The effect of branded versus standardized e-cigarette packaging and device designs: an experimental study of youth interest in vaping products

OBJECTIVES

Standardized ('plain') packaging is effective in reducing the appeal of cigarettes among young people. This study examined the impact of plain packaging and brand imagery on interest in trying e-cigarettes among youth.

STUDY DESIGN

Experimental design.

METHODS

Two online experiments were conducted in February 2020 as part of the ITC Youth Tobacco & Vaping Survey, conducted with 13,624 16- to 19-year-olds in Canada, England, and the USA. In the between-group Experiment 1, participants were randomized to view a set of 3 e-cigarette brands, in either their original external packaging ('branded' condition) or standardized olive-green packaging ('standardized' condition), and asked to select the product they would be most interested in trying. The within-group Experiment 2 examined brand imagery directly on devices, including potential differences in appeal among subgroups. Each participant viewed 4 pod-style e-cigarette devices: one 'plain' and 3 in colourful 'skins'. Logistic regression models were conducted to test the effect of condition, adjusting for demographics, smoking and vaping status.

RESULTS

In Experiment 1, participants in the 'standardized' packaging condition were significantly more likely to indicate 'I have no interest in trying any of these products' (72.3%) than those in the 'branded' condition (66.9%, AOR 1.45, 95% CI 1.33-1.59). Experiment 2 results indicated differences in e-cigarette appeal by sex in the selection of male- and female-oriented designs, and by cannabis use for a Rastafarian-themed design.

CONCLUSIONS

Brand imagery on e-cigarettes can target products to specific subgroups. Removal of imagery, in the form of standardized packaging, has the potential to reduce interest in trying e-cigarettes among young people.

Coaching to enhance qualified surgeons' non-technical skills: a systematic review

INTRODUCTION

The lack of an effective continuing professional development programme for qualified surgeons, specifically one that enhances non-technical skills (NTS), is an issue receiving increased attention. Peer-based coaching, used in multiple professions, is a proposed method to deliver this. The aim of this study was to undertake a systematic review of the literature to summarize the quantity and quality of studies involving surgical coaching of NTS in qualified surgeons.

METHODS

A systematic search of the literature was performed through MEDLINE, EMBASE, Cochrane Collaboration and PsychINFO. Studies were selected based on predefined inclusion and exclusion criteria. Data for the included studies was independently extracted by two reviewers and the quality of the studies evaluated using the Medical Education and Research Study Quality Instrument (MERSQI).

RESULTS

Some 4319 articles were screened from which 19 met the inclusion criteria. Ten studies involved coaching of individual surgeons and nine looked at group coaching of surgeons as part of a team. Group coaching studies used non-surgeons as coaches, included objective assessment of NTS, and were of a higher quality (average MERSQI 13.58). Individual coaching studies focused on learner perception, used experienced surgeons as coaches and were of a lower quality (average MERSQI 11.58). Individual coaching did not show an objective improvement in NTS for qualified surgeons in any study.

CONCLUSION

Surgical coaching of qualified surgeons' NTS in a group setting was found to be effective. Coaching of individual surgeons revealed an overall positive learner perception but did not show an objective improvement in NTS for qualified surgeons.

Maternal and Fetal Platelet Responses and Adrenoceptor Binding Characteristics

Paired blood samples were obtained from mothers (venous) and babies (cord venous blood) at the time of delivery by caesarean section under epidural anaesthetic. Fetal platelets failed to aggregate in response to adrenaline in vitro although adrenaline could potentiate the threshold response to adenosine diphosphate (1 μM). Fetal platelet responses to collagen and 8 Arg vasopressin did not differ significantly from maternal responses. Maternal and fetal platelets also showed similar inhibition of aggregation after activation of adenylate cyclase (PGE1 and parathormone), in contrast to the inhibition of adenylate cyclase by adrenaline.

Alpha2 adrenoceptors were investigated using [3H] yohimbine binding receptor number and were reduced modestly but significantly on fetal compared to maternal platelets. The failure of fetal platelet aggregation in response to adrenaline appears to be related to a failure of receptor coupling and may represent a delayed maturation of fetal platelet alpha receptors or a response- to increased circulating catecholamines during birth.

Reducing Stroke Risk in Hypertensive Patients: Asian Consensus Conference Recommendations

Stroke results in substantial morbidity and mortality globally. Asia-Pacific countries bear a disproportionate share of the burden of stroke, a burden that will grow as their populations' life expectancies rise. Hypertension is the single most important reversible risk factor for stroke, and effective measures to reduce blood pressure contribute significantly to reducing the incidence of stroke. The Asia-Pacific Consensus Conference on Stroke Prevention in Hypertensive Patients assembled leading experts from the region to reach an actionable consensus aimed at reducing stroke-induced morbidity and mortality in Asia through the evidence-based treatment of hypertension. The discussions of the group focused on how best to improve blood pressure control, how to promote lifestyle changes at the population level, and how to reduce the clinical and health system barriers and other challenges facing developing and low-income countries. The experts concluded that physicians must place an increased priority on reducing their patients' risk of stroke and recognise that all hypertensive patients are at greater risk of having a stroke compared with nonhypertensive individuals. They advocated that physicians must educate hypertensive patients about the risk of stroke, promote lifestyle modification to all patients diagnosed with hypertension, and prescribe rigorous antihypertensive treatment to get patients to recommended blood pressure goals.

The cardiovascular effects of bromocriptine in Parkinsonism

The cardiovascular effects of bromocriptine, a dopamine receptor agonist, were investigated in twenty-eight Parkinsonian patients. Bromocriptine caused a significant impairment of postural compensation with a fall in systolic pressure and an absence of the rise in diastolic pressure after standing for 1 min when patients taking active drug were compared to the same patients on placebo. The hypotensive effect persisted for at least 6 weeks of treatment. There was also a significant reduction in supine heart rate. One patient had marked falls in supine and erect blood pressure after a single oral dose of bromocriptine (2.5 mg) and a further patient developed paroxysmal atrial tachyarrhythmias. Both blood pressure and heart rate changes reversed spontaneously after stopping bromocriptine. It is proposed that dopaminergic mechanisms either in the central nervous system or the periphery contribute to cardiovascular regulation in man.

Factors related to adolescents' estimation of peer smoking prevalence

Although adolescents who overestimate peer smoking prevalence are more likely to smoke, little research has focused on the factors associated with why the majority of adolescents overestimate peer smoking rate. The purpose of this study was to examine demographic, social, environmental and behavioural characteristics related to overestimation of peer smoking prevalence among secondary school students. The current study analysed data collected in two Canadian studies that used the Tobacco Module of the School Health Action, Planning and Evaluation System, a school-based questionnaire. One study surveyed 23 458 students (Grades 9-13) in 29 schools during 2001-02, and the other surveyed 25 452 students in 39 schools in 2003. Results of multiple logistic regression indicate that grade, gender, close friends' smoking, seeing smoking at school, family members' smoking, smoking in the home and smoking status have a clear association with overestimation; school smoking rate and susceptibility to smoking show a tentative relationship and warrant further study. Other factors may also be important for prevalence estimation, and further research is needed to identify these factors. Since adolescents tend to overestimate peer smoking prevalence and perceived prevalence is in turn linked to smoking behaviour, interventions should focus on creating realistic perceptions of smoking prevalence.

