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Breast cancer is a global concern as a leading cause of death for women. Early and precise diagnosis can be vital in handling the disease efficiently. Breast cancer subtyping based on estrogen receptor (ER) status is crucial for determining prognosis and treatment. This study uses metabolomics data from plasma samples to detect metabolite biomarkers that could distinguish ER-positive from ER-negative breast cancers in a non-invasive manner. The dataset includes demographic information, ER status, and metabolite levels from 188 breast cancer patients and 73 healthy controls. Recursive Feature Elimination (RFE) with a Random Forest (RF) classifier identified an optimal subset of 30 features-29 biomarkers and age-that achieved the highest area under the curve (AUC). To address the class imbalance, Gaussian noise-based augmentation and Adaptive Synthetic Oversampling (ADASYN) were applied, ensuring balanced representation during training. Four machine learning (ML) algorithms-Random Forest, Support Vector Classifier (SVC), XGBoost, and Logistic Regression (LR)-were evaluated using grid search. The Random Forest classifier emerged as the top performer, achieving an AUC of 0.95 and an accuracy of 93%. These results suggest that ML has great promise for identifying specific metabolites linked to ER expression, paving the development of a novel analytical tool that can minimize current challenges in identifying ER status, and improve the precision of breast cancer subtyping.

Breast cancer remains a major public health concern, and early detection is crucial for improving survival rates. Metabolomics offers the potential to develop non-invasive screening and diagnostic tools based on metabolic biomarkers. However, the inherent complexity of metabolomic datasets and the high dimensionality of biomarkers complicates the identification of diagnostically relevant features, with multiple studies demonstrating limited consensus on the specific metabolites involved. Unlike previous studies that rely on singular feature selection techniques such as Partial Least Square (PLS) or LASSO regression, this research combines supervised and unsupervised machine learning methods with random sampling strategies, offering a more robust and interpretable approach to feature selection. This study aimed to identify a parsimonious and robust set of biomarkers for breast cancer diagnosis using metabolomics data. Plasma samples from 185 breast cancer patients and 53 controls (from the Cooperative Human Tissue Network, USA) were analyzed. This study also overcomes the common issue of dataset imbalance by using propensity score matching (PSM), which ensures reliable comparisons between cancer and control groups. We employed Univariate Naïve Bayes, L2-regularized Support Vector Classifier (SVC), Principal Component Analysis (PCA), and feature engineering techniques to refine and select the most informative features. Our best-performing feature set comprised 11 biomarkers, including 9 metabolites (SM(OH) C22:2, SM C18:0, C0, C3OH, C14:2OH, C16:2OH, LysoPC a C18:1, PC aa C36:0 and Asparagine), a metabolite ratio (Kynurenine-to-Tryptophan), and 1 demographic variable (Age), achieving an area under the ROC curve (AUC) of 98%. These results demonstrate the potential for a robust, cost-effective, and non-invasive breast cancer screening and diagnostic tool, offering significant clinical value for early detection and personalized patient management.

Parkinson's disease (PD) is a neurodegenerative and progressive disease that impacts the nerve cells in the brain and varies from person to person. The exact cause of PD is still unknown, and the diagnosis of PD does not include a specific objective test with certainty. Although deep learning has made great progress in medical neuroimaging analysis, these methods are very susceptible to biases present in neuroimaging datasets. An innovative decorrelated deep learning technique is introduced to mitigate class bias and scanner bias while simultaneously focusing on finding distinguishing characteristics in resting-state functional MRI (rs-fMRI) data, which assists in recognizing PD with good accuracy. The decorrelation function reduces the nonlinear correlation between features and bias in order to learn bias-invariant features. The publicly available Parkinson's Progression Markers Initiative (PPMI) dataset, referred to as a single-scanner imbalanced dataset in this study, was used to validate our method. The imbalanced dataset problem affects the performance of the deep learning framework by overfitting to the majority class. To resolve this problem, we propose a new decorrelated convolutional neural network (DcCNN) framework by applying decorrelation-based optimization to convolutional neural networks (CNNs). An analysis of evaluation metrics comparisons shows that integrating the decorrelation function boosts the performance of PD recognition by removing class bias. Specifically, our DcCNN models perform significantly better than existing traditional approaches to tackle the imbalance problem. Finally, the same framework can be extended to create scanner-invariant features without significantly impacting the performance of a model. The obtained dataset is a multiscanner dataset, which leads to scanner bias due to the differences in acquisition protocols and scanners. The multiscanner dataset is a combination of two publicly available datasets, namely, PPMI and FTLDNI-the frontotemporal lobar degeneration neuroimaging initiative (NIFD) dataset. The results of t-distributed stochastic neighbor embedding (t-SNE) and scanner classification accuracy of our proposed feature extraction-DcCNN (FE-DcCNN) model validated the effective removal of scanner bias. Our method achieves an average accuracy of 77.80% on a multiscanner dataset for differentiating PD from a healthy control, which is superior to the DcCNN model trained on a single-scanner imbalanced dataset.

