Acetaminophen increases blood pressure in patients with coronary artery disease.

BACKGROUND: Because traditional nonsteroidal antiinflammatory drugs are associated with increased risk for acute cardiovascular events, current guidelines recommend acetaminophen as the first-line analgesic of choice on the assumption of its greater cardiovascular safety. Data from randomized clinical trials prospectively addressing cardiovascular safety of acetaminophen, however, are still lacking, particularly in patients at increased cardiovascular risk. Hence, the aim of this study was to evaluate the safety of acetaminophen in patients with coronary artery disease. METHODS AND RESULTS: The 33 patients with coronary artery disease included in this randomized, double-blind, placebo-controlled, crossover study received acetaminophen (1 g TID) on top of standard cardiovascular therapy for 2 weeks. Ambulatory blood pressure, heart rate, endothelium-dependent and -independent vasodilatation, platelet function, endothelial progenitor cells, markers of the renin-angiotensin system, inflammation, and oxidative stress were determined at baseline and after each treatment period. Treatment with acetaminophen resulted in a significant increase in mean systolic (from 122.4±11.9 to 125.3±12.0 mm Hg P=0.02 versus placebo) and diastolic (from 73.2±6.9 to 75.4±7.9 mm Hg P=0.02 versus placebo) ambulatory blood pressures. On the other hand, heart rate, endothelial function, early endothelial progenitor cells, and platelet function did not change. CONCLUSIONS: This study demonstrates for the first time that acetaminophen induces a significant increase in ambulatory blood pressure in patients with coronary artery disease. Thus, the use of acetaminophen should be evaluated as rigorously as traditional nonsteroidal antiinflammatory drugs and cyclooxygenase-2 inhibitors, particularly in patients at increased cardiovascular risk. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00534651.

No use for waist-for-height ratio in addition to body mass index to identify children with elevated blood pressure.

Abstract Background. In children, waist-for-height ratio (WHtR) has been proposed to identify subjects at higher risk of cardiovascular diseases. The utility of WHtR to identify children with elevated blood pressure (BP) is unclear. Design. Cross-sectional population-based study of schoolchildren. Methods. Weight, height, waist circumference and BP were measured in all sixth-grade schoolchildren of the canton de Vaud (Switzerland) in 2005/06. WHtR was computed as waist [cm]/height [cm]. Elevated BP was defined according to sex-, age- and height-specific US reference data. The area under the receiver operating characteristic curve (AUC) statistic was computed to compare the ability of body mass index (BMI) z-score and WHtR, alone or in combination, to identify children with elevated BP. Results. 5207 children participated (76% response) [2621 boys, 2586 girls; mean (± SD) age, 12.3 ± 0.5 years; range: 10.1-14.9]. The prevalence of elevated BP was 11%. Mean WHtR was 0.44 ± 0.05 (range: 0.29- 0.77) and 11% had high WHtR (> 0.5). BMI z-score and WHtR were strongly correlated (Spearman correlation coefficient r = 0.76). Both indices were positively associated with elevated BP. AUCs for elevated BP was relatively low for BMI z-score (0.62) or for WHtR (0.62), and was not substantially improved when both indices were considered together (0.63). Conclusions. The ability of BMI z-score or WHtR to identify children aged 10-14 with elevated BP was weak. Adding WHtR did not confer additional discriminative power to BMI alone. These findings do not support the measurement of WHtR in addition to BMI to identify children with elevated BP.

Risk of cardiovascular events and blood pressure control in hypertensive HIV-infected patients: Swiss HIV Cohort Study (SHCS).

BACKGROUND: Prevalence of hypertension in HIV infection is high, and information on blood pressure control in HIV-infected individuals is insufficient. We modeled blood pressure over time and the risk of cardiovascular events in hypertensive HIV-infected individuals. METHODS: All patients from the Swiss HIV Cohort Study with confirmed hypertension (systolic or diastolic blood pressure above 139 or 89 mm Hg on 2 consecutive visits and presence of at least 1 additional cardiovascular risk factor) between April 1, 2000 and March 31, 2011 were included. Patients with previous cardiovascular events, already on antihypertensive drugs, and pregnant women were excluded. Change in blood pressure over time was modeled using linear mixed models with repeated measurement. RESULTS: Hypertension was diagnosed in 2595 of 10,361 eligible patients. Of those, 869 initiated antihypertensive treatment. For patients treated for hypertension, we found a mean (95% confidence interval) decrease in systolic and diastolic blood pressure of -0.82 (-1.06 to -0.58) mm Hg and -0.89 (-1.05 to -0.73) mm Hg/yr, respectively. Factors associated with a decline in systolic blood pressure were baseline blood pressure, presence of chronic kidney disease, cardiovascular events, and the typical risk factors for cardiovascular disease. In patients with hypertension, increase in systolic blood pressure [(hazard ratio 1.18 (1.06 to 1.32) per 10 mm Hg increase], total cholesterol, smoking, age, and cumulative exposure to protease inhibitor-based and triple nucleoside regimens were associated with cardiovascular events. CONCLUSIONS: Insufficient control of hypertension was associated with increased risk of cardiovascular events indicating the need for improved management of hypertension in HIV-infected individuals.

