Venous Vascular Closure System Versus Figure-of-Eight Suture Following Atrial Fibrillation Ablation - The STYLE-AF Study

BACKGROUND

Simplified ablation technologies for pulmonary vein isolation (PVI) are increasingly performed worldwide. One of the most common complications following PVI are vascular access-related complications. Lately, venous closure systems (VCS) were introduced into clinical practice, aiming to reduce the time of bedrest, to increase the patients' comfort and to reduce vascular access-related complications.

AIMS

To compare the safety and efficacy of using a VCS to achieve haemostasis following single shot PVI to the actual standard of care (figure-of-eight suture and manual compression (MC)).

METHODS

This is a prospective, multicentre, randomized, controlled, open-label trial performed at 3 German centres. Patients were randomized 1:1 to undergo haemostasis either by means of VCS (VCS group) or of a figure-of-eight suture and MC (F8 group). The primary efficacy endpoint was the time to ambulation, while the primary safety endpoint was the incidence of major periprocedural adverse events until hospital discharge.

RESULTS

A total of 125 patients were randomized. The baseline characteristics were similar between the groups. The VCS group showed a shorter time to ambulation (109.0 (82.0, 160.0) vs. 269.0 (243.8, 340.5) min; p<0.001), shorter time to haemostasis (1 (1, 2) vs. 5 (2, 10) min; p<0.001) and shorter time to discharge eligibility (270 (270, 270) vs. 340 (300, 458) min; p<0.001). No major vascular access related complication was reported in either group. A trend towards a lower incidence of minor vascular access related complications on the day of procedure was observed in the VCS group (7 (11.1%) vs. 15 (24.2%); p=0.063) as compared to the control group.

CONCLUSION

Following AF ablation, the use of a VCS results in a significantly shorter time to ambulation, time to haemostasis and time to discharge eligibility. No major vascular access related complications were identified. The use of MC and a figure-of-eight suture showed a trend towards a higher incidence of minor vascular access related complications.

Case-mix and outcome variability in people with diabetic foot complications in England and Scotland

Background

We assessed the difference in survival rates for people with diabetes experiencing LEA in England and Scotland, using large databases held by the Royal College of General Practitioners (RCGP) and the Scottish Diabetes Register (SCI-DC).

Methods

Observational retrospective study of T2D adults 18+ years with LEA between 1/1/2008-1/1/2018 from 1,800 general practices in England (7.4%) and all primary, secondary care units in Scotland. Significance tests were carried out using univariate odds ratios within each database.

Results

On 1/1/2018, N = 127,100 people with T2D were registered alive in RCGP, with N = 1,052 (832 per 100,000) experiencing prior LEA, vs N = 2,200 (783 per 100,000) out of 280,908 in SCI-DC. Among them, England recorded N = 405 patients (72.5%) with prior DFU diagnosis vs N = 993 in Scotland (74.3%), with a median time DFU to LEA of 2.0 vs 2.4 years. The median time spent with LEA was 3.4 years in England vs 3.9 years in Scotland. After including those dying earlier, different univariate patterns were found for England and Scotland. In both networks, increased risk was found for those aged 50+ at first LEA, with prior history of acute myocardial infarction, peripheral arterial disease, ischemic heart disease, cerebrovascular event, higher glomerular filtration rate and major LEA first. In England, reduced risks were found for males (OR = 0.77, 95%CI: 0.64-0.93) and people with retinopathy (0.69; 0.57-0.82), while higher risk were found for hypertension (1.29; 1.09-1.54). In Scotland, lower risks were found for obese (0.59; 0.52-0.66) and those with DFU after LEA (0.74; 0.62-0.89), vs higher rates among those of non-white ethnicity (1.63; 1.19-2.23) and dyalisis (2.31; 1.75-3.07).

Conclusions

Notable differences were found between England and Scotland in terms of characteristics associated with different outcomes following LEA among T2D adults. Multivariate analyses of aggregate patterns are currently ongoing to adjust for potential confounding.

Key messages

• Routine datasets from England and Scotland showed a differential impact of case-mix characteristics on lower extremity amputations among adults with Type 2 diabetes.

• Information available from different clinical networks can be mapped against the available standard sets to compare health care outcomes of people with different complex conditions.

