Nitroprusside and metal nitroprusside nano analogues for cancer therapy

Sodium nitroprusside (SNP), U.S approved drug has been used in clinical emergency as a hypertensive drug for more than a decade. It is well established for its various biomedical applications such as angiogenesis, wound healing, neurological disorders including anti-microbial applications etc. Apart from that, SNP have been considered as excellent biomedical materials for its use as anti-cancer agent because of its behavior as NO-donor. Recent reports suggest that incorporation of metals in SNP/encapsulation of SNP in metal nanoparticles (metal nitroprusside analogues) shows better therapeutic anti-cancer activity. Although there are numerous reports available regarding the biological applications of SNP and metal-based SNP analogue nanoparticles, unfortunately there is not a single comprehensive review which highlights the anti-cancer activity of SNP and its derivative metal analogues in detail along with the future perspective. To this end, the present review article focuses the recent development of anti-cancer activity of SNP and metal-based SNP analogues, their plausible mechanism of action, current status. Furthermore, the future perspectives and challenges of these biomedical materials are also discussed. Overall, this review article represents a new perspective in the area of cancer nanomedicine that will attract a wider spectrum of scientific community.

Organ perfusion pressure at admission and clinical outcomes in patients hospitalized for acute heart failure

AIMS

Hypoperfusion portends adverse outcomes in acute heart failure (AHF). The gradient between end-organ inflow and outflow pressures may more closely reflect hypoperfusion than mean arterial pressure (MAP) alone. The aim of this study was to investigate organ perfusion pressure (OPP), calculated as MAP minus central venous pressure (CVP), as a prognostic marker in AHF.

METHODS AND RESULTS

The Sodium NItroPrusside Treatment in Acute Heart Failure (SNIP)-AHF study was a multicentre retrospective cohort study of 200 consecutive patients hospitalized for AHF treated with sodium nitroprusside. Only patients with both MAP and invasive CVP data available from the SNIP-AHF cohort were included in this analysis. The primary endpoint was to assess OPP as a predictor of worsening heart failure (WHF), defined as the worsening of signs and symptoms of heart failure leading to intensification of therapy at 48 h. One hundred and forty-six patients fulfilling the inclusion criteria were included [mean age: 61.1 ± 13.5 years, 32 (21.9%) females; mean body mass index: 26.2 ± 11.7 kg/m2; mean left ventricular ejection fraction: 23.8%±11.4%, mean MAP: 80.2 ± 13.2 mmHg, and mean CVP: 14.0 ± 6.1 mmHg]. WHF occurred in 14 (9.6%) patients. At multivariable models including hemodynamic variables (OPP, shock index, and CVP), OPP at admission was the best predictor of WHF at 48 h [OR 0.91 (95% confidence interval 0.86-0.96), P-value = 0.001] with an optimal cut-off value of 67.5 mmHg (specificity 47.3%, sensitivity 100%, and AUC 0.784 ± 0.054). In multivariable models, including univariable significant parameters available at first bedside assessment, namely New York Heart Association functional class, OPP, shock index, CVP, and left ventricular end-diastolic diameter, OPP consistently and significantly predicted WHF at 48 h.

CONCLUSION

In this retrospective analysis on patients hospitalized for AHF treated with sodium nitroprusside, on-admission OPP significantly predicted WHF at 48 h with high sensitivity.

Silver nitroprusside as an efficient chemodynamic therapeutic agent and a peroxynitrite nanogenerator for targeted cancer therapies

INTRODUCTION

Chemodynamic therapy (CDT) holds great promise in achieving cancer therapy through Fenton and Fenton-like reactions, which generate highly toxic reactive species. However, CDT is limited by the lower amount of catalyst ions that can decompose already existing intracellular H2O2 and produce reactive oxygen species (ROS) to attain a therapeutic outcome.

OBJECTIVES

To overcome these limitations, a tailored approach, which utilizes dual metals cations (Ag+, Fe2+) based silver pentacyanonitrosylferrate or silver nitroprusside (AgNP) were developed for Fenton like reactions that can specifically kill cancer cells by taking advantage of tumor acidic environment without used of any external stimuli.

METHODS

A simple solution mixing procedure was used to synthesize AgNP as CDT agent. AgNP were structurally and morphologically characterized, and it was observed that a minimal dose of AgNP is required to destroy cancer cells with limited effects on normal cells. Moreover, comprehensive in vitro studies were conducted to evaluate antitumoral mechanism.

RESULTS

AgNP have an effective ability to decompose endogenous H2O2 in cells. The decomposed endogenous H2O2 generates several different types of reactive species (•OH, O2•-) including peroxynitrite (ONOO-) species as apoptotic inducers that kill cancer cells, specifically. Cellular internalization data demonstrated that in short time, AgNP enters in lysosomes, avoid degradation and due to the acidic pH of lysosomes significantly generate high ROS levels. These data are further confirmed by the activation of different oxidative genes. Additionally, we demonstrated the biocompatibility of AgNP on mouse liver and ovarian organoids as an ex vivo model while AgNP showed the therapeutic efficacy on patient derived tumor organoids (PDTO).

CONCLUSION

This work demonstrates the therapeutic application of silver nitroprusside as a multiple ROS generator utilizing Fenton like reaction. Thereby, our study exhibits a potential application of CDT against HGSOC (High Grade Serous Ovarian Cancer), a deadly cancer through altering the redox homeostasis.

Randomized controlled dose-escalation design to evaluate the safety of a novel pharmacological cardiopulmonary resuscitation strategy

BACKGROUND/AIMS

The motivating randomized controlled phase I trial evaluates three sodium nitroprusside doses in a novel sodium nitroprusside-enhanced cardiopulmonary resuscitation strategy for improved end-organ perfusion relative to local standard of care. Sodium nitroprusside is a vasodilator with an established safety profile in other indications, whereas the local standard of care uses vasoconstrictors, typically epinephrine. The purpose of the proposed trial is to identify the highest safe dose of sodium nitroprusside in this new context as excessive doses may cause severe hypotension with compromised end-organ perfusion.

METHODS

The proposed phase I trial design expands upon traditional dose-finding designs to include a randomized control arm, which is needed to assess safety through the relative increase in serum lactate on hospital admission. For guiding dose escalation, we propose and compare six Bayesian models which characterize expected serum lactate as a function of sodium nitroprusside dose and randomization group. Each model makes a different assumption about the expected change in serum lactate across control cohorts concurrently randomized with each dose. Model selection aims to minimize the expected number of times that a dose is incorrectly classified as safe or unsafe while sample size selection targets an expected number of incorrectly classified doses. Randomization is 1:1 for the initial cohort, and for subsequent cohorts is chosen to maximize the lower confidence bound.

RESULTS

The spike-and-slab model minimizes the expected number of times that a dose is incorrectly classified as safe or unsafe under the most scenarios in the motivating three-dose trial, but all six models exhibit relatively similar performance. A 2:1 randomization ratio for the second and third cohorts maximizes the lower confidence bound when using the spike-and-slab model. With the optimal design, on average, 70 individuals will ensure 1 incorrectly classified dose in 6 opportunities.

