Morphometric and gut microbial evaluation of Tilapia (Oreochromis niloticus) fed on different levels of Moringa oleifera

Abstract In current study, different feeding levels of Moringa oleifera formulated diet was compared to analyze the growth performance, feed conversion ratio, feed conversion efficiency and gut microbiology of Oreochromis niloticus. The study was comprised of four treatment groups including 4%, 8% and 12% Moringa oleifera and one control group which was devoid of Moringa leaves. The experimental trial was conducted at the Zoology laboratory of Pakistan Institute of Applied and Social Sciences, (PIASS) Kasur. The physicochemical parameters of water such as temperature, dissolve oxygen, pH, total dissolved solids and salinity in all aquaria were found non-significantly different from each other. In control condition T1, the average weight gain was 14.89±16.90a grams, while average length gain was 11.52±7.444a cm. However, the total viable count on Eosin methylene blue was 7.4×107, 5.8×107 on Tryptic soy agar and 5.8×107on Nutrient agar. In T2, the average weight gain was 16.22±16.09b grams and average length gain was 12.97±7.79b cm. The total viable count on Eosin methylene blue was 7×107, 5.5×107 on Tryptic soy agar and 5.8×107on Nutrient agar. In T3, the average weight gain was 37.88±27.43c grams, while the average length gain was recorded as 16.48±12.56c cm. However, the total viable count for treatment 3 was 6.4×10 on Eosin methylene blue, 4.8×107 on Tryptic soy agar and 5.2×107on Nutrient agar. In T4, the average weight gain was 44.22±31.67d grams, while the average length gain was 15.25±10.49d cm. The total viable count was 4.3×107on Eosin methylene blue, 3.1×107 on Tryptic soy agar and 3.8×107 on Nutrient agar. The effect of Moringa oleifera on the growth of Oreochromis niloticus was found to be significant and 12% Moringa extract showed maximum length and weight gain and minimum feed conversion ratio with the least microbial count in fish intestine.

Uterocutaneous Fistula and its Repair

A uterocutaneous fistula is a rare condition with a few reports in the literature. A 29-year female presented to our department with infected discharge at her previous Pfannenstiel incision. She was P3+1 with her last hysterotomy 16 months back due to previous two cesarean sections and missed miscarriage at 24 weeks of gestational amenorrhea. Over a period of time, she developed a fistulous tract between uterus and anterior abdominal wall and had pussy discharge from the same. MRI showed a fistulous tract extending from the endometrial cavity till the anterior abdominal wall. Her laparotomy was done. The fistulous tract was removed and uterus was repaired successfully. Key Words: Fistula, Uterus, Hysterotomy.

Methadone Blockade of Cardiac Inward Rectifier K+ Current Augments Membrane Instability and Amplifies U Waves on Surface ECGs: A Translational Study

Background Methadone is associated with a disproportionate risk of sudden death and ventricular tachyarrhythmia despite only modest inhibition of delayed rectifier K⁺ current (I_Kr)_, the principal mechanism of drug-associated arrhythmia. Congenital defects of inward rectifier K⁺ current (I_K1) have been linked to increased U-wave amplitude on ECG and fatal arrhythmia. We hypothesized that methadone may also be a potent inhibitor of I_K1, contributing to delayed repolarization and manifesting on surface ECGs as augmented U-wave integrals. Methods and Results Using a whole-cell voltage clamp, methadone inhibited both recombinant and native I_K1 with a half-maximal inhibitory concentration IC50) of 1.5 μmol/L, similar to that observed for I_Kr block (half-maximal inhibitory concentration of 2.9 μmol/L). Methadone modestly increased the action potential duration at 90% repolarization and slowed terminal repolarization at low concentrations. At higher concentrations, action potential duration at 90% repolarization lengthening was abolished, but its effect on terminal repolarization rose steadily and correlated with increased fluctuations of diastolic membrane potential. In parallel, patient ECGs were analyzed before and after methadone initiation, with 68% of patients having a markedly increased U-wave integral compared with premethadone (lead V3; mean +38%±15%, P=0.016), along with increased QT and T_Peak to T_End intervals, likely reflective of I_Kr block. Conclusions Methadone is a potent I_K1 inhibitor that causes augmentation of U waves on surface ECG. We propose that increased membrane instability resulting from I_K1 block may better explain methadone's arrhythmia risk beyond I_Kr inhibition alone. Drug-induced augmentation of U waves may represent evidence of blockade of multiple repolarizing ion channels, and evaluation of the effect of that agent on I_K1 may be warranted.

