Species differences in lipoprotein lipase and hepatic lipase activities: comparative studies of animal models of lifestyle-related diseases.

Lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) have an important role in lifestyle-related diseases. To evaluate species differences, we compared LPL and HTGL activities in different animal models of lifestyle-related diseases using the same assay kit. Normal animals (JW rabbits, ICR mice, and SD rats), a hypercholesterolemic animal model (WHHLMI rabbits), and obese animal models (KK-Ay mice and Zucker fatty rats) fed standard chow were used in this study. Plasma was prepared before and after an intravenous injection of heparin sodium under fasting and feeding. LPL and HTGL activities were measured with the LPL/HTGL activity assay kit (Immuno-Biological Laboratories) using an auto-analyzer. Only in mice, high HTGL activity was observed in pre-heparin plasma. In normal animals, LPL and HTGL activities were high in ICR mice and SD rats but low in JW rabbits. Compared to normal animals, LPL activity was high in Zucker fatty rats and WHHLMI rabbits at both fasting and feeding, while LPL activity after feeding was low in KK-Ay mice. HTGL activity was higher in fasted and fed WHHLMI rabbits and fasted Zucker fatty rats, but was lower in fed KK-Ay mice. Gender difference was observed in HTGL activity in SD rats and LPL activity in WHHLMI rabbits but not in ICR mice. In conclusion, this simple assay method was effective for measuring LPL and HTGL activities of experimental animals, and the activities are highly regulated depending on animal species, animal models, feeding/fasting conditions and genders.

An automated method for measuring lipoprotein lipase and hepatic triglyceride lipase activities in post-heparin plasma.

BACKGROUND: Lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) play a central role in triglyceride-rich lipoprotein metabolism by catalyzing the hydrolysis of triglycerides. Quantification of LPL and HTGL activity is useful for diagnosing lipid disorders, but there has been no automated method for measuring these lipase activities. METHODS: The automated kinetic colorimetric method was used for assaying LPL and HTGL activity in the post-heparin plasma using the natural long-chain fatty acid 2-diglyceride as a substrate. LPL activity was determined with apoCII and HTGL activity was determined without apoCII with 2 channel of auto-analyzer. RESULTS: The calibration curve for dilution tests of the LPL and HTGL activity assay ranged from 0.0 to 500 U/L. Within-run CV was obtained within a range of 5%. No interference was observed in the testing of specimens containing potentially interfering substances. The measurement range of LPL activity in the post-heparin plasma was 30-153 U/L, while HTGL activity was 135-431 U/L in normal controls. CONCLUSIONS: The L PL and HTGL activity assays are applicable to quantitating the LPL and HTGL activity in the post-heparin plasma. This assay is more convenient and faster than radiochemical assay and highly suitable for the detection of lipid disorders.

Functionally undefined gene, yggE, alleviates oxidative stress generated by monoamine oxidase in recombinant Escherichia coli.

Real-time PCR analysis showed that yggE gene was about two and three times up-regulated in Escherichia coli cells exposed to UVA irradiation and thermal elevation, respectively, suggesting that this gene is responsive to physiological stress. The yggE gene was introduced into E. coli BL21 cells, together with a monoamine oxidase (MAO) gene as a model source for oxidative stress generation. The distribution of independently isolated transformants (two dozen isolates) was examined in terms of MAO activity and cell vitality. In the case of control strain expressing MAO alone, the largest number of transformants existed in the low range of MAO activity less than 2 units mg(-1) and the number significantly decreased at increased MAO activity. On the other hand, the distribution of MAO/YggE-coexpressing transformants shifted to higher MAO activity with frequent appearance in the activity range of 4-8 units mg(-1). The yggE gene product therefore has a possible function for alleviating the stress generated in the cells.

Observing quantum correlation of photons in Laguerre-Gauss modes using the Gouy phase.

The effect of the Gouy phase, which is one of the geometrical phases of photons, is observed through quantum correlation in Laguerre-Gaussian (LG) modes. In an experiment, the relative phase of two different LG modes of measurement basis states is manipulated via the Gouy phase, and the observed coincidence count rates agree well with theoretical predictions. This result suggests that the Gouy phase can be used as a new tool to manipulate multidimensional photonic quantum states.

Serum tenascin-C might be a novel predictor of left ventricular remodeling and prognosis after acute myocardial infarction.

OBJECTIVES: We investigated clinical implications of serum tenascin-C (TN-C) levels in patients with acute myocardial infarction (AMI). BACKGROUND: Tenascin-C, an extracellular matrix glycoprotein, is not normally expressed in the adult heart, but transiently appears during pathological conditions and plays important roles in tissue remodeling. METHODS: Serum TN-C levels were measured by ELISA in 105 AMI patients at various time points, in 10 old myocardial infarction (OMI) patients, and 20 normal controls. RESULTS: The mean serum TN-C level of AMI patients on admission (63.3 +/- 30.1 ng/ml) was significantly higher than that of controls and OMI (30.9 +/- 8.8 ng/ml and 27.4 +/- 11.7 ng/ml, respectively, p < 0.01), and peaked at 5 days (83.2 +/- 43.0 ng/ml). Follow-up examination (mean: 43.9 +/- 19.6 months) revealed that 25 of 105 AMI (23.8%) patients showed left ventricular (LV) remodeling (> or =20% end-diastolic volume increase), and in 15 (14.3%), major adverse cardiac events (MACE) were detected. The peak TN-C level was significantly higher in the remodeling group than the nonremodeling group (112 +/- 37 ng/ml vs. 66 +/- 29 ng/ml; p < 0.0001). By receiver-operating characteristic (ROC) analysis, TN-C levels clearly discriminated prediction of LV remodeling and MACE compared with other variables including plasma B-type natriuretic peptide, creatine kinase-MB, and LV function. Best predictive values of TN-C for remodeling and MACE were 84.8 and 92.8 ng/ml, respectively. Cox proportional hazards model analysis showed that TN-C was an important independent predictor of MACE. CONCLUSIONS: The findings suggest that serum TN-C levels might be useful in predicting LV remodeling and prognosis after AMI.

Tenascin-C concentration in synovial fluid correlates with radiographic progression of knee osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a major cause of disability and represents the most common disease in the aging population. Although the course of the disease is generally assessed using standard radiographic images, biochemical markers may be employed to detect the disease and determine the degree of severity. We developed an enzyme linked immunosorbent assay (ELISA) system using a monoclonal antibody specific for the large-splice variants of tenascin-C (TN-C) and examined whether TN-C in synovial fluid (SF) is an adequate biochemical marker of OA progression. METHODS: SF samples were obtained from knees of 74 patients with OA and 16 without OA. Based on the radiographic grading of the OA severity, the knees were divided into 3 groups: mild, moderate, and severe OA. Expression of TN-C splice variants was examined using immunoblotting. TN-C concentrations were determined by ELISA. RESULTS: Western blotting showed the presence of large TN-C variants in SF from severe OA. TN-C levels were 5-fold higher in OA samples compared to subjects without OA (p < 0.0001). TN-C levels were not different between control cases and mild OA, but increased significantly in moderate (p = 0.0244) and severe OA (p < 0.0001). After adjusting TN-C levels for age, body mass index, and sex, TN-C levels correlated with radiographic progression of knee OA (R2 = 0.404, p < 0.0001). CONCLUSION: TN-C, including the large-variant subunits, is a useful biochemical marker for OA progression in the later stages of disease.