Prevalence of Helicobacter pylori positivity in patients undergoing percutaneous coronary intervention.

BACKGROUND: The adverse effect of haemorrhagic complications after percutaneous coronary intervention (PCI) on outcome is well established with Helicobacter pylori infection known to be an important precipitant of peptic ulcer disease in patients receiving non-steroidal anti-inflammatory drug therapy. The prevalence of H. pylori positivity in patients undergoing PCI and receiving subsequent antiplatelet therapy is unknown. AIMS: We sought to determine the prevalence and features associated with H. pylori positivity in patients undergoing PCI. METHODS: All patients undergoing PCI between August 2008 and April 2009 were identified and assessed for H. pylori positivity with serological status determined by using a commercially supplied enzyme-linked immunosorbent assay. RESULTS: A total of 245 patients undergoing PCI during the study period had samples obtained for H. pylori serology. Of these, 91 were positive for H. pylori serology (37%) and 148 were negative (60%) with six samples being equivocal (3%). Of those patients positive for H. pylori, 75% were on agents at admission known to promote or precipitate gastrointestinal haemorrhage. Patients positive for H. pylori tended to be older, with increased creatinine and more likely to be receiving proton pump inhibitor therapy. CONCLUSIONS: In an unselected cohort of patients undergoing PCI in a single centre, we detected a prevalence of H. pylori positivity in 37% of patients; this denotes a potentially treatable precipitant of haemorrhage in a considerable portion of patients receiving dual antiplatelet therapy after PCI. Further prospective study is required to determine if the presence of H. pylori positivity is associated with adverse events in terms of gastrointestinal and cardiac outcomes.

A survey to ascertain peer support models available in Head and Neck cancer across the United Kingdom.

In cancers and chronic conditions, peer support (PS) has been shown to improve quality of life (QOL) and provide an important coping mechanism for patients, however there is little evidence for this intervention in Head and Neck cancer (HNC). Peer support allows individuals to come together and share information, encouragement, and experiences. It is delivered in a variety of ways including one-to-one, online, and support groups. There is limited literature regarding the timing, barriers, and types of PS available for individuals with HNC across the United Kingdom (UK). The aim of this project was to survey healthcare professionals with respect to their experience regarding types, timings, and barriers to PS in HNC. The survey was developed based on the literature, feedback and advice from a HNC patient research group and healthcare professionals. It was conducted online and consisted of twelve questions. Eighty-eight individuals responded covering twenty-four of twenty-six cancer alliances across the UK. Three main themes with subthemes were identified: patient barriers (emotional barriers and patient limitations), organisational barriers (administrative problems, limited time and resources and COVID-19), and staff barriers (lack of departmental support, concerns with PS and matching and timing of support). The survey demonstrated the different types of PS available across the UK and the barriers faced when implementing this support. It highlighted the complexity of being able to satisfactorily deliver appropriate and effective PS in HNC and the challenges involved.

Case report: prehospital use of intranasal ketamine for paediatric burn injury.

In this study, the administration of an intravenous ketamine formulation to the nasal mucosa of a paediatric burn victim is described in the prehospital environment. Effective analgesia was achieved without the need for vascular or osseous access. Intranasal ketamine has been previously described for chronic pain and anaesthetic premedication. This case highlights its potential as an option for prehospital analgesia.

Charge transfer between acenes and PbS nanocrystals.

Organic-inorganic hybrid heterojunctions have potential as the basis for future photovoltaic devices. Herein, we report the results of investigations exploring the possibility of using pentacene and tetracene as photoelectron donors in conjunction with PbS nanocrystals (PbS-NCs). Photoinduced charge transfer was probed using external quantum efficiency measurements on acene:PbS-NC hybrid photovoltaic devices in conjunction with photoluminescence studies of the corresponding bilayer films. It is shown that photoelectron transfer from pentacene to the PbS-NCs is inefficient as compared to that between tetracene and PbS-NCs. The latter case can be rationalized in terms of the energy level alignment at the heterojunction assuming a common vacuum level. However, in the case of pentacene:PbS-NC junctions an interfacial energy level shift must be considered in order to explain the observations.

The fabrication and analysis of a PbS nanocrystal:C(60) bilayer hybrid photovoltaic system.