Physical performance among post-COVID and non-COVID individuals: a comparative study

In this comparative cross-sectional study, we compare the physical performance among post-COVID and non-COVID subjects. A sample of 64 subjects recovered from COVID-19 and 64 subjects who were not infected with COVID-19 were recruited for the study. Both groups were tested for physical performance by 30-s sit-to-stand test, 6-min walk test, and HUMAC balance system. The findings of the present study reveal that there was a significant difference in physical performance between both the groups. In conclusion, this study demonstrated that physical performance is impaired in the post-COVID subjects as compared to the matched non-COVID subjects. Therefore, physical therapy exercise program/regimen should be a part of recovery from COVID-19.

Phytochemical and biological attributes of Bauhinia variegata L. (Caesalpiniaceae)

Abstract Bauhinia variegata plant is a very popular and traditionally potent ethnomedicine. Therefore, it is need of hour to study ameliorative characteristics of B. variegata for novel secondary metabolites. The current study was designed to explore antiproliferative potential of B. variegata due to scant reports on this aspect. Extracts of various parts (flowers, leaves, bark, stem, and roots) were prepared by successive maceration using organic solvents in increasing order of polarity (n-hexane, ethyl acetate, methanol, and water). The determination of polyphenolic contents was done by using colorimetric methods while antioxidant potential was measured using reducing power assay. Brine shrimp lethality assay was performed for determining preliminary cytotoxicity and antiproliferative activity against breast cancer MCF-7 cell line using MTT protocols. Moreover, antimicrobial activities were detected by using disc diffusion assay. The alpha-amylase assay was performed to monitor the antidiabetic potential of the plant. In case of phytochemical analysis methanolic extract of leaves and bark showed highest phenolic and flavonoids contents. n-Hexane and ethyl acetate extracts of stem and roots exhibited more than 90% mortality with LD50 ranges between 1-25 µg/mL when studied by brine shrimp lethality assay. n-Hexane and ethyl acetate extracts of roots and stem also showed antiproliferative activity against human breast cancer MCF-7 cell line with IC50 values ranges between 12.10-14.20 µg/mL. Most of the extracts displayed moderately high antibacterial and antifungal activities. The n-hexane extract of roots showed antidiabetic activity with 60.80 ± 0.20% inhibition of alpha-amylase. In sum, these preliminary results will be useful for further compound isolation from selected plant parts for the discovery of antibacterial, antidiabetic, and anticancer lead candidates.

Impact of idiopathic pulmonary fibrosis on the clinical outcomes of patients admitted for acute decompensated heart failure: an analysis of U.S national inpatient sample

Background

The cardiovascular manifestations of idiopathic pulmonary fibrosis (IPF) include heart failure, pulmonary hypertension, coronary artery disease, cardiac arrhythmias and cardiac manifestations of drugs used to treat IPF. Cardiac disease can be worsened by hypoxia and pulmonary hypertension by IPF. The impact of IPF on the outcomes of acute decompensated heart failure (ADHF) is not well studied.

Purpose

We aim to determine the outcomes of patients admitted for ADHF with co-morbid IPF.

Methods

Data were extracted from the National Inpatient Sample (NIS) 2016 - 2018 Database. The NIS was searched for hospitalizations for adult patients with ADHF as principal discharge diagnosis with and without IPF as secondary diagnosis using ICD-10 codes. The primary outcome was inpatient mortality. Secondary outcomes are detailed in table 1. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. A univariate screen was done to further confirm that these factors affected outcomes with variables having a p-value less than 0.2 included in the multivariate regression analysis. STATA software was used to for analysis.

Results

Of 1,007,824 patients admitted for ADHF, 1850 (0.2%) had IPF. Patients with IPF were significantly younger at the time of hospitalization for ADHF (71 years vs. 76 years, p<0.001). There were 46% females in IPF group compared to 48% in the non-IPF group, p=0.451. The adjusted odds ratio (aOR) for inpatient mortality for ADHF with IPF compared to those without IPF was 2.82 (95% CI 1.897–4.215, p<0.001). Patients with comorbid IPF had 1 day increase in mean length of stay (95% CI 0.475–1.525, p<0.001). Detailed outcomes are listed in table 1.

