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We have studied defect charging and discharging resulting from negative bias temperature instability in nitrided SiO2 gate insulator field effect transistors. Using pseudo-DC and pulsed stressing methods, we are able to extract at least three individual components associated with a) interface states at the semiconductor/insulator boundary, b) dynamically recoverable positive charging in the “bulk” of the insulator, and c) positive charge in the insulator which can be “eliminated” by application of a positive electric field across the insulator. It is argued that the charge variation in c) in fact arises via a charge neutralization process involving electron capture at switching traps and that this process can be simply reversed using a small negative field. The important role played by neutral oxygen vacancies (O3≡Si-Si≡O3) and/or their variants involving partial N substitutions is emphasized. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Background When engineers and students engage in mathematical modeling, the models they create are representational systems of real-world problem situations. These representational systems reveal modelers' interpretations of the relative importance of various real-world aspects. Purpose This paper illustrates how interpretations of student teams' solution models (i.e., their representational systems) to a particular problem can be used to inform educational decisions. Design/Method First-year engineering teams' iterative solution models to the Travel Mode Choice Model-Eliciting Activity (MEA) were interpreted for the purpose of identifying patterns within and across teams' responses. This MEA requires the creation of a model for a client who wants to predict the mode of transportation an individual will likely take to a college campus. Teams were provided with the client's needs and sample data concerning individuals' actual travel mode and travel time, cost, and convenience for various travel modes (walk, bus, or drive). Results Student teams were required to submit their intermediate and final model descriptions in narrative form. Systematic study of their models resulted in identification of four different types of models. Patterns within and across model types were then used to suggest changes to the instructional system. Conclusion When instructors study student models as representations of their interpretation of a real-world problem situation, insights gained can lead to practical proposals for improving instruction with authentic open-ended problems including revisions to tasks, implementation strategies, formative assessment strategies, and course content.

Aims: To determine how the ability to oxygenate the blood develops after birth in infants of extremely low gestational age (ELGANs) and to find risk factors for chronic lung disease. Method: A prospective, population-based, cohort study was undertaken in one tertiary-care centre. The alveolar-arterial oxygen pressure difference (AaDO(2) ) was monitored. Results: Of 41 survivors, 21 had a period of normal lung function in the first week of life, after which oxygenation deteriorated. Low gestational age and low Apgar score at 5 min were found to be strong and independent predictors of AaDO(2) in the first month of life. Mechanical ventilation did not appear as a risk factor. Lung function at 36 weeks of gestation and duration of oxygen treatment could be better predicted by the severity of lung disease in the first month than by gestational age at birth. Conclusions: Difficulty in oxygenation was a general observation in ELGANs and not only a particular subset. Gestational age and Apgar score were independent predictors of the degree of difficulty over the first month of life. As oxygenation failure often developed after a few days, the process may be possible to treat or prevent once the pathogenesis is known.

Aim: To evaluate the accuracy in transcutaneous (Tc) blood gas monitoring in newborn infants, including extremely low birth weight infants, during neonatal intensive care. Methods: Tc PO2/PCO2 was monitored in the neonatal intensive care unit (NICU) during stable infant conditions. In comparison, simultaneous arterial PO2 and PCO2 was measured. Sixty measurements were taken in 46 infants with median (range) birth weight of 0.93 (0.53–4.7) kg and at median (range) age of 8.5 (1–44) days. Comparison of measurements was performed using Bland–Altman plots, and the mean (95% CI) of the difference was calculated. Comparison was also performed in relation to body weight, postnatal age and oxygen requirement. Results: The mean (95% CI) difference in PO2 (TcPO2–aPO2) was 0.3 (−0.2–0.9) kPa, and the corresponding difference in PCO2 (TcPCO2–aPCO2) was 0.4 (0.03–0.8, p

A double-blind trial with the beta 1-selective blocker metoprolol in suspected acute myocardial infarction and during 3 months' follow-up included 1395 patients, aged 40-74 years, 698 on metoprolol and 697 on placebo. In order to further evaluate the tolerability to beta-blockade in the elderly, the total series was divided into 2 groups according to median age (61 years) and into quartiles, the lowest quartile (40-57 years) being compared with the highest (67-74 years). The decrease in heart rate and systolic blood pressure after intravenous metoprolol in the acute phase was similar in the elderly and the younger patients. Hypotension was observed more often in the metoprolol-treated than in the placebo-treated younger patients, while no difference was observed in the elderly. Bradycardia was observed more often in the metoprolol group in both age groups, while there was no difference regarding the incidence of congestive heart failure in either the younger or in the elderly patients. The effect on mortality, serious ventricular arrhythmias and chest pain seemed to be similar in different age groups. From the present series we conclude that hemodynamic reactions and tolerability to beta-blockade can be expected to be similar in elderly and younger patients.

