518 research outputs found
Angiotensin II-receptor subtypes in human atria and evidence for alterations in patients with cardiac dysfunction
Angiotensin II (All) has been implicated as an important factor in the pathophysiology of heart diseases. Following the recent identification of two subtypes of the All receptor in cardiac tissue of animals, we investigated the possible occurrence of these, or similar, subtypes in human atrial tissue. In right-atrial tissue from patients undergoing heart surgery, we determined the All-receptor profile in receptor binding studies, using [125I]-angiotensin as radioligand and All as well as two compounds selective for the receptor subtypes to identify and quantify All-receptor subpopulations. In 35 patients (23 requiring coronary bypasses, 10 vaivular surgery and two combined coronary and valvular surgery), the left-ventricular ejection fraction was determined in the preoperative phase, and right- and left-atrial pressure during surgery. In membranes of human right atria, All receptors are present in high density (median: Bmax= 294 fmol. mgâ1 protein, range: 111-2073) and two different subtypes can be distinguished. Type-1 receptors (AT1) accounted for 33 ± l0% of the population whereas type-2 receptors (AT2) made up 67 ± 10% of the population. There was no correlation between any of the measured cardiac functions and total All-receptor density or receptor affinity. However, the percentage of AT1 receptors was higher in the atria of patients with normal right-atrial pressure; left-ventricular ejection fraction was positively and right-atrial pressure inversely correlated with the percentage of AT1 receptors (r=0·740 and -0·901, respectively; P<0·001, for both). Moreover, the percentage of AT receptors was directly correlated with the levels of left-atrial pressure (r=0·853; P<0·001). It is concluded that the ratio of AT1 to AT2 receptors correlates well with right-atrial pressure and left-ventricular function. This is a first indication of a possible involvement of All-receptor subtypes in the pathophysiology of cardiac dysfunction
Risk Factors Promoting Hypertensive Crises: Evidence From a Longitudinal Study
Background Current knowledge about risk factors promoting hypertensive crisis originates from retrospective data. Therefore, potential risk factors of hypertensive crisis were assessed in a prospective longitudinal study. Methods Eighty-nine patients of the medical outpatient unit at the University Hospital of Bern (Bern, Switzerland) with previously diagnosed hypertension participated in this study. At baseline, 33 potential risk factors were assessed. All patients were followed-up for the outcome of hypertensive crisis. Cox regression models were used to detect relationships between risk factors and hypertensive crisis (defined as acute rise of systolic blood pressure (BP) â„200mmHg and/or diastolic BP â„120mmHg). Results The mean duration of follow-up was 1.6 ± 0.3 years (range 1.0-2.4 years). Four patients (4.5%) were lost to follow-up. Thirteen patients (15.3%) experienced hypertensive crisis during follow-up. Several potential risk factors were significantly associated with hypertensive crisis: female sex, higher grades of obesity, the presence of a hypertensive or coronary heart disease, the presence of a somatoform disorder, a higher number of antihypertensive drugs, and nonadherence to medication. As measured by the hazard ratio, nonadherence was the most important factor associated with hypertensive crisis (hazard ratio 5.88, 95% confidence interval 1.59-21.77, P < 0.01). Conclusions This study identified several potential risk factors of hypertensive crisis. Results of this study are consistent with the hypothesis that improvement of medical adherence in antihypertensive therapy would help to prevent hypertensive crises. However, larger studies are needed to assess potential confounding, other risk factors and the possibility of interaction between predictor
Event Generators for WW Physics
The report summarizes the results of the activities of the Working Group on
Event Generators for WW Physics at CERN during 1995.Comment: 99 Latex, including 30 figures, 24 tables. The report is part of:
G.Altarelli,T.Sjostrand and F.Zwirner (eds), Physics at LEP2 CERN 96-0
AMS INSIGHTâAbsorbable Metal Stent Implantation for Treatment of Below-the-Knee Critical Limb Ischemia: 6-Month Analysis
