Feasibility of Establishing a Comprehensive Yoga Program and its Dose-Effect Relationship on Cardiovascular Risk Factors and Wellness Parameters: A Pilot Study.

BACKGROUND: We sought to study the feasibility of establishing a comprehensive, mostly self-directed yoga program in a hospital and its dose-effect relationship on cardiovascular risk factors and quality of life (QoL) measures over six months. METHODS: Yoga-based techniques (Advanced Yoga Practices; AYP; advancedyogapractices.com) were taught in 12 biweekly group sessions and self-directed practice at home was emphasized. Cardiovascular risk factors were elucidated by interview and review of medical history. Quality of life (QoL) outcomes included the SF-36, the Cohen Perceived Stress Scale (CPSS), and the Hospital Anxiety and Depression Scale (HADS). Risk factors and QoL measures were compared in participants at baseline and six months, as well as between those practicing ≥ 7 times versus < 7 times per week. RESULTS: A total of 22 individuals (19 women, mean age 59 ± 8.7 years) completed the study. At six months, changes were noted in the Mental Component Scale (MCS) of the SF-36 (p=0.0004) and the CPSS (p = 0.022). A greater improvement in CPSS was noted in those practicing ≥ 7 times versus < 7 times a week (p=0.045). No changes were noted in cardiovascular risk factors. CONCLUSIONS: The prescription of a self-directed yoga program was feasible in a hospital setting and resulted in improvement in QoL measures at six months. Practicing more than seven times per week correlated with greater improvement in the perception of stress. Thus, at least a once-daily dose of AYP techniques for a significant improvement in perceived stress is an appropriate dose to employ and study in hospital settings.

Injury or activity-related pain sustained by a population of at-risk women during a 6-month exercise program.

BACKGROUND: Exercise provides numerous cardiovascular (CV) benefits to women; however, identifying women who are likely to sustain musculoskeletal injury or discomfort is important when tailoring exercise activities. PURPOSE: To evaluate factors associated with the incidence of injury in women at risk for CV disease (CVD) during their participation in a structured exercise intervention for primary CVD prevention. STUDY DESIGN: Retrospective comparative study. METHODS: Baseline anthropometric measures, CV efficiency (via standardized submaximal treadmill testing), and questionnaire-based assessments of functional capacity (Duke Activity Status Index [DASI]), daytime sleepiness (Epworth Sleepiness Scale), and depression (9-item Patient Health Questionnaire) were compared between participants sustaining an injury or experiencing persistent pain, regardless of cause, with those reporting no such events. RESULTS: Of 117 women enrolled in the study, 27 (23%) experienced an injury or activity-related musculoskeletal pain during the program (injured group). Baseline characteristics for the entire group were: age, 57.3 years; weight, 203 lb; body mass index, 34.8 kg/m 2 ; and waist circumference, 39.9 in. Characteristics did not differ significantly between the injured and non-injured groups for baseline demographics (P > 0.05), but obesity incidence (body mass index ≥ 30 kg/m 2 ) was more prevalent in the injured group (P = 0.02). On univariate analysis, 9-item Patient Health Questionnaire depression scores were higher for injured participants (5.6 vs 4.1, P = 0.16) and DASI activity scores were significantly lower for injured participants (31.3 vs 41.0, P = 0.004) despite there being no significant difference in baseline exercise capacity, expressed as metabolic equivalents (8.1 vs 7.5, P = 0.20) between groups. The DASI score was an independent predictor of injury by multivariate analysis (P = 0.0092). CONCLUSION: Women study participants who were injured or experienced activity-related pain during a 6-month structured exercise intervention (injured group) had similar waist measurements, lipid/lipoprotein level profiles, and hemodynamic responses compared with women study participants who were event free (non-injured group); however, injured-group participants were more obese, more depressed, and reported lower functional capacity. Women who have the characteristics of the injured-group participants may be at greater risk for activity-induced injury when participating in exercise-based prevention programs for CV health.

Long-term safety and efficacy of telmisartan/amlodipine single pill combination in the treatment of hypertension.