In previous experimental and clinical studies on aortic valvular stenosis it has been suggested that in addition to the degree of stenosis, other factors, such as the pathoanatomy of the valve and turbulence-induced vibrations, might be of importance. Using echocardiography, vibrations of the interventricular septum were demonstrated in six consecutive patients with congenital aortic stenosis. In comparable normal subjects no such vibrations could be seen. The clinical significance of ventricular wall vibrations has not yet been established.

A double-blind study including three different cardioselective beta-blockers, practolol, H 87/07 and metoprolol, was performed in 54 patients with acute myocardial infarction and chest pain shortly after onset of symptoms. Transmural infarctions were found in 42 patients while 12 patients had nontransmural infarctions. Chest pain and the product of heart rate and systolic blood pressure were significantly reduced in the beta-blocker groups whereas no changes were seen after saline. All patients with nontransmural infarctions and 14 out of 29 with transmural infarctions got pain relief lasting for at least 30 min. None of the patients developed signs of left ventricular backward failure, shock, or bradycardia. A decrease in ST segment elevation was observed in all the transmural infarctions after beta-blockade. No changes in ST segment elevation were found after analgesics when given after saline, but in some cases an increase was seen in this parameter when analgesics were given due to insufficient pain relief after beta-blockers or due to return of chest pain. It is suggested that pain relief by beta-blockers indicates decrease of myocardial ischemia.

Whole-heart ischemia has been induced in isolated working rat heart. The distribution of the reduced coronary flow was even, as judged by 3H-antipyrine autoradiographs. Reducing the coronary flow resulted in myocardial ischemia, as indicated by a lowered tissue content of glycogen, ATP and creatine phosphate and accumulation of lactate. After a reperfusion period of 30 min there was a restoration of glycogen, ATP and creatine phosphate for hearts that were ischemic for 5 and 10 min, with a concomitant normalization of tissue lactate. Hearts that were ischemic for 30 min did not show restoration of high energy phosphates and glycogen. There was a leakage of ASAT, CK and LD in all groups of hearts, suggesting that a release of these enzymes does not necessarily indicate an irreversibly damaged myocardial cell.

Hemodynamic changes were studied in ten patients with uncomplicated transmural myocardial infection during 24 hours on beta-blockade. The cardioselective beta-adrenergic blocking drug metoprolol was injected (15 mg i.v.) within the first 24 hours after onset of chest pain and was followed by oral therapy (25-50 mg at 6-hour intervals). There was a decrease in heart rate, systolic BP, and cardiac output, which was most marked after the injection. The stroke volume and diastolic BP for the whole group of patients remained unchanged. The pulmonary artery end diastolic pressure did not change significantly after the injection but a continuous fall was obtained in three out of four patients with initially elevated values. The preejection period, measured from the ECG and carotid pressure curve, as initially short and was prolonged in all patients after administration of the beta-blocking drug. It is concluded that the cardioselective beta-blocking drug metoprolol may be used in selected patients in the acute phase of myocardial infarction without danger of hemodynamic deterioration during the first 24 hours of therapy. The selection of patients can be based on clinical criteria. In this study signs of left heart failure, hypotension, poor peripheral circulation, bradycardia, and AV block were regarded as contraindications.