A near-infrared sensitive hybrid photovoltaic system between PbS nanocrystals (PbS-NCs) and C(60) is demonstrated. Up to 0.44% power conversion efficiency is obtained under AM1.5G with a short circuit current density (J(sc)) of 5 mA cm(-2) when the PbS-NC layer is treated in anhydrous methanol. The observed J(sc) is found be approximately one-third of the maximum expected from this hybrid configuration, indicating the potential for further optimization. Crucial for device operation, a smooth film of nanocrystals is seen to form on the hole transporting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer deposited on the transparent electrode, facilitated through an ionic interaction between nanocrystal capping ligands and the PEDOT:PSS. The formation of the open circuit voltage in this system is seen to be influenced by an interfacial dipole formed at the hole-extracting electrode, providing insights for further optimization.

Volumetric analysis of a specific language region - the planum temporale.

Planum temporale volumes were determined for 42 control children (ages 4.2-15.7 years) using magnetic resonance imaging. The mean left planum temporale volume was 2729 mm3 (SD = 567) and the mean right planum temporale volume was 2758 mm3 (SD = 546). No significant hemispheric asymmetry was demonstrated. Analysis of co-variance (ANCOVA) showed that the absolute and proportional planum temporale volumes were not significantly associated with age or gender. We also demonstrated a reproducible method for planum temporale volume measurement by acquiring images in the coronal plane and then visualising the sagittal plane to improve accuracy for the posterior border.

Angiotensin-converting enzyme inhibitor resets baroreceptor reflexes in conscious dogs.

The present experiments investigate whether the absence of tachycardia during lowering of blood pressure (BP) with an angiotensin-converting enzyme inhibitor (CEI) in salt-depleted dogs is due to an alteration in the activity of the baroreflex. Baroreflex activity was measured after pharmacological manipulation of BP using intravenous nitroglycerin or phenylephrine, and the heart period (R-R interval) relative to the arterial pressure pulse was recorded. The slope of the relationship between BP and R-R interval is a measure of the sensitivity of the baroreceptor reflex and displacement of the line indicates a change in the setpoint of BP. On normal sodium diet, the sensitivity and setpoint of the baroreflex were unaltered by the nonapeptide CEI given both intravenously and into a lateral cerebral ventricle. During salt depletion. however, intravenously but not centrally administered CEI altered the setpoint of the baroreflex without modifying the sensitivity. The alteration in the setpoint that occurred following intravenous CEI in the salt-depleted dog could well account for the fact that the fall in BP induced by CEI does not cause reflex tachycardia. These results indicate that circulating but not brain angiotensin II is essential for the maintenance of baroreflex function during sodium depletion and provide further evidence for the important interactions between angiotensin and the autonomic nervous system.

The role of angiotensin in the control of blood pressure during sodium depletion.

Sodium depletion was induced in dogs to raise plasma renin activity (PRA) from 1.11 to 26.48 ng/ml/hr. Little overall change in blood pressure (BP) occurred, but cardiac output (CO) and central venous pressure fell, while total peripheral resistance and heart rate (HR) increased. A nonapeptide converting enzyme inhibitor (CEI) produced a fall in BP which was linearly related to log. PRA; the intercept with PRA was at 1.05 ng/ml/hr, close to the average value for dogs on a normal diet. The fall in BP with this agent was not accompanied by an increase in HR or CO. When Sar1-Ala8 angiotensin II was used to antagonize the action of angiotensin, the fall in BP was also linearly related to log. PRA. However, for a given level of PRA this fall in BP was less than that achieved with CEI and the intercept of BP fall with PRA was 2.6 ng/ml/hr. Again with this agent there was little change in HR or CO as BP was reduced. Thus, both antagonists lowered peripheral resistance without exciting the homeostatic reflexes indicating that, as PRA rose above the normal resting level, the angiotensin generated had both a direct and indirect effect in maintaining BP.

Hypotensive action of captopril in spontaneously hypertensive and normotensive rats. Interference with neurogenic vasoconstriction.

The effects of captopril and angiotensin II on adrenergic neurotransmission have been studied in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). In a pithed rat preparation, vasoconstrictor responses evoked by spinal stimulation were greater in SHR than WKY (p less than 0.01). Captopril reduced responses to electrical stimulation and this reduction was greater in the SHR (p less than 0.001). Bilateral nephrectomy reduced the vasoconstrictor responses to nerve stimulation in both strains of rat and abolished the effects of captopril. In an isolated perfused mesenteric artery WKY (p less than 0.05). Angiotensin II potentiated responses from both strains of rat, however the amplitude of the potentiation was greater in preparations from the SHR than those from WKY (p less than 0.002). Captopril (30 mg/kg by mouth) reduced blood pressure in conscious SHR over a 5-day dosing period. In WKY rats, no hypertensive action of captopril was observed. However, in another normotensive strain, the Alderley Park Wistar rat (APW), captopril lowered blood pressure. Plasma renin activity was not significantly different among these three strains of rat. The APW have previously been shown to be very sensitive to the adrenergic potentiating actions of angiotensin II. Captopril thus lowers blood pressure in SHR and APW, and both these strains are sensitive to the adrenergic potentiating actions of angiotensin II. It does not lower blood pressure in WKY, which is relatively insensitive to these actions of the octapeptide. Therefore, the hypotensive action of captopril in the rat may be due to its interference with the adrenergic potentiating effect of angiotensin II.