A high percentage of asthma patients have symptoms that are not well controlled, despite effective drugs being available. One potential reason for this may be that poor inhaler technique limits the dose delivered to the lungs, thereby reducing the therapeutic efficacy. The aim of this study was to assess the prevalence of poor inhaler technique in an asthma patient population and to probe the impact of various demographic parameters on technique quality. This study was conducted at community pharmacies across Wales, UK. Patients diagnosed with asthma and 12 years or older were invited to participate. An aerosol inhalation monitor (AIM, Vitalograph ® ) was used to measure the quality of patient inhaler technique. A total of 295 AIM assessments were carried out. There were significant differences in the quality of inhaler technique across the different inhaler types ( p < 0.001, Chi squared). The best technique was associated with dry-powder inhalers (DPI devices, 58% of 72 having good technique), compared with pressurized metered-dose inhalers (pMDI) or pMDIs with a spacer device (18% of 174 and 47% of 49 AIM assessments, respectively). There were some significant associations between gender, age, and quality of inhaler technique, as determined with adjusted odds ratios. It seems that the majority of asthmatic patients were not using their inhalers appropriately. We recommend that healthcare professionals place more emphasis on assessing and correcting inhaler technique, as poor inhaler technique might be responsible for the observed lack of symptom control in the asthma patient population.

The role of the community pharmacist has evolved to include the provision of more clinical services for patients. Those people who have stable chronic conditions will be managed in community pharmacies. This qualitative study used semi-structured in-depth interviews to understand the potential of providing additional patient-centred care for patients with stable chronic conditions in community pharmacies and identify potential limitations of this approach. Participants were recruited from Welsh Government, Local Health Boards (LHBS), Community Pharmacy Wales (CPW) and the Royal Pharmaceutical Society Wales (RPSW). The interviews were audio-recorded, transcribed verbatim, and analysed thematically. Eight interviews were conducted. The identified themes were as follows: (1) inconsistency and bureaucracy in commissioning pharmacy services; (2) availability of funding and resources; (3) disagreement and uncertainty about the contribution of the community pharmacy sector; (4) continuity of patient medical information and fragmented care; (5) accessibility, capacity and facilities in community pharmacy; (6) pharmacy education and clinical expertise, and (7) patient acceptability. It was clear that the potential benefit of managing stable chronic diseases in community pharmacies was recognised; however, several limitations expressed by stakeholders of pharmacy services need to be considered prior to moving forward.

Asthma is still an incurable disease, and there is a recognized need for novel small-molecule therapies for people with asthma, especially those poorly controlled by current treatments. We previously demonstrated that calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs), calcilytics, uniquely suppress both airway hyperresponsiveness (AHR) and inflammation in human cells and murine asthma surrogates. Here we assess the feasibility of repurposing four CaSR NAMs, which were originally developed for oral therapy for osteoporosis and previously tested in the clinic as a novel, single, and comprehensive topical antiasthma therapy. We address the hypotheses, using murine asthma surrogates, that topically delivered CaSR NAMs 1) abolish AHR; 2) are unlikely to cause unwanted systemic effects; 3) are suitable for topical application; and 4) inhibit airway inflammation to the same degree as the current standard of care, inhaled corticosteroids, and, furthermore, inhibit airway remodeling. All four CaSR NAMs inhibited poly-L-arginine-induced AHR in naïve mice and suppressed both AHR and airway inflammation in a murine surrogate of acute asthma, confirming class specificity. Repeated exposure to inhaled CaSR NAMs did not alter blood pressure, heart rate, or serum calcium concentrations. Optimal candidates for repurposing were identified based on anti-AHR/inflammatory activities, pharmacokinetics/pharmacodynamics, formulation, and micronization studies. Whereas both inhaled CaSR NAMs and inhaled corticosteroids reduced airways inflammation, only the former prevented goblet cell hyperplasia in a chronic asthma model. We conclude that inhaled CaSR NAMs are likely a single, safe, and effective topical therapy for human asthma, abolishing AHR, suppressing airways inflammation, and abrogating some features of airway remodeling. SIGNIFICANCE STATEMENT: Calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs) reduce airway smooth muscle hyperresponsiveness, reverse airway inflammation as efficiently as topical corticosteroids, and suppress airway remodeling in asthma surrogates. CaSR NAMs, which were initially developed for oral therapy of osteoporosis proved inefficacious for this indication despite being safe and well tolerated. Here we show that structurally unrelated CaSR NAMs are suitable for inhaled delivery and represent a one-stop, steroid-free approach to asthma control and prophylaxis., (Copyright © 2020 by The American Society for Pharmacology and Experimental Therapeutics.)

