Immunogenicity and safety of a live attenuated varicella vaccine in children 1-12 years of age: A randomized, blinded, controlled, non-inferiority phase 3 clinical trial.

OBJECTIVES: To evaluate the immunogenicity and safety of a live attenuated varicella vaccine produced using a cell factory process. METHODS: In this randomized, blinded, controlled, non-inferiority phase 3 clinical trial conducted in Guizhou, healthy children aged 1-12 years were randomly assigned in a 2: 1 ratio to receive one dose of experimental or control vaccine. Physical examination and first blood collection were performed preimmunization on day 0. Diary cards were collected after day 15. Contact cards and second blood samples were collected on day 30. The primary immunogenicity endpoint was the positive conversion rate of the anti-varicella virus antibody at 30 days postimmunization in susceptible children. Secondary endpoints were the fourfold increase rate, positive conversion rate, geometric mean titer, and geometric mean increase at 30 days after immunization in the total cohort. RESULTS: Of the 900 children assessed for eligibility, 894 received an experimental or control vaccine. Both the full analysis and safety analysis sets included 894 subjects. The seroconversion rate in the susceptible population was 95.84% in the experimental and 94.76% in the control group. The lower limit of the 95% confidence interval difference was -2.37%, which was greater than the non-inferiority margin set by the program (-10%). No significant difference in solicited adverse reactions was found between the groups. Within 6 months postimmunization, a total of 24 serious adverse events were reported, none related to the studied vaccine. CONCLUSION: The live attenuated varicella vaccine produced using a cell factory process was highly immunogenic, safe, and non-inferior to the product in the market. Further studies need to be implemented in the immune persistence, the epidemiological effectiveness and the rare adverse reactions.

Carnitine palmitoyltransferase-1b deficiency aggravates pressure overload-induced cardiac hypertrophy caused by lipotoxicity.

BACKGROUND: Carnitine palmitoyltransferase-1 (CPT1) is a rate-limiting step of mitochondrial ß-oxidation by controlling the mitochondrial uptake of long-chain acyl-CoAs. The muscle isoform, CPT1b, is the predominant isoform expressed in the heart. It has been suggested that inhibiting CPT1 activity by specific CPT1 inhibitors exerts protective effects against cardiac hypertrophy and heart failure. However, clinical and animal studies have shown mixed results, thereby creating concerns about the safety of this class of drugs. Preclinical studies using genetically modified animal models should provide a better understanding of targeting CPT1 to evaluate it as a safe and effective therapeutic approach. METHODS AND RESULTS: Heterozygous CPT1b knockout (CPT1b(+/-)) mice were subjected to transverse aorta constriction-induced pressure overload. These mice showed overtly normal cardiac structure/function under the basal condition. Under a severe pressure-overload condition induced by 2 weeks of transverse aorta constriction, CPT1b(+/-) mice were susceptible to premature death with congestive heart failure. Under a milder pressure-overload condition, CPT1b(+/-) mice exhibited exacerbated cardiac hypertrophy and remodeling compared with wild-type littermates. There were more pronounced impairments of cardiac contraction with greater eccentric cardiac hypertrophy in CPT1b(+/-) mice than in control mice. Moreover, the CPT1b(+/-) heart exhibited exacerbated mitochondrial abnormalities and myocardial lipid accumulation with elevated triglycerides and ceramide content, leading to greater cardiomyocyte apoptosis. CONCLUSIONS: CPT1b deficiency can cause lipotoxicity in the heart under pathological stress, leading to exacerbation of cardiac pathology. Therefore, caution should be exercised in the clinical use of CPT1 inhibitors.

Cardiomyocyte-Restricted Deletion of PPARß/δ in PPARα-Null Mice Causes Impaired Mitochondrial Biogenesis and Defense, but No Further Depression of Myocardial Fatty Acid Oxidation.

It is well documented that PPARα and PPARß/δ share overlapping functions in regulating myocardial lipid metabolism. However, previous studies demonstrated that cardiomyocyte-restricted PPARß/δ deficiency in mice leads to severe cardiac pathological development, whereas global PPARα knockout shows a benign cardiac phenotype. It is unknown whether a PPARα-null background would alter the pathological development in mice with cardiomyocyte-restricted PPARß/δ deficiency. In the present study, a mouse model with long-term PPARß/δ deficiency in PPARα-null background showed a comparably reduced cardiac expression of lipid metabolism to those of single PPAR-deficient mouse models. The PPARα-null background did not rescue or aggravate the cardiac pathological development linked to cardiomyocyte-restricted PPARß/δ deficiency. Moreover, PPARα-null did not alter the phenotypic development in adult mice with the short-term deletion of PPARß/δ in their hearts, which showed mitochondrial abnormalities, depressed cardiac performance, and cardiac hypertrophy with attenuated expression of key factors in mitochondrial biogenesis and defense. The present study demonstrates that cardiomyocyte-restricted deletion of PPARß/δ in PPARα-null mice causes impaired mitochondrial biogenesis and defense, but no further depression of fatty acid oxidation. Therefore, PPARß/δ is essential for maintaining mitochondrial biogenesis and defense in cardiomyocytes independent of PPARα.