Prior events predict cerebrovascular and coronary outcomes in the PROGRESS trial

BACKGROUND AND PURPOSE

The relationship between baseline and recurrent vascular events may be important in the targeting of secondary prevention strategies. We examined the relationship between initial event and various types of further vascular outcomes and associated effects of blood pressure (BP)-lowering.

METHODS

Subsidiary analyses of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS) trial, a randomized, placebo-controlled trial that established the benefits of BP-lowering in 6105 patients (mean age 64 years, 30% female) with cerebrovascular disease, randomly assigned to either active treatment (perindopril for all, plus indapamide in those with neither an indication for, nor a contraindication to, a diuretic) or placebo(s).

RESULTS

Stroke subtypes and coronary events were associated with 1.5- to 6.6-fold greater risk of recurrence of the same event (hazard ratios, 1.51 to 6.64; P=0.1 for large artery infarction, P<0.0001 for other events). However, 46% to 92% of further vascular outcomes were not of the same type. Active treatment produced comparable reductions in the risk of vascular outcomes among patients with a broad range of vascular events at entry (relative risk reduction, 25%; P<0.0001 for ischemic stroke; 42%, P=0.0006 for hemorrhagic stroke; 17%, P=0.3 for coronary events; P homogeneity=0.4).

CONCLUSIONS

Patients with previous vascular events are at high risk of recurrences of the same event. However, because they are also at risk of other vascular outcomes, a broad range of secondary prevention strategies is necessary for their treatment. BP-lowering is likely to be one of the most effective and generalizable strategies across a variety of major vascular events including stroke and myocardial infarction.

The angiotensin II receptor antagonist telmisartan reduces urinary albumin excretion in patients with isolated systolic hypertension: results of a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To examine the effect of telmisartan or hydrochlorothiazide on the control of urinary albumin excretion (UAE) in patients with isolated systolic hypertension (ISH) unselected for albuminuria in a pre-planned substudy of a large, multicentre, double-blind, placebo-controlled, randomized study.

METHODS

The Angiotensin II Receptor Antagonist Micardis in Isolated Systolic hypertension (ARAMIS) study compared the antihypertensive efficacy after 6 weeks of once-daily fixed doses of telmisartan 20, 40 or 80 mg versus hydrochlorothiazide 12.5 mg or placebo in patients (n = 1039, aged 35-84 years) with ISH (seated blood pressure 150-179/< 90 mmHg). The prospective substudy analysed UAE using spot morning samples.

RESULTS

Urinary albumin (> 2.2-901.6 mg/l) was detected at baseline in 614 out of 918 patients who were included in the substudy analysis. In the telmisartan group (n = 354, all doses combined), a median reduction in UAE from a baseline of 14.1% [95% confidence interval (CI) 7.3, 21.8] was observed versus 1.1% (95% CI -13.5 to 16.0) and 2.7% (95% CI -0.9 to 19.9) in the hydrochlorothiazide (n = 140) and placebo (n = 120) groups, respectively. The difference between telmisartan and hydrochlorothiazide was significant (P = 0.017). Reductions in UAE with telmisartan were observed in patients with baseline normoalbuminuria, microalbuminuria or macroalbuminuria. Telmisartan and hydrochlorothiazide produced comparable reductions in systolic blood pressure in these patients.

CONCLUSION

In patients with ISH unselected for baseline albuminuria, telmisartan 20-80 mg after 6 weeks' treatment afforded significantly greater lowering of UAE than hydrochlorothiazide 12.5 mg, irrespective of the baseline UAE, and despite comparable reductions in systolic blood pressure with both drugs.

Medicine-taking behavior: implications of suboptimal compliance in Parkinson's disease

Management of Parkinson's disease (PD) depends primarily on oral medication. There are several drug classes and multiple doses and formulations, which make optimizing therapy complex. Variable drug absorption and the short half-life of most antiparkinson treatments, especially levodopa, are a main focus in understanding complications and have encouraged alternative delivery systems to limit fluctuation and dyskinesia at later stages. Comparatively little attention is paid to the way patients take their oral medication. Variable medicine-taking behavior can affect the clinician's understanding of the diagnosis and rate of progression, and further prescription of PD medication. Medicine overuse in later stage PD is well documented and causes psychiatric disturbance and increases motor complications, but evidence of undertreatment and erratic intake is emerging, which is likely to affect motor control and quality of life adversely. Methods of quantifying compliance are compared for accuracy and limitations. Understanding medicine-taking behavior is a first step in optimizing therapy and requires consideration of a patient's personal beliefs about their medicines. Although the benefits of regularizing oral medicine-taking in a practical, achievable way in PD remain untested, such an approach might prolong and smooth the benefits of oral medication and is worthy of further research.

Measuring therapy adherence in Parkinson's disease: a comparison of methods

The objective of this study was to assess different methods of measuring therapy adherence in Parkinson's disease (PD). In a single centre observational study, 112 patients with idiopathic PD were randomised to a crossover trial of active monitoring (n = 69, simple tablet count and electronic monitoring), or to no monitoring (n = 43, control group). All patients completed a self report and visual analogue scale (VAS) indicating therapy intake. In the active monitoring group, 56 (81% of cases) used > or = 80% of their medication, and 13 (19% of cases) used <80%, based on electronic monitoring. Median adherence for self report was 100% (interquartile range (IQR) 100 to 100) and for VAS was 100% (IQR 95 to 100), in both active and control groups. Patients taking > or = 80% of prescribed medication had a median total adherence of 98% (IQR 93 to 101) by electronic monitoring, which was similar to that from other

METHODS

self report 100%, IQR 100 to 100; VAS 100%, IQR 95 to 100; simple tablet count 98%, IQR 89 to 100. Median total adherence in patients taking <80% of medication was significantly lower by electronic monitoring (69%, IQR 44 to 74) than by other methods: self report 100%, IQR 100 to 100; VAS 100%, IQR 95 to 100; and simple tablet count 90%, IQR 78 to 100 (all p<0.0001). Sensitivities of self report (10%), VAS (17%), and simple tablet count (50%) were all low for detecting suboptimal medicine intake. Self report, VAS, and simple tablet counts are insensitive as predictors of suboptimal medicine usage in PD. How patients take their medicines influences interpretation of the therapy response and consequent management decisions, with implications for clinical trial analysis and clinical practice.

Molecular-specific effects of angiotensin II antagonists: clinical relevance to treating hypertension?

Angiotensin II receptor blockers (ARBs) may produce a number of molecule-specific effects that appear to be independent of interaction with the angiotensin II type 1 (AT1)-receptor. These include antagonism of the thromboxane A2 receptor, inhibition of platelet aggregation, induction of peroxisome proliferator- activated receptor gamma (PPARgamma) activity, and reduction of serum uric acid levels. However, definitive evidence is lacking that these molecule-specific effects give rise to a therapeutic advantage of one ARB over another. Currently, the possibility of a link between a molecule-specific effect of an ARB and an improvement in clinical outcomes is best illustrated by a reduction in serum uric acid levels with losartan. Data from Losartan Intervention For Endpoint reduction in hypertension (LIFE) study suggest a treatment-induced decrease in serum uric acid may contribute to the treatment benefit of a losartan-based versus atenolol-based therapy on the composite endpoint (death, myocardial infarction, or stroke). This finding should prompt further studies to investigate the long-term cardioprotective benefits issue of reducing hyperuricaemia in hypertensive patients.