The central Sesia-Lanzo zone (Western Italian Alps) - New field observations and lithostratigraphic subdivisions

An extensive study of the central part of the Sesia Lanzo Zone has been undertaken to identify pre-Alpine protoliths and to reconstruct the lithologic and tectonic setting of this part of the Western Alps. Three main complexes have been defined: 1) the Polymetamorphic Basement Complex, corresponding to the lower unit of the Sesia Lanzo Zone after COMPAGNONI et al. (1977), is further subdivided into the three following units: a) an Internal Unit characterized by eo-Alpine high pressure (HP) assemblages (DAL PIAZ et al., 1972) (Eclogitic Micaschists); b) an Intermediate Unit where HP parageneses are partially re-equilibrated under greenschist conditions and c) an External Unit where the main foliation is defined by a greenschist paragenesis (Gneiss Minuti auct.). 2) the Monometamorphic Cover Complex, subdivided into the followings: a) the Bonze Unit, composed of sheared metagabbros, eclogitized metabasalts with MORB geochemical affinity and related metasediments (micaschists, quartzites and Mn-cherts) and b) the Scalaro Unit, containing predominantly metasediments of supposed Permo-Triassic age (yellow dolomitic marbles, calcschists and conglomeratic limestones, micaschists and quartzites with thin levels of basic rocks with within plate basalts [WPB] geochimical affinity). Multiple lithostratigraphic sequences for the Monometamorphic Cover Complex are proposed. The contact between the Bonze and Scalaro Units is defined by repetitions of dolomitic marbles and metabasalts; the ages of the metasediments have been assigned solely by analogy with other sediments of the Western Alps, due to the absence of fossils. The Monometamorphic Cover Complex can be considered as the autochthonous cover of the Sesia Lanzo Zone because of the primary contacts with the basement and because of the presence of preAlpine HT basement blocks in the cover sequences. 3) The pre-Alpine high temperature (HT) Basement Complex (or `'Seconda Zona Diorito-Kinzigitica''), comprises HT Hercynian rocks like kinzigites, amphibolites, granulites and calcite marbles; this Complex is always located between the Internal and the External Units and can be followed continuously for several kilometers south of the Gressoney Valley to the Orco Valley. A schematic evolution for the Sesia Lanzo Zone is proposed; based on available data together with new geochronological data, this study shows that the internal and external parts of the polymetamorphic basement of the Sesia Zone experienced different cooling histories .

Metallogenic model of the Trepca Pb-Zn-Ag skarn deposit, Kosovo: Evidence from fluid inclusions, Rare Earth Elements, and stable isotope data

The Trepca Pb-Zn-Ag skarn deposit (29 Mt of ore at 3.45% Pb, 2.30% Zn, and 80 g/t Ag) is located in the Kopaonik block of the western Vardar zone, Kosovo. The mineralization, hosted by recrystallized limestone of Upper Triassic age, was structurally and lithologically controlled. Ore deposition is spatially and temporally related with the postcollisional magmatism of Oligocene age (23-26 Ma). The deposit was formed during two distinct mineralization stages: an early prograde closed-system and a later retrograde open-system stage. The prograde mineralization consisting mainly of pyroxenes (Hd(54-100)Jo(0-45)Di(0-45)) resulted from the interaction of magmatic fluids associated with Oligocene (23-26 Ma) postcollisional magmatism. Whereas there is no direct contact between magmatic rocks and the mineralization, the deposit is classified as a distal Pb-Zn-Ag skarn. Abundant pyroxene reflects low oxygen fugacity (<10(-31) bar) and anhydrous environment. Fluid inclusion data and mineral assemblage limit the prograde stage within a temperature range between 390 degrees and 475 degrees C. Formation pressure is estimated below 900 bars. Isotopic composition of aqueous fluid, inclusions hosted by hedenbergite (delta D = -108 to -130 parts per thousand; delta O-18 = 7.5-8.0 parts per thousand), Mn-enriched mineralogy and high REE content of the host carbonates at the contact with the skarn mineralization suggest that a magmatic fluid was modified during its infiltration through the country rocks. The retrograde mineral assemblage comprises ilvaite, magnetite, arsenopyrite, pyrrhotite, marcasite, pyrite, quartz, and various carbonates. Increases in oxygen and sulfur fugacities, as well as a hydrous character of mineralization, require an open-system model. The opening of the system is related to phreatomagmatic explosion and formation of the breccia. Arsenopyrite geothermometer limits the retrograde stage within the temperature range between 350 degrees and 380 degrees C and sulfur fugacity between 10(-8.8) and 10(-7.2) bars. The principal ore minerals, galena, sphalerite, pyrite, and minor chalcopyrite, were deposited from a moderately saline Ca-Na chloride fluid at around 350 degrees C. According to the isotopic composition of fluid inclusions hosted by sphalerite (delta D = -55 to -74 parts per thousand; delta O-18 = -9.6 to -13.6 parts per thousand), the fluid responsible for ore deposition was dominantly meteoric in origin. The delta S-31 values of the sulfides spanning between -5.5 and +10 parts per thousand point to a magmatic origin of sulfur. Ore deposition appears to have been largely contemporaneous with the retrograde stage of the skarn development. Postore stage accompanied the precipitation of significant amount of carbonates including the travertine deposits at the deposit surface. Mineralogical composition of travertine varies from calcite to siderite and all carbonates contain significant amounts of Mn. Decreased formation temperature and depletion in the REE content point to an influence of pH-neutralized cold ground water and dying magmatic system.