Lipopolysaccharide (LPS) contributes to asthma exacerbations and development of inhaled corticosteroid insensitivity. Complete resistance to systemic corticosteroids is rare, and most patients lie on a continuum of steroid responsiveness. This study aimed to examine the sensitivity of combined ovalbumin- (Ova) and LPS-induced functional and inflammatory responses to inhaled and systemic corticosteroid in conscious guinea pigs to test the hypothesis that the route of administration affects sensitivity. Guinea pigs were sensitized to Ova and challenged with inhaled Ova alone or combined with LPS. Airway function was determined by measuring specific airway conductance via whole-body plethysmography. Airway hyper-responsiveness to histamine was determined before and 24 hours post-Ova challenge. Airway inflammation and underlying mechanisms were determined from bronchoalveolar lavage cell counts and lung tissue cytokines. Vehicle or dexamethasone was administered by once-daily i.p. injection (5, 10, or 20 mg/kg) or twice-daily inhalation (4 or 20 mg/ml) for 6 days before Ova challenge or Ova with LPS. LPS exacerbated Ova-induced responses, elongating early asthmatic responses (EAR), prolonging histamine bronchoconstriction, and further elevating airway inflammation. Intraperitoneal dexamethasone (20 mg/kg) significantly reduced the elongated EAR and airway inflammation but not the increased bronchoconstriction to histamine. In contrast, inhaled dexamethasone (20 mg/ml), which inhibited responses to Ova alone, did not significantly reduce functional and inflammatory responses to combined Ova and LPS. Combined Ova and LPS-induced functional and inflammatory responses are insensitive to inhaled, but they are only partially sensitive to systemic, dexamethasone. This finding suggests that the route of corticosteroid administration may be important in determining corticosteroid sensitivity of asthmatic responses., (Copyright © 2017 by The Author(s).)

Background and Purpose: Asthma exacerbations contribute to corticosteroid insensitivity. LPS is ubiquitous in the environment. It causes bronchoconstriction and airway inflammation and may therefore exacerbate allergen responses. This study examined whether LPS and ovalbumin co-administration could exacerbate the airway inflammatory and functional responses to ovalbumin in conscious guinea pigs and whether these exacerbated responses were insensitive to inhaled corticosteroid treatment with fluticasone propionate (FP)., Experimental Approach: Guinea pigs were sensitized and challenged with ovalbumin and airway function recorded as specific airway conductance by whole body plethysmography. Airway inflammation was measured from lung histology and bronchoalveolar lavage. Airway hyper-reactivity (AHR) to inhaled histamine was examined 24 h after ovalbumin. LPS was inhaled alone or 24 or 48 h before ovalbumin and combined with ovalbumin. FP (0.05-1 mg·mL(-1) ) or vehicle was nebulized for 15 min twice daily for 6 days before ovalbumin or LPS exposure., Key Results: Ovalbumin inhalation caused early (EAR) and late asthmatic response (LAR), airway hyper-reactivity to histamine and influx of inflammatory cells into the lungs. LPS 48 h before and co-administered with ovalbumin exacerbated the response with increased length of the EAR, prolonged response to histamine and elevated inflammatory cells. FP 0.5 and 1 mg·mL(-1) reduced the LAR, AHR and cell influx with ovalbumin alone, but was ineffective when guinea pigs were exposed to LPS before and with ovalbumin., Conclusions and Implications: LPS exposure exacerbates airway inflammatory and functional responses to allergen inhalation and decreases corticosteroid sensitivity. Its widespread presence in the environment could contribute to asthma exacerbations and corticosteroid insensitivity in humans., (© 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.)