Statin administration prior to ischaemic stroke onset and survival: exploratory evidence from matched treatment-control study

In addition to their lipid-lowering effects, it has been speculated that statins may also have beneficial effects on cerebral circulation and brain parenchyma during ischaemic stroke and reperfusion. We hypothesized that patients who had taken statins prior to stroke onset may have a better survival rate at 1 month and during the follow-up period. We retrospectively studied consecutive ischaemic stroke patients admitted to an acute stroke unit and at least a month's follow-up. From these, we included those patients who, at admission, had reported the use of a statin prior to the stroke onset in the statin group (n = 205). Each patient in the statin group was matched with two patients who reported no statin use (n = 410). Using logistic regression and Cox proportional hazards models, we adjusted for variables that significantly differed between treatment groups or that independently predicted mortality. After adjusting for those variables, statin use was associated with reduced mortality at 1 month [odds ratio 0.24; 95% confidence interval (CI) 0.09-0.67] and during the follow-up period (hazard ratio 0.57; 95% CI 0.35-0.93). The use of statins prior to stroke onset is associated with improved stroke survival within this cohort study with matched controls.

An oral yohimbine/L-arginine combination (NMI 861) for the treatment of male erectile dysfunction: a pharmacokinetic, pharmacodynamic and interaction study with intravenous nitroglycerine in healthy male subjects

AIMS

Interaction of phosphodiesterase type 5 inhibitors for the treatment of erectile dysfunction with organic nitrates could lead to severe hypotension. NMI 861 is a combination of 7.7 mg yohimbine tartrate and 6 g l-arginine glutamate. A similar oral combination, which contains the same amount of yohimbine and L-arginine, has been shown to improve erectile function in previous studies.

METHODS

In two placebo-controlled, randomized, double-blind, two-way crossover design studies we aimed to assess first the pharmacokinetics and pharmacodynamics of a single oral dose of NMI 861 administered in 16 healthy male subjects, and then the pharmacodynamics of orally administered NMI 861 in combination with intravenous nitroglycerine (GTN) in 12 healthy male subjects. Systolic (SBP) and diastolic (DBP) blood pressures, pulse rate and adverse events were measured in each study.

RESULTS

NMI 861 was well tolerated by all subjects with no significant adverse reactions reported. For L-arginine, mean C(max) +/- SEM (range) was 42 +/- 2.2 (28-63) microg ml(-1) and t(max) (range) was 0.88 (0.50-1.5) h. AUC and t(1/2) were not calculated for L-arginine because of the presence of endogenous concentrations and the contribution from food sources. For yohimbine, mean C(max) was 42 +/- 11 (2.8-128) ng ml(-1); t(max) was 0.57 (0.25-1.0) h; mean AUC(0,8 h) was 65 +/- 24 (5.4-332), ng ml(-1) h and t(1/2) was 1.0 +/- 0.34 (0.40-6.0) h. There was a small but significant difference in the mean change from baseline for SBP from 0 to 6 h after NMI 861 treatment compared with placebo (0.8 +/- 1.4 vs-4.1 +/- 2.1 mmHg, respectively; 95% CI 0.0, 9.8 mmHg (P = 0.047)). There was no significant difference in SBP between treatments for the studied periods 6-12 h and 12-24 h. There was no significant difference in DBP or pulse between NMI 861 and placebo treatments for the three studied time periods. In the study designed to investigate the interaction of organic nitrate with NMI 861, subjects were infused intravenously with increasing doses of GTN (15 min each dose) at 2.5, 5, 10, 20 and 40 microg min(-1) starting 40 min after a single oral dose of either NMI 861 or placebo. There was no significant difference in the hypotensive response induced by GTN between the NMI 861 and placebo treatments. The mean maximum changes from baseline during GTN infusion for subjects administered with either NMI 861 or placebo were a decrease of 16.9 +/- 3.4 vs 13.6 +/- 2.4 mmHg (mean difference between treatments -3.3 mmHg, 95% CI -12.7, 6.0 mmHg (P = 0.460)) for SBP, a decrease of 14.7 +/- 2.0 vs 14.0 +/- 2.0 mmHg for DBP (mean difference -0.7 mmHg, 95% CI -8.2, 6.8 mmHg (P = 0.835)), and an increase of 11.8 +/- 1.9 vs 14.1 +/- 2.4 beats min(-1) for pulse, respectively (mean difference -2.3 beats min(-1), 95% CI -9.3, 4.5 beats min(-1) (P = 0.464)).

CONCLUSIONS

Acute oral administration of NMI 861 was found to be well tolerated and bioavailable in healthy male subjects and no significant hypotensive interaction with intravenous GTN was detected at the doses investigated.

Angiotensin II receptor antagonist telmisartan in isolated systolic hypertension (ARAMIS) study: efficacy and safety of telmisartan 20, 40 or 80 mg versus hydrochlorothiazide 12.5 mg or placebo

OBJECTIVE

To identify telmisartan doses that are more effective than placebo and non-inferior to hydrochlorothiazide (HCTZ) 12.5 mg, and are well tolerated, in lowering systolic blood pressure (SBP) in patients with isolated systolic hypertension (ISH).

PATIENTS AND METHODS

A 2-4-week single-blind placebo run-in was followed by randomization of 1039 patients (age 36-84 years) with ISH [seated SBP 150-179 mmHg and seated diastolic blood pressure (DBP) < 90 mmHg] to once-daily double-blind treatment with telmisartan 20, 40 or 80 mg, HCTZ 12.5 mg, or placebo. The change in seated trough SBP after 6 weeks compared with baseline was the primary end point. Secondary end points were the percentage achieving the target fall in SBP and the change from baseline in seated trough DBP. Incidence and severity of adverse events and physical examination and laboratory parameters were monitored for the safety evaluation.

RESULTS

Baseline demographics in telmisartan 20 mg (n = 206), 40 mg (n = 210), 80 mg (n = 207), HCTZ 12.5 mg (n = 205) and placebo (n = 211) treatment groups were comparable: (mean +/- SD) age, 63.0 +/- 10.9 years; SBP, 162.9 +/- 8.1 mmHg; and DBP 83.4 +/- 5.0 mmHg. No previous antihypertensive therapy had been received by 66% of the patients. Mean reductions in seated trough SBP (adjusted for baseline and country) were: telmisartan 20 mg, 15.6 mmHg (n = 204); 40 mg, 17.9 mmHg (n = 209); and 80 mg, 16.9 mmHg (n = 205), compared with placebo, 11.4 mmHg (n = 208), and HCTZ 12.5 mg, 15.7 mmHg (n = 204). The target fall in seated trough SBP (< or =140 mmHg or reduction by > or =20 mmHg) was achieved in 46.6% (telmisartan 20 mg), 51.7% (telmisartan 40 mg), 53.9% (telmisartan 80 mg), 27.4% (placebo) and 42.7% (HCTZ 12.5 mg); the response rate was significantly higher for telmisartan 80 mg than for HCTZ 12.5 mg (P = 0.03). All-causality adverse events occurred in 19.9, 17.6 and 20.3% receiving telmisartan 20, 40 and 80 mg, respectively; 20.9% receiving placebo and 22.0% receiving HCTZ 12.5 mg. No drug-related serious adverse events occurred.

CONCLUSIONS

All doses of telmisartan (20-80 mg) were significantly superior to placebo in reducing SBP in patients with ISH and clinically comparable to HCTZ 12.5 mg. Tolerability of telmisartan was similar to that of placebo.