The use of multiple drug regimens is increasingly recognized as a tacit requirement for the management of hypertension, a necessity fueled in part by rising rates of metabolic syndrome and diabetes. By targeting complementary pathways, combinations of antihypertensive drugs can be applied to provide effective blood pressure control while minimizing side effects and reducing exposure to high doses of individual medications. In addition, combination therapies, including angiotensin converting enzyme (ACE) inhibitors and calcium channel blockers (CCBs), have the added benefit of reducing cardiovascular mortality and morbidity over other dual therapies while providing equivalent blood pressure control. It is possible that angiotensin receptor blockers (ARBs), which unlike ACE inhibitors are minimally affected by upregulation of alternative pathways for angiotensin II accumulation following long-term treatment, would also provide such outcome benefits. At issue, however, is maintaining patient compliance, as adding medications is known to reduce adherence to treatment regimens. The purpose of this review is to summarize existing trial data for the long-term safety and efficacy of a recent addition to the armamentarium of dual-antihypertensive therapeutic options, the telmisartan/amlodipine single pill combination. The areas where long-term data are lacking, notably clinical information regarding minorities and women, will also be discussed.

Putting the benefits and risks of aerobic exercise in perspective.

Although considerable epidemiologic and clinical evidence suggests that structured exercise, increased lifestyle activity, or both are cardioprotective, the absolute and relative risk of cardiovascular and musculoskeletal complications appear to increase transiently during vigorous physical activity. The estimated relative risk of exercise-related cardiac events ranges from 2.1 to 56 and is highest among habitually sedentary individuals with underlying cardiovascular disease who were performing unaccustomed vigorous physical exertion. Moreover, an estimated 7 million Americans receive medical attention for sports and recreation-related injuries each year. These risks, and their modulators, should be considered when endorsing strenuous leisure time or exercise interventions. If the current mantra "exercise is medicine" is embraced, underdosing and overdosing are possible. Thus, exercise may have a typical dose-response curve with a plateau in benefit or even adverse effects, in some individuals, at more extreme levels.

Nitric oxide synthase, ADMA, SDMA, and nitric oxide activity in the paraventricular nucleus throughout the etiology of renal wrap hypertension.

Within the paraventricular nucleus (PVN), there is a balance between the excitatory and inhibitory neurotransmitters that regulate blood pressure; in hypertension, the balance shifts to enhanced excitation. Nitric oxide (NO) is an atypical neurotransmitter that elicits inhibitory effects on cardiovascular function. We hypothesized that reduced PVN NO led to elevations in blood pressure during both the onset and sustained phases of hypertension due to decreased NO synthase (NOS) and increased asymmetrical dimethylarginine (ADMA; an endogenous NOS inhibitor) and symmetric dimethylarginine (SDMA). Elevated blood pressure, in response to PVN bilateral microinjections of a NO inhibitor, nitro-L-arginine methyl ester, was blunted in renal wrapped rats during the onset of hypertension (day 7) and sustained renal wrap hypertension (day 28) compared with sham-operated rats. Adenoviruses (Ad) encoding endothelial NOS (eNOS) or LacZ microinjected into the PVN [1 × 10(9) plaque-forming units, bilateral (200 nl/site)] reduced mean arterial pressure compared with control (Day 7, Ad LacZ wrap: 144 ± 7 mmHg and Ad eNOS wrap: 117 ± 5 mmHg, P ≤ 0.05) throughout the study (Day 28, Ad LacZ wrap: 123 ± 1 mmHg and Ad eNOS wrap: 108 ± 4 mmHg, P ≤ 0.05). Western blot analyses of PVN NOS revealed significantly lower PVN neuronal NOS during the onset of hypertension but not in sustained hypertension. Reduced SDMA was found in the PVN during the onset of hypertension; however, no change in ADMA was observed. In conclusion, functional indexes of NO activity indicated an overall downregulation of NO in renal wrap hypertension, but the mechanism by which this occurs likely differs throughout the development of hypertension.

Aliskiren/amlodipine combination for the treatment of hypertension.