CONCLUSION

We recommend that the motivating trial use the spike-and-slab model with a 1:1 randomization ratio for the initial cohort and 2:1 randomization ratio for subsequent cohorts; however, the simpler fixed effects approaches performed similarly well.

Endothelial dysfunction is associated with reduced myocardial mechano-energetic efficiency in drug-naïve hypertensive individuals

Impaired myocardial mechano-energetics efficiency (MEE) was shown to predict incident heart failure, but pathophysiological mechanisms linking impaired MEE with heart failure have not been elucidated. Endothelial dysfunction is a plausible candidate because it has been associated with heart failure. This study aims to investigate the association between MEE and endothelium-dependent vasodilation, among drug-naïve hypertensive individuals. 198 Drug-naïve hypertensive individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study were included. All participants underwent to an oral glucose tolerance test and to an echocardiogram for myocardial LVM-normalized mechano-energetic efficiency (MEEi) measurement. Endothelial-dependent and endothelial-independent vasodilatation were measured by strain-gauge plethysmography during intra-arterial infusion of acetylcholine and sodium nitroprusside, respectively. A multivariate linear regression analysis was conducted to investigate the independent association between maximal endothelial-dependent vasodilation and MEEi. Maximal ACh-stimulated forearm blood flow (FBF) was associated to decreased myocardial MEEi (β = 0.205, p = 0.002) independently of well-established cardiovascular risk factors including age, sex, BMI, waist circumference, smoking status, total and HDL cholesterol, triglycerides, hsCRP, glucose tolerance status, and HOMA-IR index of insulin resistance. Conversely, no association was observed between SNP-stimulated vasodilation and MEEi. Endothelium-mediated vasodilation may contribute to reduce myocardial MEEi independently of several potential confounders. Because diminished myocardial MEE has been previously associated with incident heart failure, a non-invasive assessment of myocardial MEEi may improve the identification of individuals at higher cardiovascular risk who may benefit from the initiation of pharmacological treatments ameliorating the endothelial dysfunction.

Comparison of Clinical Efficacy of Sodium Nitroprusside and Urapidil in the Treatment of Acute Hypertensive Cerebral Hemorrhage

This paper mainly studies the clinical efficacy of sodium nitroprusside and urapidil in the treatment of acute hypertensive intracerebral hemorrhage and analyzes the brain CT image detection based on a deep learning algorithm. A total of 132 cases of acute hypertension admitted to XXX hospital from XX 2019 to XX 2020 were retrospectively analyzed. The diseases of all patients were clinically confirmed, and patients were divided into groups according to the differences in treatment methods. Urapidil was used for group 1; sodium nitroprusside was used for group 2; and urapidil combined with sodium nitroprusside was used for group 3. A convolutional neural network in deep learning is used to construct intelligent processing to classify brain CT images of patients. The network performance of AlexNet, GoogLeNet, and CNN3 is predicted. The results show that GoogLeNet has the highest prediction accuracy of 0.83, followed by AlexNet with 0.80 and CNN3 with 0.74. The results of the performance parameter curve show that the GoogLeNet has the highest performance parameter of 0.89, followed by AlexNet and CNN3 network. The performance parameter curve of machine learning is above 0.80. After five weeks of drug treatment, the hematoma volume was (3.8 ± 2.6) mL in group1, (7.6 ± 2.8) mL in group 2, and (2.8 ± 1.5) mL in group 3. After 5 days of treatment, the patients' heart rate changed compared with before treatment. Compared with group 2, there were significant differences between groups 1 and 3 (P < 0.01), indicating that the therapeutic effect of the combination group was significantly better than that of the other groups alone. In summary, the combination of sodium nitroprusside and urapidil has a significantly better effect than that of urapidil alone. A convolutional neural network based on deep learning improves the recognition accuracy of medical images.

Ag2[Fe(CN)5NO]-Fabricated Hydrophobic Cotton as a Potential Wound Healing Dressing: An In Vivo Approach

There have been reports of different types of wound dressings for various functions and purposes. Cotton being one of the most widely used wound dressing material due to its non-toxic, biodegradable, and other properties is used for fabrication as well as in the form of scaffolds for faster and effective wound closure. Our research team has already demonstrated the role of silver nitroprusside nanoparticles (SNPNPs) for wound healing and antibacterial activity. In the current study, we have developed cotton fabric impregnated with SNPNPs (SNPCFs) which remain photo inert and displayed long-term antimicrobial activity due to the surface modification with the silver nitroprusside complex. These SNPCFs were characterized by various analytical techniques (XRD, FTIR, UV spectroscopy, TGA, TEM, FESEM, EDAX, ICP-OES). The fabricated cotton dressings with nanoparticles showed an improved water contact angle (113-130°) than that of bare cotton gauze (60°) and exhibited more antibacterial property in case of both Gram-negative bacteria (Klebsiella aerogenes and Escherichia coli) and Gram-positive bacteria (Pseudomonas aeruginosa and Bacillus subtilis) even after several washings. The biocompatible nature of SNPCFs was assessed by in vivo chorioallantoic membrane assay that showed no obstruction in the formation of blood vessels. The SNPCFs exhibited better wound healing activity compared to the bare cotton and AgCFs as observed in the C57BL6/J mouse. The histopathological investigation reveals increase in re-epithelialization and deposition of connective tissue. The macrophage (M2) counts in SNPCF-treated skin tissues were supportive of more wound healing activity than mice treated with cotton fabric impregnated with chemically synthesized silver nanoparticles. Based on biodistribution analysis using ICP-OES, the data illustrated that a significant amount of silver is absorbed in the skin tissues of mice as compared to the blood and kidney. Furthermore, the absence of silver from the vital organs (heart, liver, and kidney) corroborates our hypothesis that the SNPCFs can act excellently in treating wounds when topically applied over skin. Thereafter, all these results highlight a strong possibility that SNPCFs exemplify the potential as a new antimicrobial and wound healing agent in future times.

Efficacy and safety of Shenfu injection combined with sodium nitroprusside in the treatment of chronic heart failure in patients with coronary heart disease: A protocol of randomized controlled trial

BACKGROUND

Coronary heart disease is a serious cardiovascular disease. There is coronary atherosclerosis, resulting in lumen stenosis, blockage, and then the symptoms of insufficient blood supply and hypoxia in the myocardium. Chronic heart failure is a kind of syndrome with abnormal ventricular filling and ejection function, which is the final stage of the development of coronary heart disease. At present, the treatment plan of Western medicine can significantly reduce the hospitalization rate, but it is still not satisfactory for the prognosis and mortality of patients. Shenfu injection has advantages in the treatment of heart failure in patients with coronary heart disease, but there is a lack of standard clinical studies to verify it, so the purpose of this randomized controlled study is to evaluate the efficacy and safety of Shenfu injection combined with sodium nitroprusside in the treatment of chronic heart failure in patients with coronary heart disease.