Increased levels of superoxide in brains from old female rats

Hypertension, aging and a range of neurodegenerative diseases are associated with increased oxidative damage. The present study examined whether superoxide (O2*-) levels in brain are increased during aging in female rats, and the role of superoxide dismutase (SOD) and oestrogen in regulating O2*- levels. Young adult (3 month) and old (11 month) female spontaneously hypertensive stroke prone rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) were studied. O2*- levels were measured in brain homogenates by lucigenin chemiluminescence and SOD expression by Western blotting. Ageing significantly increased brain O2*- levels in WKY (cortex +216%, hippocampus +320%, striatum +225%) and to a greater extent in SHRSP (cortex +540%, hippocampus +580%, striatum +533%). Older SHRSP showed a decline in cortical Cu/Zn SOD expression compared to young adult SHRSP. Oestrogen did not attenuate O2*- levels. The results show a significant age-dependent increase in brain O2*- levels which is exaggerated in SHRSP. The excess cortical O2*- levels in the SHRSP may be associated with a down-regulation of Cu/Zn SOD but are not related to a decrease in oestrogen.

The effect of losartan on global and focal cerebral perfusion and on renal function in hypertensives in mild early ischaemic stroke

BACKGROUND

Secondary prevention of stroke with antihypertensive drugs is now standard practice, but it is unclear how soon after a cerebrovascular event antihypertensive therapy should be initiated or re-started. Due to impaired cerebral autoregulation, changes in systemic blood pressure may be reflected in cerebral perfusion, especially in hypertensive patients immediately post-stroke. Conversely, early initiation in hospital may better assure continued long-term treatment. We have investigated the effect of the angiotensin II receptor antagonist (ARA) losartan on mean arterial blood pressure (MABP), global and focal cerebral blood flow (CBF), and glomerular filtration rate (GFR) in hypertensive patients 2-7 days after stroke.

METHODS

Twenty-four patients without occlusive carotid disease but with MABP between 110 and 145 mmHg were studied within 2-7 days of ischaemic stroke/transient ischaemic attack (TIA). They were randomized to receive either placebo or losartan (25 or 50 mg daily). MABP and internal carotid artery (ICA) flow were measured at baseline, over the following 24 h and at 2 weeks. Brain hexamethylpropyleneamine oxime single photon emission computed tomography (HMPAO SPECT) was performed before dosing and at the estimated time of peak drug effect (6-8 h after the first dose). GFR was measured at baseline and at 2 weeks.

RESULTS

The mean National Institutes of Health (NIH) score of randomized patients was 2.6; losartan was generally well tolerated and no patient suffered a deterioration in neurological function. A mean placebo-corrected intra-subject reduction in MABP of 9.5 mmHg was observed in treated patients from 1-12 h (P = 0.0001), with a maximal fall of 18.1 mmHg at 9 h post-dose (P = 0.002). No change occurred in ICA flow, or cortical or hemispheric CBF measured by HMPAO SPECT. No significant change in GFR was seen within or between groups.

DISCUSSION

Losartan may be introduced within 2-7 days of mild stroke in hypertensive patients in whom significant carotid occlusive disease has been excluded without affecting global or regional CBF, or affecting GFR.

Efficacy and tolerability of long-term rilmenidine treatment in hypertensive diabetic patients. A retrospective analysis of a general practice study

INTRODUCTION

Rilmenidine is a centrally acting antihypertensive which differs from the other representatives of this class by its very high specificity for the imidazoline I1 receptors and its good tolerability. Recent studies have shown rilmenidine improves glucose tolerance and reduces micro-albuminuria in patients with diabetes mellitus.

METHODOLOGY

The evidence of these potentially favorable characteristics encouraged a secondary retrospective analysis of a subgroup of 2738 diabetic patients included in a previous long-term open study of rilmenidine alone, or in combination with other classes of antihypertensives.

RESULTS

The antihypertensive efficacy of rilmenidine demonstrated previously in controlled studies was confirmed during the 12-month follow-up. In addition, favorable effects of drug treatment on fasting blood glucose and plasma triglyceride levels were consistent with an improvement in glucose and lipid metabolism during treatment. The profile of adverse events was similar to that observed in the nondiabetic population, the occurrence of postural hypotension being observed in <1% of patients and not necessitating any withdrawals from the study.

CONCLUSION

Diabetic hypertensive patients frequently require the use of multiple medications and consideration of the metabolic interactions between treatments. The results of this retrospective analysis support the use of rilmenidine in patients with hypertension and diabetes mellitus and should encourage the conduct of controlled trials of cardiovascular and renal protection and outcome with this compound.

Clinical Pharmacology and the Management of Cardiovascular Diseases

Clinical pharmacology contributes to many stages of drug development including discovery, registration, and application in clinical practice. The clinical pharmacologists working in academia, in industries, and with government agencies play an important role in optimizing efficacy and efficiency of drug use. The integration of drug therapy into overall long-term clinical care offers further possibilities. For example, long-term care of cardiovascular and metabolic diseases including hypertension and heart failure have been improved by clinical pharmacologists applying evidence-based practice and rational treatment choices.

Effect of area-based deprivation on the severity, subtype, and outcome of ischemic stroke

BACKGROUND AND PURPOSE

Markers of low socioeconomic status (deprivation) are associated with stroke and its causes. In the United Kingdom, area-based deprivation measures are available routinely through links with postal codes. We hypothesized that deprivation is associated with ischemic stroke risk factors, severity, subtype, and outcome.

METHODS

We studied 2026 patients, each with at least 2 years of outcome follow-up by record linkage after first admission with ischemic stroke to an acute stroke unit. Baseline factors recorded routinely were age, sex, medical history, blood pressure, and stroke severity and subtype. Deprivation was assessed by the Womersley score (WS) and Murray score (MS).

RESULTS

Higher WS and MS were associated with stroke at younger age (eg, WS linear regression coefficient (r)=-0.26; 95% confidence interval [CI], -0.51 to -0.01 per additional point), smoking (odds ratio [OR], 1.12; 95% CI, 1.08 to 1.17), and claudication (OR, 1.09; 95% CI, 1.01 to 1.17); WS was associated with higher systolic blood pressure (r=0.13; 95% CI, 0.02 to 0.24); and MS was associated with severe stroke. Deprivation was not associated with case fatality in univariate analysis or after correction for all baseline factors. Deprivation was associated with readmission to hospital as a result of any vascular event in univariate analysis (hazard ratio [HR], 1.05; 95% CI, 1.02 to 1.09) and after correction for all baseline factors (HR, 1.06; 95% CI, 1.02 to 1.10).

CONCLUSIONS

Tackling health inequalities in stroke should focus on stroke primary prevention by tackling deprivation, including promoting changes in lifestyle.

Calcium antagonist lacidipine slows down progression of asymptomatic carotid atherosclerosis: principal results of the European Lacidipine Study on Atherosclerosis (ELSA), a randomized, double-blind, long-term trial

BACKGROUND

Most cardiovascular events associated with hypertension are complications of atherosclerosis. Some antihypertensive agents influence experimental models of atherosclerosis through mechanisms independent of blood pressure lowering.