Impact of very wide antral pulmonary vein isolation on esophageal temperature changes during pulsed field ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Esophageal thermal injury (ETI) is a serious drawback of available energy sources for atrial fibrillation (AF) ablation, especially on the posterior left atrial (LA) wall. Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety advantages over existing methods due to its unique myocardial tissue specificity sparing the esophagus.

Objective

To evaluate esophageal temperature changes during very wide antral pulmonary vein isolation (PVI) using the PFA system.

Methods

Thirteen consecutive AF patients (62% with paroxysmal AF; age: 61 years; 70% male) underwent first-time PFA under deep sedation. Eight pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). Extra pulse trains in the flower configuration were added for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with an S-shaped esophageal temperature probe.

Results

A median of 32 (IQR 32;32) and 8 (IQR 8;9) pulse trains for PVI and vWACA with a procedural time and catheter dwell time of 67 min (IQR 61-69) and 17 min (IQR 16-18) were applied. PFA with vWACA resulted in consecutive posterior LA wall isolation in 11/13 patients. Fluoroscopically, the esophagus coursed near the right PVs in 2/13, left PVs in 8/13 and mid-posterior wall position in 3/13 patients. Maximum TESO increase from baseline was 0.8 ±0.9 °C. However, no clinically relevant TESO changes occurred (Table 1). On short-term, all patients remained asymptomatic for sore throat, cough, or other symptoms potentially related to ETI. No esophago-duodenoscopy was necessary.

Conclusion

PFA of the PVs and lesion extension to the posterior LA wall demonstrated clinically non-significant TESO changes and has the potential to eliminate the risk of a thermal damage to the esophagus.

Very high-power short-duration temperature-controlled ablation for cavotricuspid isthmus block : the Fast-and-Furious CTI study

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation for typical right atrial flutter (AFL) provides an effective treatment associated with encouraging clinical outcome. The novel micro-electrode ablation catheter allows very high-power short-duration (vHP-SD, 90 W/4 sec) ablation and potentially offers the ability to perform a safe, effective and faster cavotricuspid isthmus (CTI) ablation.

Aims

We evaluated feasibility and efficacy of a vHP-SD (90 W/4 sec) temperature-controlled radiofrequency (RF) CTI ablation for AFL using a novel contact force (CF) sensing ablation catheter with micro-electrodes.

Methods

Fifteen consecutive patients (median age 75 years (interquartile range, IQR: 67, 79), 67 % male) with documented typical AFL were prospectively enrolled and underwent vHP-SD based CTI ablation (90 W/4 sec). Durability of CTI block was proven by pacing maneuvers from both sides of the ablation line.

Results

Complete CTI block using vHP-SD ablation was achieved in all patients (Figure 1). At median 23 (IQR 20; 39) RF applications over a median RF ablation time of 92 (IQR 78, 154) seconds were applied. It was not necessary to switch to the standard temperature-controlled mode to achieve durable CTI block. No periprocedural complications, no charring and no steam pops were observed.

Conclusions

Very high-power short-duration (90 W/4 sec) CTI ablation for the treatment of typical AFL is feasible and efficient. Effective CTI block can be achieved in about 1.5 minutes of RF time.

Comparison of ostial versus very wide antral circumferential pulmonary vein isolation using pulsed field ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is the gold standard for first-time atrial fibrillation (AF) ablation procedures. Wide antral circumferential ablation (WACA) in comparison to ostial PVI has been attributed to an improved rhythm outcome after AF ablation. Pulsed field ablation (PFA) is a novel energy source with promising safety and efficacy advantages over existing ablation methods due to its unique myocardial tissue specificity. Feasibility of PFA for very WACA has not been investigated so far.

Objective

To evaluate procedural characteristics and lesion formation during wide antral circumferential PVI in comparison to ostial PVI using a PFA system.

Methods

Thirty-seven consecutive AF patients underwent first-time PFA under deep sedation. Patients eighter received ostial (ostial group; N = 15: 66 % paroxysmal AF; age: 69 years; 66 % male) or very wide antral (vWACA group; N = 22: 59 % paroxysmal AF; age: 62 years; 73 % male) PFA. Pre and post ablation LA voltage maps were acquired using a 20-pole spiral catheter together with a 3-dimensional electroanatomic mapping system (voltage cutoff ≤0.5 mV). On post ablation maps, lesion size by encircling the ablated area was measured. In all patients, 8 pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). In the vWACA-group, extra pulse trains in flower configuration were added to each PV in a wide antral position continuous intraluminal esophageal temperatures (TESO) were monitored with an S-shaped esophageal temperature probe.

