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.

Tubuloglomerular feedback (TGF) is an important mechanism in control of signal nephron glomerular filtration rate. The oxidative stress in the macula densa, primarily determined by the interactions between nitric oxide (NO) and superoxide (O2-), is essential in maintaining the TGF responsiveness. However, few studies examining the interactions between and amount of NO and O2- generated by the macula densa during normal and hypertensive states.', 'In this study, we used isolated perfused juxtaglomerular apparatus to directly measure the amount and also studied the interactions between NO and O2- in macula densa in both physiological and slow pressor Angiotensin II (Ang II)-induced hypertensive mice.', 'We found that slow pressor Ang II at a dose of 600ng kg(-1) min(-1) for two weeks increased mean arterial pressure by 26.1 5.7mmHg. TGF response increased from 3.40.2m in control to 5.20.2m in hypertensive mice. We first measured O2- generation by the macula densa and found it was undetectable in control mice. However, O2- generation by the macula densa increased to 21.42.5 unit min(-1) in Ang II-induced hypertensive mice. We then measured NO generation and found that NO generation by the macula densa was 138.59.3 unit min(-1) in control mice. The NO was undetectable in the macula densa in hypertensive mice infused with Ang II.
Does oxidative status in the macula densa modulate tubuloglomerular feedback responsiveness in angiotensin II-induced hypertension?

The antifibrotic substance pirfenidone and the angiotensin II type I receptor antagonist candesartan cilexetil, given alone and in combination, were tested in rats with chronic anti-glomerular basement membrane glomerulonephritis (anti-GBM GN).', 'Male Wistar rats with anti-GBM GN were treated for 8 weeks with candesartan (4 mg/kg body weight/day), pirfenidone (500 mg/kg body weight/day) or a combination of both drugs. One GN group received no treatment and untreated non-GN-rats were used as controls. Blood pressure and urinary protein excretion were measured after 3 and 7 weeks. Kidney histology was complemented by ultrastructural investigation and by quantification of collagen Ialpha mRNA.', 'The percentage of glomeruli with adsorption droplets in podocytes correlated well with the amount of proteinuria (r = 0.873, P<0.01) and was significantly lowered in rats treated with candesartan (8.3 vs GN 24.6%), pirfenidone (9.8%) and combined treatment (2.6%, P<0.05 vs candesartan alone). A comparable lowering was seen for segmental sclerosis (GN 11%, candesartan 0.7%, P<0.05 vs GN, pirfenidone 1.8%, P = 0.09 vs GN, candesartan/pirfenidone 0.1%, P>0.5 vs candesartan alone). Cortical collagen Ialpha mRNA expression was significantly decreased in all treatment groups. Ultrastructural investigation showed an amelioration of basement membrane alterations and podocyte damage in the treatment groups. Candesartan caused significant blood pressure reduction and the effect was significantly enhanced by combination therapy after 3 weeks. Rats treated with pirfenidone showed blood pressure values similar to control rats.
Do pirfenidone and candesartan ameliorate morphological damage in mild chronic anti-GBM nephritis in rats?

To compare a simple meal plan emphasizing healthy food choices with a traditional exchange-based meal plan in reducing HbA(1c) levels in urban African Americans with type 2 diabetes.', 'A total of 648 patients with type 2 diabetes were randomized to receive instruction in either a healthy food choices meal plan (HFC) or an exchange-based meal plan (EXCH) to compare the impact on glycemic control, weight loss, serum lipids, and blood pressure at 6 months of follow-up. Dietary practices were assessed with food frequency questionnaires.', 'At presentation, the HFC and EXCH groups were comparable in age (52 years), sex (65% women), weight (94 kg), BMI (33.5), duration of diabetes (4.8 years), fasting plasma glucose (10.5 mmol/l), and HbA(1c) (9.4%). Improvements in glycemic control over 6 months were significant (P < 0.0001) but similar in both groups: HbA(1c) decreased from 9.7 to 7.8% with the HFC and from 9.6 to 7.7% with the EXCH. Improvements in HDL cholesterol and triglycerides were comparable in both groups, whereas other lipids and blood pressure were not altered. The HFC and EXCH groups exhibited similar improvement in dietary practices with respect to intake of fats and sugar sweetened foods. Among obese patients, average weight change, the percentage of patients losing weight, and the distribution of weight lost were comparable with the two approaches.
Is a simple meal plan emphasizing healthy food choices as effective as an exchange-based meal plan for urban African Americans with type 2 diabetes?