Cardamonin mitigates kidney injury by modulating inflammation, oxidative stress, and apoptotic signaling in rats subjected to renal ischemia and reperfusion

Renal ischemia-reperfusion injury (IRI) is a critical health concern that aggravates the pathophysiology of acute kidney injury (AKI), leading to high mortality rates in intensive care units. Cardamonin is a natural compound with anti-inflammatory and antioxidant properties. The current study aimed to evaluate the renoprotective impact of cardamonin against AKI induced by renal IRI. Male rats (n=5 per group) were divided into four groups: the sham group underwent anesthesia and abdominal incision only; the control group experienced bilateral renal artery clamping for 30 minutes followed by 2 hours of reperfusion; the vehicle group received the cardamonin vehicle 30 minutes before ischemia induction; and the cardamonin group was administered 5 mg/kg of cardamonin 30 minutes before ischemia. Blood urea nitrogen (BUN) and creatinine were measured to assess the renal function. Tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin-6 (IL-6), caspase 3, and F2-isoprostane were assessed in renal tissues. Kidney injury was examined using the hematoxylin and eosin stain method. Compared to the sham group, the control group exhibited significantly higher levels of BUN, creatinine, TNF-α, IL-1β, IL-6, F2-isoprostane, and caspase 3 in renal tissues, along with severe kidney injury as evidenced by histological analysis. Compared to the control group, pretreatment with cardamonin resulted in a significant reduction in these biomarkers and alleviated renal damage. Cardamonin had renoprotective effects against renal ischemia and reperfusion injury via modulating inflammation, oxidative stress, and apoptosis pathways.

Routine Kt/V and Normalized Protein Nitrogen Appearance Rate Determined From Conductivity Access Clearance With Infrequent Postdialysis Serum Urea Nitrogen Measurements

RATIONALE & OBJECTIVES

Conventional monitoring of hemodialysis dose is implemented using urea kinetic modeling based on single-pool Kt/V, which requires both pre- and postdialysis serum urea nitrogen (SUN) measurements. We compared this conventional approach to one in which Kt/V is calculated using conductivity clearance, thereby reducing the need for regular postdialysis SUN measurements.

STUDY DESIGN

Comparative study of 2 diagnostic tests.

SETTING & PARTICIPANTS

Prevalent patients receiving maintenance hemodialysis for at least 2 years for whom both urea reduction ratio (URR) and average conductivity clearance (Kecn) were measured.

TESTS COMPARED

During the initial 8 months (baseline interval), average Kecn and URR were used to calculate a median patient-specific, modeled, calibration solute distribution volume (Vcal). During months 9 to 16 (period 1) and 17 to 24 (period 2), Kt/V was conventionally computed using URR and also by a new method using Vcal and Kecn without postdialysis SUN values. We examined the percentage error between these 2 methods of calculating Kt/V.

OUTCOMES

Concordance between the 2 methods of calculating Kt/V.

RESULTS

Among 1,093 patients, mean individual-level median single-pool Kt/V values derived using the conventional method during the baseline interval, period 1, and period 2 were 1.62±0.24 (SD), 1.66±0.24, and 1.67±0.24, respectively. During periods 1 and 2, patient-level median Kt/V values derived using Kecn were 1.64±0.24 and 1.65±0.24, respectively. Percent differences between patient-level median values of Kt/V (conductivity minus conventional URR methods) were-0.63%±7.7% and-0.75%±8.4% for periods 1 and 2. Normalized protein nitrogen appearance were comparable between the 2 methods.

LIMITATIONS

Data were collected over 2 years. Study was limited to in-center hemodialysis patients dialyzed 3 times per week. Dialysis session length was not adjusted for treatment interruptions.

CONCLUSIONS

A new method of calculating Kt/V based on Kecn that requires fewer postdialysis SUN measurements provided diagnostic data comparable to those from conventional use of URR and has the potential to avoid errors related to postdialysis blood sampling and measurement.

Rapidity of Correction of Hyponatremia Due to Syndrome of Inappropriate Secretion of Antidiuretic Hormone Following Tolvaptan

BACKGROUND

Tolvaptan effectively corrects hyponatremia due to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), but undesired overcorrection can occur. We hypothesized that pretherapy parameters can predict the rapidity of response to tolvaptan in SIADH.

STUDY DESIGN

Multicenter historical cohort study.

SETTING & PARTICIPANTS

Adults with SIADH or congestive heart failure (CHF) treated with tolvaptan for a serum sodium concentration ≤ 130 mEq/L at 5 US hospitals.

PREDICTORS

Demographic and laboratory parameters.

OUTCOMES

Rate of change in serum sodium concentration.

MEASUREMENTS

Spearman correlations, analysis of variance, and multivariable linear mixed-effects models.

RESULTS

28 patients with SIADH and 39 patients with CHF treated with tolvaptan (mean baseline serum sodium, 120.6 and 122.4 mEq/L, respectively) were studied. Correction of serum sodium concentration > 12 mEq/L/d occurred in 25% of patients with SIADH compared to 3% of those with CHF (P<0.001). Among patients with SIADH, the increase in serum sodium over 24 hours was correlated with baseline serum sodium concentration (r=-0.78; P<0.001), serum urea nitrogen concentration (SUN; r=-0.76; P<0.001), and estimated glomerular filtration rate (r=0.58; P=0.01). Baseline serum sodium and SUN concentrations were identified as independent predictors of change in serum sodium concentration in multivariable analyses. When patients were grouped into 4 categories according to baseline serum sodium and SUN median values, those with both low baseline serum sodium (≤121 mEq/L) and low baseline SUN concentrations (≤10mg/dL) exhibited a significantly greater rate of increase in serum sodium concentration (mean 24-hour increase of 15.4 mEq/L) than the other 3 categories (P<0.05). Among patients with CHF, only baseline SUN concentration was identified as an independent predictor of change in serum sodium concentration over time.

LIMITATIONS

Lack of uniformity in serial serum sodium concentration determinations and documentation of water intake.

CONCLUSIONS

Baseline serum sodium and SUN values are predictive of the rapidity of hyponatremia correction following tolvaptan use in SIADH. We advise caution when dosing tolvaptan in patients with both low serum sodium and SUN concentrations.