Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

In this study, we examined chondrogenic regulation of 2 types of mesenchymal stem cells seeded on the bioengineered substrate in monolayer cultures under mechanically defined conditions to mimic the in vivo microenvironment of chondrocytes within articular cartilage tissues.', 'Human adipose-derived mesenchymal stem cells (ASCs) and bone marrow mesenchymal stem cells (BSCs) were exposed to 0.2 Pa shear stress, 3 MPa cyclic hydrostatic pressure, and combined loading with different sequences on chemically designed medical-grade silicone rubber, while no soluble growth factors were added to the culture medium. The expression levels of chondrogenic-specific genes of SOX9, aggrecan, and type II collagen (Col II) were measured. Results were compared to those of cells treated by biological growth factor.', 'Gene expression patterns were dependent on the loading regime. Moreover, the source of mesenchymal stem cells (adipose or bone marrow) was influential in gene expression. Overall, enhanced expression of chondrogenic markers was found through application of mechanical stimuli. The response was generally found to be significantly promoted when the 2 loading regimes were superimposed.
Do the synergistic effects of shear stress and cyclic hydrostatic pressure modulate chondrogenic induction of human mesenchymal stem cells?

Left ventricular aneurysm repair (LVR) reduces LV wall stress and improves LV function. However, as we reported previously, the initial improvement of LVR was short-term because of LV remodeling but could be maintained longer with postoperative use of an angiotensin-converting enzyme (ACE) inhibitor. Atrial natriuretic peptide (ANP) has been used to treat patients with heart failure by natriuretic and vasodilatory actions. Recent reports have suggested that ANP inhibits the rennin-angiotensin system. In this study, the effects of ANP after LVR were evaluated.', 'Rats that had an LV aneurysm 4 weeks after left anterior descending artery ligation underwent LVR by plicating the LV aneurysm and were randomized into 2 groups: LVR+A group was intravenously administrated with 10 microg/h of carperitide, recombinant alpha-hANP, by osmotic-pump for 4 weeks, and the LVR group was given normal saline. Echocardiography revealed better LV remodeling and function in LVR+A group than in LVR group. Four weeks after LVR, left ventricular end diastolic pressure (LVEDP) and Tau were significantly lower in LVR+A group (LVEDP: 10+/-4 in LVR+A group versus 18+/-6 mm Hg in LVR group, Tau: 13+/-2 versus 17+/-2ms). End-systolic elastance (Ees) was higher in LVR+A group (Ees: 0.34+/-0.2 versus 0.19+/-0.11 mm Hg/microL). The levels of myocardial ACE activity in LVR+A group was significantly lower than in LVR group. The mRNA expressions of brain natriuretic peptide and transforming growth factor beta1 inducing fibrosis significantly decreased in LV myocardium in LVR+A group. Histologically, myocardial fibrosis was significantly reduced in LVR+A group.
Does atrial natriuretic peptide help prevent late remodeling after left ventricular aneurysm repair?

It is well documented that oxidized low-density lipoproteins (LDLs) can stimulate human vascular endothelial cells to produce monocyte chemoattractant protein-1 (MCP-1). Vitamin C is known to be an important antioxidant for vasodilatation. The purpose of this study was to determine whether pretreatment with vitamin C could protect against oxidized-LDL-induced expression of MCP-1 in cultured human umbilical vein endothelial cells (HUVECs).', 'Cultured HUVECs were used for desired experiments before passage 4. Lysophosphatidylcholine (lysoPC), an oxidized component of LDL, was designated as the stimulator for MCP-1 synthesis from cultured HUVECs. MCP-1 concentrations in the cultured media were determined by enzyme-linked immunosorbent assay. MCP-1 RNA was evaluated by a semi-quantitative reverse transcriptase-polymerase chain reaction.', 'HUVECs secreted MCP-1 within 30 minutes after exposure to 50 microM lysoPC. Compared with samples treated with lysoPC alone, pretreatment with vitamin C in concentrations of 50, 100, 150, and 200 microM, reduced levels of MCP-1 in the culture medium by 44%, 51%, 60%, and 67%, respectively, while levels of MCP-1 mRNA decreased by 15%, 18%, 80%, and 82%, respectively.
Does vitamin C protect against lysophosphatidylcholine-induced expression of monocyte chemoattractant protein-1 in cultured human umbilical vein endothelial cells?