Endoluminal treatment of infrapopliteal artery lesions is a matter of controversy. Bioabsorbable stents are discussed as a means to combine mechanical prevention of vessel recoil with the advantages of long-term perspectives. The possibility of not having a permanent metallic implant could permit the occurrence of positive remodeling with lumen enlargement to compensate for the development of new lesions. The present study was designed to investigate the safety of absorbable metal stents (AMSs) in the infrapopliteal arteries based on 1- and 6-month clinical follow-up and efficacy based on 6-month angiographic patency. One hundred seventeen patients with 149 lesions with chronic limb ischemia (CLI) were randomized to implantation of an AMS (60 patients, 74 lesions) or stand-alone percutaneous transluminal angioplasty (PTA; 57 patients, 75 lesions). Seven PTA-group patients âcrossed overâ to AMS stenting. The study population consisted of patients with symptomatic CLI (Rutherford categories 4 and 5) and de novo stenotic (>50%) or occlusive atherosclerotic disease of the infrapopliteal arteries who presented with a reference diameter of between 3.0 and 3.5 mm and a lesion length of <15 mm. The primary safety endpoint was defined as absence of major amputation and/or death within 30 days after index intervention and the primary efficacy endpoint was the 6-month angiographic patency rate as confirmed by core-lab quantitative vessel analysis. The 30-day complication rate was 5.3% (3/57) and 5.0% (3/60) in patients randomized for PTA alone and PTA followed by AMS implantation, respectively. On an intention-to-treat basis, the 6-month angiographic patency rate for lesions treated with AMS (31.8%) was significantly lower (p = 0.013) than the rate for those treated with PTA (58.0%). Although the present study indicates that the AMS technology can be safely applied, it did not demonstrate efficacy in long-term patency over standard PTA in the infrapopliteal vessels
Equal pay by gender and by nationality: a comparative analysis of Switzerland's unequal equal pay policy regimes across time
What explains the adoption of two different policies on equal pay by gender (EPG) and by nationality (EPN) in Switzerland? And why is the liberal, litigation-based, equal pay policy regime set up by the Gender Equality Act of 1996 much less effective than the neocorporatist âaccompanying measures' to the Bilateral European Union-Switzerland Agreement on Free Movement of Persons adopted in 1999 to ensure equal pay for workers of different national origins? The formation of two different policy regimes cannot be explained by different levels of political will. Equally, different âvarieties of capitalism' cannot explain the setup of the two different equal pay policy regimes within the very same country. Instead, our qualitative comparative analysis across time suggests that the differences can be best explained by a particular constellation of attributes, namely the use of different policy framesâi.e. âanti-discrimination' in the EPG and âunfair competition' in the EPN caseâand the different setting of interest politics epitomised by the opposite stances adopted by Switzerland's employer associations in the two case
Klinische Effekte der katheterbasierten Nierennervenablation bei therapieresistenter Hypertonie
Background: High blood pressure is one of the most common chronic cardiovascular diseases. Despite a plethora of drugs to lower blood pressure, adequate blood pressure reduction cannot be achieved in many patients with high blood pressure. Ablation of the nerves of the renal arteries is used in these patients.
Methods: Renal nerve ablation is a catheter-based, minimally-invasive method which, with the appropriate experience, is relatively easy to carry out, and has already demonstrated very promising results in patients with treatment-resistant hypertension.
Results: The data presented in this article confirm that catheter-based renal nerve ablation, used in 38 patients with treatment-resistant hypertension, is a safe and highly effective method of achieving optimal blood pressure stabilisation.
Conclusion: It remains to be seen whether the promising results of current studies will be confirmed in the long-term progress and lead to a reduction of cardiovascular morbidity and mortality
Search for Charginos with a Small Mass Difference with the Lightest Supersymmetric Particle at \sqrt{s} = 189 GeV
A search for charginos nearly mass-degenerate with the lightest
supersymmetric particle is performed using the 176 pb^-1 of data collected at
189 GeV in 1998 with the L3 detector. Mass differences between the chargino and
the lightest supersymmetric particle below 4 GeV are considered. The presence
of a high transverse momentum photon is required to single out the signal from
the photon-photon interaction background. No evidence for charginos is found
and upper limits on the cross section for chargino pair production are set. For
the first time, in the case of heavy scalar leptons, chargino mass limits are
obtained for any \tilde{\chi}^{+-}_1 - \tilde{\chi}^0_1 mass difference
Study of Z Boson Pair Production in e+e- Collisions at LEP at \sqrt{s}=189 GeV
The pair production of Z bosons is studied using the data collected by the L3
detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189
GeV. All the visible final states are considered and the cross section of this
process is measured to be 0.74 +0.15 -0.14 (stat.) +/- 0.04 (syst.) pb. Final
states containing b quarks are enhanced by a dedicated selection and their
production cross section is found to be 0.18 +0.09 -0.07 (stat.) +/- 0.02
(syst.) pb. Both results are in agreement with the Standard Model predictions.
Limits on anomalous couplings between neutral gauge bosons are derived from
these measurements
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