Peroxisome proliferator-activated receptor ß/δ activation in adult hearts facilitates mitochondrial function and cardiac performance under pressure-overload condition.

Peroxisome proliferator-activated receptor ß/δ (PPARß/δ) is an essential transcription factor in myocardial metabolism. This study aims to investigate the effects of PPARß/δ activation in the adult heart on mitochondrial biology and oxidative metabolism under normal and pressure-overload conditions. We have investigated the effects of cardiac constitutively active PPARß/δ in adult mice using a tamoxifen-inducible transgenic approach with Cre-LoxP recombination. The expression of PPARß/δ mRNA and protein in cardiomyocytes of adult mice was substantially increased after short-term induction. In these mice, the cardiac expression of key factors involved in mitochondrial biogenesis, such as PPARγ coactivator-1, endogenous antioxidants Cu/Zn superoxide dismutase, and catalase, fatty acid, and glucose metabolism, such as carnitine palmitoyltransferase Ib, carnitine palmitoyltransferase II, and glucose transporter 4, were upregulated. Subsequently, myocardial oxidative metabolism was elevated concomitant with an increased mitochondrial DNA copy number and an enhanced cardiac performance. Moreover, activation of PPARß/δ in the adult heart improved cardiac function and resisted progression to pathological development in mechanical stress condition. We conclude that PPARß/δ activation in the adult heart will promote cardiac performance along with transcriptional upregulation of mitochondrial biogenesis and defense, as well as oxidative metabolism at basal and pressure-overload conditions.

[Evaluation of heart impact in the 100 m extreme intensity sport using near-infrared non-invasive muscle oxygen detecting device and sports heart rate detection technology].

Using continuous two wavelength near-infrared technology to detect the variation in the consistency of oxygen hemoglobin in the muscle and the sports heart rate wireless real time collection technology, we devised the real time muscle tissue oxygenation and instantaneous heart rate experiment scheme and implemented it for the process of the 100 m run with two parameters given simultaneously. The experiment shows that the concentration of the oxygen hemoglobin in the muscle tissue continues decreasing after the end of the 100 m run, and the time interval between the moment when the concentration of the oxygen hemoglobin attains the minimum value and the moment when the athletes finish the 100 m run is (6.65 +/- 1.10) sec; while the heart rate continues increasing after the end of the 100 m run, and the time interval between the moment when the heart rate attains the maximum value and the moment when the athletes finish the 100 m run is (8.00 +/- 1.57) sec. The results show that the two wavelength near-infrared tissue oxygenation detection technology and the sports heart rate real time collection equipment can accurately measure the sports tissue oxygenation and the heart rate in the extreme intensity sport, and reveal the process of muscle oxygen transportation and consumption and its dynamic character with the heart rate in the extreme intensity sport.

Peroxisome proliferator-activated receptor {delta} is an essential transcriptional regulator for mitochondrial protection and biogenesis in adult heart.

RATIONALE: Peroxisome proliferator-activated receptors (PPARs) (alpha, gamma, and delta/beta) are nuclear hormone receptors and ligand-activated transcription factors that serve as key determinants of myocardial fatty acid metabolism. Long-term cardiomyocyte-restricted PPARdelta deficiency in mice leads to depressed myocardial fatty acid oxidation, bioenergetics, and premature death with lipotoxic cardiomyopathy. OBJECTIVE: To explore the essential role of PPARdelta in the adult heart. METHODS AND RESULTS: We investigated the consequences of inducible short-term PPARdelta knockout in the adult mouse heart. In addition to a substantial transcriptional downregulation of lipid metabolic proteins, short-term PPARdelta knockout in the adult mouse heart attenuated cardiac expression of both Cu/Zn superoxide dismutase and manganese superoxide dismutase, leading to increased oxidative damage to the heart. Moreover, expression of key mitochondrial biogenesis determinants such as PPARgamma coactivator-1 were substantially decreased in the short-term PPARdelta deficient heart, concomitant with a decreased mitochondrial DNA copy number. Rates of palmitate and glucose oxidation were markedly depressed in cardiomyocytes of PPARdelta knockout hearts. Consequently, PPARdelta deficiency in the adult heart led to depressed cardiac performance and cardiac hypertrophy. CONCLUSIONS: PPARdelta is an essential regulator of cardiac mitochondrial protection and biogenesis and PPARdelta activation can be a potential therapeutic target for cardiac disorders.

Peroxisome proliferator-activated receptor delta regulates mitofusin 2 expression in the heart.