Conclusions

Co-morbid IPF leads to higher inpatient mortality and higher length of hospitalization in patients with acute decompensated heart failure. It is prudent to risk stratify these patients to improve overall morbidity and mortality.

Funding Acknowledgement

Type of funding sources: None.

Mortality among patients hospitalized with heart failure and type 2 diabetes mellitus: results from United States national inpatient sample 2008 to 2018

Background

Type 2 diabetes mellitus (T2DM) is an important risk factor for, and a frequent co-existing condition with heart failure (HF). With increasing prevalence of heart failure and type 2 diabetes, patients with concomitant HF and T2DM have worse clinical outcomes.

Purpose

We sought to determine the in-patient mortality for type 2 diabetics admitted for heart failure in the U.S hospitals from 2008 to 2018.

Methods

Data were extracted from the National Inpatient Sample (NIS) 2008 to 2018 Database. The NIS was searched for hospitalizations for adult patients with heart failure as principal discharge diagnosis with type 2 diabetes mellitus as a secondary diagnosis using ICD-9 and ICD-10 codes. The primary outcome was inpatient mortality. Multivariate logistic regression analysis was used determine the impact of evolving demographic characteristics (age, sex and race/ethnicity) on in-hospital mortality. STATA software was used to for analysis.

Results

Hospitalization with a primary discharge diagnosis of heart failure steadily decreased from 1,011,094 in 2008 to 807,764 in 2016 and 139,315 in 2018. The patient characteristics of hospitalizations for heart failure in type 2 diabetics are shown in table 1. Adjusted in-hospital mortality in HF with T2DM decreased significantly from 2008 to 2018 (3.6% in 2008 to 2.0% in 2018, P trend 0.003) as shown in graph 1.

Conclusion

Hospitalization for heart failure decreased steadily from 2008 to 2018 in the United States. In-hospital mortality rate for type 2 diabetics admitted for heart failure decreased significantly from 2008 to 2018.

Funding Acknowledgement

Type of funding sources: None.

Interaction of tacrolimus through hedgehog signaling pathway: An in vitro evaluation using rat hepatocytes

Tacrolimus (TAC) is the drug of choice in immunosuppressive therapy for organ transplantation; however, adverse effects are still a major concern. The current study aims to decipher the short-term exposure of TAC on rat hepatocytes in relation to activation of hedgehog (HH) signaling pathway. Time dependent study was conducted using primary rat hepatocytes treated with TAC (36 µM) for 6, 12, 24 and 48 h. Western blot analysis was performed using cell lysate in order to analyze the regulation of HH pathway proteins including HHIP, SMO, PTCH, IHH, SHH, and GLI transcription factors. The study revealed change in protein expression of HH signaling molecules with activation of HH pathway, due to downregulation of HHIP, and enrichment of HH ligands with activation of SMO and GLI transcription factors. It is therefore, concluded that short term TAC exposure leads to upregulation of HH pathway in liver, which may initially act to repair the liver damage but can worsen the condition in case of prolonged immunosuppressive therapy. This insight could lead to understand association of off target effects of immunosuppressive drugs and occurrence of other liver diseases in transplant patients when it comes to long term immunosuppressive therapy. These findings also illuminate a novel direction that use of HH inhibitor might provide a therapeutic strategy for immune suppression related liver disorders.

Impact of Chronic kidney disease on the outcomes of hospitalizations for implantable cardioverter defibrillator or cardiac resynchronization defibrillator placement: An analysis of Inpatient Sample

Funding Acknowledgements

Type of funding sources: None.

1. Background

Implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) are indicated in primary and secondary prevention of dysrhythmias among other indications. We sought to determine the impact of chronic kidney disease (CKD) on hospitalizations for ICD or CRT-D placement.

2. Purpose

Determine how CKD impacts in-patient mortality and cardiovascular outcomes in patients undergoing ICD or CRT-D placement while hospitalized.

3. Methods

Data were extracted from the National Inpatient Sample (NIS) 2016 - 2018 Database. The NIS was searched for patients who underwent ICD or CRT-D placement. The patients were divided into two groups based on presence or absence of CKD as secondary diagnosis using ICD-10 codes. The primary outcome was inpatient mortality. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders (A univariate screen was done to confirm the confounders affected outcomes with variables having a p less than 0.2 were included in the multivariate regression analysis). STATA software was used to for analysis.