Results

A median of 8 [IQR 8;8] and 10 [IQR 10;11] pulse trains per PV for ostial and vWACA PVI were applied. vWACA PFA resulted in significant larger lesion formation (47.3 cm2 [IQR 39.1; 52.0]) in comparison to ostial PFA (35.5 cm2 [IQR 30.3; 38.1], p=0.013) with consecutive posterior LA wall isolation in 19/22 (86 %) patients (Figure 1). In the vWACA group, median TESO increased by 0.7 °C (TESOmax 36.5 °C [IQR 36.0;36.9]). However, the vWACA approach was not associated with a significant increase in procedure time, sedation dosage or exposure to radiation.

Conclusion

Very wide antral circumferential PFA of the PVs is feasible and was associated with significant larger lesion formation in comparison to conventional ostial PFA. Concomitant posterior LA wall isolation occurred in the majority of patient and did not result in a clinically significant increase of intraluminal esophageal temperatures, procedure time, sedation and radiation dosage.

Sodium-glucose co-transporter-2 inhibitor cardiovascular outcome trials and generalizability to English primary care

AIM

To identify people in English primary care with equivalent cardiovascular risk to participants in the sodium-glucose co-transporter-2 inhibitor (SGLT-2i) cardiovascular outcome trials (CVOTs). A secondary objective was to report the usage of SGLT-2is.

METHODS

Cross-sectional analysis of people registered with participating practices in the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) network on the 31 December 2016. We derived: (1) proportions of the primary care population eligible for inclusion in each SGLT-2i CVOT (CANVAS, DECLARE, EMPA-REG and VERTIS); (2) characteristics of the eligible population compared with trial participants (demographics, disease duration and vascular risk); and (3) differences within the eligible population prescribed SGLT-2is.

RESULTS

The proportions of people with type 2 diabetes (N = 84 394) meeting the inclusion criteria for each CVOT were: DECLARE 27% [95% confidence interval (CI) 26.5-27.1]; CANVAS 17% (16.6-17.1); VERTIS 7% (7.1-7.4); and EMPA-REG 7% (6.5-6.8). Primary care populations fulfilling inclusion criteria were 5-8 years older than trial cohorts, and <10% with inclusion criteria of each trial were prescribed an SGLT-2i; a greater proportion were men, and of white ethnicity.

CONCLUSIONS

There was variation in proportions of the primary care type 2 diabetes population fulfilling inclusion criteria of SGLT-2i CVOTs. The more stringent the inclusion criteria, the lower the proportion identified in a primary care setting. Prescription rates for SGLT-2is were low in this national database, and there were demographic disparities in prescribing.

A review of the NG17 recommendations for the use of basal insulin in type 1 diabetes

AIMS

To revisit the data analysis used to inform National Institute of Health and Care Excellence (NICE) NG17 guidance for initiating basal insulin in adults with type 1 diabetes mellitus (diabetes).

METHODS

We replicated the data, methodology and analysis used by NICE diabetes in the NG17 network meta-analysis (NMA). We expanded this data cohort to a more contemporary data set (extended 2017 NMA) and restricted the studies included to improve the robustness of the data set (restricted 2017 NMA) and in a post hoc analysis, changed the index comparator from neutral protamine Hagedorn (NPH) insulin twice daily to insulin detemir twice daily.

RESULTS

The absolute changes in HbA_1c were similar to those reported in the NG17. However, all 95% credible intervals for change in HbA_1c point estimates crossed the line of null effect, except for detemir twice daily (in the NICE and extended 2017 NMAs) and NPH four times daily. In the detemir twice-daily centred post hoc analysis, the 95% credible intervals for change in HbA_1c crossed the line of null effect for all basal therapies, except NPH.

CONCLUSIONS

In NG17, comparisons of basal insulins were based solely on efficacy of glycaemic control. Many of the trials used in this analysis were treat-to-target, which minimize differences in HbA_1c . In the NMAs, statistical significance was severely undermined by the wide credible intervals. Despite these limitations, point estimates of HbA_1c were used to rank the insulins and formed the basis of NG17 guidance. This study queries whether such analyses should be used to make specific clinical recommendations.