In 585 patients with acute myocardial infarction (AMI) and no previous MI the maximal activity of serum heat-stable lactate dehydrogenase (LD) (EC 1.1.1.27) activity was related to 1-year and 2-year mortality rates. All patients participated in a double-blind trial with metoprolol during the first three months after an AMI. Thereafter both groups were treated in a similar way. A strong relationship was found between LD maximum activity and the in-hospital prognosis (p less than 0.001), the 1-year survival rate (p less than 0.001) and the 2-year survival rate (p less than 0.001). When the patients who were alive after primary hospitalization were analyzed as a separate group, the relationship between LD maximum activity and 1-year and 2-year survival rates remained (p less than 0.001). In a subsample of 171 patients the maximal activity of creatine kinase (CK) (EC 2.7.3.2) and CK subunit B did not correlate either with in-hospital, 1-year or 2-year survival rates. We conclude that, when a sufficiently large number of patients are investigated, there is a strong relationship between serum enzyme maximum activity and short- and long-term survival.

In studies using an experimental infarction as a model it has been shown that factors increasing myocardial oxygen consumption will increase the size of infarction, while factors reducing the oxygen consumption have the opposite effect. The presence of catecholamines might be most important. It is suggested that local release of noradrenaline from the sympathetic nerve endings in ischemic myocardium can induce vigorous contractions and deleterious ischemia and result in cellular necrosis. A retrospective study was performed in 81 patients hospitalized in Göteborg in 1964-1965 due to attacks of severe chest pain with no previous documented myocardial infarction. In 31 of these patients definite congestive heart failure was seen at hospitalization or developed later. During 10 years of follow up the mortality was 48 per cent and an acute myocardial infarction was found in 64 per cent of the patients without congestive heart failure. In patients with congestive heart failure the mortality was 42 per cent, and 6.4 per cent had an acute myocardial infarction. The poor mechanical performance and a lower myocardial content of noradrenaline of the failing heart might protect from the acute myocardial infarction and instead be predisposed to a slow degeneration, pump failure, and serious arrhythmias. Severe angina pectoris and congestive heart failure might represent opposite ends of the spectrum of ischemic heart disease with similar degrees of luminal narrowing of the coronary arteries.

Aims Few prognostic models in heart failure have been developed in typically elderly patients treated with modern pharmacological therapy and even fewer included simple biochemical tests (such as creatinine), new biomarkers (such as natriuretic peptides), or, especially, both. In addition, most models have been developed for the single outcome of all-cause mortality. Methods and results We built a series of models for nine different fatal and non-fatal outcomes. For each outcome, a model was first built using demographic and clinical variables (Step 1), then with the addition of biochemical measures (serum creatinine, alanine aminotransferase, creatine kinase, thyrotrophin, apolipoproteins A-1 and B, and triglycerides) (Step 2) and finally with the incorporation of high-sensitivity C-reactive protein (hsCRP) and N-terminal pro B-type natriuretic peptide (NT-proBNP). Ranked according to the Wald χ2 value, age (56), ejection fraction (44), and body mass index (42) were most predictive of all-cause mortality in Step 1 (total model χ2 343). Creatinine was the most powerful predictor at Step 2 (48) and ApoA-1 ranked fifth (25), with the overall χ2 increasing to 440. Log NT-proBNP (167) was the most powerful of the 14 independently predictive variables identified at Step 3 and the overall χ2 increased to 600. NT-proBNP was the most powerful predictor of each other outcome. hsCRP was not a predictor of all-cause mortality but did predict the composite atherothrombotic outcome. Conclusion Of the two new biomarkers studied in prognostic models in heart failure, NT-proBNP, but not hsCRP, added substantial and independent predictive information, for a range of clinical outcomes, to that provided by simple demographic, clinical, and biochemical measures. ApoA-1 was more predictive than LDL or HDL.

Time-dependent, two-dimensional, electrothermal simulations based on random Voronoi networks have been developed to study the internal heating, current distributions and breakdown effects in ZnO varistors in response to high-voltage pulsing. The simulations allow for dynamic predictions of internal failures and to track the progression of hot-spots and thermal stresses. The focus is on internal grain-size variations and relative disorder including micropores. Our results predict that parameters such as the hold-off voltage, internal temperature, and average dissipated energy density would be higher with more uniform grains. This uniformity is also predicted to produce lower thermal stresses and to allow for the application of longer duration pulses. It is shown that the principal failure mechanism arises from internal localized melting, while thermal stresses are well below the thresholds for cracking. Finally, detrimental effects of micropores have been quantified and shown to be in agreement with experimental trends.