Hypotensive and sedative effects of alpha-adrenoceptor agonists: relationship to alpha 1- and alpha 2-adrenoceptor potency.

1 The purpose of this study was to investigate whether the separation between the hypotensive and sedative effects of a new series of centrally acting antihypertensive drugs was due to differences between the relative pre-junctional (alpha(2)) and post-junctional (alpha(1)) adrenoceptor agonist properties of the compounds.2 In anaesthetized rats the intravenous doses of clonidine, ICI 101187, ICI 106270, ICI 109683 and ICI 110802 required to lower blood pressure (BP) by 20 mm Hg were 1.2, 5.1, 5.5, 3.3 and 5.4 mug/kg respectively.3 In a test for sedation, ICI 101187 had at least 10 times less sedative effect than clonidine, ICI 106270 and ICI 109683 had at least 30 times less sedative effect than clonidine while ICI 110802 was not active. In a locomotor activity test the intravenous dose of clonidine required to reduce activity by 50% was 15.3 mug/kg, for ICI 101187 it was 194, for ICI 106270 it was 238 and for 110802 it was 313 mug/kg.4 In the pithed rat the ED(50)s of clonidine, ICI 101187, ICI 106270, ICI 109683 and ICI 110802 as alpha(2)-agonists were 19.4, 9.3, 63.2, 43.0 and 78.5 mug/kg respectively. The alpha(1)-adrenoceptor potencies were quite similar for the five drugs and varied between 3.2 mug/kg for ICI 110802 and 8.7 mu/kg for ICI 106720. Potency as alpha(2)-adrenoceptor agonists was also assessed in the mouse vas deferens. Clonidine and ICI 101187 were similar in potency with IC(50)s of 9.3 x 10(-9)m and 8.9 x 10(-9)m respectively. ICI 106270 and ICI 110802 were much weaker with IC(50)s of 4.9 x 10(-8)m and over 5.7 x 10(-8)m respectively.5 Since all the compounds had similar potencies as alpha(1)-agonists, this could not explain their different sedative effects. The weakest compounds as sedatives were also weakest as alpha(2)-agonists, although ICI 101187 which was as potent as clonidine as an alpha(2)-agonist was still 10 times weaker as a sedative.6 Hypotensive activity appears to be more closely related to alpha(1)- than to alpha(2)-potency.7 Clonidine was more potent as both a sedative and a hypotensive agent than would be predicted from its activity at either the alpha(1)- or the alpha(2)-adrenoceptor.

Angiotensin II is generated from angiotensin I by bone cells and stimulates osteoclastic bone resorption in vitro.

During bone resorption, osteoclasts are closely associated with endothelial cells. The latter are able to produce several agents that regulate bone resorption. In view of the increasing evidence that angiotensin II, which can be generated by endothelial cells, has actions outside the traditional renin-angiotensin system, we tested the effect of angiotensin II on bone resorption Angiotensin II showed no effect either on osteoclast formation or on bone resorption by isolated osteoclasts. However, in co-cultures of osteoclasts with calvarial or MC3T3-E1 osteoblastic cells, and in osteoclastic cultures co-cultured with other bone cells obtained by prolonged sedimentation, angiotensin II stimulated bone resorption to a similar degree to that observed with 1,25(OH)2 vitamin D3. Stimulation of resorption was noted at concentrations of 10(-7) M and above. We found that angiotensin I also stimulated bone resorption in co-cultures of osteoclasts with osteoblastic cells, and that this action was inhibited by inhibitors of angiotensin-converting enzyme. These results identify angiotensin I and II as potent stimulators of osteoclastic bone resorption, and raise the possibility that bone might contain a tissue-renin-angiotensin system that might play a role in the regulation of bone resorption.

Artifactually low glycated haemoglobin in a patient with severe hypertriglyceridaemia.