Introduction: Inhalation of antigen in atopic asthma induces early (EAR) and late asthmatic responses (LARs), inflammatory cell infiltration and airways hyperresponsiveness (AHR). Previously, we have established a protocol of sensitisation and subsequent ovalbumin (Ova) inhalation challenge in guinea-pigs which induced these 4 features (Smith & Broadley, 2007). However, the responses of guinea-pigs to Ova challenge have recently declined, producing no LAR or AHR and diminished EAR and cells. By making cumulative modifications to the protocol, we sought to restore these features., Methods: Guinea-pigs were sensitised with Ova (i.p. 100 or 150 μg) on days 1 and 5 or days 1, 4 and 7 and challenged with nebulised Ova (100 or 300 μg/ml, 1h) on day 15. Airway function was measured in conscious guinea-pigs by whole-body plethysmography to record specific airway conductance (sGaw). Airway responsiveness to aerosolized histamine (0.3mM) was determined before and 24h after Ova challenge. Bronchoalveolar lavage was performed for total and differential inflammatory cell counts. Lung sections were stained for counting of eosinophils., Results: Lack of AHR and LAR with the original protocol was confirmed. Increasing the Ova challenge concentration from 100 to 300 μg/ml restored AHR and eosinophils and increased the peak of the EAR. Increasing the number of sensitisation injections from 2 to 3 did not alter the responses. Increasing the Ova sensitisation concentration from 100 to 150 μg significantly increased total cells, particularly eosinophils. A LAR was revealed and lymphocytes and eosinophils increased when either the Al(OH)3 concentration was increased or the duration between the final sensitisation injection and Ova challenge was extended from 15 to 21 days., Discussion: This study has shown that declining allergic responses to Ova in guinea-pigs could be restored by increasing the sensitisation and challenge conditions. It has also demonstrated an important dissociation between EAR, LAR, AHR and inflammation., (Copyright © 2014. Published by Elsevier Inc.)

Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and beta-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

Although the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide share a similar pharmacology, 2-AG reportedly limits myocardial ischaemia-reperfusion injury whereas anandamide does not. We therefore investigated whether or not anandamide reduces infarct size and which, if any, of the known cannabinoid-signalling pathways are involved. Rat isolated perfused hearts were subjected to global, no-flow ischaemia (30 min) and reperfusion (1 h). Agonists were present from 5 min before ischaemia until the end of reperfusion. Antagonists, where used, were present throughout the protocol. Recovery of left ventricular developed pressure and coronary flow was incomplete in control hearts and not significantly affected by any drug treatment. In vehicle-treated hearts, 26+/-3% (n=13) of the left ventricle was infarcted at the end of reperfusion. Infarction of the left ventricle was significantly reduced after 1 microM anandamide (10+/-1%, n=7) or 1 microM methanandamide (12+/-4%, n=6) but not 1 microM HU210. Neither ACPA (1 microM; CB1 receptor agonist) nor JWH133 (1 microM; CB2 receptor agonist), individually or combined significantly affected infarct size. Anandamide (1 microM) did not reduce infarct size in the presence of the CB1 receptor antagonist rimonabant (SR141716A, 1 microM) or the CB2 receptor antagonist, SR144528 (1 microM). Despite sensitivity to CB1 and CB2 receptor antagonists, the infarct-limiting action of anandamide was not mimicked by agonists selective for CB1 or CB2 receptors suggesting the involvement of a novel cannabinoid site of action.