4. Results

Of 145,550 patients admitted for ICD or CRT-D placement, 47740 (32.8%) had CKD. The adjusted odds ratio (aOR) for inpatient mortality for patients undergoing ICD or CRT-D placement with co-morbid CKD compared to those without CKD was 1.66 (95% CI 1.194 – 2.329, p = 0.003). Patients with comorbid CKD had lower odds of developing cardiogenic shock (aOR: 0.83, 95% CI 0.718 – 0.948, p = 0.007) and cardiac arrest (aOR: 0.88, 95% CI 0.766 – 0.999, p = 0.048) compared to patients without CKD. Detailed outcomes are listed in table 1.

5. Conclusion

Chronic kidney disease is a risk factor associated with increased in-patient mortality in patients admitted for ICD or CRT-D placement.

Outcome Without CKD, % With CKD, % aOR (95% CI) p-value* Primary outcome In hospital mortality 0.6 1.9 1.66 (1.194 - 2.329) 0.003* Secondary outcomes Length of stay (days), mean 7.0 9.2 -0.01 (-0.345 - 0.322) # 0.945 Total hospital charges (US$), mean 218,962 241,679 -13047 (-20924 - -5171) # 0.001* Cardiogenic shock 6.8 8.0 0.83 (0.718 - 0.948) 0.007* IABP placement 1.7 1.7 0.52 (0.399 - 0.671) <0.001* Cardiac arrest 12..1 8.5 0.88 (0.766 - 0.999) 0.048* Acute renal failure 17.9 48.1 2.89 (2.648 - 3.163) <0.001* Abbreviations: *; statistically significant, #; adjusted mean difference, aOR: adjusted odds ratio, CI: confidence interval, IABP: Intra-aortic balloon placement.Adjusting factors: Age, Charlson comorbidity index, patient’s insurance, location and teaching status of the admitting hospital, dyslipidemia, old myocardial infarction, cerebral infarction, hypertension, diabetes mellitus, liver disease, smoking status and obesity.

Impact of obesity on the clinical outcomes of patients undergoing pacemaker insertion during hospitalization: An analysis of the United States National Inpatient Sample

Funding Acknowledgements

Type of funding sources: None.

1. Introduction

Obesity causes significant cardiovascular morbidity. Nonetheless, there is also evidence supporting obesity paradox particularly in heart failure patients. The impact of obesity on the outcomes of patients undergoing pacemaker insertion is not well studied.

2. Purpose

The purpose of this study is to determine if obesity paradox exists for the patients who undergo pacemaker insertion.

3. Methods

Data were extracted from the National Inpatient Sample (NIS) 2016 - 2018 Database. The NIS was searched for patients who underwent pacemaker insertion while hospitalized. The patients were divided into two groups based on presence or absence of obesity as secondary diagnosis using ICD-10 codes. The primary outcome was inpatient mortality. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. STATA software was used to for analysis.

4. Results

Of 408,040 patients who underwent pacemaker insertion, 64185 (15.7%) were obese. The adjusted odds ratio for inpatient mortality for obese patient undergoing pacemaker insertion compared to non-obese patients was 0.65 (95% CI 0.516 – 0.821, p < 0.001). Secondary outcomes are listed in table 1.

5. Conclusion

Obese patients who underwent pacemaker insertion had lower inpatient mortality compared to non-obese patients. Also, obese patients undergoing pacemaker insertion were less likely to have cardiac arrest but they were more likely to develop decompensated heart failure and acute renal failure compared to non-obese patients.