The challenge of managing hypertension is exemplified by the limited success of monotherapy and necessity for multiple drug regimens targeting complimentary pathways. Recent evidence suggests that combination therapy including angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers (CCBs) provides blood pressure control while reducing cardiovascular mortality and morbidity over ACE inhibitor/diuretic therapy. However, CCBs, ACE inhibitors and angiotensin receptor blockers all increase plasma renin activity (PRA), promoting angiotensin I accumulation and angiotensin II production through alternative pathways. While the clinical ramifications of this and other compensatory pathways activating the renin-angiotensin-aldosterone system are unclear, the recently approved aliskiren/amlodipine antihypertensive combination pill has been shown to decrease PRA via aliskiren's direct inhibition of renin. The purpose of this monograph is to review the mechanisms of action, pharmacodynamics, and safety and efficacy profile of the aliskiren/amlodipine combination pill.

Pheochromocytoma presenting with Takotsubo syndrome.

The clinical presentation of Takotsubo syndrome, or apical ballooning syndrome, resembles an extensive anterolateral myocardial infarction with chest pain symptoms and electrocardiographic ST-elevation or T-wave inversion noted in most patients. However, coronary arteries are invariably found to be normal or to display minimal atherosclerotic disease despite modest elevation of cardiac enzymes. Since most cases of Takotsubo syndrome occur after intense physical and/or emotional stress, catecholamine surge appears to be a common underlying mechanism. We present a case of Takotsubo syndrome, which presented with unusual symptoms and was found to be caused by pheochromocytoma. A sudden rise in blood pressure moments after completion of echocardiographic stress testing aided in uncovering the diagnosis.

Usefulness of breast arterial calcium detected on mammography for predicting coronary artery disease or cardiovascular events in women with angina pectoris and/or positive stress tests.

Breast arterial calcium (BAC) has been suggested as a marker and predictor of cardiovascular risk and coronary artery disease (CAD). However, an association between BAC and these cardiovascular end points has not been fully elucidated in patients undergoing cardiac catheterization. Consecutive patients undergoing mammography and cardiac catheterization within a 36-month period were retrospectively evaluated through chart review. Cardiac catheterization films and mammograms from 94 patients were independently reviewed for the presence of CAD and BAC, respectively. Cardiovascular risk factors, history of revascularization, and history of myocardial infarction were compared between women with and without BAC. BAC was more prevalent in older women (mean age 69 + or - 10 vs 63 + or - 11 years, p = 0.02). Aside from an inverse correlation with smoking, there was no difference in the presence of CAD or cardiovascular risk factors between patients with and without BAC. Patients with BAC had a lesser history of acute myocardial infarction (21% vs 41%, p <0.05) and were less likely to undergo revascularization (23% vs 43%, p <0.05). In conclusion, BAC was not positively associated with cardiovascular risk factors, documented CAD, or acute cardiovascular events, suggesting that the presence of BAC as determined by mammography is not a useful predictor of CAD in intermediate- to high-risk patients.

Blood content of asymmetric dimethylarginine: new insights into its dysregulation in renal disease.

BACKGROUND: Plasma asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is significantly elevated in patients with kidney disease and is a potential risk factor for cardiovascular disease. Here, we tested whether human whole blood (WB), as in rodent blood, can accumulate free ADMA and whether this accumulation is a function of disease burden. METHODS: In 16 healthy control subjects (CO), 18 patients with ESRD and 18 matched hypertensive patients with normal renal function (HTN), we compared using high-pressure liquid chromatography baseline plasma and WB supernatant (WBSUP) ADMA and symmetrical dimethylarginine (SDMA) concentrations and accumulation during a 5-h incubation. We measured protein turnover in incubated WBSUP to determine if proteolytic processes drive ADMA accumulation. RESULTS: Elevated plasma ADMA was confirmed in ESRD and HTN populations while basal WBSUP ADMA was significantly higher in ESRD subjects than controls (P = 0.05 versus CO; P = 0.02 versus HTN). Plasma SDMA followed a similar pattern. Incubation of WBSUP resulted in ADMA release from protein-incorporated stores while SDMA was unaffected. ADMA accumulation in ESRD samples was significantly greater than that in HTN (P = 0.03). CO and HTN men showed significantly greater ADMA accumulation than women (P = 0.01 and P = 0.003, respectively) but no gender difference was observed in the ESRD group (P = 0.26). ADMA accumulation correlated with ex vivo protein turnover (R = 0.76, P < 0.0001). CONCLUSIONS: Human blood is capable of releasing physiologically significant quantities of ADMA via proteolytic pathways. Dysregulated ADMA release from WB reservoirs may contribute to the distinctly high plasma ADMA levels in ESRD populations.