Structural and functional maturation of a number of fetal organs and physiological systems occurs in the immediate period prior to term, in association with the prepartum increase in fetal plasma cortisol concentration. At present, little is known about how myocardial sensitivity to adrenergic and muscarinic cholinergic stimulation changes as the fetus approaches term, nor the role of the prepartum increase in plasma cortisol concentration in mediating these changes. This study used a novel Langendorff, biventricular, ovine fetal heart preparation to investigate the effects of advancing gestation and cortisol treatment on myocardial sensitivity to adrenergic (isoprenaline) and muscarinic cholinergic (carbachol) stimulation. It was hypothesized that cortisol infusion would fully mimic developmental changes in myocardial responsiveness to adrenergic and cholinergic stimulation. Sixteen Welsh Mountain sheep fetuses were surgically prepared under general anaesthesia with vascular catheters. At 125 +/- 1 days gestational age (dGA; term, 145 dGA) fetuses were infused with saline vehicle (n= 7; Premature Control) or with cortisol (n= 4; 2-3 mg kg(-1) d(-1)i.v.; Premature Cortisol) for 5 days. The Term Control group (n= 5) comprised fetuses that were surgically prepared at 130 dGA and infused with vehicle for 5 days prior to delivery (n= 2), or that received no surgery (n= 3). Under terminal anaesthesia, Premature Control and Premature Cortisol fetuses were delivered at 130 dGA and Term Control fetuses between 135 and 143 dGA. Following exsanguination under anaesthesia, fetal hearts were mounted in the Langendorff preparation, allowing measurement of left ventricular (LV) developed pressure and right ventricular (RV) developed pressure, heart rate (HR), coronary perfusion pressure and perfusate distribution to the myocardium. Cortisol infusion elevated fetal plasma cortisol concentrations to values similar to those measured close to term (45.0 +/- 7.1 ng ml(-1)). Advancing gestational age, but not cortisol treatment, enhanced fetal LV developed pressure, RV developed pressure and HR responses to carbachol (P < 0.05). Advancing gestational age, but not cortisol treatment, suppressed fetal LV developed pressure, RV developed pressure and HR responses to isoprenaline (P < 0.05). Maximum doses of either carbachol or isoprenaline had no effect on coronary perfusate distribution. Changes in myocardial responsiveness to adrenergic and muscarinic cholinergic stimulation with advancing gestation provide mechanisms that contribute to the maturation of the cardiovascular system as the ovine fetus approaches term. These changes in myocardial responsiveness are not solely dependent on preparturient elevations in fetal plasma cortisol concentration.

We assessed ANG II type 1 (AT(1)) and type 2 (AT(2)) receptor (R) expression and functional recovery after ischemia-reperfusion with or without AT(1)R/AT(2)R blockade in isolated working rat hearts. Groups of six hearts were subjected to global ischemia (30 min) followed by reperfusion (30 min) and exposed to no drug and no ischemia-reperfusion (control), ischemia-reperfusion and no drug, and ischemia-reperfusion with losartan (an AT(1)R antagonist; 1 micromol/l), PD-123319 (an AT(2)R antagonist; 0.3 micromol/l), N(6)-cyclohexyladenosine (CHA, a cardioprotective adenosine A(1) receptor agonist; 0.5 micromol/l as positive control), enalaprilat (an ANG-converting enzyme inhibitor; 1 micromol/l), PD-123319 + losartan, ANG II (1 nmol/l), or ANG II + losartan. Compared with controls, ischemia-reperfusion decreased AT(2)R protein (Western immunoblots) and mRNA (Northern immunoblots, RT-PCR) and impaired functional recovery. PD-123319 increased AT(2)R protein and mRNA and improved functional recovery. Losartan increased AT(1)R mRNA (but not AT(1)R/AT(2)R protein) and impaired recovery. Other groups (except CHA) did not improve recovery. The results suggest that, in isolated working hearts, AT(2)R plays a significant role in ischemia-reperfusion and AT(2)R blockade induces increased AT(2)R protein and cardioprotection.

1. Cannabinoids are known to cause coronary vasodilatation and reduce left ventricular developed pressure (LVDP) in isolated hearts although the identity of the receptor(s) mediating these responses is unknown. Our objective was to pharmacologically characterize cannabinoid receptors mediating cardiac responses to the endocannabinoid, anandamide. 2. Dose-response curves for coronary perfusion pressure (CPP) and LVDP were constructed to anandamide, R-(+)-methanandamide, palmitoylethanolamide (PEA) and JWH015 in isolated Langendorff-perfused rat hearts. Anandamide dose-response curves were also constructed in the presence of antagonists selective for CB(1), CB(2) or VR(1) receptors. 3. Anandamide and methanadamide significantly reduced CPP and LVDP but the selective CB(2) receptor agonists, PEA and JWH015 had no significant effect, compared with equivalent vehicle doses. 4. Single bolus additions of the selective CB(1)-receptor agonist, ACEA (5 nmol), decreased LVDP and CPP. When combined with JWH015 (5 nmol) these responses were not augmented. 5. Anandamide-mediated reductions in CPP were significantly blocked by the selective CB(1) receptor antagonists SR 141716A (1 microM) and AM251 (1 microM) and the selective CB(2) receptor antagonist SR 144528 (1 microM) but not by another selective CB(2) receptor antagonist AM630 (10 microM) nor the vanilloid VR(1) receptor antagonist capsazepine (10 microM). 6. SR 141716A, AM281 and SR 144528 significantly blocked negative inotropic responses to anandamide that were not significantly affected by AM251, AM630 and capsazepine. 7. One or more novel sites mediate negative inotropic and coronary vasodilatatory responses to anandamide. These sites can be distinguished from classical CB(1) and CB(2) receptors, as responses are sensitive to both SR 141716A and SR 144528.