Individual patient data systematic review and meta-analysis of optic nerve sheath diameter ultrasonography for detecting raised intracranial pressure: protocol of the ONSD research group.

BACKGROUND: The purpose of the optic nerve sheath diameter (ONSD) research group project is to establish an individual patient-level database from high quality studies of ONSD ultrasonography for the detection of raised intracranial pressure (ICP), and to perform a systematic review and an individual patient data meta-analysis (IPDMA), which will provide a cutoff value to help physicians making decisions and encourage further research. Previous meta-analyses were able to assess the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP but failed to determine a precise cutoff value. Thus, the ONSD research group was founded to synthesize data from several recent studies on the subject and to provide evidence on the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP. METHODS: This IPDMA will be conducted in different phases. First, we will systematically search for eligible studies. To be eligible, studies must have compared ONSD ultrasonography to invasive intracranial devices, the current reference standard for diagnosing raised ICP. Subsequently, we will assess the quality of studies included based on the QUADAS-2 tool, and then collect and validate individual patient data. The objectives of the primary analyses will be to assess the diagnostic accuracy of ONSD ultrasonography and to determine a precise cutoff value for detecting raised ICP. Secondly, we will construct a logistic regression model to assess whether patient and study characteristics influence diagnostic accuracy. DISCUSSION: We believe that this IPD MA will provide the most reliable basis for the assessment of diagnostic accuracy of ONSD ultrasonography for detecting raised ICP and to provide a cutoff value. We also hope that the creation of the ONSD research group will encourage further study. TRIAL REGISTRATION: PROSPERO registration number: CRD42012003072.

Target blood pressure attainment with antihypertensive therapy in Swiss primary care.

Introduction: The control of high blood pressure (BP) remains insufficient in developed as well as in developing countries. We conducted a cross-sectional survey to investigate the management of hypertension and the achievement of target BPs in a large population of hypertensive patients treated by Swiss primary care physicians. Methods. Data from 4594 hypertensive patients were collected and assessed for demographic data, mode of treatment and BP achievements for the overall population and for high-risk patients such as diabetics and patients with impaired renal function (CKD patients). Furthermore, we analysed the achieved BP in patients receiving single pill combinations or dual free combinations for the three most commonly prescribed substances. Results. In this large patient population, 84% of patients were receiving an antihypertensive treatment of which 54% showed BP control (< 140/90 mmHg or < 130/80 mmHg for diabetics and patients with CKD). Considering the higher BP target in the elderly, 60.6% of treated patients were on target. In contrast, 28.8% of treated diabetics and 29.7% of patients with impaired renal function met BP goals. Diuretics and blockers of the renin-angiotensin system were the most commonly prescribed substances. High-risk patients and patients at advanced age (≥ 80 years) received dual free combination more frequently than younger patients. The use of diuretics was particularly high because of the prescription of single pill formulations. Differences in the pattern of drug prescription were found according to the linguistic areas. Conclusion. The control of hypertension in the Swiss hypertensive population is relatively high but still insufficient particularly among high cardiovascular risk patients such as diabetics and patients with impaired renal function. A further improvement of BP control could perhaps be achieved with a greater use of single pill combinations particularly in patients with complicated hypertension.