Estrogen esters as substrates for human paraoxonases.

Mammalian paraoxonases (PONs 1, 2 and 3) are a highly conserved family of esterases, with uncertain physiological functions and natural substrates. Here we characterize the ability of purified recombinant human PONs to hydrolyze estrogen esters, a class of compounds previously not known to be PON substrates. PONs hydrolyzed estrogen mono- and diesters at position 3 of the steroid A-ring. Diesters were better substrates for the PONs and were very efficiently hydrolyzed, particularly by PON3. Esters at position 17 were not cleaved by the PONs unless an adjacent double bound was present. Purified human serum butyryl cholinesterase also hydrolyzed estrogen esters, however it preferably hydrolyzed the mono-esters. The ability of the PONs' to effectively hydrolyze a variety of estrogen esters provides further insight into the structure of their active sites and suggests that natural compounds with aromatic ester groups might be relevant substrates for the PONs.

Contribution of whole blood to the control of plasma asymmetrical dimethylarginine.

The endogenous nitric oxide (NO) synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is elevated in many patients and may contribute to the initiation and progression of their disease. While some mechanistic pathways have been identified, tissue-specific contributions to ADMA control remain unclear. We sought to determine if whole blood (WB) could participate in ADMA control ex vivo. Anesthetized male Sprague-Dawley rats underwent exsanguinations, and WB preparations were incubated at 37 degrees C for 5 h. ADMA and symmetrical dimethylarginine were analyzed by high-pressure liquid chromatography. Incubation of lysed red blood cell (RBC) supernatant yielded a significant decrease in ADMA that was blocked by 4124W, a synthetic inhibitor of dimethylarginine dimethylaminohydrolase, the only reported enzyme to hydrolyze ADMA. Hydrolysis of ADMA was diminished by addition of physiologically relevant concentrations of zinc (i.e., 20 microM). Conversely, when rat WB or WB supernatant was incubated at 37 degrees C, it liberated quantities of free ADMA (1-2 microM) that in vivo would likely have pathological consequences. Addition of arginine methyltransferase inhibitors to these incubations did not reduce ADMA release, indicating no dominant role for active protein methylation during these incubations. This ADMA liberation was significantly reduced by addition of protease inhibitors, indicating a dependence on peptide bond hydrolysis. Total ADMA (protein incorporated plus free) was determined by acid hydrolysis and found to be 43.18 +/- 4.79 microM in WB with approximately 95% of this in RBCs. These ex vivo data demonstrate the potential of blood to control the NO-NOS system by modulating free ADMA.

Asymmetrical dimethylarginine plasma clearance persists after acute total nephrectomy in rats.

Elevated plasma concentrations of symmetrical dimethylarginine (SDMA) and asymmetrical dimethylarginine (ADMA) are repeatedly associated with kidney failure. Both ADMA and SDMA can be excreted in urine. We tested whether renal excretion is necessary for acute, short-term maintenance of plasma ADMA and SDMA. Sprague-Dawley rats underwent sham operation, bilateral nephrectomy (NPX), ureteral ligation, or ureteral section under isoflurane anesthesia. Tail-snip blood samples (250 microl) were taken before and at 6- or 12-h intervals for 72 h after operation. Plasma clearance was assessed in intact and NPX rats. High-performance liquid chromatography determined SDMA and ADMA concentrations. Sodium, potassium, creatinine, blood urea nitrogen (BUN), and body weight were also measured. Forty-eight hours after NPX, SDMA increased 25 times (0.23 +/- 0.03 to 5.68 +/- 0.30 microM), whereas ADMA decreased (1.17 +/- 0.08 to 0.73 +/- 0.08 microM) by 38%. Creatinine and BUN increased, paralleling SDMA. Sham-operated animals showed no significant changes. Increased SDMA confirms continuous systemic production of SDMA and its obligatory renal excretion, much like creatinine. In contrast, decreased plasma ADMA suggests that acute total NPX either reduced systemic ADMA formation and/or systemic hydrolysis of ADMA increased 48-h post-NPX. However, plasma clearance of ADMA appeared unchanged 48 h after NPX. We conclude that renal excretory function is needed for SDMA elimination but not needed for acute, short-term ADMA elimination in that systemic hydrolysis is fully capable of clearing plasma ADMA.