METHODS

This is a prospective randomized controlled trial to study the efficacy and safety of Shenfu injection combined with sodium nitroprusside in the treatment of chronic heart failure in patients with coronary heart disease. The patients will be randomly divided into a treatment group and the control group according to 1:1, in which the treatment group is treated with Shenfu injection combined with sodium nitroprusside, and the control group is treated with sodium nitroprusside alone. Both groups will be treated with standard treatment for 7 days and followed up for 30 days to pay attention to their efficacy and safety indexes. The observation indexes include TCM syndrome score, N-terminal pro-brain natriuretic peptide, left ventricular ejection fraction, brain natriuretic peptide, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, stroke volume, adverse reactions and so on. We will use SPSS 25.0 software for data analysis.

DISCUSSION

This study will evaluate the efficacy and safety of Shenfu injection combined with sodium nitroprusside in the treatment of chronic heart failure in patients with coronary heart disease. The results of this experiment will provide a clinical basis for Shenfu injection combined with sodium nitroprusside in the treatment of chronic heart failure in coronary heart disease.

TRIAL REGISTRATION

DOI 10.17605/OSF.IO/4KNG3.

Combined effects of hydralazine and nitrate on serum biochemistry and left ventricular remodeling in chronic heart failure patients

To investigate the effects of hydralazine combined with nitrate on serum levels of Adropin and brain natriuretic peptide (BNP), left ventricular remodeling and prognosis in patients with chronic heart failure (CHF). 126 CHF patients were divided into control group (n=13, sodium nitroprusside) and combined treatment group (n=63, sodium nitroprusside ± hydralazine). Serum Adropin and BNP levels and left ventricular mass index (LVMI) of patients before treatment and 10 days after treatment were recorded, so did patient's end-point events. It was found that compared with those before treatment, the serum levels of Adropin, BNP, and LVMI in combined group and control group after 10 days of treatment were lower (P<0.05). The end-point event rate in the combined group was 19.05% (12/63). The serum levels of Adropin, BNP, and LVMI in the combined group with end-point events were higher than those of patients without end-point events (P<0.05). Spearman correlation analysis showed that serum levels of Adropin and BNP were positively correlated with LVMI and the end-point events rate (P<0.05). To sum up, hydralazine combined with sodium nitroprusside treatment can effectively reduce serum Adropin and BNP levels, and the risk of left ventricular remodeling and poor prognosis in patients with CHF.

Transcriptional analysis reveals sodium nitroprusside affects alfalfa in response to PEG-induced osmotic stress at germination stage

Drought is one of the most common environmental factors that affect alfalfa germination and development. Nitric oxide (NO) could mediate stress tolerance in plants. The goal of this study was to determine exogenous NO donor-mediated drought adaption molecular mechanisms during the alfalfa germination stage. In this study, physiological and transcriptome analyses were performed on 7 days of the growth period seedlings by sodium nitroprusside (SNP) and polyethylene glycol (PEG) treatment. The results showed that SNP supplementation alleviated malondialdehyde accumulation, increased levels of proline and soluble sugars, and enhanced antioxidant enzyme activity under osmotic stress conditions. RNA-Seq experiments identified 5828 genes exhibiting differential expression in seedlings treated with PEG, SNP, or SNP+PEG relative to seedlings treated with distilled water. Of these DEGs, 3235 were upregulated, and 2593 were downregulated relative to the controls. Fifteen DEGs were amplified by qRT-PCR to verify the changes in expression determined by RNA-Seq, revealing that PIF3, glnA, PLCG1, and RP-S11e exhibited enhanced expression under the SNP+PEG treatment. SNP was found to modulate redox homeostasis-related genes such as GSTs, SOD2, GPX, and RBOH, and triggered calcium signaling transduction. It also induced some key genes relating to the abscisic acid, ethylene, and auxin signaling transduction in response to PEG stress. Conversely, genes associated with secondary metabolite biosynthesis and the metabolism of starch and sucrose during osmotic stress were downregulated by SNP. These results provide new insights into SNP-mediated drought adaption mechanisms at transcriptome-wide in alfalfa and reveal key drought tolerance pathways in this species.

Comparison of sodium nitroprusside and adenosine for fractional flow reserve assessment: a systematic review and meta-analysis

BACKGROUND

Fractional flow reserve (FFR) has become a useful tool in the assessment of physiological significance of coronary artery stenosis (CAS), and Adenosine (ADE) is associated with a high incidence of transient side effects. Sodium nitroprusside (NPS) has been proposed as an alternative vasodilator agent. A meta-analysis of studies comparing ADE and NPS for FFR assessment in the same coronary lesions was performed.

METHODS

Authors searched for articles comparing NPS and ADE for FFR assessment in intermediate coronary lesions published through January 2018. The following keywords were used: 'fractional flow reserve' AND 'nitroprusside'. Data were summarized using weighted mean differences for paired data.

RESULTS

Seven studies were identified comprising 342 patients and 401 lesions. Four studies evaluated intravenous ADE and 3 studies intracoronary ADE administration. Weighted means FFR values obtained with ADE and NPS were 0.8411 and 0.8445, respectively (weighted mean difference: 0.00, 95% confidence interval (CI) -0.01 to 0.01, p = 0,548). Adverse events were significantly reduced with IC NPS (RR = 0.08, 95%CI 0.02-0.30, P < 0.0001).

CONCLUSIONS

NPS produces similar FFR measurements compared to ADE with a significant reduction in adverse effects. These results may support its use as a suitable alternative to ADE for FFR assessment.

Use of sodium nitroprusside in retrograde percutaneous coronary intervention for chronic total occlusion: A case report

RATIONALE

Chronic total occlusion continues to be a challenging lesion subset for percutaneous coronary intervention.

PATIENT CONCERNS

A 65-year-old male patient was admitted with symptoms of angina pectoris for 9 months.

DIAGNOSES

Coronary angiography showed a severe stenosis in the proximal left anterior descending artery and a chronic total occlusion (CTO) in the proximal right coronary artery. The complexity of the CTO was stratified using the J-CTO score and the PROGRESS CTO score.

INTERVENTIONS

Antegrade wire escalation for CTO of RCA failed. The septal collaterals to RCA were initially judged to be poor and not suitable for intervention.

OUTCOMES

However, administration of sodium nitroprusside improved collateral flow and enabled the identification of retrograde channels suitable for wire crossing and successful retrograde PCI.

LESSIONS

The study showed that faintly visible to even invisible septal collateral connections can be crossed with the septal "trial and error" surfing technique after the administration of sodium nitroprusside.

A Simple and Effective Method to Improve Intrasplenic Rat Hepatocyte Transplantation

Transplanted hepatocytes integrate, survive, and express their specific functions in the liver parenchyma. The aim of this study was to determine whether a large number of hepatocytes could move from the spleen to the liver when the cells are injected together with sodium nitroprusside, and if the improved hepatocyte migration may be related with portal vein dilatation. Wistar rats were transplanted in the spleen with fluorescent-labeled hepatocytes alone or together with sodium nitroprusside. At 1, 3, 6, and 24 h after the transplant, the liver from recipient animals was removed and morphometric analyses were performed. Portal and arterial pressures were also measured immediately after intrasplenic injection of a solution of sodium nitroprusside, hepatocytes alone, or hepatocytes plus sodium nitroprusside. Intrasplenically injected sodium nitroprusside produced a transient drop in arterial pressure and a sustained reduction in portal pressure. During hepatocyte transplantation it increased the number of transplanted cells migrating to the liver after 3 h. Sodium nitroprusside simultaneously injected with hepatocytes in the spleen allowed more cells to migrate into the liver of the host animal without risk in animal survival.