Background: Previous prospective outcome studies of statins have not provided any guidance on benefit-risk in patients with heart failure. Aim: The primary objective is to determine whether rosuvastatin (10 mg) reduces the combined endpoint of cardiovascular mortality, nonfatal myocardial infarction or non-fatal stroke (time to first event). The first secondary endpoint is all-cause mortality. Methods: CORONA is a randomized, double-blind, placebo-controlled trial. Briefly, men and women, aged 60 years with chronic symptomatic systolic heart failure of ischemic aetiology and ejection fraction 0.40 (NYHA class III and IV) or 0.35 (NYHA class II) were eligible if they were not using or in need of cholesterol lowering drugs. Results: Mean age was 73 years (n=5016; 24% women), with 37% in NYHA II and 62% in NYHA III, ejection fraction 0.31, total cholesterol 5.2 mmol/L. Sixty percent have a history of myocardial infarction, 63% hypertension, and 30% diabetes. Patients are well treated for heart failure with 90% on loop or thiazide diuretics, 42% aldosterone antagonists, 91% ACE inhibitor or AT-I blocker, 75% beta-blockers, and 32% digitalis. Conclusion: CORONA is important for three main reasons: (1) A positive result is very important because of the high risk of the population studied, the increasing prevalence of elderly patients with chronic symptomatic systolic heart failure in our society, and the health economic issues involved. (2) If negative, new mechanistic questions about heart failure have to be raised. (3) If neutral we can avoid unnecessary polypharmacy.

Observations with the Odin mm/submm space telescope have been made towards the Sgr A Complex (the CircumNuclear Disk, the +20 and +50 km s–1molecular clouds) in the Galactic Centre and we report here on the results of searches for H2O2, H218O and other molecules in these regions.

Tonnesen P, Tonstad S, Hjalmarson A, Lebargy F, van Spiegel PI, Hider A, Sweet R, Townsend J (Gentofte University Hospital, Gentofte, Denmark; Clinic for Preventive Medicine, Ulleval University Hospital, Oslo, Norway; Smoking Cessation Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden; Hospital Maison Blanche, Reims Cedex, France; Slotervaart Hospital, Amsterdam, The Netherlands; and GlaxoSmithKline Research and Development, Greenford, Middlesex, UK). A multicentre, randomized, double-blind, placebo-controlled, 1-year study of bupropion SR for smoking cessation. J Intern Med 2003; 254: 184–192. Background. Bupropion sustained release (bupropion SR) has been shown to increase smoking cessation success rates in the US studies. Objective. To determine whether bupropion SR, in combination with counselling, is effective for smoking cessation in a multi-country study. Methods. This randomized, double-blind, placebo-controlled trial enrolled 707 smokers. A total of 527 received bupropion SR 300 mg daily for 7 weeks and 180 received placebo. A total of 11 clinic visits and 10 telephone contacts were scheduled, during the course of 1 year. Seven-week and 12-month abstinence rates were the study outcomes. Results. Both continuous and weekly point prevalence smoking abstinence rates were significantly higher in the bupropion SR group compared with placebo. The continuous abstinence rate from weeks 4 to 7 was 46% in the bupropion SR group compared with 23% in the placebo group [odds ratio (OR) = 2.82; 95% confidence interval (CI) 1.89–4.28; P

Monoclonal antibodies were raised against a peptide corresponding to the second extracellular loop of the M2 acetylcholine receptor. One of the monoclonal antibodies, B8E5, was selected for further characterization on the basis of its high yield, its isotype (IgG2a), its dissociation kinetics and its agonist-like activity. The epitope recognized by B8E5 corresponded to the N-terminal part of the second extracellular loop of the receptor (V-R-T-V-E-) as determined by competition immunoassays and epitope scanning. The KA of B8E5 for the target peptide was assessed by surface plasmon resonance (SPR) to be 6.5x10(7) M(-1) by equilibrium and 3.7x10(7) M(-1) by kinetic analysis. B8E5 recognized the M2 acetylcholine receptor on rat cardiac tissue. It only recognized the non-reduced receptor in immunoblots. The antibody had no effect on antagonist binding but decreased the affinity for the agonist carbachol. B8E5 decreased the beating frequency of neonatal rat cardiomyocytes. The effect was specific since it was blocked by the target peptide and the antagonist atropine. The EC50 of the antibody corresponded to the KA measured by surface plasmon resonance. The physiological effect of the antibody did not lead to desensitization. The Fab fragments had no physiological effect; subsequent addition of anti-mouse IgG however restored the physiological effect. These results confirm that the N-terminus of the second extracellular loop is a functional target for antibodies against the M2 acetylcholine receptor. They suggest that the functional epitope is only accessible in the non-reduced receptor. The antibodies act through a functional dimerization of the receptor.