1. The cannabinoid arachidonyl ethanolamide (anandamide) caused concentration-dependent relaxation of 5-HT-precontracted, myograph-mounted, segments of rat left anterior descending coronary artery. 2. This relaxation was endothelium-independent, unaffected by the fatty acid amide hydrolase inhibitor, arachidonyl trifluoromethyl ketone (10 microM), and mimicked by the non-hydrolysable anandamide derivative, methanandamide. 3. Relaxations to anandamide were attenuated by the cannabinoid receptor antagonist, SR 141716A (3 microM), but unaffected by AM 251 (1 microM) and AM 630 (1 microM), more selective antagonists of cannabinoid CB(1) and CB(2) receptors respectively. Palmitoylethanolamide, a selective CB(2) receptor agonist, did not relax precontracted coronary arteries. 4. Anandamide relaxations were not affected by inhibition of sensory nerve transmission with capsaicin (10 microM) or blockade of vanilloid VR1 receptors with capsazepine (5 microM). Nevertheless capsaicin relaxed coronary arteries in a concentration-dependent and capsazepine-sensitive manner, confirming functional sensory nerves were present. In contrast, capsazepine and capsaicin did inhibit anandamide relaxations in methoxamine-precontracted rat small mesenteric arteries. 5. Relaxations to anandamide were inhibited by TEA (1 mM) or iberiotoxin (50 nM), blockers of large conductance, Ca(2+)-activated K(+) channels (BK(Ca)). Gap junction inhibition with 18alpha-glycyrrhetinic acid (100 microM) did not affect anandamide relaxations. 6. This study shows anandamide relaxes the rat coronary artery by a novel mechanism. Anandamide-induced relaxations do not involve the endothelium, degradation into active metabolites, or activation of cannabinoid CB(1) or CB(2) receptors, but may involve activation of BK(Ca). Vanilloid receptor activation also has no role in the effects of anandamide in coronary arteries, even though functional sensory nerves are present.

1. In order to test the hypothesis that angiotensin II exacerbates myocardial ischaemia-reperfusion (IR) injury, we examined the effects of graded angiotension II concentrations of angiotensin II on IR injury in both working and non-working (Langendorff) isolated rat hearts. 2. Non-working hearts were subjected to 30 min aerobic perfusion (baseline) then 25 min of global, no-flow ischaemia followed by 30 min of reperfusion either in the absence (control, n=7) or presence of 1 (n=6) or 10 nM (n=5) angiotensin II). Recoveries of LV developed pressure and coronary flow after 30 min reperfusion in control hearts (58+/-9 and 40+/-8% of baseline levels, respectively) were no different from hearts treated with 1 or 10 nM angiotensin II. Infarct size (determined at the end of reperfusion by triphenyltetrazolium chloride staining) was reduced by angiotensin II in a concentration-dependent manner (from a control value of 27+/-3 to 18+/-4% and 9+/-3% of the LV, respectively). 3. Working hearts were subjected to 50 min pre-ischaemic (pre-I) aerobic perfusion then 30 min of global, no-flow ischaemia followed by 30 min of reperfusion either in the absence (control, n=14) or presence of 1 (n=8), 10 (n=7) or 100 nM (n=7) angiotensin II). In controls, post-ischaemic (post-I) left ventricular (LV) work and efficiency of oxygen consumption were depressed (43+/-9 and 42+/-10% of pre-I levels, respectively). The presence of angiotensin II throughout IR had no effect on LV work compared with control. 4. Thus, angiotensin II reduces infarct size in a concentration-dependent manner but has no effect on contractile stunning associated with IR in isolated rat hearts.