METHODS AND RESULTS

The European Lacidipine Study on Atherosclerosis (ELSA) was a randomized, double-blind trial in 2334 patients with hypertension that compared the effects of a 4-year treatment based on either lacidipine or atenolol on an index of carotid atherosclerosis, the mean of the maximum intima-media thicknesses (IMT) in far walls of common carotids and bifurcations (CBM(max)). This index has been shown by epidemiological studies to be predictive of cardiovascular events. A significant (P<0.0001) effect of lacidipine was found compared with atenolol, with a treatment difference in 4-year CBM(max) progression of -0.0227 mm (intention-to-treat population) and -0.0281 mm (completers). The yearly IMT progression rate was 0.0145 mm/y in atenolol-treated and 0.0087 mm/y in lacidipine-treated patients (completers, 40% reduction; P=0.0073). Patients with plaque progression were significantly less common, and patients with plaque regression were significantly more common in the lacidipine group. Clinic blood pressure reductions were identical with both treatments, but 24-hour ambulatory systolic/diastolic blood pressure changes were greater with atenolol (-10/-9 mm Hg) than with lacidipine (-7/-5 mm Hg). No significant difference between treatments was found in any cardiovascular events, although the relative risk for stroke, major cardiovascular events, and mortality showed a trend favoring lacidipine.

CONCLUSION

The greater efficacy of lacidipine on carotid IMT progression and number of plaques per patient, despite a smaller ambulatory blood pressure reduction, indicates an antiatherosclerotic action of lacidipine independent of its antihypertensive action.

Renal cell carcinoma may adapt to and overcome anti-angiogenic intervention with thalidomide

OBJECTIVE

To report on the failure of thalidomide to inhibit tumour growth in an animal model of human renal cell carcinoma (RCC).

MATERIALS AND METHODS

An orthotopic xenograft model of human RCC was used in which tumour cells were implanted in the left kidney of male 'severe combined immunodeficient' mice. Thalidomide was administered by intraperitoneal injection and after 34 days the mice were killed. The extent of tumour growth was compared in treated and untreated mice. Total RNA was extracted from both tumour-affected and contralateral kidneys, and analysed by reverse transcription-polymerase chain reaction for various genes implicated in angiogenesis and metastasis in RCC.

RESULTS

Thalidomide failed to inhibit the growth of xenograft tumours. The expression of angiogenic genes, e.g. vascular endothelial growth factor and fibroblast growth factor type 2 (FGF-2) within normal and tumour-affected kidney tissue was not reduced by thalidomide. Intratumoral transcription of beta3-integrin, a critical component of angiogenesis, was significantly increased in response to thalidomide treatment (P < 0.01). There was also a trend to increased expression of FGF-2 and tumour necrosis factor-alpha in thalidomide-treated tumours.

CONCLUSIONS

These findings suggest that RCC is capable of adapting to the inhibitory effects of thalidomide. The current uncertainty surrounding the action of thalidomide in vivo warrants caution about its use in humans. Further studies of thalidomide should be carried out in animal models, particularly to establish its safety and effectiveness as part of a combined therapeutic strategy.

Antihypertensive drugs in the elderly--the evidence of benefit

Hypertension is a major cardiovascular risk factor. The commonest mode of death in the elderly is a cardiovascular one and so the treatment of hypertension in the elderly population is an important clinical objective. The choice of which antihypertensive drug to prescribe is expanding and an evidence-based approach should be applied. In recent years more studies have been carried out into the efficacy of the various antihypertensive drugs in the elderly. This review looks at the "hard" outcome data for each major drug class and their suitability for prescribing in the elderly. The differing drug classes are divided into 3 categories based on the weight of evidence supporting them--established, emerging, and add-on therapies. Currently, and until the publication of ongoing trials into newer therapies such as ACE inhibitors and calcium-channel blockers, outcome data suggests that thiazides remain the drug of first choice except where other therapies are indicated for coexistant conditions or more than one drug is required to achieve the desired response.

Vasorelaxant properties of isolated human radial arteries: comparison with internal mammary arteries

Radial arteries, used in revascularisation surgery, are prone to spasm. We have examined the ability of nitrovasodilators, calcium channel blockers, and K(ATP) channel openers to cause vasodilation, and to attenuate contractions due to depolarisation and receptor activation in radial and mammary arteries used in coronary artery bypass graft surgery. Two to three millimetre rings of artery obtained from patients at surgery were studied in organ baths in vitro. Constriction to KC1 and phenylephrine was examined before and again after treatment of the rings with drug or vehicle. Calcium channel blockers were the only compounds to inhibit contractions to both KC1 and phenylephrine. Sodium nitroprusside attenuated constriction to phenylephrine but not KC1 in both vessels. K(ATP) channel openers similarly attenuated constriction to phenylephrine in radial arteries but were much less effective in mammary arteries. These studies support the continued use of calcium blockers after revascularisation with radial artery but suggest that other classes of drug may be as effective at minimising spasm due to receptor mediated constriction.

Update on rilmenidine: clinical benefits

Rilmenidine is an imidazoline derivative that appears to lower blood pressure (BP) by an interaction with imidazoline (I1) receptors in the brainstem (and kidneys). Rilmenidine is as effective in monotherapy as all other first-line classes of drugs, including diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and calcium antagonists. It is well tolerated and can be taken in combination for greater efficacy. Sedation and dry mouth are not prominent side effects and withdrawal hypertension is not seen when treatment is stopped abruptly. Recently, in addition to a reduction in BP, this agent has been shown to improve glucose tolerance, lipid risk factors, and insulin sensitivity. These changes would be consistent with a reduction in long-term cardiovascular risk, as would recently described actions on the heart (reducing left ventricular hypertrophy) and the kidney (reducing microalbuminuria). Although no data are yet available from prospective long-term outcome studies, rilmenidine could represent an important new development in antihypertensive therapy and the prevention of cardiovascular disease.

Radial artery hypertrophy occurs in coronary atherosclerosis and is independent of blood pressure

Endothelial dysfunction, believed to underlie the structural changes of atherosclerosis, is a systemic phenomenon. Despite this, the radial artery has been considered as devoid of atherosclerosis and is commonly used as a conduit in coronary artery bypass grafting (CABG). Recently, histological study has shown intimal hyperplasia and other structural changes consistent with early atherosclerosis in the radial artery. The objective of the present study was to determine if structural changes in the radial artery could be detected in vivo in patients with coronary atherosclerosis. Using high resolution echo-tracking, measurements of radial artery internal diameter, wall thickness and wall cross-sectional area were made in 25 patients awaiting CABG and in 20 controls. Digital and brachial blood pressures were also recorded. Mean arterial pressures did not differ between the patient and control groups. All measures of wall thickness were greater in the patient than the control group. Neither current arterial pressures nor past history of hypertension correlated with wall thickness. Using a model of analysis of covariance, coronary artery disease was the best single predictor of intima-media thickness, R(2)=48%, n=44, P<0.0005. We concluded that increased radial artery wall thickness can be demonstrated in vivo in patients with coronary atherosclerosis. This is a novel observation which seems to be independent of blood pressure, and is consistent both with the hypothesis of systemic endothelial dysfunction leading to systemic structural changes and also to the recent histological evidence for atherosclerotic changes in this vessel.