Moment analysis (MA) of multibreath nitrogen washout (MBNW) has not previously been applied to newborn infants. The aim of the present study was to adapt this method to healthy preterm infants using an improved technique suitable for small infants, and to determine reference values of MA. Twenty healthy preterm infants with a mean birth weight (+/-SD) of 1,666+/-402 g and a mean gestational age of 31.3+/-2.1 weeks were studied during their first 7-28 days of life. Computerized bedside equipment with very low dead space was constructed. The limits of normal variability were determined from results of duplicate studies. Outcome variables included functional residual capacity (FRC), the first-to-zeroth moment ratio (M1/M0), the second-to-zeroth moment ratio (M2/M0), and the lung clearance index (LCI). The starting point for MA had considerable impact on the results. Mean M1/M0 and M2/M0 were 2.18+/-0.18 and 8.71+/-1.24, respectively. No significant relation between moment ratios and weight, gender or age was found. Intrasubject coefficients of variation (CV) for M1/M0 (7.9+/-5.9%) and for M2/M0 (12.1+/-9.1%) and intersubject CV for M1/M0 (8%) and M2/M0 (14%) were similar to those reported in children and adults. Mean lung clearance index was 10.8+/-1.4 and intra- and intersubject CVs were 11.3+/-8.9% and 13%, respectively. Mean functional residual capacity (FRC) was 22.5+/-2.1 ml/kg. Mean intra- and intersubject CVs for FRC were 8.3% and 9%, respectively. We conclude that the MBNW test can be performed by a simple bedside method and that MA appears to be a suitable method for measuring gas mixing in preterm infants.

The inhibitory guanine nucleotide binding regulatory protein (Gi)-mediated muscarinic receptor-adenylyl cyclase system was studied in myocardium from adult male Wistar rats with 10 weeks of diabetes induced by a single intravenous injection of streptozotocin (60 mg/kg). Neither the messenger ribonucleic acid level nor the amount of Gi was changed in the streptozotocin diabetic group as compared to the control group. The activity of the adenylyl cyclase stimulated by guanyliminodiphosphate was decreased by 48% in the streptozotocin diabetic group whereas stimulated activities of adenylyl cyclase by sodium fluoride and forskolin remained unchanged. The inhibition of forskolin-stimulated adenylyl cyclase activity by carbachol was more potent in membranes from the streptozotocin diabetic group than that in membranes from the control group. The competition binding curve between (3H)- quinuclidinyl benzilate and carbachol obtained from the streptozotocin diabetic group was shifted to the left as compared to the control group. These results suggest that the myocardium of streptozotocin-induced diabetic rats exhibited an increase in Gi function as demonstrated by the increased inhibition of guanyliminodiphosphate-mediated adenylyl cyclase and the superhigh affinity for carbachol of the muscarinic receptors. As there were signs, similar to those seen in clinical heart failure, in the streptozotocin diabetic group, these results demonstrate that functional alteration of Gi might underlie, at least in part, the cardiac dysfunction that is associated with diabetes.