The beneficial hemodynamic effects of afterload reduction by sodium nitroprusside during rewarming from experimental hypothermia

BACKGROUND

Rewarming from hypothermia is associated with depressed cardiac function, known as hypothermia-induced cardiac dysfunction (HCD), and increased systemic vascular resistance (SVR). Previous studies on pharmacological treatment of HCD have demonstrated beneficial effects when using drugs with the combined effects; cardiac inotropic support and peripheral vasodilation. The presented study aims to investigate the isolated effects of arterial dilatation on cardiac functional variables during rewarming from hypothermia using sodium nitroprusside (SNP).

METHODS

We utilized a rat model designed to induce HCD following 4 h at 15 °C and rewarming. To study effects on left ventricular (LV) functional variables in response to afterload reduction by SNP during rewarming a conductance catheter was used. Index of LV contractility, preload recruitable stroke work (PRSW), was obtained with inferior vena cava occlusions at 37 °C before and after hypothermia. Pressure signals from a catheter in the left femoral artery was used to pharmacologically adjust SVR.

RESULTS

After rewarming both animal groups showed significant reduction in both SV and CO as a manifestation of HCD. However, compared to saline controls, SV and CO in SNP-treated animals increased significantly during rewarming in response to afterload reduction displayed as reduced SVR, mean arterial- and end-systolic pressures. The cardiac contractility variable PRSW was equally reduced after rewarming in both groups.

CONCLUSION

When rewarming the present model of HCD a significant increase in SVR takes place. In this context, pharmacologic intervention aimed at reducing SVR show clear positive results on CO and SV. However, a reduction in SVR alone is not sufficient to fully alleviate CO during HCD, and indicate the need of additional inotropic support.

Comparison of the Effects of Nitroglycerin and Nitroprusside on Transmitral Doppler Flow Parameters in Patients with Hypertensive Urgency

BACKGROUND:

Sodium nitroprusside (NIP) and nitroglycerin (NIT) are frequently selected agents for acutely reducing blood pressure. However, it is not clear which agent is more efficacious in improving left ventricular filling pressure in hypertensive crises.

OBJECTIVE:

To compare the acute effects of nitroglycerin (NIT) and nitroprusside (NIP) on transmitral Doppler filling parameters in patients with hypertensive urgency.

METHODS:

We identified 37 patients from our emergency department with hypertensive urgency and left ventricular filling abnormalities. Hypertensive urgency was defined as a severe blood pressure elevation without evidence of progressive end-organ injury. Patients were randomized to receive an infusion of NIT or NIP. NIT was infused at a starting dose of 10 μg/min; NIP was infused at a starting dose of 0.25 μg/kg/min. The infusion rates were adjusted to decrease mean arterial pressure by 25%, and this reduction was obtained within 2 hours in all patients. Diastolic filling parameters were measured by using echocardiography before and after treatment. Pulsed-wave Doppler transmitral flow velocities were used. Early diastolic flow, atrial contraction signal, early diastolic flow/atrial contraction signal, deceleration time, and isovolumetric relaxation time (IVRT) were measured.

RESULTS:

There were no differences between groups in baseline demographic and echocardiographic parameters. Blood pressure decreased significantly in both treatment groups. In posttreatment echocardiographic examinations, atrial contraction signal, deceleration time, and IVRT were significantly decreased in both treatment groups. Early diastolic flow was significantly decreased in the NIT group. There were no significant differences between the groups in terms of posttreatment early diastolic flow, atrial contraction signal, deceleration time, and IVRT values.

CONCLUSIONS:

In hypertensive urgency with left ventricular filling abnormalities, reduction of blood pressure associated with NIT or NIP treatment may improve transmitral Doppler filling parameters. There were no differences demonstrated between the 2 agents.

The effect of sodium nitroprusside on psychotic symptoms and spatial working memory in patients with schizophrenia: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Sodium nitroprusside (SNP) has been reported to rapidly reduce psychotic symptoms in patients with schizophrenia. This has the potential to revolutionize treatment for schizophrenia. In this study, we tested the hypothesis that SNP leads to a reduction in psychotic symptoms and an improvement in spatial working memory (SWM) performance in patients with schizophrenia.

METHOD

This was a single-centre, randomized, double-blind, placebo-controlled trial performed from 27 August 2014 to 10 February 2016 (clinicaltrials.gov identifier: NCT02176044). Twenty patients with schizophrenia aged 18-60 years with a diagnosis of schizophrenia or schizoaffective disorder were recruited from psychiatric outpatient clinics in the South London and Maudsley NHS Trust, London, UK. Baseline symptoms were measured using the Positive and Negative Syndrome Scale (PANSS) and the 18-item Brief Psychiatric Rating Scale (BPRS-18), and SWM was assessed using the CANTAB computerized test. Participants received either an infusion of SNP (0.5 μg/kg per min for 4 h) or placebo and were re-assessed for symptoms and SWM performance immediately after the infusion, and 4 weeks later.

RESULTS

SNP did not lead to any reduction in psychotic symptoms or improvement in SWM performance compared to placebo.

CONCLUSIONS

Although this study was negative, it is possible that the beneficial effects of SNP may occur in patients with a shorter history of illness, or with more acute exacerbation of symptoms.

Branch vessel complications are increased in aortic dissection patients with renal insufficiency

Morbidity and mortality from aortic dissection remain high despite advances in diagnosis and treatment. Simple markers to identify patients at high risk for non-aortic complications of dissection are lacking. We investigated the effect of renal insufficiency on the presentation, complications, and outcome of patients with acute aortic dissection. We evaluated 638 patients with type A and 365 patients with type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD) between January 1996 and December 2000. Chi-squared and Student’s t testing were performed to identify the effect of renal insufficiency on patient presentation, management, and outcome. Patients with renal insufficiency more often required nitroprusside for blood pressure control (type A: 40.7% vs 31.1%, p 1/4-0.049; type B: 66.7% vs 37.3, p 1/4-0.0001) and had a greater risk of mesenteric ischemia (type A: 10.7% vs 1.4%, p < 0.0001; type B: 17.7% vs 3.0%, p < 0.0001). In conclusion, aortic dissection patients with renal insufficiency are at increased risk for drug-resistant hypertension and aortic branch vessel compromise. Routine measurement of serum creatinine provides a readily accessible clinical marker for important complications. Upon recognition, renal impairment indicates a need for close monitoring, aggressive blood pressure control, and evaluation of aortic branch vessel circulations.