Obstructive sleep apnoea in Type 2 diabetes mellitus: increased risk for overweight as well as obese people included in a national primary care database analysis

AIMS

To determine obstructive sleep apnoea prevalence in people with Type 2 or Type 1 diabetes in a national primary care setting, stratified by BMI category, and to explore the relationship between patient characteristics and obstructive sleep apnoea.

METHODS

Using the Royal College of General Practitioners Research and Surveillance Centre database, a cross-sectional analysis was conducted. Diabetes type was identified using a seven-step algorithm and was grouped by Type 2 diabetes, Type 1 diabetes and no diabetes. The clinical characteristics of these groups were analysed, BMI-stratified obstructive sleep apnoea prevalence rates were calculated, and a multilevel logistic regression analysis was completed on the Type 2 diabetes group.

RESULTS

Analysis of 1 275 461 adult records in the Royal College of General Practitioners Research and Surveillance Centre network showed that obstructive sleep apnoea was prevalent in 0.7%. In people with Type 2 diabetes, obstructive sleep apnoea prevalence increased with each increasing BMI category, from 0.5% in those of normal weight to 9.6% in those in the highest obesity class. By comparison, obstructive sleep apnoea prevalence rates for these BMI categories in Type 1 diabetes were 0.3% and 4.3%, and in those without diabetes 1.2% and 3.9%, respectively. Obstructive sleep apnoea was more prevalent in men than women in both diabetes types. When known risk factors were adjusted for, there were increased odds ratios for obstructive sleep apnoea in people with Type 2 diabetes in the overweight and higher BMI categories.

CONCLUSIONS

Obstructive sleep apnoea was reported in people with both types of diabetes across the range of overweight categories and not simply in the highest obesity class.

Management of type 2 diabetes: the current situation and key opportunities to improve care in the UK

In common with global trends, the number of individuals with type 2 diabetes in the UK is rising, driven largely by obesity. The increasing prevalence of younger individuals with type 2 diabetes is of particular concern because of the accelerated course of diabetes-related complications that is observed in this population. The importance of good glycaemic control in the prevention of microvascular complications of diabetes is widely accepted, and there is a growing body of evidence to support a benefit in the reduction of cardiovascular events in the long term. Despite the importance of maintaining a healthy weight for the prevention of type 2 diabetes, the results from trials of lifestyle intervention strategies to reduce body weight have been disappointing. New glucose-lowering agents offer some promise in this regard, offering an opportunity to combat the dual burden of hyperglycaemia and obesity simultaneously. The timing and appropriate choice of glucose-lowering therapy has never been more complex as a result of rising prevalence of obesity in the young, concomitant obesity in some 90% of adults with type 2 diabetes and an ever-increasing range of therapeutic options. The present review evaluates performance measures specific to weight and glycaemic control in type 2 diabetes in the UK using data from the Quality and Outcomes Framework in England and Wales, and the Scottish Diabetes Survey. Potential barriers to improvement in standards of care for people with type 2 diabetes are considered, including patient factors, clinical inertia and the difficulties in translating therapeutic guidelines into everyday clinical practice.

Precision evaluation of panoramic morphometric index measurement's performed by experienced clinicians and dental students

Osteoporosis is a chronic degenerative disease of bones in which the primary type of it affects generally women after postmenopause. According to the literature the panoramic indices are valuable morphometric and visual tools to detect the disorder in a n early and asymptomnatic stage. The goals of study were to evaluate the reproducibility of mandibular cortical and panoramic indices and to assess population-specific index parameters. Panoramic radiographs of 50 osteoporotic (age = 65,1 ? 5,9) and 36 control (age = 66,4 ? 7,1) women were evaluated for the cortical (MCI) and panoramic (PMI) indices by 2 experienced clinicians and 40 dental students with basic clinical experiences. Statistical analysis of data was preformed using SPSS software. the result of MCI and PMI indexes demonstrated high interobserver agreement between the two clinicians but in MCI data, recorded by the clinicians and students, showed statistically significant differences. On the other hand the mean and threshold values of the indices proved to be different from what we had expected from other surveys. Although the panoramic images are taken for specific dental indications that would improve the screening efficiency of osteoporosis when the clinician recognizes the signs of it on the radiographs.