This study investigated the role of beta-adrenoceptors in the cardioprotective and metabolic actions of adenosine A(1) receptor stimulation. Isolated paced (300 beats min(-1)) working rat hearts were perfused with Krebs-Henseleit solution containing 1.2 mM palmitate. Left ventricular minute work (LV work), O(2) consumption and rates of glycolysis and glucose oxidation were measured during reperfusion (30 min) following global ischaemia (30 min) as well as during aerobic conditions. Relative to untreated hearts, N(6)-cyclohexyladenosine (CHA, 0.5 microM) improved post-ischaemic LV work (158%) and reduced glycolysis and proton production (53 and 42%, respectively). CHA+propranolol (1 microM) had similar beneficial effects, while propranolol alone did not affect post-ischaemic LV work or glucose metabolism. Isoprenaline (10 nM) impaired post-ischaemic function and after 25 min ischaemia recovery was comparable with 30 min ischaemia in untreated hearts (41 and 53%, respectively). Relative to isoprenaline alone, CHA+isoprenaline improved recovery of LV work (181%) and reduced glycolysis and proton production (64 and 60%, respectively). In aerobic hearts, CHA, propranolol or CHA+propranolol had no effect on LV work or glucose oxidation. Glycolysis was inhibited by CHA, propranolol and CHA+propranolol (50, 53 and 52%, respectively). Isoprenaline-induced increases in heart rate, glycolysis and proton production were attenuated by CHA (85, 57 and 53%, respectively). The cardioprotective efficacy of CHA was unaffected by antagonism or activation of beta-adrenoceptors. Thus, the mechanism of protection by adenosine A(1) receptor activation does not involve functional antagonism of beta-adrenoceptors.

1. Optimization of myocardial energy substrate metabolism improves the recovery of mechanical function of the post-ischaemic heart. This study investigated the role of K(ATP)-channels in the regulation of the metabolic and mechanical function of the aerobic and post-ischaemic heart by measuring the effects of the selective K(ATP)-channel activator, cromakalim, and the effects of the K(ATP)-channel antagonist, glibenclamide, in rat fatty acid perfused, working hearts in vitro. The role of K(ATP) channels in the cardioprotective actions of the adenosine A1-receptor agonist, N6-cyclohexyladenosine (CHA) was also investigated. 2. Myocardial glucose metabolism, mechanical function and efficiency were measured simultaneously in hearts perfused with modified Krebs-Henseleit solution containing 2.5 mM Ca2+, 11 mM glucose, 1.2 mM palmitate and 100 mu l(-1) insulin, and paced at 300 beats min(-1). Rates of glycolysis and glucose oxidation were measured from the quantitative production of 3H20 and 14CO2, respectively, from [5-3H/ U-14C]-glucose. 3. In hearts perfused under aerobic conditions, cromakalim (10 microM), CHA (0.5 microM) or glibenclamide (30 microM) had no effect on mechanical function. Cromakalim did not affect glycolysis or glucose oxidation, whereas glibenclamide significantly increased rates of glycolysis and proton production. CHA significantly reduced rates of glycolysis and proton production but had no effect on glucose oxidation. Glibenclamide did not alter CHA-induced inhibition of glycolysis and proton production. 4. In hearts reperfused for 30 min following 30 min of ischaemia, left ventricular minute work (LV work) recovered to 24% of aerobic baseline values. Cromakalim (10 microM), administered 5 min before ischaemia, had no significant effect on mechanical recovery or glucose metabolism. CHA (0.5 microM) significantly increased the recovery of LV work to 67% of aerobic baseline values and also significantly inhibited rates of glycolysis and proton production. Glibenclamide (30 microM) significantly depressed the recovery of mechanical function to < 1% of aerobic baseline values and stimulated glycolysis and proton production. 5. Despite the deleterious actions of glibenclamide per se in post-ischaemic hearts, the beneficial effects of CHA (0.5 microM) on the recovery of mechanical function and proton production were not affected by glibenclamide. 6. The data indicate that the cardioprotective mechanism of adenosine A1-receptor stimulation does not involve the activation of K(ATP)-channels. Furthermore, in rat fatty acid perfused, working hearts, stimulation of K(ATP)-channels is not cardioprotective and has no significant effects on myocardial glucose metabolism.

