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Unlabelled: This study examined the effect of delayed reperfusion of myocardial hibernation from 24 hours to 7 days on myocardial ultrastructural and functional changes and their recoveries after reperfusion., Background: We have previously shown in pigs that after reperfusion the functional and structural alterations in short-term myocardial hibernation which was reperfused in 24 hours can recover in 7 days. The effect of delayed reperfusion of hibernating myocardium on the extent and severity of cellular and extracellular structural changes of hibernating myocardium, and their recoveries after reperfusion is not known., Methods and Results: A severe LAD stenosis was created in 27 pigs, reducing resting flow by 30-40% immediately after placement of the stenosis and producing acute ischemia as evidenced by regional lactate production, a decrease in regional coronary venous pH, reduced regional wall thickening (from 38.5 +/- 5.1% to 10.4 +/- 8.0%) and a 33% reduction of regional oxygen consumption. The stenosis was maintained either for 24 hours in 9 pigs (group 1) with LAD flow of 0.65 +/- 0.13 ml/min/g (38% reduction), or for 7 days in 17 pigs (group 2) with LAD flow of 0.67 +/- 0.14 ml/min/g (36% reduction). There were no differences (p = NS) in the reduction of wall thickening, rate-pressure product, lactate production, or regional oxygen consumption between group 1 and group 2. Quantitative morphometric evaluation of the ultrastructure on electromicrographs revealed a greater decrease in sarcomere volume and a higher incidence of myocytes with reduced sarcomere volume in 7-day than in 24-hour hibernating regions (53 +/- 19% versus 33 +/- 14%, p < 0.05). Patchy myocardial necrosis with replacement fibrosis was common, but 6 of the 18 pigs had no myocardial necrosis or replacement fibrosis in the 7-day hibernating group, and 4 of 9 pigs had no patchy myocyte necrosis in the 24 hour hibernating group. In 6 pigs in group 1 in which the stenosis was then released and hibernating myocardium reperfused in 24 hours, regional wall thickening recovered to 30 +/- 6% (p = NS compared to baseline) after one week of reperfusion. In 12 pigs in group 2 in which the stenosis was released and hibernating myocardium reperfused in 7 days, regional wall thickening recovered slowly, from 10.1 +/- 7.2% to 18.1 +/- 8.3% at one week (n = 5) and to 28.0 +/- 3.6% at 3-4 weeks of reperfusion (n = 7, p < 0.05 compared to baseline). Similarly, the sarcomere volume or myofilament recovered significantly (p < 0.01) and was not different compared to the normal region (p = NS) in the 24-hour hibernating region of group 1, but the recovery was much slower and was incomplete at 4 weeks (p < 0.01) compared to baseline in the 7-day hibernating region of group 2. Recovery of regional wall thickening correlated with ultrstructural recovery (p < 0.01). By multivariate stepwise regression analysis, the degree of LAD flow reduction, the extent of fibrosis, and myofilament loss were independent predictors of the extent of functional recovery., Conclusions: In a porcine model of myocardial hibernation with myocardial hypoperfusion, systolic dysfunction, and metabolic adaptations, a longer period of myocardial hibernation with delayed reperfusion was associated with more severe abnormalities of myocytes. an increasing interstitial fibrosis, and more protracted myofibrillar and functional recoveries after reperfusion. The extent of functional recovery is related to the degree of coronary flow reduction, the severity of the ultrastructural changes, and the extent of interstitial fibrosis.

Objective: To study the immunophenotype and P-glycoprotein expression in CD7 positive adult acute myeloid leukemia (CD7+ AML)., Methods: Morphology, P-glycoprotein, cytogenetics and immunophenotype were examined in 30 previously untreated CD7+ AML patients., Results: The CD7 positive rate was 11.4% in 262 AML patients. CD7+ AML patients had a significantly higher incidence of peripheral leukocytosis and blasts and FAB M1 subtype and were associated with CD34 and P-glycoprotein expression. 42.3% of CD7+ AML achieved complete remission with a median remission duration of 4 months, and a median time to CR of 48 days., Conclusion: Patients with CD7+ AML are usually CD34 and P-glycoprotein positive. These patients had a lower CR rate and a shorter remission duration.

Objective: To explore megakaryocytic (MK) antigen expression in previously untreated adult acute myeloid leukemia (AML) and its relation to the clinical and biological characteristics., Methods: Two hundred and eleven cases of AML were detected with flow cytometric immunofluorescence assay., Results: Twenty-seven cases (12.8%) were MK antigen positive with the higher positive rates in hybrid acute leukemia (45.5%) and acute monoblastic leukemia (24.1%). MK antigen expression was significantly correlated with CD34 antigen expression, high white cell count, high P-glycoprotein positivity and had no correlation with chromosome aberration. 33.3% of MK positive AML patients achieved complete remission which was significantly lower than that (71.9%) in MK negative cases., Conclusion: MK antigen positive AML might derived from malignant transformation of hemotopoietic stem cell at earlier stage and the detection of MK expression was of values in predicting treatment effect and prognosis for adult AML.