Coplanar Recognition by a Rebek Cleft Is Provided by Cooperative Structural Effects Involving a Combination of O−H···O, O−H···N, and C−H···O Forces

Reaction of 2,7-di-tert-butyl-9,9-dimethyl-4,5-xanthenedicarboxylic acid (1), a Rebek cleft, with 1,2-trans-bis(2-pyridyl)ethylene (2) yields a three-component organic assembly, 2(1).2 (3), of nanoscale dimensions that is held together by 10 cooperative O-H.N, O-H.O, and C-H.O hydrogen bonds. The cleft adopts a planar conformation, by forming an intramolecular O-H.O hydrogen bond, which enables the host to recognize the guest in a coplanar orientation that facilitates the cooperativity displayed by the multiple forces.

Coordinate regulation of yeast ribosomal protein genes is associated with targeted recruitment of Esa1 histone acetylase

The Esa1-containing NuA4 histone acetylase complex can interact with activation domains in vitro and stimulate transcription on reconstituted chromatin templates. In yeast cells, Esa1 is targeted to a small subset of promoters in an activator-specific manner. Esa1 is specifically recruited to ribosomal protein (RP) promoters, and this recruitment appears to require binding by Rap1 or Abf1. Esa1 is important for RP transcription, and Esa1 recruitment to RP promoters correlates with coordinate regulation of RP genes in response to growth stimuli. However, following Esa1 depletion, H4 acetylation decreases dramatically at many loci, but transcription is not generally affected. Therefore, the transcription-associated targeted recruitment of Esa1 to RP promoters occurs in a background of more global nontargeted acetylation that is itself not required for transcription.

Bradykinin B(2) receptor antagonism attenuates blood pressure response to acute angiotensin-converting enzyme inhibition in normal men

The physiological effects of angiotensin-converting enzyme (ACE) inhibition may be in part mediated by bradykinin. We investigated the effect of coadministration of the specific bradykinin B(2) receptor antagonist icatibant on hemodynamic and neurohormonal responses to acute intravenous ACE inhibition in normal men on a normal sodium diet. We performed a 4-phase, double-blind, double-dummy, placebo-controlled study in 12 male volunteers. The bradykinin antagonist icatibant (10 mg IV) was coadministered over the first 15 minutes of a 2-hour infusion of the ACE inhibitor perindoprilat (1.5 mg IV). Perindoprilat inhibited ACE activity and elicited the expected changes in active renin concentration and angiotensin peptides. Over the 3 hours after the start of drug infusion, perindoprilat lowered and icatibant increased mean arterial blood pressure (each P<0.0005 versus placebo). Coadministration of icatibant attenuated the mean arterial blood pressure response to perindoprilat (P<0.0005) but had no effect on neurohormonal responses to perindoprilat. Our study indicates that the bradykinin B(2) receptor antagonist icatibant attenuates the short-term blood pressure-lowering effect of acute ACE inhibition in normal men on a normal sodium diet. Bradykinin B(2) receptor antagonism alone increases resting blood pressure. Bradykinin may be involved in the control of blood pressure in the resting state in humans.

DNA synthesis and apoptosis in smooth muscle cells from a model of genetic hypertension

The present study was designed to assess vascular smooth muscle cell (VSMC) proliferation and apoptosis in primary cultured VSMCs prepared from the aortic tunica media of adult (4 to 5 months old) age- and gender-matched groups of stroke-prone spontaneously hypertensive rats (SHRSP) and the normotensive reference strain, Wistar-Kyoto (WKY) rats. In the present study, VSMC proliferation was assessed with measurement of DNA synthesis in response to stimulation of G(0)/G(1) arrested VSMCs with 10% serum, whereas apoptosis was measured in response to serum deprivation. Apoptosis in aortic VSMCs was assessed in vitro with the technique of Annexin V binding in combination with propidium iodide exclusion with bivariate flow cytometric analysis. The percentage of necrotic VSMCs in the cell populations was assessed simultaneously. The light-scattering properties of the cells were assessed to provide further information on cell shrinkage and chromatin condensation. Results of the present study have shown enhanced DNA synthesis in VSMCs from SHRSP (n=10; 5.2+/-0.9 cpmx10(3)/mg protein) compared with WKY (n=12; 2.4+/-0.7 cpmx10(3) /mg protein; P<0.05, 95% CI, -5271 to -296). In addition, the results of the present study have demonstrated the role of serum in the survival of VSMCs in vitro, because SHRSP VSMCs underwent significantly more apoptosis in response to insult by serum deprivation (n=13; 10.21+/-1.8%) than WKY VSMCs (n=7; 3.44+/-1.4%; P<0.01, 95% CI, -11.5 to -2.0). Thus, it appears that both proliferation and apoptosis are enhanced in synthetic phenotype aortic medial VSMCs from the SHRSP in vitro.

Rilmenidine: a clinical overview

Rilmenidine is an antihypertensive agent with selectivity for I1 imidazoline receptors that acts both centrally by reducing sympathetic overactivity and in the kidney by inhibiting the Na+/H+ antiport. Rilmenidine provides antihypertensive efficacy comparable with that of diuretics, beta-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors. Experience from trials and clinical practice highlights rilmenidine's clinical and metabolic acceptability in hypertensive populations, including those at special risk because of old age, renal impairment, diabetes mellitus, or dyslipidemia. In the at-risk hypertensive, rilmenidine reduces left ventricular hypertrophy to a similar degree to other reference agents. New studies show a significant improvement in glucose metabolism in metabolic syndrome patients treated with rilmenidine, and a significant reduction in microalbuminuria during rilmenidine treatment of hypertensive type 2 diabetics. Thus the efficacy/tolerance ratio of rilmenidine supports its role as a first-line antihypertensive option for all groups of hypertensive patient, with specific advantages in some at-risk populations.

Mortality amongst patients of the Glasgow Blood Pressure Clinic was high in the 1970s and 80s but has fallen since, why?

Established in 1968 the Glasgow Blood Pressure Clinic has over 11,000 patients on its computer record. Up to 1980, mortality from all-causes and from cardiovascular causes was high: relative risks compared with two local control populations were greater than 2.0. Since 1980, all-cause mortality has decreased to 1.31 (859 deaths, CI 1.23-1.39). Lower mortality from cardiovascular causes, particularly coronary heart disease, contributes to the decrease. Reasons for the decrease are under investigation currently. Referral of patients with slightly lower blood pressure contributes, as may better blood pressure control with newer antihypertensive drugs. ACE inhibitors and calcium channel blockers were introduced in 1980 and during the 16-year period to 1995, all-cause mortality has decreased most in patients taking ACE inhibitor. A decrease also occurred in patients taking antihypertensive drugs other than ACE inhibitor.

Drug treatment--antihypertensive drugs--the present role of beta blockers and alpha blockers

There are several lines of evidence implicating increased sympathetic activity not only in the maintenance of raised blood pressure but in the pathophysiology of hypertensive complications including atherosclerosis. Beta blockers are one of the best documented classes of drugs in terms of long term safety and improvement in outcome in hypertension. They are also well established to reduce reinfarction in patients after myocardial infarction and to improve survival in patients with congestive heart failure. Side effects of beta blockers are predictable and result from excess pharmacological activity. They can often be controlled by dose adjustments. Alpha blockers reduce peripheral resistance. They are as effective as other classes at lowering blood pressure although to date there is little or no long term outcome data with this class. Reduction of sympathetic activity with beta and/or alpha blockers should remain amongst the first choices for monotherapy (or add-on therapy) in essential hypertension.

Is cancer related to hypertension or to its treatment?

