Electron microscopic analysis of the specific granule content of human atria. An investigation of the role of atrial pressure and atrial rhythm in the release of atrial natriuretic peptide

Knowledge about the stimulus for the release of atrial natriuretic peptide (ANP) from human atria is incomplete. Atrial stretch is known to be a stimulus and atrial tachyarrhythmias are thought to be another. The effects of atrial size (by two-dimensional echocardiography) and atrial fibrillation on the atrial specific granule content of human atria were studied to gain insight into the secretory mechanisms of ANP. An electron microscopic analysis of the atrial granule content was used to study 12 patients--5 with mitral stenosis and sinus rhythm, 3 with mitral stenosis and atrial fibrillation and 4 controls. Granules were counted using a free count and montage method. This is the first report of such a morphometric analysis in humans. Granule counts were significantly raised in the patients with mitral stenosis compared with controls (P less than 0.014). This observation probably reflects a high turnover state induced by elevated atrial pressures. Further support for this conclusion is provided by the demonstration of a positive correlation between granule counts and left atrial size (r = 0.86; P less than 0.01). The tendency for higher counts in patients with atrial fibrillation may be related to the rhythm disturbance itself, but clinical and echocardiographic data suggest more severe atrial pressure overload in this group.     

Pharmacodynamic specification and membrane stabilising action of a homologous series of silasympathomimetics

The pharmacodynamic effect of a homologous series of aminomethyldimethyl-(methoxyphenyl)-silane derivatives have been tested on isolated guinea-pig left atria. All molecules increase the force of contraction to different degrees by a partly direct and partly indirect mechanism (measured on atria isolated from reserpine treated guinea-pigs). The positive inotropic effect is reduced by bupranolol. Furthermore the compounds show an antagonistic effect to orciprenaline. The membrane stabilising action is lowest for those compounds showing the highest inotropic effects and vice versa.     

Fanconi anemia in black African children

Fanconi anemia (FA) has rarely been reported in black children either in the United States or Africa. This report describes 25 black African children with FA seen in Johannesburg over an 11-year period. The prevalence of homozygotes was estimated to be 1:476,000. Clinical manifestations, mean age at diagnosis, and hematologic and chromosome abnormalities were similar to those described in other ethnic groups. Response to androgens was poor and most patients required regular transfusions. Seventeen (68%) of the children died during the 11-year observation period. Leukemia was the terminal event in 2 patients. The mean age at death was 9.8 years and the mean time between diagnosis and death 2.3 years. The poor response to androgens, high mortality, and early mean age at death would favor consideration of early bone marrow transplantation in these children.     

Pre-admission clinical course of meningococcal disease and opportunities for the earlier start of appropriate intervention: a prospective epidemiological study on 752 patients in the Netherlands, 2003–2005

To improve the timeliness of health care delivery to patients with meningococcal disease, the early disease evolution and clinical manifestation at admission were studied in all 752 patients with invasive meningococcal disease in the Netherlands in 2003–2005. Eighty-eight percent (88%) had serogroup B disease. The case fatality rate (CFR) was 6.7% overall, but reached 16% among adults over 50 years of age. The CFR was similar for serogroups B (6.3%) and C (5.2%). Admission followed 17 h (median) after the onset of symptoms. The CFR in patients admitted within 12 h, 12–18 h, 18–36 h or >36 h after the first symptoms was 10.2, 7.8, 3.5 and 2.2%, respectively. Only 60% of patients had skin lesions, and admission followed 2 h (median) later. Earlier recognition can be achieved when non-petechial clues are included in the diagnosis. A short duration of disease before admission is a simple tool in the recognition of patients with severe disease. Declaration of interest: none.     

Prevention of hospital infections by intervention and training (PROHIBIT): results of a pan-European cluster-randomized multicentre study to reduce central venous catheter-related bloodstream infections

Purpose

To test the effectiveness of a central venous catheter (CVC) insertion strategy and a hand hygiene (HH) improvement strategy to prevent central venous catheter-related bloodstream infections (CRBSI) in European intensive care units (ICUs), measuring both process and outcome indicators.

Methods

Adult ICUs from 14 hospitals in 11 European countries participated in this stepped-wedge cluster randomised controlled multicentre intervention study. After a 6 month baseline, three hospitals were randomised to one of three interventions every quarter: (1) CVC insertion strategy (CVCi); (2) HH promotion strategy (HHi); and (3) both interventions combined (COMBi). Primary outcome was prospective CRBSI incidence density. Secondary outcomes were a CVC insertion score and HH compliance.

Results

Overall 25,348 patients with 35,831 CVCs were included. CRBSI incidence density decreased from 2.4/1000 CVC-days at baseline to 0.9/1000 (p < 0.0001). When adjusted for patient and CVC characteristics all three interventions significantly reduced CRBSI incidence density. When additionally adjusted for the baseline decreasing trend, the HHi and COMBi arms were still effective. CVC insertion scores and HH compliance increased significantly with all three interventions.

Conclusions

This study demonstrates that multimodal prevention strategies aiming at improving CVC insertion practice and HH reduce CRBSI in diverse European ICUs. Compliance explained CRBSI reduction and future quality improvement studies should encourage measuring process indicators.

     

Accuracy assessment of the Tensoval duo control according to the British and European Hypertension Societies' standards

OBJECTIVE: Noninvasive blood pressure (BP) measurement is dependent on either auscultation or oscillometry. The Tensoval duo control device uses auscultatory and/or oscillometric technology to determine BP. We evaluated the accuracy of this device in adults according to the British Hypertension Society (BHS) protocol and the International Protocol of the European Hypertension Society. METHODS: Ethical approval was obtained and participants gave written informed consent. Eighty-five participants who fulfilled the protocol criteria were recruited. Nine sequential same arm measurements were taken from each participant by two trained observers, comparing the device to mercury sphygmomanometery. Data analysis was performed according to the respective protocol guidelines. RESULTS: The device achieved an A grade for both systolic and diastolic pressures with 68, 91 and 98% of systolic and 73, 91 and 98% of diastolic differences within the 相似文献   

Zum Wirkungsmechanismus der neuen herzwirksamen Sterinderivate Prednison- und Prednisolon-bisguanylhydrazon

Ohne Zusammenfassung     

Arterial hypertension as a paraneoplastic phenomenon in hepatocellular carcinoma

Three South African blacks with hepatocellular carcinoma and arterial hypertension are described. Plasma angiotensinogen (renin substrate) concentrations were increased eightfold to 10-fold in the two patients in whom these concentrations were measured. One of these two patients also showed a 34-fold rise in plasma inactive, active, and total renin concentrations, and an elevated plasma renin activity (2.73 ng.L-1.s-1 angiotensin l/mL/h). Inactive renin (prorenin) constituted 90% of the total plasma renin concentration. In the third patient only plasma renin activity was measured, and this was considerably raised (6.05 ng.L-1.s-1; angiotensin l/mL/h). Thus, the arterial hypertension that rarely complicates hepatocellular carcinoma may be caused either by a combination of eutopic synthesis of excessive quantities of angiotensinogen and ectopic production and secretion of active renin by malignant hepatocytes, or by eutopic production of angiotensinogen alone.