TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: To test the hypothesis that effective pulmonary capillary blood flow can be a useful indicator for estimating appropriate oxygenation and ventilation during one-lung ventilation in lung surgery.', 'Prospective data analysis.', 'A 770-bed general teaching hospital.', '15 ASA physical status II and III patients undergoing elective lung surgery.', 'Patients received general and thoracic epidural anesthesia and underwent lung operation with one-lung ventilation.', 'We measured effective pulmonary capillary blood flow by a partial CO2 rebreathing method and oxygenation parameters during two-lung ventilation before surgery, during one-lung ventilation, and during two-lung ventilation after lung surgery.', 'The effective pulmonary capillary blood flow index significantly decreased by 31.6%, which was associated with a significant decrease in arterial oxygen tension (PaO2). The pulmonary shunt fraction increased to 46.3% during one-lung ventilation. During two-lung ventilation, after chest closure, effective pulmonary capillary blood flow index divided by heart rate (i.e., effective pulmonary blood stroke flow index) was still significantly lower than that seen during two-lung ventilation before thoracotomy. There were significant correlations between effective pulmonary capillary blood flow, pulmonary blood stroke flow index, and PaO2.\Question: Is a noninvasive partial carbon dioxide rebreathing technique for measurement of pulmonary capillary blood flow also a useful oxygenation monitor during one-lung ventilation?

SOLUTION: Effective pulmonary capillary blood flow index and effective pulmonary blood stroke flow index are useful indicators for determining appropriate oxygenation therapy during one-lung ventilation.

PROBLEM: Context: Vitamin A plays a major role in lipid metabolism. Previously, we reported that chronic vitamin A feeding (129 mg/kg) for two months normalized the abnormally high plasma HDL-cholesterol (HDL-C) levels in hypercholesterolemic obese rats by upregulating the hepatic scavenger receptor class B type 1 (SR-BI) expression. In this report, we hypothesize that the administration of a dose less than 129 mg of vitamin A/kg would also be effective in lowering the plasma HDL-C levels in these rats.', 'Changes in the activity and expression of proteins related to RCT were analyzed together with blood parameters in five-month-old male lean and obese rats supplemented with 2.6 (control group), 26, 52 and 129 mg of vitamin A/kg as retinyl palmitate for 20 weeks.', 'Vitamin A supplementation in the obese rats decreased the plasma HDL-C levels with a concomitant increase in the hepatic SR-BI expression and lipase activity compared to that observed in the control diet-fed obese rats treated with 2.6 mg of vitamin A/kg diet. Furthermore, vitamin A supplementation at doses of 52 and 129 mg/kg diet reduced the plasma lecithin cholesterol acyltransferase activity and increased the hepatic ATP-binding cassette transporter protein A1 expression in the obese rats. Interestingly, most of these changes were not observed in the lean rats fed a vitamin A-enriched diet.\Question: Does vitamin A-enriched diet modulate reverse cholesterol transport in hypercholesterolemic obese rats of the WNIN/Ob strain?

SOLUTION: Chronic feeding of a vitamin A-enriched diet in hypercholesterolemic obese rats normalizes the plasma HDL-C level and presumably improves RCT, with an effective dose of 52 mg/kg diet. Further studies should focus on the pharmacological potential of vitamin A supplementation to correct an abnormal human obesity-associated lipoprotein metabolism.

PROBLEM: Context: Uterine vascular remodeling at mid gestation includes the thinning of the vessel walls and, typically, an increase in lumen diameter. This study aimed to elucidate any differences in structural remodeling in normal murine pregnancies versus those differences that resulted from the crossing of CBA/J female mice by DBA/2 male mice, a combination that is known to exhibit recurrent resorption/pregnancy loss.', 'CBA/J female mice that were pregnant by DBA/2 male mice (abnormals) and DBA/2 female mice that were pregnant by CBA/J male mice (normals) were killed at mid gestation, which is a time when fetal resorption can be identified. Tissues were collected for permanent fixation and gene expression studies with complementary DNA macroarrays that were specific for extracellular matrix proteins. A 2-fold increase in expression or a 50% decline was considered significant. Expression changes were confirmed by real-time reverse transcriptase-polymerase chain reaction.', 'The vessel-to-lumen diameter ratios were found to be significantly greater for the CBA/J implantation sites (1.50 +/- 0.05 vs 1.22 +/- 0.02, respectively; P < .0001), which indicates a lack of vascular remodeling. There was also a trend towards smaller lumen diameters for the CBA/J vessels, but this was not statistically significant (78.2 +/- 4.4 microm vs 93.5 +/- 6.8 microm, respectively; P = .22). The mean coefficient of variation for lumen measurements was 0.8% and for vessel diameter was 0.3%. The ranges were 0 to 3.2% and 0 to 1.4%, respectively. Tissue inhibitor of metalloproteinase 2 expression was up-regulated in the placentas of the group with higher resorption rates when compared with normals. This was confirmed with reverse transcriptase-polymerase chain reaction, where abnormals exhibited 2.6-fold greater tissue inhibitor of metalloproteinase 2 protein quantities when compared with normal controls (P = .03).\Question: Is failure of decidual arteriolar remodeling in the CBA/J x DBA/2 murine model of recurrent pregnancy loss linked to increased expression of tissue inhibitor of metalloproteinase 2 ( TIMP-2 )?

SOLUTION:
The expansive vascular remodeling of decidual vessels that is characteristic of normal murine pregnancy is attenuated significantly in the CBA/J x DBA/2 mating combination, which is known for its tendency to recurrent fetal resorption. This has been correlated with a relative overexpression of tissue inhibitor of metalloproteinase 2 protein in placentas of this strain combination and compared with normals.