The Gi-mediated muscarinic receptor-adenylyl cyclase system was examined in stunned myocardium induced by either three or five brief ischaemic periods after beta-adrenoceptor blockade by timolol (0.1 mg kg-1). The mid-left anterior descending coronary artery was occluded for 2, 10 and 2 min in four pigs, and for 2, 2, 5, 10 and 2 min in four other pigs. All the ischaemic periods were separated by 30 min of reperfusion and the biopsies were obtained 60 min after the last ischaemic period. Segment length function was measured in the ischaemic region and in the control region supplied by the left circumflex artery. In the two groups, the percentage systolic shortening was reduced equally, to 59 +/- 9 and 58 +/- 10% of control in the region subjected to ischaemia and only minimally in the control region. The biopsies from the stunned region from both groups showed: (1) no change in either the affinity for carbachol or the number of binding sites of the muscarinic receptors; (2) no alterations in messenger RNA encoding for the alpha subunit-2 of the inhibitory guanine nucleotide binding protein, as demonstrated by northern blot and solution hybridization; (3) no change in membrane-bound inhibitory guanine nucleotide binding protein, as shown by enzyme immunoassay utilizing a specific anti-peptide antibody, and (4) unchanged inhibition of stimulated adenylyl cyclase activity. These results suggest that there is an intact inhibitory guanine nucleotide binding protein-mediated muscarinic receptor adenylyl cyclase system in the stunned porcine myocardium.

To describe the characteristics and the severity of symptoms amongst patients on the waiting list for possible coronary revascularization.All the patients were sent a postal questionnaire for symptom evaluation.All hospitals in western Sweden.All patients in western Sweden on the waiting list in September 1990, who had been referred for coronary angiography or revascularization (n = 904) and a sex- and age-matched reference group (n = 809).More than half of the patients had daily attacks of chest pain, whereas 16% reported less than one attack per week or no pain at all. However, other symptoms such as dyspnoea, tachycardia and nervous reactions were also common and 25% of all patients used sedatives. A long waiting time for a given procedure was not associated with more pain but with more nervous symptoms such as restlessness and insomnia (P0.0001) and greater use of sedatives and cigarettes (P0.05).We conclude that a long waiting time for possible coronary revascularization is associated with more nervous symptoms but not with more pain.

The only class of drugs with significant effects on ventricular fibrillation and sudden death in humans is that of beta-blockers. The exact mechanisms for these prophylactic effects are not known but may be related to both antiischemic or antiarrhythmic influences. It seems reasonable to suggest that one should use a beta-blocker with proven effect on total mortality and sudden cardiac death after myocardial infarction as prophylaxis. Therefore, propranolol, timolol, or metoprolol, should be instituted in order to improve prognosis when there are no contraindications. In addition to possible effects on survival one would also expect to reduce the risk for new ischemic events with angina or reinfarction. In contrast, class I antiarrhythmic agents are useful for symptomatic ventricular arrhythmias but there is no proof for any effect on ventricular fibrillation and sudden cardiac death.

Previous descriptions of the prognosis after acute myocardial infarction (AMI) have mainly included patients admitted to coronary care units, often with an upper age limit. This study describes the prognosis, with emphasis on morbidity, during 1 year in 921 patients admitted to one single hospital with AMI regardless of age and regardless of whether or not they were admitted to the coronary care unit. During the first year, 29% of the patients died and 16% developed a reinfarction. Fifty-four percent required rehospitalization for various reasons, mainly for AMI, chest pain of other origins, and congestive heart failure. After 1 year, 52% of the surviving patients had symptoms of angina pectoris. Among patients younger than 65 years, only 37% were back to work full time after 1 year. Of patients alive after 1 year, 25% fulfilled the following criteria: no reinfarction, no rehospitalization, and no angina pectoris. Of patients aged less than 65 years at follow-up, 12% fulfilled the same criteria and were back to work full time after 1 year. In this unselected, consecutive series of patients with AMI, mortality and morbidity were high during the first year. Only a small percentage of patients were free of events or symptoms of angina pectoris.

In all 4,232 patients admitted to a single hospital during a 21-month period due to initially suspected acute myocardial infarction (AMI), the prognosis and risk factor pattern were related to whether patients had chest pain or not. Symptoms other than chest pain that raised a suspicion of AMI were mainly acute heart failure, arrhythmia, and loss of consciousness. In 377 patients (9%) symptoms other than chest pain raised an initial suspicion of AMI. These patients developed a confirmed infarction during the first three days in hospital with a similar frequency (22%) as compared with patients having chest pain (22%). However, patients with "other symptoms" had a one-year mortality of 28% versus 15% for chest pain patients (p less than 0.001). Patients with "other symptoms" more often died in association with ventricular fibrillation and less often in association with cardiogenic shock as compared with chest pain patients. Among the 921 patients who developed early AMI, 64 (7%) had symptoms other than chest pain. They had a one-year mortality of 48% versus 27% for chest pain patients (p less than 0.001). We conclude that in a nonselected group of patients hospitalized due to suspected AMI, those with symptoms other than chest pain have a one-year mortality, which is nearly twice that of patients with chest pain.