Metabolic-inflammatory changes, and accelerated atherosclerosis in HIV patients: rationale for preventative measures

Human immunodeficiency virus (HIV)-infected patients are at a significantly higher risk from coronary heart diseases (CHD) and myocardial infarction (MI) compared to gender- and age-matched non-infected individuals. Combination antiretroviral therapy (cART) has transformed a fatal illness into a chronic stable condition. However, cART induces metabolic abnormalities in HIV-infected patients, while its role in vascular atherosclerosis is still under investigation. The use of cART is linked to inflammation - a key mechanism in atherosclerotic progression and destabilisation that precedes clinical events like MI. There is evidence of visceral fat abnormal distribution in HIV infected patients, and inflammatory changes in HIV infected patients drive the initiation, progression and, ultimately, thrombotic clinical complications induced by atherosclerosis. Visceral adipose tissue, a virtual factory for manufacturing pro-inflammatory mediators, affects the liver function. The inflamed liver promotes the development of pro-atherogenic dyslipidaemia. Pro-inflammatory cytokines released by adipocytes travel to the skeletal muscles and other peripheral tissues, worsening insulin sensitivity and leading to hyperglycaemia. Increased high sensitivity C-reactive protein (hs-CRP) inflammatory marker is associated with endothelial dysfunction in HIV-infected patients. Increased levels of monocytic nuclear factor kappa-B (NFkappa-B), a master switch in the inflammatory cascade, are documented in patients with elevated hs-CRP levels. It can be assumed that, as a result of NFkappa-B activation, hs-CRP up-regulates cytokines that contribute to MI by recruiting leukocytes and promoting thrombosis. This review focuses on the association of HIV-infection, metabolic abnormalities and known mechanisms involved in inducing accelerated atherosclerosis and inflammation in HIV-infected patients, as well as the role of lipid lowering agents in potentially preventing CHD.

Insulin for type 2 diabetes: choosing a second-line insulin regimen

Guidance has been published on the choice of initial insulin regimen for patients with type 2 diabetes [NPH (isophane) insulin or a long-acting insulin analogue] but not on how to choose a second regimen when glycaemic control becomes unsatisfactory.

AIMS

To develop pragmatic clinical guidance for choosing a second-line insulin regimen tailored to the individual needs of patients with type 2 diabetes after failure of first-line insulin therapy.

METHODS

Formulation of a consensus by expert panel based on published evidence and best clinical practice, taking into account patient preferences, lifestyle and functional capacity.

RESULTS

Six patient-dependent factors relevant to the choice of second-line insulin regimen and three alternative insulin regimens (twice-daily premixed, basal-plus and basal-bolus) were identified. The panel recommended one or more insulin regimens compatible with each factor, emphasising the fundamental importance of a healthy lifestyle that includes exercise and weight reduction. These recommendations were incorporated into an algorithm to provide pragmatic guidance for clinicians.

CONCLUSION

The three alternative insulin regimens offer different benefits and drawbacks and it is important to make the right choice to optimise outcomes for patients.

Predicting synthetic accessibility: application in drug discovery and development

The estimation and use of synthetic accessibility in the drug discovery process is discussed. A distinction is drawn between synthetic feasibility and accessibility and the practical uses of an accessibility score are examined. Various techniques used in the estimation of accessibility are described and their utility and potential accuracy compared.

Identifying potential binding modes and explaining partitioning behavior using flexible alignments and multidimensional scaling

A method is described for the rapid and automatic analysis of flexible molecular alignments using multidimensional scaling and a normalized scoring scheme. A projection scheme was devised to separate orientational and conformational effects. It is shown that the approach can be utilized for the identification of common binding orientations or to the study of differences in partioning behavior. It is suggested that the method can be employed as a novel approach exploring molecular similarity as a dynamic property, so that it includes aspects of motion (by way of mutual orientations), conformations and molecular properties.

Flexible alignment of small molecules

A method is presented for flexibly aligning small molecules. The method accepts a collection of small molecules with 3D coordinates as input and computes a collection of alignments. Each alignment is given a score, which quantifies the quality of the alignment both in terms of internal strain and overlap of molecular features. The results of several computational experiments on pairs of compounds with known binding conformations are used to systematically and objectively tune the parameters for the method. The results indicate the method's utility for the elucidation of pharmacophores and comparative field analysis.

Metric and multidimensional scaling: efficient tools for clustering molecular conformations

The application of metric and multidimensional scaling to conformer ensembles was demonstrated in this work. An automated process was devised to cluster and assign group memberships and cluster representatives. The method allows rapid clustering, leading to intuitive results that can be visually inspected. Multidimensional scaling was found to be superior to metric scaling for clustering conformers. The performance of different hierarchical clustering algorithms was compared using multidimensional plots, and the group average method was found to perform best.