Comparison of Antihypertensives after Coronary Artery Surgery

Hypertension following coronary artery bypass grafting is a common problem that may result in postoperative myocardial infraction or bleeding, Hemodynamic effects were compared in 45 hypertensive coronary bypass patients randomized to receive either diltiazem, nitroglycerin, or sodium nitroprusside. Diltiazem was administered as an intravenous bolus of 0.3 mg·kg−1 within 5 min, followed by infusion of 0.1–0.8 mg·kg−1·h−1 in group 1. Nitroglycerin was infused at a rate of 1–3 μg·kg·h−1 in group 2, and sodium nitroprusside was given at a rate of 1–3 μg·kg−1·min−1 in group 3. Hemodynamic measurements were carried out before infusion (T1) and at 30 min (T2), 2 h (T3), and 12 h (T4) after initiation of treatment in the intensive care unit. Mean arterial pressure decreased significantly in all groups. There were no differences among groups at T1 and T2. At T3, heart rate in group 2 was significantly higher than group 1. At T3 and T4, the double product was highest in group 3 (group 1 vs. 3, p < 0.001). These results suggest that the hemodynamic effects of the 3 drugs are similar within the first 30 min. However, after 30 min, diltiazem affords better myocardial performance and more effective control of hypertension.

Nitric Oxide Resistance Reduces Arteriovenous Fistula Maturation in Chronic Kidney Disease in Rats

Background

Autologous arteriovenous (AV) fistulas are the first choice for vascular access but have a high risk of non-maturation due to insufficient vessel adaptation, a process dependent on nitric oxide (NO)-signaling. Chronic kidney disease (CKD) is associated with oxidative stress that can disturb NO-signaling. Here, we evaluated the influence of CKD on AV fistula maturation and NO-signaling.

Methods

CKD was established in rats by a 5/6^th nephrectomy and after 6 weeks, an AV fistula was created between the carotid artery and jugular vein, which was followed up at 3 weeks with ultrasound and flow assessments. Vessel wall histology was assessed afterwards and vasoreactivity of carotid arteries was studied in a wire myograph. The soluble guanylate cyclase (sGC) activator BAY 60–2770 was administered daily to CKD animals for 3 weeks to enhance fistula maturation.

Results

CKD animals showed lower flow rates, smaller fistula diameters and increased oxidative stress levels in the vessel wall. Endothelium-dependent relaxation was comparable but vasorelaxation after sodium nitroprusside was diminished in CKD vessels, indicating NO resistance of the NO-receptor sGC. This was confirmed by stimulation with BAY 60–2770 resulting in increased vasorelaxation in CKD vessels. Oral administration of BAY 60–2770 to CKD animals induced larger fistula diameters, however; flow was not significantly different from vehicle-treated CKD animals.

Conclusions

CKD induces oxidative stress resulting in NO resistance that can hamper AV fistula maturation. sGC activators like BAY 60–2770 could offer therapeutic potential to increase AV fistula maturation.

Comparison of the hemodynamic effects of nitroprusside and remifentanil for controlled hypotension during endoscopic sinus surgery

PURPOSE

Controlled hypotension (CH) is a well-established technique to decrease blood loss and improve surgical visibility. Although nitroprusside and remifentanil have been safely and effectively used for this purpose, the hemodynamic changes that occur during CH are unclear. This study compared the effects of nitroprusside and remifentanil on hemodynamics using a noninvasive cardiac output monitor (Cheetah NICOM(®); Cheetah Medical Inc., Maidenhead, Berkshire, UK) for endoscopic sinus surgery (ESS).

METHODS

Twenty-eight adult patients scheduled for ESS were randomly assigned to the nitroprusside group (n = 14) or remifentanil group (n = 14). After anesthesia induction, hypotension was induced with continuous infusion of nitroprusside or remifentanil at a target mean arterial blood pressure (MAP) of 60-70 mmHg. Cardiac index (CI), stroke volume index (SVI) and total peripheral resistance index (TPRI) were measured at 10-min intervals.

RESULTS

The heart rate was higher and SVI was lower in the nitroprusside group than in the remifentanil group during CH. There were no significant differences in MAP, CI or TPRI between the two groups. Both nitroprusside and remifentanil reduced MAP and TPRI during CH compared with baseline values. However, there was no significant change in CI.

CONCLUSIONS

Both nitroprusside and remifentanil were effective to induce CH and maintain CI during CH.

Single dose regorafenib-induced hypertensive crisis

Gastrointestinal stromal tumors (GISTs) are uncommon tumors of the gastrointestinal (GI) tract. Regorafenib is a new multikinase inhibitor and is approved for the treatment of GISTs in patients who develop resistance to imatinib and sunitinib. The most common drug-related adverse events with regorafenib are hypertension, hand-foot skin reactions, and diarrhea. Grade IV hypertensive side effect has never been reported after a single dose. In this report, we present a case of Grade IV hypertensive side effect (hypertensive crisis and seizure) after a single dose of regorafenib. A 54-year-old male normotensive GIST patient was admitted to the emergency department with seizure and encephalopathy after the first dosage of regorafenib. His blood pressure was 240/140 mmHg upon admission. After intensive treatment with nitrate and nitroprusside, his blood pressure returned to normal levels in five days. Regorafenib was discontinued, and he did not experience hypertension again. This paper reports the first case of Grade IV hypertension after the first dosage of regorafenib. We can suggest that hypertension is an idiosyncratic side effect unrelated to the dosage.

[A high-volume single center experience of no-reflow post-percutaneous coronary intervention]

BACKGROUND

The no-reflow (NR) phenomenon is frequent in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). However, its real incidence and prognostic significance, so far derived from relatively small patient cohorts, remain poorly defined.

METHODS

We have retrospectively analyzed 19 290 consecutive PCI performed at our hospital between January 1998 and November 2010. NR was defined as a TIMI flow ≤2 at the end of the PCI.

RESULTS

In the 1257 patients with STEMI, NR occurred in 9.4% of cases and was more common when the left anterior descending coronary artery was the culprit vessel. STEMI-NR patients had longer ischemic times and more frequently multivessel disease. In the STEMI-NR group, glycoprotein IIb/IIIa inhibitors were used in 60.2%, nitroprusside in 39.6%, thrombus aspiration in 10.7% and adenosine in 8.7%. In the remaining 18033 patients without STEMI undergoing PCI, the NR phenomenon occurred only in 0.2% of cases. STEMI-NR patients had lower left ventricular ejection fraction at discharge (50.3 ± 7.2 vs 44.9 ± 8.4%; p<0.01) and showed higher rates of adverse events (death, non-fatal myocardial infarction, coronary revascularization, new hospital admission for heart failure: 67.8 vs 36.9%, p=0.001), death (25.4 vs 13.2%, p<0.01), myocardial infarction (13.6 vs 4.8%, p<0.01) and hospitalizations for heart failure (13.6 vs 4.8%, p<0.001).

CONCLUSIONS

Our data, derived from a large cohort of patients from a single center, allow a more correct estimate of the occurrence and prognostic significance of NR. The NR phenomenon is more common in STEMI patients undergoing primary PCI and has an important negative prognostic value.