Background: Angiotensin II type 1 (AT1) receptor antagonists, when given over the long term, reduce the deleterious consequences of ischemia-reperfusion injury. Whether short-term administration of AT1 or angiotensin II type 2 (AT2) receptor antagonists is cardioprotective has not been investigated., Methods and Results: The effects of short-term administration of selective AT1 and AT2 receptor antagonists on the recovery of mechanical function during reperfusion after 30 minutes of global, no-flow ischemia were studied in left atrium-perfused isolated working rat hearts. Control hearts (n = 8) showed incomplete recovery of left ventricular minute work (LV work) and cardiac efficiency during reperfusion to 51 +/- 15% and 61 +/- 19% of preischemic levels, respectively. Compared with control hearts, the selective AT2 receptor antagonist PD123,319 (0.3 mumol/L) given before ischemia (n = 7) improved the recovery of LV work and efficiency to 82 +/- 4% and 98 +/- 7% of preischemic levels, respectively (P < .01). In contrast, the selective AT1 antagonist losartan (1 mumol/L) blocked the recovery of LV work and depressed efficiency to 0 +/- 0% and 1 +/- 0% (n = 7) of preischemic levels, respectively (P < .01; n = 7). Neither antagonist altered coronary vascular conductance., Conclusions: This is the first demonstration that short-term treatment with a selective AT1 versus AT2 antagonist exerts different effects on recovery of mechanical function after ischemia-reperfusion: the AT2 antagonist was cardioprotective, whereas the AT1 antagonist was not. These data suggest that AT2 antagonists and AT1 agonists may offer novel approaches for the treatment of mechanical dysfunction after ischemia-reperfusion.

The negative inotropic responses of guinea pig isolated left atria to the P1-receptor agonists adenosine and L-N6-phenylisopropyladenosine (L-PIA), the muscarinic receptor agonist carbachol, and the potassium channel activator cromakalim were examined. The potassium channel blocker 4-aminopyridine (4-AP, 10 mM) decreased the concentration-response curve for L-N-6-phenylisopropyladenosine (L-PIA) so that the maximum reduction in atrial tension was significantly reduced from 77.8 to 61.9%. The concentration-response curve for the negative inotropic response to carbachol was displaced to the right by a substantially greater amount (521-fold), partly due to the muscarinic receptor blocking activity of 4-AP. The response to a single submaximum dose of L-PIA (520 nM) was slow in onset and monophasic, whereas adenosine induced a rapid reduction in tension followed by a gradual return toward the resting level. In the presence of 4-AP (10 mM), the peak response to L-PIA was significantly reduced from a 59.7 to 31.0% inhibition of tension. In addition, the rate of development of the response was significantly slowed. The peak inhibition of tension by adenosine (112 microM) (60.0%) was also significantly reduced to 37.4% in the presence of 4-AP (10 mM). Furthermore, there was no rapid decrease in tension but a gradual decrease to a peak effect which was no different from that in the absence of 4-AP. These results suggest that the P1-receptor agonists exert negative inotropy through a K+ channel-dependent component which is blocked by 4-AP and a slower-onset K+ channel-independent component. The potassium channel blocker, bromobenzoylmethyladamantylamine (BMA 100 microM) also shifted (11-fold) the concentration-response curve for the negative inotropic response to adenosine, and to a lesser extent that to cromakalim (2.1-fold) and carbachol. Glibenclamide (0.3, 3, and 30 microM), a selective antagonist of ATP-regulated potassium channels, was a potent antagonist of the negative inotropic responses to cromakalim. However, 30 microM failed to antagonize the responses to L-PIA, adenosine, or carbachol, indicating that they do not mediate their responses through ATP-regulated potassium channels. 4-AP (10 mM) caused a slight shift (2.3-fold) of the concentration-response curve for cromakalim, indicating weak activity against ATP-regulated potassium channels in the left atrium. This study showed that P1-receptor agonists exert negative inotropic responses in guinea pig left atria only in part through activation of potassium channels. These channels differ from the ATP-regulated potassium channels activated by cromakalim.

To combat the problem of excess capacity and to meet the needs of its elder community. Highland Park Hospital (HPH) in Highland Park, Illinois decided to convert an unused acute care unit into a skilled nursing facility (SNF). Detailed here is the methodology used to determine the number of SNF beds needed by HPH, the options for development available, and the factors considered when choosing the type of facility to be designed.