Ubiquitination and degradation of neuronal nitric-oxide synthase in vitro: dimer stabilization protects the enzyme from proteolysis.

It is established that neuronal NO synthase (nNOS) is ubiquitinated and proteasomally degraded. The metabolism-based inactivation of nNOS and the inhibition of heat shock protein 90 (hsp90)-based chaperones, which are known to regulate nNOS, both lead to enhanced proteasomal degradation of nNOS. The mechanism of this selective proteolytic degradation, or in essence how the nNOS becomes labilized and recognized for ubiquitination and subsequent degradation, has not been determined. In the current study, we used a crude preparation of reticulocyte proteins, which contains ubiquitin-conjugating enzymes and the proteasome, to determine how nNOS is labilized. We found that the inactive monomeric heme-deficient nNOS (apo-nNOS) is rapidly degraded in vitro, consistent with the finding that both metabolism-based inactivation and inhibition of hsp90-based chaperones cause the formation of apo-nNOS and enhance its degradation in vivo. In the current study, we discovered that destabilization of the dimeric nNOS, as determined by measuring the SDS-resistant dimer, is sufficient to trigger ubiquitin-proteasomal degradation. Treatment of nNOS with NG-nitro-L-arginine or 7-nitroindazole led to stabilization of the dimeric nNOS and decreased proteasomal degradation of the enzyme, consistent with that observed in cells. Thus, it seems that the dimeric structure is a major determinant of nNOS stability and proteolysis.

The role of hsp90 in heme-dependent activation of apo-neuronal nitric-oxide synthase.

Like other nitric-oxide synthase (NOS) enzymes, neuronal NOS (nNOS) turnover and activity are regulated by the ubiquitous protein chaperone hsp90. We have shown previously that nNOS expressed in Sf9 cells where endogenous heme levels are low is activated from the apo- to the holo-enzyme by addition of exogenous heme to the culture medium, and this activation is inhibited by radicicol, a specific inhibitor of hsp90 (Billecke, S. S., Bender, A. T., Kanelakis, K. C., Murphy, P. J. M., Lowe, E. R., Kamada, Y., Pratt, W. B., and Osawa, Y. (2002) J. Biol. Chem. 278, 15465-15468). In this work, we examine heme binding by apo-nNOS to form the active enzyme in a cell-free system. We show that cytosol from Sf9 cells facilitates heme-dependent apo-nNOS activation by promoting functional heme insertion into the enzyme. Sf9 cytosol also converts the glucocorticoid receptor (GR) to a state where the hydrophobic ligand binding cleft is open to access by steroid. Both cell-free heme activation of purified nNOS and activation of steroid binding activity of the immunopurified GR are inhibited by radicicol treatment of Sf9 cells prior to cytosol preparation, and addition of purified hsp90 to cytosol partially overcomes this inhibition. Although there is an hsp90-dependent machinery in Sf9 cytosol that facilitates heme binding by apo-nNOS, it is clearly different from the machinery that facilitates steroid binding by the GR. hsp90 regulation of apo-nNOS heme activation is very dynamic and requires higher concentrations of radicicol for its inhibition, whereas GR steroid binding is determined by assembly of stable GR.hsp90 heterocomplexes that are formed by a purified five-chaperone machinery that does not activate apo-nNOS.