[Effect of intracoronary tirofiban combined with nitroprusside injection through thrombus aspiration catheter during primary percutaneous coronary intervention on acute anterior myocardial infarction patients with heavy thrombosis burden]

OBJECTIVE

To explore the impact of intracoronary bolus administration of tirofiban combined with nitroprusside through thrombus aspiration catheter or thrombus aspiration alone on myocardial reperfusion and major adverse cardiovascular events rate in acute anterior myocardial infarction patients with heavy thrombosis burden.

METHODS

Ninety consecutive acute anterior myocardial infarction patients with heavy thrombosis burden [(59.8 ± 11.5) years old] were randomly assigned to thrombus aspiration group (Group A, n = 30), thrombus aspiration and intracoronary tirofiban bolus (25 µg/kg prior to the first balloon inflation,Group B, n = 30), thrombus aspiration and intracoronary tirofiban combined with nitroprusside bolus (200 µg prior to the first balloon inflation, Group C, n = 30) with random number table. Baseline clinical data, angiographic features before and after percutaneous coronary intervention (PCI) and major adverse cardiovascular events after PCI between 3 groups were compared.

RESULTS

The baseline clinical data and angiographic features among 3 groups were similar (all P > 0.05) . The time of pain to balloon was (5.5 ± 3.8) hours. After primary PCI, myocardial tissue perfusion was significantly better in Group C than in Group A and Group B: TMP grade < 3 [10.0% (3/30) vs. 40.0% (12/30) and 33.3% (10/30), P < 0.01 and P < 0.05]. Left ventricular ejection fraction at 5 to 7 days after PCI also tended higher in Group C than in the other 2 groups (P = 0.05). One patient died of heart failure at 7th day after PCI in Group A, and no patient died in Group B and C. Thirty days after PCI, there was no re-myocardial infarction and target vessel revascularization event among 3 groups. The bleeding complication rate during 30 days follow-up was similar among 3 groups (P > 0.05) .

CONCLUSION

Intracoronary bolus application of tirofiban combined with nitroprusside through thrombus aspiration catheter after thrombus aspiration is associated with an improvement of myocardial reperfusion without increasing bleeding complication and other adverse cardiovascular events rate compared with thrombus aspiration alone in patients with acute anterior myocardial infarction and heavy thrombosis burden undergoing primary PCI.

Treatment with the nitric oxide donor SNP increases triiodothyronine levels in hyper- and hypothyroid Sprague-Dawley rats

Nitric oxide pathway might play a crucial role in the pathophysiology of thyroid dysfunctions. This study aimed to investigate the impact of nitric oxide (NO) on hypothyroid and hyperthyroid Sprague-Dawley rats under controlled diet. Furthermore, the effects of the nitric oxide donor sodium nitroprusside (SNP) on thyroid dysfunctions were also assessed. Sprague-Dawley rats (n=107) were subdivided into normal diet and high-fat diet (HFD) groups and grouped into controls, hypothyroid, hyperthyroid, and SNP treated groups. Hypothyroidism was induced through propylthiouracil, whereas hyperthyroidism by triiodothyronine (T3). After 12 weeks of T3 treatment, serum nitric oxides (NOX), endogenous asymmetric dimethylarginine (ADMA), body weight and food intake were analyzed. Hypothyroid rats showed decreased serum T3 levels, hyperthyroid rats increased T3 compared to controls. Diet had no impact on T3. Thyroid dysfunctions were accompanied by changes in calorie intake and body weight. Serum NOX was significantly reduced in normal diet hypothyroid rats. SNP administration compensated the decrease and markedly increased T3. NO synthase inhibitor ADMA levels were significantly higher in the HFD control group than in the normal diet controls. ADMA was declined in both hypothyroid groups and increased in normal diet hyperthyroid rats. An association of thyroid dysfunctions with reduced bioavailability of NO and alterations of ADMA levels could be established. Treatment with the NO donor SNP resulted in an increase of serum T3 levels. These results demonstrate that the NO pathway is implicated in thyroid dysfunctions, which may be of clinical relevance.

Chemical and metabolomic screens identify novel biomarkers and antidotes for cyanide exposure

Exposure to cyanide causes a spectrum of cardiac, neurological, and metabolic dysfunctions that can be fatal. Improved cyanide antidotes are needed, but the ideal biological pathways to target are not known. To understand better the metabolic effects of cyanide and to discover novel cyanide antidotes, we developed a zebrafish model of cyanide exposure and scaled it for high-throughput chemical screening. In a screen of 3120 small molecules, we discovered 4 novel antidotes that block cyanide toxicity. The most potent antidote was riboflavin. Metabolomic profiling of cyanide-treated zebrafish revealed changes in bile acid and purine metabolism, most notably by an increase in inosine levels. Riboflavin normalizes many of the cyanide-induced neurological and metabolic perturbations in zebrafish. The metabolic effects of cyanide observed in zebrafish were conserved in a rabbit model of cyanide toxicity. Further, humans treated with nitroprusside, a drug that releases nitric oxide and cyanide ions, display increased circulating bile acids and inosine. In summary, riboflavin may be a novel treatment for cyanide toxicity and prophylactic measure during nitroprusside treatment, inosine may serve as a biomarker of cyanide exposure, and metabolites in the bile acid and purine metabolism pathways may shed light on the pathways critical to reversing cyanide toxicity.

Central versus peripheral blood pressure in malignant hypertension; effects of antihypertensive treatment

BACKGROUND

Sodium nitroprusside (SNP) and labetalol are recommended for the immediate treatment of malignant hypertension. Both are intravenous agents but have different effects on systemic hemodynamics, and may have differential effects on pulse-wave reflection and pulse-pressure amplification, with consequences for peripheral versus central blood pressures (BPs).

METHODS

We conducted a nonrandomized, open-label study of 8 patients treated with sodium nitroprusside (mean age (±SD), 44±14 years; 6 males; diastolic/systolic BP, 225±22/135±8mm Hg) and 6 patients treated with intravenous labetalol (mean age, 39±15 years; 4 males; systolic/diastolic BP, 232±22/138±17mm Hg) before and after treatment for malignant hypertension, aiming at a 25% reduction in mean arterial pressure. We measured peripheral pressures with an intra-arterial catheter in the radial artery and derived central pressures with a generalized transfer filter.

RESULTS

Mean arterial pressure was similarly reduced with sodium nitroprusside and labetalol (by 27% and 30%, respectively; P = 0.76). There was a nonsignificantly greater reduction in peripheral systolic blood pressure (SBP) with labetalol than with sodium nitroprusside (29±11% vs. 18±7%, P = 0.08). The decline in peripheral diastolic blood pressure (DBP) with the two agents was comparable, whereas the reduction in peripheral pulse pressure was 8±16% with SNP and 33±17% with labetalol (P = 0.01). The decline in reflection magnitude was greater with SNP than with labetalol. There were no significant differences in the reduction of central BP with SNP and labetalol. The amplification of PP increased with SNP but did not change with labetalol.