Outcome Without Obesity, % With Obesity, % aOR (95% CI) p-value* Primary outcome In hospital mortality 10.8 7.0 0.65 (0.516 - 0.821) <0.001* Secondary outcomes Length of stay (days), mean 5.7 6.3 0.031 (-0.105 - 0.168) # 0.654 Total hospital charges (US$), mean 121250 134757 720 (-2307 - 3747) # 0.641 Decompensated heart failure 13.3 19.2 1.53 (1.451 - 1.629) <0.001* Cardiogenic shock 2.3 2.7 1.00 (0.883 - 1.141) 0.954 IABP placement 0.5 0.6 0.98 (0.746 - 1.294) 0.898 Cardiac arrest 4.27 4.30 0.83 (0.753 - 0.920) <0.001* Acute renal failure 20.7 25.4 1.17 (1.112 - 1.231) <0.001* Abbreviations: *; statistically significant, #; adjusted mean difference, aOR: adjusted odds ratio, CI: confidence interval, IABP: Intra-aortic balloon pump.Adjusting factors: Age, race, Charlson comorbidity index, primary insurance, median household income for patient’s zip code, location and teaching status of the admitting hospital, dyslipidemia, chronic obstructive pulmonary disease, hypertension, peripheral vascular disease, diabetes mellitus, chronic kidney disease, liver disease and smoking status. Table 1: Clinical outcomes of hospitalizations for pacemaker insertion based on presence or absence of obesity, analysis of United States National Inpatient Sample from 2016 through 2018.

Novel cholesterol-dependent regulation of cardiac KATP subunit expression revealed using histone deacetylase inhibitors

We recently discovered that the histone deacetylase inhibitor, trichostatin A (TSA), increases expression of the sulfonylurea receptor 2 (SUR2; Abcc9) subunit of the ATP-sensitive K+ (KATP ) channel in HL-1 cardiomyocytes. Interestingly, the increase in SUR2 was abolished with exogenous cholesterol, suggesting that cholesterol may regulate channel expression. In the present study, we tested the hypothesis that TSA increases SUR2 by depleting cholesterol and activating the sterol response element binding protein (SREBP) family of transcription factors. Treatment of HL-1 cardiomyocytes with TSA (30 ng/ml) caused a time-dependent increase in SUR2 mRNA expression that correlates with the time course of cholesterol depletion assessed by filipin staining. Consistent with the cholesterol-dependent regulation of SREBP increasing SUR2 mRNA expression, we observe a significant increase in SREBP cleavage and translocation to the nucleus following TSA treatment that is inhibited by exogenous cholesterol. Further supporting the role of SREBP in mediating the effect of TSA on KATP subunit expression, SREBP1 significantly increased luciferase reporter gene expression driven by the upstream SUR2 promoter. Lastly, HL-1 cardiomyocytes treated with the SREBP inhibitor PF429242 significantly suppresses the effect of TSA on SUR2 gene expression. These results demonstrate that SREBP is an important regulator of KATP channel expression and suggest a novel method by which hypercholesterolemia may exert negative effects on the cardiovascular system, namely, by suppressing expression of the KATP channel.

Synergic effects of cancer stem cells markers, CD44 and embryonic stem cell transcription factor Nanog, on bladder cancer prognosis

Background: Therapy that targets cancer stem cells has the potential to eradicate cancer and prevent tumour recurrence. Therefore, we hypothesized the combined prognostic significance of stem cell markers CD44 (prevalent in basal layer of urothelial carcinoma) and Nanog (embryonic stem cell transcription factor) in bladder cancer.Material and Methods: CD44 and Nanog expression were determined by immunohistochemistry in 112 bladder cancer cases of which 79 were non-muscle invasive and 33 muscle invasive.Results: A significant correlation was found between CD44 and Nanog expression (r = 0.41, p < 0.001). The bladder cancer patients with high CD44 and Nanog expression had poor recurrence-free survival and poor overall survival (all p < 0.01). Multivariate Cox regression analysis identified lymph node positivity (hazard ratio; HR 3.81, 95% confidence interval; CI 1.66-8.75), CD44 (HR/95%CI 7.03 [3.04-16.22]) and Nanog (HR/95%CI 2.89 [1.23-6.77]) as independent prognostic biomarkers for recurrence-free survival, whilst a combined index of CD44 and Nanog expression (high expression group; HR/95%CI 25.45 [6.71-96.50] for recurrence-free survival) and lymph node positivity (HR/95%CI 3.68 [1.63-8.33] for recurrence-free survival) were independent prognostic biomarkers for recurrence-free survival and overall survival (all p < 0.001).Conclusions: A combined index of CD44 and Nanog expression is a promising prognostic predictor of recurrence-free survival and overall survival in bladder cancer. It may help identification of patients who will benefit from intensive treatment.

Acute blood transfusion reactions in a tertiary care hospital in Pakistan - an initiative towards haemovigilance

OBJECTIVE

In this study, we report acute blood transfusion reactions at our hospital, compare our analysis with the reported data and identify areas for improvement.