Mitofusin 2 (Mfn2) has been proposed as an important mitochondrial protein in maintaining mitochondrial network and bioenergetics. Mfn2 is highly expressed in the heart, but is downregulated in response to hypertrophic stimuli. However, little is known about how Mfn2's expression is regulated in cardiomyocytes. Here, we have investigated how Mfn2 expression in the heart responds to fasting condition and determined if Mfn2 is one of those PPARdelta-selective target genes that are involved in myocardial energy metabolism. Fasting for 48 h in mice led to a robust increase of Mfn2 expression in the heart. On the other hand, cardiomyocyte-restricted PPARdelta deficiency in mice led to substantially diminished cardiac expression of Mfn2 transcript and protein compared to that of controls. Fasting induced cardiac expression of Mfn2 was blunted in cardiomyocyte-restricted PPARdelta deficient hearts. Moreover, PPARdelta-selective ligand treatment in cultured cardiomyocytes induced elevated Mfn2 expression. A functional PPRE consensus sequence located at -837 to -817 bp upstream of the mouse Mfn2 promoter was identified and confirmed by Electrophoretic Mobility Shift Assays and Luciferase Promoter Reporter Assays. We conclude that Mfn2 is a PPARdelta-selective target, which may play an important role in regulating myocardial energy homeostasis.

Prefilming twin-fluid nozzle assisted precipitation method for preparing nanocrystalline HNS and its characterization.

The ultra-fine HNS (2,2',4,4',6,6'-hexanitrostilbene) with desired properties is needed for military and civilian applications because of its reliable threshold energy to short impulse shock waves and its excellent thermal and shock stability. This paper reports on prefilming twin-fluid nozzle assisted precipitation (PTFN-P) to obtain ultra-fine HNS explosive with high specific surface area (SSA), high purity, and narrow particle size distribution. The properties of ultra-fine HNS have been confirmed by SEM, BET, HPLC, XRD, DSC and TGA-SDTA. SEM photograph revealed that the PTFN-P process offers ellipsoid crystalline morphology with particle size of 90-150 nm. The BET and Langmuir SSA of nanocrystalline HNS with purity of 99.44 wt.% were determined to be 19.28 m(2)/g and 29.26 m(2)/g, respectively. The XRD peaks of nanocrystalline HNS seemed to have similar diffraction angles as those of synthesized HNS, and the weakening of peak strength was observed apparently. DSC results of the nanocrystalline HNS showed that the exothermic decomposing at the temperature range of 323-398 degrees C. Furthermore, HNS samples were submitted to impact and small scale gap test and the results indicated that nanocrystalline HNS is less sensitive than synthesized HNS (50 microm) to impact and shock stimuli.

[Monitoring cerebral oxygenation using near infrared spectroscopy during cardiopulmonary bypass surgery].

To avoid cerebral hypoxia caused by the imbalance between cerebral oxygen supply and consumption, regional cerebral oxygenation of patients need to be monitored at real time during cardiopulmonary bypass (CPB) surgery, and the physiological parameters can be regulated and emergent treatment can be used according to it. Using the near infrared (NIR) instrument developed by our group, cerebral oxygenation of the patients under cardiac surgery was monitored. The instrument consists of a two-wavelength near infrared light source and two near infrared detectors. Hemoglobin concentration changes of regional cerebral tissue were calculated, and by steady-state spatially resolved spectroscopy (SRS) algorithm, regional cerebral oxygen saturation (rSO2) was also calculated. Physiological parameters of patients, such as mixed venous oxygen saturation (SvO2), were measured by another monitor during CPB. Hemoglobin concentration changes were easily disturbed, but the anti-disturbance ability of rSO2 was good. The value of rSO2 could be detected all over the surgeries, but SvO2 could be detected only during CPB. There were positive correlations between rSO2 and SvO2 in most of the patients, but the correlation coefficients were not very high. This was because SvO2 reflects the saturation of the main venous, but rSO2 reflects regional cerebral oxygenation. So the physiological meaning of rSO2 and SvO2 is different. The results indicate that cerebral oxygenation of patients can be reflected by rSO2 during CPB, while only monitoring SvO2 is not enough.

[Role of bcl-2 transcriptional regulation induced by calmodulin I pressure overload rat hypertrophic hearts].

This study was designed to evaluate the role of bcl-2 transcriptional regulation induced by calmodulin I (CaM I) in pressure overload rat hypertrophic hearts. The model of hypertensive Sprague-Dawley rat was established by abdominal aortic constriction. The hearts were collected four weeks after abdominal aortic constriction. Velocity and isopyknic gradient centrifugation was employed to fractionate rat myocardial nuclei. Western blot analysis revealed a marked increase in phosphorylated cAMP response-element binding protein (pCREB) of cardiac hypertrophy group compared with that in control group (P<0.05), while the protein level of cAMP response-element binding protein (CREB) was constant (P>0.05). Immunohistochemistry results showed a significant increase of CaM I protein in cardiac hypertrophy group relative to the control group (P<0.05). Nuclear run off transcription assay displayed a significant increase in bcl-2 mRNA treated with trifluoperazne compared with non-drug treatment (P<0.05). The results obtained suggest that the transcription of bcl-2 is possibly regulated by CaM I hypertrophic rat hearts, and CREB phosphorylation seems to be a minor factor in bcl-2 transcriptional regulation.