CONCLUSIONS

We found no difference in central SBP or PP in subjects treated with SNP and labetalol, but labetalol produced a greater reduction in peripheral SBP and PP in the immediate treatment of malignant hypertension.

[Effect of sodium nitroprusside on hemoglobin oxygen binding properties of the blood during hepatic ischemia-reperfusion in rabbits]

The parameters of blood oxygen transport were determined in rabbits during the hepatic ischemia/reperfusion (HIR) with or without sodium nitroprusside (SNP) administration. Hepatic ischemia was induced for 30 min by a. hepatica propria clamping, reperfusion lasted 120 min. Indices of blood oxygen transport (hemoglobin-oxygen affinity index (p50), pO2, pH, pCO2, HCO3-, TCO2, ABE, etc.) and nitrite/nitrate (NO(x)) amounts were measured in blood during HIR. Animals were subdivided into two groups: 1st group--HIR; 2nd--HIR plus SNP infusion (SNP, Sigma, i.v. 10 mcmol/kg). The experiments had shown that HIR led to significant acidic changes in the acid-base balance and high blood p50. The SNP infusion in the 2nd group led to less changing in the p50 values during HIR which were accompanied with high NO(x) levels. We conclude that oxyhemoglobin dissociation curve shift leftwards after SNP administration promotes the maintenance liver during ischemia-reperfusion.

Hemodynamic evaluation and anti-hypertensive schemes used in puerperal women following pre-eclampsia

Pre-eclampsia is still a very prevalent disease with critical hemodynamic changes. This study was evaluated the major anti-hypertensive schemes used at the Materno Perinatal Hospital "Monica Pretelini" (HMPMP) hospitalized at the Obstetric Intensive Care Unit (OICU) for at least seven days. In other group of patients we compared hemodynamic monitoring with Swan-Ganz catheter versus transthoracic electrical bioimpedance (TEB) and gasometric formulas. Statistical analysis was done using the Statistical Package for Social Science (SPSS) software, version 17. Amlodipine + temisartan + prazocin was the preferred anti-hypertensive drug combination used in our intensive care unit. Sodium nitroprusside is required in 25% of patients until reaching control. There was no statistically significant difference in cardiac output calculated with gasometric formulas compared to thermodilution with Swan-Ganz catheter. Calcium antagonists + angiotensin II receptor blocker (ARB) + α-blockers offer the best option to control hypertension in puerperal women that followed pre-eclampsia, but oral and IV drugs to control hypertension is required in 20% of cases, in a Mexican Intensive Care Unit specialized in obstetrical patients. Hemodynamic monitoring with gasometric formulas is still usefull in this set of patients, without discarding TEB with a correction factor due to the accumulated extravascular water in these patients.

[A randomized controlled trial of rapid artificial cardiac pacing in thoracic endovascular aortic repair]

OBJECTIVE

To compare the safety, efficacy and their impact on stent graft positioning between rapid artificial cardiac pacing induced hypotension and sodium nitroprusside induced hypotension during thoracic endovascular aortic repair (TEVAR).

METHODS

From September 2007 to February 2009, a randomized controlled trial as approved by the Ethics Committee of our hospital was conducted in 197 patients undergoing elective thoracic endovascular aortic repair of thoracic aortic dissection (n = 175) or aneurysm (n = 22). The patients were randomized into sodium nitroprusside group (n = 98) and rapid artificial cardiac pacing group (n = 99). During the localization and deployment of stent graft, hypotension was induced by intravenous sodium nitroprusside or rapid artificial cardiac pacing. Hemodynamics, landing precision (deviation from planned placement site), duration of procedure, renal function, neurocognitive function, incidence of endoleaks and paraplegia/hemiplegia were compared.

RESULTS

Rapid artificial cardiac pacing was conducted without technical difficulty in all 99 patients. The level of hypotension (mm Hg, 1 mm Hg = 0.133 kPa) was most pronounced in the rapid artificial cardiac pacing group (47 ± 5 vs 82 ± 7, P = 0.003. Once rapid pacing ceased, blood pressure recovered more quickly to the preparing levels in the rapid artificial cardiac pacing group [(9 ± 2) s vs (481 ± 107) s, P < 0.01]. And the duration of procedure was also shorter in the rapid artificial cardiac pacing group [(94 ± 16) min vs (103 ± 24) min, P < 0.01]. Moreover, precise positioning and deployment was observed in rapid artificial cardiac pacing group versus to the sodium nitroprusside group (P < 0.01). There was no difference in renal function and neurocognitive function before and after the procedure in both groups. There was no difference in the incidences of endoleaks and paraplegia/hemiplegia between different groups (P > 0.05).

CONCLUSION

As compared with sodium nitroprusside, rapid artificial cardiac pacing is safer in thoracic endovascular aortic repair. It shortens the endovascular procedure and enables more precise positioning and deployment of stent graft.

Dutch guideline for the management of hypertensive crisis -- 2010 revision

Hypertensive crises are divided into hypertensive urgencies and emergencies. Together they form a heterogeneous group of acute hypertensive disorders depending on the presence or type of target organs involved. Despite better treatment options for hypertension, hypertensive crisis and its associated complications remain relatively common. In the Netherlands the number of patients starting renal replacement therapy because of 'malignant hypertension' has increased in the past two decades. In 2003, the first Dutch guideline on hypertensive crisis was released to allow a standardised evidence-based approach for patients presenting with a hypertensive crisis. In this paper we give an overview of the current management of hypertensive crisis and discuss several important changes incorporated in the 2010 revision. These changes include a modification in terminology replacing 'malignant hypertension' with 'hypertensive crisis with retinopathy and reclassification of hypertensive crisis with retinopathy under hypertensive emergencies instead of urgencies. With regard to the treatment of hypertensive emergencies, nicardipine instead of nitroprusside or labetalol is favoured for the management of perioperative hypertension, whereas labetalol has become the drug of choice for the treatment of hypertension associated with pre-eclampsia. For the treatment of hypertensive urgencies, oral administration of nifedipine retard instead of captopril is recommended as first-line therapy. In addition, a section on the management of hypertensive emergencies according to the type of target organ involved has been added. Efforts to increase the awareness and treatment of hypertension in the population at large may lower the incidence of hypertensive crisis and its complications.

A biphasic response to nitric oxide donation in an ex vivo model of donation after cardiac death renal transplantation

BACKGROUND

Donation after cardiac death (DCD) donors are vital to maximize the organ donor pool. Reperfusion injury (RI) is an important sequela in DCD organs due to warm and cold ischemia. RI manifests clinically as a high incidence of delayed graft function (DGF) and primary non-function (PNF) compared with donation after brain death organs. The importance of nitric oxide (NO) in the generation of reperfusion injury is pivotal.

METHODS

Using an ex vivo porcine model of kidney transplantation the effects of reperfusion with and without NO supplementation on initial renal blood flow and function were compared. Real-time hemodynamic measurements were recorded and biochemical samples taken at set time-points. Molecular markers of reperfusion injury were also measured. Sodium nitroprusside was chosen as the NO donor.