Aim: To establish a modified polymerase chain reaction(PCR) method for the detection of Plasmodium vivax in the endemic areas of malaria and compare the method with the conventional light microscopy in the field., Methods: A PCR method was modified by improving the collection procedures of blood samples, template extraction, primer design and optimizing the reaction condition. The method was evaluated by examining blood samples from 310 patients with vivax malaria and compared with the conventional light microscopy in endemic areas of Hainan Province., Results: The positive rates of the modified PCR method and microscopic method were 34.2% and 31.9%, respectively., Conclusion: The modified PCR method is simple, sensitive and specific for the detection of vivax malaria patients in endemic areas.

Objective: To explore the prognostic significance of P-glycoprotein (P-gp) expression in previously untreated acute leukemia in adults., Methods: P-gp expression in 151 acute myeloblastic leukemia (AML) and 47 acute lymphoblastic leukemia (ALL) was determined by monoclonal antibody UIC2 and flow cytometry., Results: The rate of complete remission (CR) differed between P-gp+ and P-gp- AML (20.5% vs 78.5%, P < 0.001), but the CR rate did not significantly differ between P-gp+ and P-gp- ALL(66.7% vs 80%, P > 0.05). The six-month relapse rate was significantly higher in P-gp+ group than that of P-gp- group (AML: 66.7% vs 8.7%, P < 0.001; ALL: 50% vs 9.5%, P < 0.05). The median disease-free survival time was shorter in P-gp+ group than in P-gp- group (AML: 5 months vs 13 months; ALL: 4 months vs 13 months)., Conclusion: Overexpression of P-gp is a poor prognostic factor in adult acute leukemia and P-gp detection is useful for the prediction of treatment response and early relapse.

Objective: To evaluate the characteristics of P-glycoprotein (P-gp) expression of acute non-lymphocytic leukemia (ANLL) at different status and the prognostic and biological features in ANLL at diagnosis., Methods: Monoclonal antibody UIC2 and indirect immunofluorescence assay by flow cytometry were used to determine P-gp expression of 169 patients with ANLL, including 152 previously untreated, 7 refractory and 10 at remission., Results: P-gp was expressed in 28.9% of the previously untreated ANLL cases and P-gp was lower than that in 71.4% of the refractory cases (P < 0.05). No P-gp expression was found in the patients at remission. For previously untreated AN-LL, P-gp was highly expressed in hybrid acute leukemia (66.7%) and acute monoblastic leukemia (47.4%). P-gp expression was highly associated with surface markers [cluster of differentiation (CD) 34, CD7, CD14, CD42b and CD61] and unfavorable cytogenetic abnormalities. About 23% of P-gp-ANLL obtained complete remission, which was significantly lower than that (76%) in P-gp-cases., Conclusions: P-gp expression is higher in refractory ANLL cases than that in cases at diagnosis or at remission. P-gp is an index of poor prognosis in adults with ANLL. P-gp+ ANLL cases have unique clinical and biological characteristics.

To evaluate the clinical and biological significance of P-glycoprotein (P-gp) expression in adult acute nonlymphocytic leukemia (ANLL), P-gp was detected in 169 patients including 152 previously untreated cases, 7 refractory cases, and 10 cases at remission by using monoclonal antibody UIC2 and flow cytometry. P-gp was expressed in 29% of previously untreated cases, being less than in 71% of the refractory cases. P-gp expression was not found in patients at remission. Morphologically, P-gp expression was high in hybrid acute leukemia (67%) and acute monoblastic leukemia (47%) subtypes. Immunologically, P-gp expression was significantly associated with CD34, CD7, CD14 or CD42b/CD61. Cytogenetically, P-gp expression was highly associated with poor prognosis abnormalities (54%), which was significantly higher than 7% of P-gp expression in good prognosis abnormalities. 23% of P-gp positive previously untreated ANLL (not including M3) achieved complete remission; this was significantly lower than 76% in P-gp negative cases. These suggested that P-gp expression is an index of poor prognosis in adult ANLL and P-gp positive ANLL has unique clinical and biological features.

A cDNA encoding the Renilla reniformis luciferase was expressed in similan and murine cells in a transient and stable manner, respectively. Light emission catalyzed by luciferase was detected from transfected cells both in vitro and in vivo. This work establishes the Renilla luciferase gene as a new efficient marker of gene expression in mammalian cells.