This report describes a case of artifactually low glycated haemoglobin (Hb) in a patient with type II diabetes and severe hypertriglyceridaemia. The effect of hypertriglyceridaemia on glycated Hb determination using the Abbott Vision method was investigated in a series of patients with diabetes. The interference of triglycerides in glycated Hb assays was also investigated by two other methods, the Beckman Synchron CX4 delta immunoturbidimetric method, and the Primus affinity chromatography high performance liquid chromatography assay.

Rheological response of neutrophils to different types of stimulation.

The potential for neutrophils to obstruct microvessels was evaluated by measuring transit of individual neutrophils through 8-microns pores in an automated cell transit analyzer (CTA) or into micropipettes (4-8 microns ID). Stimulation in vitro by the chemotactic agent N-formyl-methionyl-leucyl-phenylalanine. (fMLP), cigarette smoke, or purified antineutrophil cytoplasm antibodies greatly increased flow resistance, but the response varied in its dependence on time and pore diameter. Cigarette smoke or fMLP caused rapid loss of cellular deformability, although observations were complicated by changes in cell shape: progressive bipolar shape formation (after treatment with fMLP) could facilitate entry into larger pores (approximately 8 microns), whereas blebs induced by cigarette smoke caused bridging of these pores with cell immobilization. These processes led to an underestimation of the changes in deformability by the CTA. Neutrophils responded slowly to the antineutrophil cytoplasm antibodies (approximately 30 min), with a greater increase in flow resistance evaluated by a micro-pipette (4-6 microns ID) than by the CTA. We conclude that the effect of neutrophil stimulation on flow through capillary-sized vessels is potentially great (with resistance typically increased 10-fold or even complete blockage) but may depend on the vascular and cellular geometry and may be local or disseminated, depending on the rate of the rheological response.

Discontinuation rates of Helicobacter pylori treatment regimens: a meta-analysis.

We conducted a meta-analysis to determine what factors in treatment regimens for Helicobacter pylori are associated with increased discontinuation rates. Studies were selected from the 1990-1996 MEDLINE data base, and references in published articles and reviews were obtained. Each article was uniformally abstracted for factors that could potentially affect dropout rates. Drug regimens with high numbers of doses per day had highest dropout rates (p=0.0001). The total dropout rate was lowest for regimens containing a proton pump inhibitor (OR = 0.75, CI 0.57, 0.98). The rate was high in regimens containing a bismuth compound due to side effects (OR = 2.79, CI 1.78, 4.36). The main finding was that drug regimens for eradication of H. pylori that have a high number of doses per day result in higher discontinuation rates than regimens with fewer doses per day.

Interaction of environmental temperature and anti-quality factors on the severity of summer fescue toxicosis.

Two experimental strains of tall fescue grass (Festuca arundinacea Schreb) that had previously been shown to produce differences in animal performance during the summer period were fed to Holstein calves in temperature controlled rooms. In the first year, GI-306 (less toxic) and GI-307 (more toxic) tall fescues were fed during July in rooms maintained at 10 to 13, 21 to 23 and 34 to 35 C. In the second year, the same tall fescues and orchardgrass were fed at a high temperature during May (32 to 33 C), July (34 to 35 C) and October (31 to 32 C). A comparison at a lower temperature (16 to 18 C) was also included in the July and October trials, On both years, calves consuming GI-307 tall fescue consistently had lower dry matter intakes, higher rectal temperatures, higher respiration rates and lower weight gains than those fed GI-306 tall fescue or orchardgrass at temperatures above 31 C. At lower ambient temperatures, differences in dry matter intake, rectal temperature and respiration rates between animals on the two strains of forage were not statistically different. The results demonstrate the poor performance of cattle grazing fescue is related to environmental temperature and that the toxic substance(s) is present throughout the growing season.

Physicians' perceptions and knowledge of drug costs: results of a survey.

The objective of this survey was to determine physicians' opinions of the importance of drug costs, sources of drug cost information used, preferences for mechanisms to lower drug costs, and to assess knowledge of the relative cost of common drugs. A questionnaire containing opinion statements and five categories of drugs to be ranked from least to most expensive was sent to 598 physicians at our tertiary-care, university-affiliated teaching hospital. In all, 398 (66.6%) surveys were completed. Survey results indicate that physicians are interested in lowering the cost of drug therapy, and that they are knowledgeable of relative drug costs but would like more cost information to make more informed prescribing decisions. Most believe that a readily available drug cost index is the most beneficial mechanism to decrease drug expenditures.