Nonantioxidant functions of alpha-tocopherol in smooth muscle cells

Most tocopherols and tocotrienols, with the exception of alpha-tocopherol, are not retained by humans. This suggests that alpha-tocopherol is recognized uniquely; therefore, it may exert an exclusive function. alpha-Tocopherol possesses distinct properties that are independent of its prooxidant, antioxidant or radical-scavenging ability. alpha-Tocopherol specifically inhibits protein kinase C, the growth of certain cells and the transcription of the CD36 and collagenase genes. Activation events have also been seen on the protein phosphatase 2A (PP(2)A) and on the expression of other genes (alpha-tropomyosin and connective tissue growth factor). Neither ss-tocopherol nor probucol possessed the same specialty functions as alpha-tocopherol. Recently, we isolated a new ubiquitous cytosolic alpha-tocopherol binding protein (TAP). Its motifs suggest that it is a member of the hydrophobic ligand-binding protein family (CRAL-TRIO). TAP may also be involved in the regulation of cellular alpha-tocopherol concentration and alpha-tocopherol-mediated signaling.

Fears and phobias in people with diabetes

Phobic disorders are more common in people with diabetes than in the general population. The management of phobic disorders in patients with diabetes, particularly when associated with a fear of hypoglycaemia, is especially challenging and requires close collaboration between psychological medicine and diabetes teams. Difficulty in distinguishing symptoms of anxiety from those of hypoglycaemia, and the real dangers associated with hypoglycaemia, complicate the delivery of psychological interventions that are used routinely in the treatment of phobias. Avoidance of hypoglycaemia can lead to deterioration in diabetes control. This case report describes a man with Type 1 diabetes who developed agoraphobia with panic disorder, associated with fear of hypoglycaemia and deterioration in glycaemic control. The management of patients with diabetes and phobic disorders, with particular reference to those associated with fear of hypoglycaemia, is discussed.

Specific cellular responses to alpha-tocopherol

In the last 10 years precise cellular functions of alpha-tocopherol, some of which are independent of its antioxidant/radical-scavenging ability, have been revealed. Absorption of alpha-tocopherol from the gut is a selective process. Other tocopherols are not absorbed or are absorbed to a lesser extent. At the post-translational level, alpha-tocopherol inhibits protein kinase C and 5-lipoxygenase and activates protein phosphatase 2A and diacylglycerol kinase. Some genes [platelet glycoprotein IV/thrombospondin receptor/class B scavenger receptor (CD36), alpha-tocopherol transfer protein (alpha-TTP), alpha-tropomyosin, connective tissue growth factor and collagenase] are affected by alpha-tocopherol at the transcriptional level. alpha-Tocopherol also inhibits cell proliferation, platelet aggregation, monocyte adhesion and the oxygen burst in neutrophils. Other antioxidants, such as beta-tocopherol and probucol, do not mimic these effects, suggesting a nonantioxidant, alpha-tocopherol-specific molecular mechanism.

A simple model for the prediction of blood-brain partitioning

We derived a simple model for the prediction of blood-brain barrier penetration using three descriptors. The model contains the calculated octanol-water partition coefficient, the number of hydrogen-bond acceptors in an aqueous medium and the polar surface area. It was validated using an extensive dataset, comprising 100 diverse drug molecules. The descriptors are easily calculated and the model is suitable for the rapid prediction of the blood-brain barrier partitioning of drugs.

Multiple flexible alignment with SEAL: a study of molecules acting on the colchicine binding site

An extension of the steric and electrostatic alignment alignment (SEAL) method (MultiSEAL) is described that allows the overlay of multiple molecules and conformations. The method is well-suited for the systematic study of possible alignments, also revealing information about the conformational energies associated with a given overlay. It has been tested on three examples: angiotensin II antagonists, 5-HT3 antagonists, and dopaminergic compounds. The utility of the method is further demonstrated in an analysis of molecules that putatively bind to the colchicine site of tubulin. On the basis of its overlay with colchicine, allocolchicine, 2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone, and combretastatin A-4, it appears that 2-methoxyestradiol (2-ME) is unlikely to fit the colchine site properly. The weak antimitotic activity of 2-ME may be explained by its partial fit in the site.