Three questions related to cancer and blood pressure are discussed. (i) Is cancer related in some way to hypertension, or to blood pressure? Several studies show a relation of blood pressure and cancer in populations. However, our own experience, based on a cohort of 15,411 subjects with BP measured in the 1970s and with 1,392 fatal cancers since, shows no relation of cancer risk and diastolic pressure. Nor were cancer numbers (n=72) observed in the 1,078 untreated hypertensives of the Glasgow Blood Pressure Clinic different from those expected (n=71.2) in a control population matched for age, sex and smoking habit. (ii) Do antihypertensive drugs promote cancer? Atenolol and calcium channel blockers have been suspected of this, but evidence of larger studies, including two of our own, is negative: relative risk for cancer in our patients taking CCB was 1.02 (CI 0.82-1.27). (iii) Do antihypertensive drugs protect against cancer? A study of ours based on the Glasgow Clinic raises this possibility: relative risk for incident cancer amongst 1,559 patients taking ACE inhibitor was 0.72 (CI 0.55-0.92).

Does potassium channel opening contribute to endothelium-dependent relaxation in human internal thoracic artery?

Opening of potassium channels can cause hyperpolarization and relaxation of vascular smooth muscle cells. The aim of this work was to investigate the contribution of potassium channel activation to vasorelaxation in internal thoracic artery taken from patients undergoing coronary artery bypass graft surgery. Relaxations to carbachol and sodium nitroprusside were studied in isolated rings of internal thoracic artery in the absence and presence of nitric oxide synthase inhibitors and potassium channel blockers. The nitric oxide synthase inhibitors Nomega-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine abolished relaxations to carbachol. Relaxations to both carbachol and sodium nitroprusside were attenuated in the presence of raised extracellular potassium and the potassium channel blockers charybdotoxin, iberiotoxin and tetraethylammonium. Neither apamin nor glibenclamide modified relaxation. ODQ (1H-[1,2,4]oxadiazolol-[4,3a] quinoxalin-1-one), an inhibitor of soluble guanylate cyclase, abolished relaxation to carbachol in rings from some but not all subjects. These results suggest that potassium channel opening may make a small contribution to endothelium-dependent vasorelaxation in internal thoracic artery. The potassium channels had characteristics consistent with those of large-conductance calcium-dependent potassium channels.

Superoxide anion production is increased in a model of genetic hypertension: role of the endothelium

The hypothesis that the decreased nitric oxide (NO) availability observed in spontaneously hypertensive stroke-prone rats (SHRSP) is due to excess superoxide (O2-) was examined. O2- generation, measured by lucigenin chemiluminescence, was studied in 12- to 16-week male and female Wistar-Kyoto rats (WKY) and SHRSP. In addition, expression of the gene encoding endothelial NO synthase, the enzyme involved in NO generation, was investigated. O2- generation was increased in male and female SHRSP (4.11+/-0.24 and 3. 84+/-0.28 nmol O2-. min-1. mg-1 respectively) compared with their WKY counterparts and was significantly higher in male than female WKY (1.22+/-0.08 in males and 0.8+/-0.08 nmol O2-. min-1. mg-1 respectively) (SHRSP versus WKY P<0.0001, 95% CI -3.39, -2.51; male versus female WKY P=0.0029, 95% CI -0.67, -0.17). Removal of the endothelium by rubbing or addition of NO synthase inhibitors attenuated O2- generation in SHRSP but not WKY. In males, removal of the endothelium reduced O2- generation from 3.86+/-0.12 to 1.35+/-0. 08 nmol. min-1. mg-1 (P<0.0001, 95% CI 2.29, 2.81), whereas addition of L-NAME caused a reduction from 4.13+/-0.17 to 1.32+/-0.16 nmol. min-1. mg-1 (P<0.0001, 95% CI 2.36, 2.83). Similar reductions were observed in females. L-arginine had no significant effect, but tetrahydrobiopterin significantly decreased O2- generation in SHRSP from 4.04+/-0.11 to 2.36+/-0.40 nmol. min-1. mg-1 (P=0.0026, 95% CI 0.89, 2.44). Endothelial NO synthase mRNA expression was significantly greater in SHRSP than in WKY and in WKY males than in WKY females. These results show that O2- generation is increased in SHRSP and that the tissue and enzymatic sources of this excess O2- appear to be the endothelium and eNOS, respectively. The increase in O2- generation could explain the decreased availability of basal NO observed in this model of genetic hypertension.

The E7 oncoprotein associates with Mi2 and histone deacetylase activity to promote cell growth

E7 is the main transforming protein of human papilloma virus type 16 (HPV16) which is implicated in the formation of cervical cancer. The transforming activity of E7 has been attributed to its interaction with the retinoblastoma (Rb) tumour suppressor. However, Rb binding is not sufficient for transformation by E7. Mutations within a zinc finger domain, which is dispensable for Rb binding, also abolish E7 transformation functions. Here we show that HPV16 E7 associates with histone deacetylase in vitro and in vivo, via its zinc finger domain. Using a genetic screen, we identify Mi2beta, a component of the recently identified NURD histone deacetylase complex, as a protein that binds directly to the E7 zinc finger. A zinc finger point mutant which is unable to bind Mi2beta and histone deacetylase but is still able to bind Rb fails to overcome cell cycle arrest in osteosarcoma cells. Our results suggest that the binding to a histone deacetylase complex is an important parameter for the growthpromoting activity of the human papilloma virus E7 protein. This provides the first indication that viral oncoproteins control cell proliferation by targeting deacetylation pathways.

Pharmacological characterisation of endothelium-dependent relaxation in human radial artery: comparison with internal thoracic artery

OBJECTIVE

The aim of this study was to investigate the contribution of nitric oxide/prostanoid-independent pathways to endothelium-dependent vasorelaxation in human conduit arteries.

METHODS

Rings of internal thoracic artery (ITA) and radial artery (RA) taken from patients undergoing coronary artery bypass graft surgery were suspended in 10-ml organ baths and relaxation to carbachol and bradykinin studied in the presence and absence of nitric oxide synthase (NOS) inhibitors and potassium channel blockers.

RESULTS

No significant relaxation to carbachol or bradykinin was observed in ITA after NOS inhibition. In contrast, in RA less than 40% attenuation of relaxation to carbachol or bradykinin was achieved with any of the NOS inhibitors. In the presence of 20 mM K+ relaxation to carbachol and bradykinin was inhibited by 28 +/- 9% and 42 +/- 9% while in the presence of L-NAME 200 microM + 20 mM K+ relaxation was inhibited by 66 +/- 6% and 70 +/- 4% respectively in this artery. Tetraethylammonium, glibenclamide, apamin and iberiotoxin had little effect on relaxation to carbachol but charybdotoxin alone and charybdotoxin plus apamin attenuated relaxation to carbachol by 23 +/- 4% and 49 +/- 9% in RA. In the presence of L-NAME 200 microM attenuation of these relaxations were increased to 60 +/- 4% and 78 +/- 4%.

CONCLUSION

In ITA relaxations to carbachol and bradykinin were mediated via nitric oxide. In contrast in RA, a conduit vessel of similar diameter, both nitric oxide-dependent and independent pathways appeared to contribute to vascular relaxation. This nitric oxide-independent relaxation involved opening of Ca2+ activated potassium channel(s). The existence of alternative pathways mediating endothelium-independent relaxation could be important under pathological conditions and may contribute to the long term survival of radial artery grafts.