Metabolism-based inactivation of neuronal nitric-oxide synthase by components of cigarette and cigarette smoke.

It has been shown that administration of cigarette smoke to rats leads to loss of neuronal nitric-oxide synthase (nNOS) activity and nNOS protein in penile tissue. The exact mechanism for this loss of activity and protein is not known. In the current study, we investigated whether extracts prepared from cigarette smoke or from the cigarette itself could directly inhibit nNOS activity. We discovered that the cigarette smoke extract and the cigarette extract cause a time-, concentration-, and calmodulin-dependent inactivation of nNOS in an in vitro system containing the purified enzyme. L-Arginine, but not D-arginine, protects nNOS from this time-dependent inactivation, suggesting an active site directed event. The kinetics of inactivation are consistent with the metabolism-based or suicide inactivation of nNOS. Based on studies with other metabolism-based inactivators, this cigarette-mediated inactivation may render nNOS more susceptible to proteasomal degradation and thereby may explain the loss of nNOS protein in vivo. The component(s) responsible for nNOS inactivation is not volatile, is not retained by a 3,000 molecular weight cut-off membrane, binds to activated charcoal, and is highly water-soluble under both acidic and basic conditions. The discovery of a direct inactivation of nNOS by an organic, cationic compound(s) present in tobacco and tobacco smoke provides a basis for further study of not only the mechanisms responsible for the biological effects of tobacco but also a search for a potentially novel inactivator of nNOS.

Proteolytic degradation of nitric oxide synthase: effect of inhibitors and role of hsp90-based chaperones.

Nitric oxide synthase (NOS) is a highly regulated enzyme that produces nitric oxide, a critical messenger in many physiological processes. In this perspective, we explore the role of proteolytic degradation of NOS, in particular the inducible and neuronal isoforms of NOS, as a mechanism of regulation of the enzyme. The ubiquitin-proteasome and calpain pathways are the major proteolytic systems identified to date that are responsible for this regulated degradation. The degradation of NOS is affected by diverse agents, including glucocorticoids, caveolin, neurotoxic compounds, and certain NOS inhibitors. Some irreversible inactivators of NOS enhance the proteolytic degradation of the enzyme, and this property may be of great importance in understanding the biological effects of these inhibitors, some of which are being developed for clinical use. Analogies with the regulated degradation of liver microsomal cytochromes P450, which are related to NOS, provide a framework for understanding these processes. Finally, a new perspective on the regulation of NOS by hsp90-based chaperones is presented that involves facilitated heme insertion into the enzyme.

hsp90 is required for heme binding and activation of apo-neuronal nitric-oxide synthase: geldanamycin-mediated oxidant generation is unrelated to any action of hsp90.

It is established that neuronal NO synthase (nNOS) is associated with the chaperone hsp90, although the functional role for this interaction has not been defined. We have discovered that inhibition of hsp90 by radicicol or geldanamycin nearly prevents the heme-mediated activation and assembly of heme-deficient apo-nNOS in insect cells. This effect is concentration-dependent with over 75% inhibition achieved at 20 microm radicicol. The ferrous carbonyl complex of nNOS is not formed when hsp90 is inhibited, indicating that functional heme insertion is prevented. We propose that the hsp90-based chaperone machinery facilitates functional heme entry into apo-nNOS by the opening of the hydrophobic heme-binding cleft in the protein. Previously, it has been reported that the hsp90 inhibitor geldanamycin uncouples endothelial NOS activity and increases endothelial NOS-dependent O(2)() production. Geldanamycin is an ansamycin benzoquinone, and we show here that it causes oxidant production from nNOS in insect cells as well as with the purified protein. At a concentration of 20 microm, geldanamycin causes a 3-fold increase in NADPH oxidation and hydrogen peroxide formation from purified nNOS, whereas the non-quinone hsp90 inhibitor radicicol had no effect. Thus, consistent with the known propensity of other quinones, geldanamycin directly redox cycles with nNOS by a process independent of any action on hsp90, cautioning against the use of geldanamycin as a specific inhibitor of hsp90 in redox-active systems.