.1%, respectively. In addition, TVDV, TBTV, TBTVsatRNA and TVDVaRNA were firstly detected of co-infection on 10 plants such as broad bean, pea, oilseed rape, pumpkin, tomato, crofton weed etc., and 1 to 4 of the TBTD causal agents were present in the samples collected from Guizhou, Hainan, Henan, Liaoning, Inner mongolia and Tibet autonomous regions. The results indicated that TBTD causal agents are expanding its host range and posing a risk to other crop in the field.

Anti-reflux procedure for difficult-to-treat asthmatic children, case report and literature review.

Gastroesophageal reflux disease (GERD) is a commonly encountered condition in children, which at times causes respiratory distress, such as asthmatic symptoms, and results in serious morbidity and even mortality. The complexity is sometimes so obscure, that it can cause paradoxical diagnoses and treatment. Here we present two cases of children with difficult-to-treat asthmatic symptoms, which were eventually found to be related to GERD. The two children were treated with anti-reflux procedures and both became symptom free. Literature was also reviewed to shed a light into this complex disease.

[Effects of cardioplegia with tetrodotoxin on intracellular sodium overload of ischemia/reperfusion cardiomyocytes].

AIM: To investigate the effects of polarizing cardioplegia solution with sodium channel inhibitor tetrodotoxin (TTX) on intracellular free Na+ concentration ([Na+]i) in isolated cardiomyocytes of rat. METHODS: Ventricular myocytes with beating were isolated from adult rat hearts by enzymatic dissociation, randomly created in group base, group STH2 (contrast group of ischemia/reperfusion) and group TFX (treated group). Both Group STH2 and group TTX were arrested by St. Thomas No. 2 cardioplegia solution and TTX cardioplegia solution respectively, the arrest/re-beating cell model imitating MIRI being established, and imaged by laser scanning confocal microscopy (LSCM) for measuring [Na+]i of cardiomyocytes in different period. The morphology of cardiomyocytes was observed under the inverted microscope. RESULTS: [Na+]i of cardiomyocytes in both group TTX and group STH2 after re-beating was higher than that in group base (P < 0.01), and [Na+]i in group TTX was lower than that in group STH2 (P < 0.01). During arrest, the elevation of [Na+]i in group TTX was lower than that in group STH2. During arrest, the elevation of [Na+]i in group TTX was lower than that in group STH2. Morphologically, after re-beating, the ratio of active cardiomyocytes with normal form in group TTX was higher than that in group STH2 (P < 0.01). CONCLUSION: Contrast depolarized cardioplegia solution, TTX cardioplegia solution could alleviate ischemia reperfusion injury and intracellular Na+ overload of cardiomyocytes.

[Protective effects of polarizing cardioplegia with Na(+) channel inhibitor in ex vivo rat heart preservation].

OBJECTIVE: To investigate the protective effects of polarizing cardioplegia with Na(+) channel inhibitor tetrodotoxin (TTX) in ex vivo rat heart preservation. METHODS: Using a Langendorff preparation, Wistar rat hearts were arrested and preserved with St. Thomas (STH) solution (n=10) or with polarizing cardioplegia (TTX, n=10) for 7 h in hypothermic storage (10 degrees Celsius). All the hearts then underwent 30 min of reperfusion. Pre-ischemia and post-ischemia indexes of the rat hearts were determined, including the hemodynamic parameters, myocardial enzymology, ATP content and ultrastructural changes. RESULTS: The recovery of hemodynamic parameters of the hearts in TTX group were better than those in STH group (P<0.01). In comparison with STH group, the leakage of creatine kinase (CK) and lactate dehydrogenase (LDH) in TTX group was significantly lower (P<0.05) and ATP level maintained a relative high level with better protected myocardial ultrastructure. CONCLUSION: TTX polarizing cardioplegia provides more effective long-term hypothermic preservation of isolated rat hearts than STH.