[Effects of angiotensin II on Ca2+ signal in cultured rat cardiac myocytes revealed by confocal laser scanning microscopy].

AIM: The effects of angiotensin II on the changes of Ca2+ signal in cultured rat neonatal myocytes were investigated in order to reveal the localization and distribution of elementary Ca2+ signaling units. METHODS: The cultured neonate rat myocytes were treated with angiotensin II, and calcium signal was detected using confocal laser scanning microscopy and fluo-4/AM calcium probe. RESULTS: The propagation of Ca2+ waves was observed in rest and angiotensin II stimulated cardiac myocytes. Calcium fluorescent intensity oscillated slightly in myocytes and the average intensity was much higher in the nucleus than in the cytosol, all of which could be magnified significantly by AngII (10(-6) mol/L). Ca2+ oscillation induced by Ang II was completely blocked by NO donor sodium nitroprusside. AngII evoked Ca2+ sparks close to the cell surface membrane, and couldn't be abolished by sodium nitroprusside. CONCLUSION: There are spatiotemporal dynamics of Ca2+ signaling patterns such as Ca2+ wave, Ca2+ spikes, Ca2+ oscillation and the whole cell Ca2+ transients induced by angiotensin II, which might play very important roles in cellular cardiac function.

[The roles of nuclear Ca2+/CaM dependent kinases and calcineurin on the development of myocardial hypertrophy in rat].

AIM: To evaluate whether protein phosphorylation and dephosphorylation in nuclei play roles in the development of myocardial hypertrophy, distribution of protein kinases and phosphatases in cell fractions were determined. METHODS: The model of hypertensive rat was established by abdominal aortic constriction. Velocity and isopyknic gradient centrifugation was employed to fractionate rat myocardium to membrane, cytosol and nuclei. Enzymatic methods were employed to determine kinases and phosphatases. RESULTS: Compare with control group, the activity of CaMK increased by 101.1% (P < 0.01) and 40.16% (P < 0.01) respectively in nuclear and membranous fractions, changed without significance in cytosolic fraction; the activity of calcineurin in nuclei increased by 43.57%, (P < 0.05), lightly changed without significance in membranous and cytosolic fractions. CONCLUSION: Nuclear translocation of CaMK and calcineurin, might play important roles on overload-induced cardiac hypertrophy.

[Comparison of ryanodine binding to cardiac sarcoplasmic reticulum and nuclear envelope of rat].

AIM: The characteristics of ryanodine receptor in rat cardiac sarcoplasmic reticulum (SR) and nuclear envelope (NE) were studied. METHODS: Velocity and isopyknic gradient centrifugation was employed to fractionate rat SR and NE. Ryanodine receptor was assayed with [3H] ryanodine saturate binding to the preparations. RESULTS: The maximal binding (Bmax) and dissociating constant (Kd) of ryanodine receptor in rat cardiac NE were, 1.7% and 60% of those in SR respectively. Phosphorylation in vitro by PKA and PKC increased Bmax of the receptors in SR by 372% and 121%, and augmented those in NE by 221% and 306%, without any effects on Kd. CONCLUSION: Ryanodine receptors were present in rat myocardial NE, with lower density and higher affinity than those located in SR, which can be activated by PKA and PKC.

A Study of the Myocardial Nuclear Calcium Transport of Rabbit in vitro.

The characteristics of nuclear calcium regulation were investigated in isolated rabbit myocardial nuclei. It was found that calcium concentration in myocardial nuclei was 2.6 fold more than that in myocardial homogenate (P<0.O1), and the nuclear calcium content was only l/6 of the total cellular calcium. Ca-ATPase of myocardial nuclei was [Ca(2+] and [ATP] dependent. [Ca2+] dependent K(a) and V(max) at 2.O mmol/L [ATP] were 226 nmol/L and 3 460 nmol/(h.mg) protein respectively. [ATP] dependent K(m) value and V(max) at 400 nmol/L [Ca2+] were 376.5 &mgr;mol/L and 2 445 nmol/(h.mg) protein respectively. A positive correlation between nuclear 45)Ca2+ transport and Ca-ATPase activity was observed (r=O.945, P<0.01). The above result suggests that myocardial nuclei are able to transport calcium actively. The pathophysiological role of myocardial nuclear calcium transport should be further determined.