Effect of Different Conditioning on Perfluorocarbon Exposed Sonicated Dextrose Albumin Manufacture

BACKGROUND: Generation of perfluorocarbon-exposed sonicated dextrose albumin (PESDA), the custom-made contrast agent, is performed under certain conditions that have been proposed by its original developer. We doubted whether the known composition and manufacturing method of PESDA is ideal and if there is an optimal method of storing batches of PESDA for a significant time duration. METHODS: PESDA was generated with several different composition of ingredients (5% human serum albumin, 5% dextrose water, and perfluorocarbon (PFC) gas), where various ratios of each were used. Sonication was performed for various durations. After manufacturing, the mean size and concentration of the microbubbles were evaluated by hemocytometer and compared. The generated PESDA was stored for 48 hours under 4 degrees C or -20 degrees C and changes in size and concentration of microbubbles were evaluated and compared. RESULTS: The best concentration of microbubbles was found with a mix ratio of albumin: PFC: dextrose of 1:1:1 and sonication time of 90 sec. The microbubble concentration of the optimal PESDA was not different to that of the conventionally manufactured one (9.47+/-1.70 x 10(8) /mL vs. 8.34+/-0.87 x 10(8) /mL, p>0.05) but the mean microbubble size was significantly smaller (1.22+/-0.31 um vs. 1.66+/-0.32 um, p<0.01). After 48 hours, the concentration of microbubbles was reduced by 34+/-3% (p=NS) and 55+/-0.2% (p<0.05) and the size increased by 77+/-25% and 108+/-41% (p=NS in both) in the 4 degrees C -stored and -20 degrees C -stored PESDA, respectively. CONCLUSION: The optimal composition of PESDA ingredients is 1:1:1 for albumin, PFC, and dextrose water, and the best duration of sonication is 90 seconds. Refrigeration under 4 degrees C may be the best way for storage of PESDA for 48 hours.

Monocrotaline-induced pulmonary hypertension correlates with upregulation of connective tissue growth factor expression in the lung

Pulmonary hypertension (PH) is characterized by structural and functional changes in the lung including proliferation of vascular smooth muscle cells (VSMCs) and excessive collagen synthesis. Although connective tissue growth factor (CTGF) is known to promote cell proliferation, migration, adhesion, and extracellular matrix production in various tissues, studies on the role of CTGF in pulmonary hypertension have been limited. Here, we examined CTGF expression in the lung tissues of male Sprague Dawley rats treated with monocrotaline (MCT, 60 microgram/kg), a pneumotoxic agent known to induce PH in animals. Establishment of PH was verified by the significantly increased right ventricular systolic pressure and right ventricle/left ventricle weight ratio in the MCT-treated rats. Histological examination of the lung revealed profound muscular hypertrophy in the media of pulmonary artery and arterioles in MCT-treated group. Lung parenchyma, vein, and bronchiole did not appear to be affected. RT-PCR analysis of the lung tissue at 5 weeks indicated significantly increased expression of CTGF in the MCT-treated group. In situ hybridization studies also confirmed abundant CTGF mRNA expression in VSMCs of the arteries and arterioles, clustered pneumocytes, and infiltrated macrophages. Interestingly, CTGF mRNA was not detected in VSMCs of vein or bronchiole. In saline-injected control, basal expression of CTGF was seen in bronchial epithelial cells, alveolar lining cells, and endothelial cells. Taken together, our results suggest that CTGF upregulation in arterial VSMC of the lung might be important in the pathogenesis of pulmonary hypertension. Antagonizing the role of CTGF could thus be one of the potential approaches for the treatment of PH.

Aldosterone Upregulates Connective Tissue Growth Factor Gene Expression via p38 MAPK Pathway and Mineralocorticoid Receptor in Ventricular Myocytes

The effect of aldosterone on connective tissue growth factor (CTGF) was examined in rat embryonic ventricular myocytes. Upon aldosterone treatment, CTGF expression was significantly increased in a dose and time-dependent manner. To explore the molecular mechanism for this upregulation, we examined the role of mineralocorticoid receptor. Pre-treatment of an antagonist (spironolactone) at 5-fold excess of aldosterone blocked the CTGF induction by aldosterone, suggesting that the upregulation was mediated by mineralocorticoid receptor. Aldosterone treatment resulted in activation of ERK1/2, p38 MAPK, and JNK pathways with a more transient pat-tern in p38 MAPK. Blocking studies using pre-treatment of the inhibitor of each path-way revealed that p38 MAPK cascade may be important for aldosterone-mediated CTGF upregulation as evidenced by the blocking of CTGF induction by SB203580 (p38 MAPK inhibitor), but not by PD098059 (ERK1/2 inhibitor) and JNK inhibitor I. Interestingly, JNK inhibitor I and PD098059 decreased the basal level of CTGF expression. On the other hand, pre-treatment of spironolactone abrogated the p38 MAPK activation, indicating that mineralocorticoid receptor mechanism is linked to p38 MAPK pathway. Taken together, our findings suggest that aldosterone induces CTGF expression via both p38 MAPK cascade and mineralocorticoid receptor and that cross-talk exists between the two pathways.

Selection Tendencies of the Lamaze Class : a Prepared Childbirth Program / 대한산부인과학회잡지

No abstract available.