Blood pressure measurement in the community: do guidelines help?

The measurement of blood pressure (BP) is a crucial part of clinical assessment and hypertension management, and is commonly performed inaccurately despite the publication of National and International consensus guidelines for its measurement. There have been no previous reports on the self-reported knowledge-base of General Practitioners (GPs) and Practice Nurses (PNs) with regard to BP measurement. A postal questionnaire survey was conducted of 831 community-based practitioners (550 GPs and 281 PNs) in north west London. The overall response rate was 61%. Previous education in BP measurement was recorded in 87% of the GPs and 95% of the nurses. Precision factors were recorded for the GPs and nurses respectively including rounding up or down (GP 67%, PNs 48%), routine use of diastolic phase V (GP 63%, PNs 70%), reading the BP to the nearest 2 mm mercury (GP 54%, PNs 70%) and failure to use a large BP cuff in the past 4 weeks (GP 33%, PNs 26%). Only 12% of the GPs and 19% of the nurses were able to name the source of the published guidelines. Overall the nurses had a statistically significantly greater knowledge base than the GPs, and both community groups had a greater knowledge for core questions than hospital practitioners from two previous surveys. Knowledge of a guideline source was associated with improved self-reported BP technique. There was a difference between reading and recording accuracy which deserves further study. These results show that there are important gaps in the knowledge of community practitioners with regard to the technique of BP measurement.

Angiotensin-converting enzyme (ACE) gene polymorphism and the erythrocyte sodium-lithium countertransporter (SLC) phenotype in hypertension

It has been suggested that the association between altered behaviour of the erythrocyte sodium-lithium countertransporter (SLC) and hypertension could be secondary to its association with the risk of vascular disease rather than raised blood pressure (BP) per se. Homozygosity for the angiotensin-converting enzyme (ACE) deletion allele has also been linked to a more severe phenotype for cardiovascular disease. The present study investigated whether there is an association between these two indicators of vascular risk in patients with hypertension. The kinetic characteristics of the countertransporter (SLC activity, Vmax and KNa) of patients having the ID ACE-genotype (n = 16) were compared with those patients who had the DD genotype (n = 12). The median (range) SLC activity (mmol Li/l Red Blood Cells.h) in the ID (0.221 [0.061-0.422]) and DD (0.173 [0.094-0.408]) groups were similar (P = 0.28; Mann-Whitney). No significant differences in Vmax (mmol Li/l RBC.h) emerged between the two study groups (0.279 + 0.124 [ID] vs 0.244 + 0.123 [DD]; P = 0.46; unpaired Student's t-test); similarly, no differences emerged between the two groups with respect to KNa (median [range]; ID, 39.8 [12.4-84.4] vs DD, 35.9 [14.6-78.3]; P = 0.47). These data suggest that the SLC phenotype and the ACE-D allele dose are risk factors for cardiovascular disease that function independently of one another.

Blood pressure measurement by junior hospital doctors--a gap in medical education?

A questionnaire survey, combined with an observational study, evaluated the knowledge of doctors in training grades on the practical aspects of blood pressure measurement. Eighty (non-consultant) junior hospital doctors, graduates from 30 separate medical schools, participated in the study. The results show that 27 (33%) doctors acknowledged no formal education on how to measure blood pressure. This lack of precise theoretical knowledge was matched by an observed poor clinical technique in over one third of the study group. The precision and accuracy of blood pressure recording is fundamental to the clinical examination of patients, and crucial in their management in both hospital and community settings. The findings of this study support the urgent need for further training and assessment of blood pressure measurement at undergraduate, and postgraduate level.

Antihypertensive drugs and the hypertensive diabetic patient

Hypertension occurs in about 40% of patients with non-insulin-dependent diabetes mellitus (NIDDM) in whom the incidence of coronary heart disease is greatly increased. Disturbances in lipid metabolism may be an important contributory factor. Patterns of lipid change in uncomplicated NIDDM are characterised by a raised serum triglyceride and a reduced high density lipoprotein. It is therefore likely that therapy for hypertension associated with NIDDM may further influence an existing atherogenic lipid profile. Recent studies in diabetic subjects have shown that alpha-blockers are associated with a trend towards improving, while beta-blockers adversely affect, the lipid profile. Calcium antagonists and ACE inhibitors have no adverse effects on the lipid profile.