BACKGROUND

Haemovigilance programmes have been implemented in many countries, and adverse events associated with blood transfusion are published in their annual reports. Pakistan has no current established programme.

MATERIAL AND METHODS

A cross-sectional study was conducted, and all adverse reactions reported to the blood bank from January 2014 to March 2016 were included. An adverse response in the patient, related to administration of blood (within 24 h), was considered an immediate transfusion reaction.

RESULTS

During the study period, 20 956 blood components were issued. A total of 32 (0·15%) adverse reactions were documented. Allergic reactions were the most common adverse event observed in 15 (46·8%) of the cases. Febrile non-haemolytic transfusion reaction (FNHTR) was the second most common reaction seen in nine (28%) followed by bacterial contamination in four (12·5%) and acute haemolytic reaction in two (6·2%) of the cases.

CONCLUSION

The low incidence indicates underreporting and the need for a formal haemovigilance system. International benchmarking between different medical systems is helpful to identify areas in the transfusion process that have to be changed to improve transfusion safety.

Potent Inhibition of hERG Channels by the Over-the-Counter Antidiarrheal Agent Loperamide

OBJECTIVES

The aim of this study was to determine the in vitro electrophysiological properties of loperamide. The authors' hypothesis was that loperamide is a potent blocker of the current carried by the human ether-à-go-go-related gene (hERG) potassium channel.

BACKGROUND

Loperamide is a peripherally-acting μ-opioid agonist available worldwide as an over-the-counter treatment for diarrhea. Like most opioids, it is not currently known to be proarrhythmic. Recent cases of torsade de pointes in association with high-dose loperamide raise concern given its structural similarity to methadone, another synthetic opioid with an established arrhythmia risk.

METHODS

Effects of loperamide on blockade of the hERG potassium channel ion current were assessed in Chinese Hamster Ovary (CHO) cells stably expressing hERG to elucidate current amplitude and kinetics. The concentration required to produce 50% inhibition of hERG current was assessed from the amplitude of tail currents and the impact on action potential duration was assessed in isolated swine ventricular cardiomyocytes.

RESULTS

The 50% inhibitory concentration for loperamide inhibition of hERG ionic tail currents was approximately 40 nmol/l. In current-voltage measurements, loperamide reduced steady and tail currents and shifted the current activation to more negative potentials. Loperamide (10 nmol/l) also increased the action potential duration, assessed at 90% of repolarization, in ventricular myocytes by 16.4 ± 1.7% (n = 6; p < 0.004). The maximum rate of rise of phase 0 of the action potential, however, was not significantly altered at any tested concentration of loperamide.

CONCLUSIONS

Loperamide is a potent hERG channel blocker. It significantly prolongs the action potential duration and suggests a causal association between loperamide and recent clinical cases of torsade de pointes.

Histone deacetylase inhibitors modulate KATP subunit transcription in HL-1 cardiomyocytes through effects on cholesterol homeostasis

Histone deacetylase inhibitors (HDIs) are under investigation for the treatment of a number of human health problems. HDIs have proven therapeutic value in refractory cases of cutaneous T-cell lymphoma. Electrocardiographic ST segment morphological changes associated with HDIs were observed during development. Because ST segment morphology is typically linked to changes in ATP sensitive potassium (K_ATP) channel activity, we tested the hypothesis that HDIs affect cardiac K_ATP channel subunit expression. Two different HDIs, romidepsin and trichostatin A, caused ~20-fold increase in SUR2 (Abcc9) subunit mRNA expression in HL-1 cardiomyocytes. The effect was specific for the SUR2 subunit as neither compound causes a marked change in SUR1 (Abcc8) expression. Moreover, the effect was cell specific as neither HDI markedly altered K_ATP subunit expression in MIN6 pancreatic β-cells. We observe significant enrichment of the H3K9Ac histone mark specifically at the SUR2 promoter consistent with the conclusion that chromatin remodeling at this locus plays a role in increasing SUR2 gene expression. Unexpectedly, however, we also discovered that HDI-dependent depletion of cellular cholesterol is required for the observed effects on SUR2 expression. Taken together, the data in the present study demonstrate that K_ATP subunit expression can be epigenetically regulated in cardiomyocytes, defines a role for cholesterol homeostasis in mediating epigenetic regulation and suggests a potential molecular basis for the cardiac effects of the HDIs.