Routine prenatal screening for congenital heart disease: what can be expected? A decision-analytic approach

OBJECTIVES: This study assessed the potential impact of fetal ultrasound screening on the number of newborns affected by cardiac anomalies. METHODS: A decision model was developed that included the prevalence and history of congenital heart disease, characteristics of ultrasound, risk of abortion, and attitude toward pregnancy termination. Probabilities were obtained with a literature survey; sensitivity analysis showed their influence on expected outcomes. RESULTS: Presently, screening programs may prevent the birth of approximately 1300 severely affected newborns per million second-trimester pregnancies. However, over 2000 terminations of pregnancy would be required, 750 of which would have ended in intrauterine death or spontaneous abortion. Further, 9900 false-positive screening results would occur, requiring referral. Only the sensitivity of routine screening and attitude toward termination of pregnancy appeared to influence the yield substantially. CONCLUSIONS: The impact of routine screening for congenital heart disease appeared relatively small. Further data may be required to fully assess the utility of prenatal screening.     

The “Roman pot” spectrometer and the vertex detector of experiment UA4 at the CERN SPS collider

We describe the apparatus used in experiment UA4 to study proton-antiproton elastic and inelastic interactions at the CERN SPS Collider. Elastically scattered particles, travelling at very small angles, are observed by detectors placed inside movable sections (“Roman pots”) of the SPS vacuum chamber. The deflection in the field of the machine quadrupoles allow the measurement of the particle momentum. Inelastic interactions are observed by a left-right symmetric system of trigger counter hodoscopes and drift-chamber telescopes. The apparatus reconstructs the interaction vertex and measures the pseudorapidity η of charged particles in the range 2.5 < 6η6 < 5.6.     

cDNA of eight nuclear encoded subunits of NADH:ubiquinone oxidoreductase: human complex I cDNA characterization completed

Brief elevation in postsynaptic calcium in hippocampal CA1 neurons leads to prolonged changes in synaptic strength. The calcium may enter the postsynaptic neuron via different routes, such as voltage-gated calcium channels or glutamate receptor channels of N-methyl-D-aspartate type, and/or be released from intracellular stores. The manner in which the synapse is altered, leading to the expression of an enhanced/depressed synaptic strength, is still unclear. The present study, performed using whole-cell recording from CA1 pyramidal cells of three- to five-week-old guinea-pigs, shows that postsynaptic depolarization alone, allowing for calcium influx through voltage-gated calcium channels, leads to a synaptic potentiation characterized by an altered time-course of the evoked excitatory synaptic response, an unaltered coefficient of variation of that response and a decreased paired-pulse facilitation likely related to a postsynaptic mechanism. These characteristics contrasted with those of long-term potentiation induced via activation of N-methyl-D-aspartate receptor channels, where the time-course was unaltered, the coefficient of variation was decreased and no change in paired-pulse facilitation was observed. Synapses can thus have mechanistically separate, but co-existent, potentiations of synaptic transmission initiated from separate sources for postsynaptic calcium.     

Doppler spectrum analysis versus direct femoral artery pressure measurement for rapid assessment of aortoiliac obstruction

Adequate patient selection is required to limit the clinical workload and improve the cost-effectiveness of noninvasive hemodynamic evaluation of the aortoiliac system. In a prospective blinded fashion the traditional invasive technique of direct femoral artery pressure measurements and the computerized Doppler spectrum analysis of blood flow velocities in the common femoral artery were studied. Both tests for rapid assessment of aortoiliac obstruction were compared with duplex ultrasonographic imaging, using a peak systolic velocity ratio of 2.5 to demonstrate stenoses of 50% or more. In a series of 17 consecutive patients (34 aortoiliac segments) with suspected aortoiliac obstructive disease, a good level of agreement (kappa = 0.6) was found for both methods when compared with duplex scanning. Analysis of deviations from the duplex registrations indicated an overestimation of the pathologic cases using femoral artery pressure measurements and an underestimation using Doppler spectrum analysis of blood flow velocities in the common femoral artery. Both methods were well tolerated, but femoral artery pressure measurements had a higher technical failure rate. Because of its noninvasive character and its feasibility the Doppler technique is preferred for the selection of patients for more extensive duplex sonographic investigation.     

Arterial stenting and balloon angioplasty in ostial atherosclerotic renovascular disease: a randomised trial

BACKGROUND: Percutaneous transluminal angioplasty (PTA) for ostial atherosclerotic renal-artery stenosis has poor results. Angioplasty with stent placement (PTAS) may be more effective. We undertook a randomised prospective study to compare PTA with PTAS in patients with ostial atherosclerotic renal-artery stenosis. METHODS: Patients with ostial atherosclerotic renal-artery stenosis were assigned to receive PTA or PTAS. Secondary PTAS was allowed if PTA failed immediately or during 6 months' follow-up. Analysis was by intention to treat. FINDINGS: 42 patients were assigned PTA and 43 were assigned PTAS, but one patient in the PTAS group was excluded from the study. Primary success rate (<50% residual stenosis) of PTA was 57% (24 patients) compared with 88% (37 patients) for PTAS (difference between groups 31% [95% CI 12-50]). Complications were similar. At 6 months, the primary patency rate was 29% (12 patients) for PTA, and 75% (30 patients) for PTAS (46% [24-68]). Restenosis after a successful primary procedure occurred in 48% of patients for PTA and 14% for PTAS (34% [11-58]). 12 patients underwent secondary stenting for primary or late failure of PTA within the follow-up period: success was similar to that of primary PTAS. Evaluation based on intention to treat showed no difference in clinical results at six months for PTA or PTAS. INTERPRETATION: PTAS is a better technique than PTA to achieve vessel patency in ostial atherosclerotic renal-artery stenosis. Primary PTAS and primary PTA plus PTAS as rescue therapy have similar outcomes. However, the burden of reintervention after PTA outweighs the potential saving in stents, so primary PTAS is a better approach to use.     