Role of atrial natriuretic peptides and neuropeptide Y in blood pressure regulation.

Atrial natriuretic peptides (ANP) are released into the circulation in response to enhanced atrial stretching. These peptides not only have diuretic and natriuretic properties, but also exert a relaxing effect on the vasculature. Moreover, they antagonize the contractions induced by norepinephrine and angiotensin II. Neuropeptide Y (NPY) is also a vasoactive peptide. It is widely distributed throughout the central and peripheral nervous systems. NPY is coreleased with norepinephrine by perivascular nerve endings. At high concentrations, this peptide has a direct vasoconstrictor effect. In addition, it enhances the vascular effect of various agonists, including norepinephrine and angiotensin II. Both ANP and NPY have an inhibitory effect on renin secretion. This effect may have important implications for the role of these peptides in cardiovascular regulation.

Evaluation of arterial compliance-pressure curves. Effect of antihypertensive drugs.

A new high-precision ultrasonic device was developed to determine noninvasively arterial compliance as a function of blood pressure. Because of the nonlinear elastic properties of arterial walls, measurements of compliance can be appropriately compared only if obtained over a range of pressures. This apparatus was used to evaluate in a double-blind, parallel fashion the effect of three different antihypertensive drugs and of a placebo on radial artery compliance. Thirty-two normotensive volunteers were randomly allocated to an 8-day, once-a-day oral treatment with either a placebo, 100 mg atenolol, 20 mg nitrendipine, or 20 mg lisinopril. Blood pressure, heart rate, radial artery diameter, and arterial compliance were measured immediately before as well as 6 hours after dosing on the first and last days of the study. On the eighth day of administration, within 6 hours after dosing, lisinopril induced an acute increase in radial artery diameter, from 2.99 +/- 0.06 to 3.28 +/- 0.09 mm (mean +/- SEM, p less than 0.01). The compliance-pressure curve was shifted upward on day 1 (p less than 0.01) as well as on day 8 (p less than 0.05). None of the other drugs induced any significant modification of these parameters. Arterial compliance has a strong nonlinear dependency on intra-arterial pressure and therefore has to be defined as a function of pressure. Antihypertensive drugs acting by different mechanisms may have different effects on the mechanical properties of large arteries.

Discordant prevalence of hypertension using two different automated blood pressure measurement devices: a population-based study in Dar es Salaam (Tanzania).

OBJECTIVE: The estimation of blood pressure is dependent on the accuracy of the measurement devices. We compared blood pressure readings obtained with an automated oscillometric arm-cuff device and with an automated oscillometric wrist-cuff device and then assessed the prevalence of defined blood pressure categories. METHODS: Within a population-based survey in Dar es Salaam (Tanzania), we selected all participants with a blood pressure >/= 160/95 mmHg (n=653) and a random sample of participants with blood pressure <160/95 mmHg (n=662), based on the first blood pressure reading. Blood pressure was reassessed 2 years later for 464 and 410 of the participants, respectively. In these 874 subjects, we compared the prevalence of blood pressure categories as estimated with each device. RESULTS: Overall, the wrist device gave higher blood pressure readings than the arm device (difference in systolic/diastolic blood pressure: 6.3 +/- 17.3/3.7 +/- 11.8 mmHg, P<0.001). However, the arm device tended to give lower readings than the wrist device for high blood pressure values. The prevalence of blood pressure categories differed substantially depending on which device was used, 29% and 14% for blood pressure <120/80 mmHg (arm device versus wrist device, respectively), 30% and 33% for blood pressure 120-139/80-89 mmHg, 17% and 26% for blood pressure 140-159/90-99 mmHg, 12% and 13% for blood pressure 160-179/100-109 mmHg and 13% and 14% for blood pressure >/= 180/110 mmHg. CONCLUSIONS: A large discrepancy in the estimated prevalence of blood pressure categories was observed using two different automatic measurement devices. This emphasizes that prevalence estimates based on automatic devices should be considered with caution.

Gas collisions and pressure quenching of the photoluminescence of silicon nanopowder grown by plasma-enhanced chemical vapor deposition

The quenching of the photoluminescence of Si nanopowder grown by plasma-enhanced chemical vapor deposition due to pressure was measured for various gases ( H2, O2, N2, He, Ne, Ar, and Kr) and at different temperatures. The characteristic pressure, P0, of the general dependence I(P) = I0¿exp(¿P/P0) is gas and temperature dependent. However, when the number of gas collisions is taken as the variable instead of pressure, then the quenching is the same within a gas family (mono- or diatomic) and it is temperature independent. So it is concluded that the effect depends on the number of gas collisions irrespective of the nature of the gas or its temperature.