Telemetry for cardiovascular monitoring in a pharmacological study: new approaches to data analysis

Radio-telemetry systems offer the ability to measure blood pressure and heart rate in experimental models of hypertension without the stress artifacts induced by some other methods. We therefore aimed to develop improved, nonparametric regression methods for radio-telemetry data and to use these to assess the effects of pharmacological interventions on cardiac and vascular hypertrophy in the stroke-prone spontaneously hypertensive rat. One control group and 5 groups treated either with losartan (alone or in combination with NG-nitro-L-arginine methyl ester [ L-NAME]), perindopril (also alone or in combination with L-NAME), or hydralazine plus hydrochlorothiazide were monitored for 4 weeks. Cardiac hypertrophy was assessed by the left ventricle plus septum weight to body weight ratio and vascular hypertrophy by flow-cytometry analysis of vascular smooth muscle cell polyploidy. Hemodynamic series were split into trend and cyclic components by the seasonal and trend decomposition procedure based on Loess and compared between groups by Loess regression modeling. Systolic and diastolic blood pressures were reduced systematically by losartan and perindopril (P<10(-10)) but to a lesser extent by hydralazine plus hydrochlorothiazide (P<10(-8)), and diurnal variation was reduced in the latter group (P<10(-6)). L-NAME significantly reduced the hypotensive effect only of losartan. Vascular and cardiac hypertrophy were significantly attenuated with losartan or perindopril, but were unchanged with other treatments. The new analysis proposed here identifies differential effects on trends and cyclic variation and associations with regression of end-organ damage for losartan and perindopril compared with hydralazine plus hydrochlorothiazide. The method offers a powerful tool for detailed investigation of radio-telemetry data.

The distribution of human TCR junctional region lengths shifts with age in both CD4 and CD8 T cells

Several normal and pathological antigen-driven immune responses are associated with limited TCR usage. CDR3 sequence and to some extent length represent clonal markers which can be used to follow the course of an immune response. We investigated whether differences exist in the CDR3 length distribution in the CD4 versus CD8 populations which might reflect the HLA class restriction of the T cell subpopulation. We showed that the range is similar in both the CD4 and CD8 populations for most BV families. Differences exist between CDR3 length distributions of adult versus cord blood CD4 and CD8 T cells. The percentage expressing CDR3 of 10 amino acids or more across all BV families was significantly lower in the cord blood T cells compared to the adults for both CD4 and CD8 populations. This is likely to reflect either differences in the development of the T cell population such as increased N region length post-partum or may be the result of foreign antigen exposure. To address this issue, samples of TCRBV sequences from cord and adult T cell populations were compared. No significant differences were found in either exonucleolytic removal or N region addition between the adult and cord blood samples suggesting that the population shift is the result of antigen exposure. No spectratype distortions existed for any BV family in the adult or cord blood CD4 populations; however, distortions were seen in CD8 populations from all the adults and much less frequently in the cord blood T cells. We investigated the ability to detect clonality at frequencies that one would expect to find antigen-specific T cells in the peripheral repertoire. It was possible to identify a clone at a frequency of 0.1% in a polyclonal CD4 population. This frequency corresponds to that of some individual clones after antigen-driven T cell expansion and establishes parameters within which T cell immune responses may be tracked ex vivo.

E1A directly binds and regulates the P/CAF acetyltransferase

The P/CAF protein has intrinsic histone acetyltransferase (HAT) activity and is capable of binding the transcriptional co-activator CBP. Here we show that P/CAF can regulate transcription and that this function is independent of its binding to CBP. The HAT domain of P/CAF has transcriptional activation potential in yeast. In mammalian cells P/CAF can stimulate transcription of the RSV promoter, using the activity of its HAT domain. We show that the adenovirus protein E1A targets P/CAF and sequesters its transcriptional activity. Binding of E1A to P/CAF is direct, independent of CBP and requires residues within E1A conserved region 1. We find that the P/CAF binding residues in E1A are within a motif shown to be essential for efficient disruption of myogenesis by E1A. The fact that E1A can directly bind and regulate the activity of P/CAF, independently of its regulation of CBP, highlights an important role for P/CAF in the process of cell differentiation.

Do inhibitors of angiotensin-I-converting enzyme protect against risk of cancer?

BACKGROUND

Previous studies have reported an increased risk of cancer with calcium-channel blockers in man. Other work in animals suggests that inhibitors of angiotensin-I-converting enzyme (ACE) protect against cancer. We aimed to assess the risk of cancer in hypertensive patients receiving ACE inhibitors or other antihypertensive drugs.

METHODS

Our retrospective cohort study was based on the records of 5207 patients who attended the Glasgow Blood Pressure Clinic between Jan 1, 1980, and Dec 31, 1995. The patients' records are linked with the Registrar General Scotland and the West of Scotland Cancer Registry.

FINDINGS

Compared with the West of Scotland controls, the relative risks of incident and fatal cancer among the 1559 patients receiving ACE inhibitors were 0.72 (95% CI 0.55-0.92) and 0.65 (0.44-0.93). Among the 3648 patients receiving antihypertensive drugs other than ACE inhibitors (calcium-channel blockers 1416, diuretics 2099, beta-blockers 2681), the corresponding relative risks were 110 (0.97-1.22) and 1.03 (0.87-1.20). The relative risk of cancer was lowest in women on ACE inhibitors: 0.63 (0.41-0.93) for incident cancer; 0.48 (0.23-0.88) for fatal cancer; and 0.37 (0.12-0.87) for female-specific cancers. The reduced relative risk of cancer in patients on ACE inhibitors was greatest with follow-up of longer than 3 years. Calcium-channel blockers, diuretics, and beta-blockers had no apparent effect on risk of cancer.

INTERPRETATION

Long-term use of ACE inhibitors may protect against cancer. The status of this finding is more that of hypothesis generation than of hypothesis testing; randomised controlled trials are needed.

Determinants of the blood pressure response to the first dose of ACE inhibitor in mild to moderate congestive heart failure

AIMS

To investigate the relationship in patients with heart failure between BP response to the first dose of ACE inhibitor and (1) plasma drug concentration and (2) baseline clinical and laboratory variables.

METHODS

We studied individual placebo-corrected BP responses to initiation of treatment with one of a number ACE inhibitor preparations in 132 patients with mild to moderate CHF. Various pharmacokinetic/pharmacodynamic models were compared. We assessed the strength of association between baseline physiological and laboratory variables and the BP response as assessed directly from the AUC(0,10 h) and indirectly from the slope of the PK/PD relationship. Predictive models for response variables were developing using regression analysis.

RESULTS

BP response was primarily related to plasma drug concentration. The association between the fall in BP and baseline variables was weak. The strongest single predictor of BP response was baseline mean arterial pressure (r2 = 5.8%, P = 0.02). The best combinations of predictor variables contained mean arterial pressure, plasma renin activity, creatinine concentration and age (r2 = 14.4%, P = 0.37). When the choice of ACE inhibitor was added, the predictive power of the model increased (r = 23.6%, P < 0.01) but left the majority of the variability in response unexplained.

CONCLUSIONS

The first-dose blood pressure response to ACE inhibition cannot be accurately predicted from baseline pathophysiological variables in patients with mild to moderate CHF. The choice of ACE inhibitor accounts for a small proportion of the variability in response but wide inter-individual variability exists in the response to each treatment.