RESULTS

Results showed that NO donation initially improved renal blood flow significantly over controls; at the end of reperfusion this benefit was lost. In addition, there was an improvement in creatinine clearance, fractional excretion of sodium and renal oxygen consumption. There were observed to be higher levels of urinary nitrite/nitrate excretion, but no difference in isoprostane levels.

CONCLUSION

This study represents a good model for the initial reperfusion period in large animal renal transplantation. The improvement in renal blood flow observed in the NO supplemented groups represents NO mediated vasodilatation. Later in reperfusion, accumulation of nitrogenous free radicals impairs renal blood flow. Clinically, NO supplementation during initial reperfusion of DCD kidneys improves renal blood flow but should be considered with caution due to potential deleterious effects of nitrogenous compound accumulation.

Influence of dipyridamole and its combination with NO donor or NO synthase inhibitor on adjuvant arthritis

The anti-arthritic and anti-inflammatory effects of dipyridamole and the possible involvement of NO in the dipyridamole action are not yet clear. The aim of this study was to evaluate the effects of dipyridamole alone and in combination with either the nitric oxide donor, sodium nitroprusside (SNP) or the non-selective nitric oxide synthase inhibitor, L-NG- monomethyl arginine (L-NMMA), on pathogenesis of adjuvant-induced arthritis model in rats. The results of the present work showed that prophylactic administration of dipyridamole alone and dipyridamole administration in combination with either low dose of SNP or L-NMMA significantly ameliorated pathogenesis of adjuvant arthritis in rats as evidenced by significant decrease in arthritis index, hind paws volume, loss of body weight, hyperalgesia compared with control vehicle (1% DMSO) treated adjuvant arthritic rats. Inflammatory cellular infiltrate in synovium of ankle joint and pannus formation were also markedly inhibited. Interleukin-10(IL-10) levels were significantly increased in these groups of animals. In contrast, a high dose of SNP counteracted the anti-inflammatory and anti-arthritic effects of dipyridamole. The inhibitory effect of therapeutic administration of dipyridamole alone on adjuvant arthritis syndrome was not significantly different from that of vehicle administration. In conclusion, dipyridamole has prophylactic but not therapeutic anti-arthritic and anti-inflammatory effects that appear to be dependent on inhibition of NO synthase. A synergistic combination between dipyridamole and NO synthase inhibitor or low dose of NO donor may have prophylactic and therapeutic values in autoimmune diseases like RA.

Automated drug delivery system for the management of hemodynamics and cardiac energetic in acute heart failure

We have developed a novel automated drug delivery system for simultaneous control of systemic arterial pressure (AP), cardiac output (CO), and left atrial pressure (P(LA)) in acute heart failure. The circulatory equilibrium framework we established previously discloses that AP, CO, and P(LA) are determined by equilibrium of the mechanical properties of the circulation, i.e. pumping ability of the left heart, stressed blood volume and systemic arterial resistance. Our system directly controls the three mechanical properties with cardiovascular drugs including inotropes and vasodilators, thereby controlling AP, CO, and P(LA). Furthermore, by precisely controlling bradycardia and LV inotropy, our system enables to improve cardiac energetic efficiency while preserving AP, CO, and P(LA) within acceptable ranges. In conclusion, by directly controlling the mechanical properties of the heart and vessel, our automated system realizes comprehensive management of hemodynamics in acute heart failure.

Nitroprusside in decompensated heart failure: what should a clinician really know?

Sodium nitroprusside is an older intravenous vasodilator appropriate for acute hospital treatment of patients with congestive heart failure. It is a balanced arterial and venous vasodilator with a very short half-life, facilitating rapid titration. In general, it improves hemodynamic and clinical status by reducing systemic vascular resistance, left ventricular filling pressure, and increasing cardiac output. This review summarizes recently published literature and recent data regarding the use of this intravenous vasodilator in decompensated heart failure patients.

Effect of calcitonin gene related peptide vs sodium nitroprusside to increase temperature in spontaneous canine tumours during local hyperthermia

The objectives of this study were to compare the effects of two vasodilators, sodium nitroprusside (SNP) and calcitonin gene-related peptide (CGRP) on mean arterial pressure (MAP), heart rate (HR) and temperatures in tumour and surrounding normal tissue during local hyperthermia treatment. Eleven tumour-bearing pet dogs with spontaneous soft tissue sarcomas were given SNP intravenously during local hyperthermia. The drug infusion rate was adjusted to maintain a 20% decrease in MAP. The median (95% CI) increase in the temperature distribution descriptors T(90) and T(50) was 0.2 degrees C (0.0-0.4 degrees C, p = 0.02) and 0.4 degrees C (0.1-0.7 degrees C, p = 0.02), respectively, in tumour. Normal subcutaneous tissue temperatures were mildly increased but remained below the threshold for thermal injury. The effects of CGRP were investigated in six tumour-bearing dogs following a protocol similar to that used for SNP. The median (interquartile (IQ) range) decrease in mean arterial pressure was 19% (15-26%) after CGRP administration and a significant increase was seen in tumour but not normal subcutaneous tissue temperatures. The median (95% CI) increase in the temperature distribution descriptors T(90) and T(50) was 0.5 degrees C (0.1-1.6 degrees C, p = 0.03) and 0.8 degrees C (0.1-1.6 degrees C, p = 0.13), respectively. Administration of SNP or CGRP did not result in local or systemic toxicity in tumour-bearing dogs. However, the magnitude of increase in tumour temperatures was not sufficient to improve the likelihood of increased response rates. Therefore, there is little justification for translation of this approach to human trials using conventional local hyperthermia.

Intermittent low dose intrathecal sodium nitroprusside therapy for treatment of symptomatic aneurysmal SAH-induced vasospasm

Eight patients with aneurysmal subarachnoid haemorrhage (SAH) received intrathecal sodium nitroprusside therapy (ITSNPT) in the form of intermittent bolus doses for delayed cerebral vasospasm after undergoing clipping of an aneurysm. Five patients were administered ITSNPT to combat refractory symptomatic vasospasm while three patients received prophylactic ITSNPT in view of the possibility of imminent clinical vasospasm. In five patients the therapy was instituted through the intraventricular route, while in three the drug was instilled into the basal cistern. Sodium nitroprusside (SNP) was administered at an interval of 3-12 h, in varying bolus doses ranging between 2 and 5 mg depending upon the (i) mean flow velocity values on transcranial Doppler study and (ii) clinical response. The end point of ITSNPT was either relief of vasospasm, any adverse effect or contraindication to continuation of ITSNPT. All except one patient survived. One patient had mild residual neurological deficit following an infarct. All the three patients who received prophylactic ITSNPT had good outcomes.

The no-reflow phenomenon in the coronary circulation

The no-reflow phenomenon is a poorly understood complication of percutaneous coronary intervention in which diminished blood flow to distal microvascular beds persists despite the successful treatment of the occlusive lesion from the epicardial coronary artery or arteries. In this contemporary review we endeavour to discuss the pathophysiology of coronary no-reflow, understand the predictors and describe current pharmacological and mechanical strategies to prevent and treat coronary no-reflow.