A brief review of environmentally benign antifouling and foul-release coatings for marine applications

Antifouling coatings for ship hulls are a very important topic in coating research. They are essential with respect to fuel consumption of ships: without antifouling coating, biological species start to adhere to the ship’s exterior, leading to a gradual increase in fuel consumption. To date, the working principle of most of the paint systems applied is based on slow release of toxins in time (self-polishing coatings). In this article, we discuss the environmental impact of marine antifouling coatings based on quantitative data available from literature. In addition, we critically review hydrophilic antifouling and hydrophobic foul-release coatings as toxin-free alternatives and discuss their potential for replacing self-polishing coatings.     

Primary structure and high expression of human agrin in basement membranes of adult lung and kidney

In previous in vivo studies we have reported that atrial natriuretic factor enhanced induced salivary secretion and increased isoproterenol-induced amylase release in the rat suggesting that, ANF effect could be mediated by phosphatidylinositol hydrolysis. In the present work, the effect of ANF on rat parotid tissue incubated in vitro was investigated with the aim to assess whether the phosphoinositol pathway was involved in ANF intracellular signaling in the parotid gland. Results showed that ANF induced a dose dependent increase in amylase fractional release, which was lower than that evoked by any concentration of isoproterenol. Furthermore 100 nM ANF enhanced isoproterenol-evoked amylase release. The effect of ANF was not affected in the presence of propranolol suggesting the noninvolvement of the beta adrenergic receptor, which is the main stimulus for the output of the enzyme in the parotid gland. However, ANF increased phosphatidylinositol hydrolysis, which implies an increase in intracellular calcium, which is necessary for the achievement of maximal response in amylase release. This effect was abolished in the presence of neomycin supporting ANF direct stimulation of phospholipase C. These results suggest the involvement of the C type natriuretic peptide receptor coupled to phospholipase C in ANF evoked amylase release and ANF enhancement of the isoproterenol-induced output of the enzyme.     

Two cold legs

Bilateral acute lower limb ischaemia is rare. Usually the diagnosis is based on clinical findings. In four patients, three women aged 51, 48, and 72 and a man aged 64 years, bilateral acute ischaemia of the lower limbs was diagnosed, due to different causes: arterial cardiac myxoma embolism, arterial thrombosis probably due to paraneoplastic coagulopathy, aortic dissection, and arterial thrombosis due to cardiac insufficiency, respectively. The management of these conditions includes restoring the circulation as soon as possible. Reperfusion can be achieved by thromboembolectomy or thrombolysis. In patients with underlying atherosclerosis angiography is useful, but time loss must be avoided. The outcome in patients with bilateral ischaemia of the lower limbs depends on the preoperative ischaemia time and the cardiac situation. The mortality varies between 20 and 50%.     

Comparison of signaling loads for PCS systems

We present a comparison of the control signaling load of two vastly different architectures for providing personal communication services (PCSs). One architecture is based on current cellular networks. The other architecture, called the wireless distributed call processing architecture (WDCPA), distributes processing from the mobile switching centers and cell sites and executes new procedures for tracking mobile users and locating mobile users to deliver calls. We determine the signaling load generated within each system to support mobility management and call control based on standard assumptions about the operating parameters of a cellular network. Our results show that, when compared to current cellular systems, for simple single-connection services, WDCPA has marginally reduced cross-network signaling loads. For multiconnection calls, WDCPA incurs 35% less total signaling load for mobility management, has reduced cross-network signaling load for mobility management by up to 65%, and depending on the user model (e.g., data or telecommunication), has reduced total cross-network signaling load, including procedures for call/connection and mobility management, by up to 55% when compared to current cellular systems, while more flexibly supporting services     

A cost-effectiveness analysis of colorectal screening of hereditary nonpolyposis colorectal carcinoma gene carriers

BACKGROUND: It has been estimated that the prevalence of carriers of a mutated mismatch repair (MMR) gene among the general population in Western countries is between 5 and 50 per 10,000. These carriers have a risk of >85% of developing colorectal carcinoma (CRC) and therefore need careful follow-up. The objective of this study was to analyze the cost-effectiveness of CRC surveillance of carriers of a mutated MMR gene. METHODS: The authors constructed a model to estimate the potential health effects (life expectancy) and healthcare costs of two strategies: 1) surveillance, with colonoscopy every 2-3 years, and 2) no CRC surveillance. Estimates of the lifetime risk of developing CRC and the stage distribution of CRC for symptomatic patients were derived from the Dutch hereditary nonpolyposis colorectal carcinoma (HNPCC) registry. The CRC stage specific relative survival rates and the effectiveness of surveillance in preventing or detecting cancer early were based on Finnish studies. The costs of surveillance and treatment were derived from recent American studies. RESULTS: The results showed that 1) surveillance of gene carriers led to an increase in life expectancy of 7 years, and 2) the costs of surveillance under a wide range of assumptions are less than the costs of no CRC surveillance. CONCLUSIONS: CRC surveillance of HNPCC gene carriers appears to be effective and considerably less costly than no CRC surveillance and therefore deserves to be supported by governmental agencies and health insurance organizations.