All 7157 patients (55% men) admitted to the emergency room with chest pain or other symptoms indicative of acute myocardial infarction during a period of 21 months were registered consecutively. Chest pain was reported by 93% of the patients. On the basis of history, clinical examination, and electrocardiogram in the emergency room, all patients were prospectively classified in one of four categories: (i) obvious infarction (4% of all patients); (ii) strongly suspected infarction (20%); (iii) vague suspicion of infarction (35%); and (iv) no suspected infarction (41%). In patients with no suspected infarction (n = 2910), musculoskeletal (26%), obscure (21%) and psychogenic origins (16%) of the symptoms occurred most frequently. We conclude that few of the patients had an obvious infarction on admission, and that a musculoskeletal origin of the symptoms occurred most frequently in patients with no suspected infarction.

Four classes of drugs—beta blockers, thrombolytic agents, acetyl salicylic acid, and anticoagulants—have demonstrated cardioprotective properties, preventing or limiting infarct development and reducing mortality. Beta blockers, studied in over 50 controlled randomized trials, reduced mortality and the incidence of reinfarction by 25% in more than 20,000 patients in whom therapy was initiated relatively late. In 27,000 patients who received intravenous beta-blocker therapy shortly after their arrival in the hospital, mortality was reduced an average of 13% within 1 week. Whether intervention was early or late, the beneficial effects of beta blockers were more marked in patients at higher risk, reducing mortality by as much as 30% in 2 weeks in patients with previous cardiovascular disease, diabetes, or complications at admission to the hospital. In more than 50 trials, mainly of streptokinase, in 50,000 patients with myocardial infarction, it has been demonstrated that early institution of thrombolytic therapy reduces mortality by about 25%. In 10 long-term studies in 18,500 patients, acetylsalicylic acid reduced the risk of reinfarction by 31% and mortality by 11%; very early administration of this agent had an even more marked effect on mortality, reducing it approximately 20%. A study comparing long-term treatment with warfarin to placebo found that it reduced postinfarct mortality by 24% and reinfarctions by 34%. Although bleeding complications are reported after therapy with thrombolytic agents, acetylsalicylic acid, and warfarin, the risk is low in selected patients. On the basis of these findings, beta blockers, thrombolytic agents, acetylsalicylic acid, and anticoagulants can be recommended for all patients without obvious contraindications.

Summary. For medical reasons, encouraging women to stop smoking during pregnancy and post partum has high priority. Many smokers want to stop smoking but decline clinical treatment when it is offered. The aim of this study was to find a method which was accepted by a large number of smokers, had a high success rate and, at the same time, required little involvement from personnel. For one year, all pregnant smokers attending 13 of the 14 public health maternity clinics in Gothenburg for their first appointment were invited to participate in this study. Inclusion criteria were daily smoking, a gestational age of less than 12 weeks and ability to understand Swedish. A total of 745 women was registered, but 22 of them stopped smoking before the treatment. The remaining women were randomized to a treatment group (n = 492) and a control group (n = 231). Of the 492 women in the treatment group 417 (85%) accepted the idea of using the self-help manual written especially for pregnant women and given to each woman in the treatment group by the obstetrician. Overall 10.4% of the treatment group stopped smoking up to 8 weeks after delivery compared with 5.2% of the control group (odds ratio 0.5, 95% CI 0.2–0.9). The ex-smoking status was verified by measurement of thiocyanate in blood. The self-help manual had a high acceptance rate and a success rate that was double the rate in the control group.

We have studied the effects on lung volume, respiratory mechanics and ventilation during the first hours after instillation of 60 mg/kg of human surfactant into the trachea of 4 very preterm, newborn infants with severe IRDS under mechanical ventilation. Measurements were made with a “face-out” body plethysmograph and a modified nitrogen wash-out method. In addition to a transient decrease in total and alveolar ventilation immediately after the instillation we found an immediate rise in lung volume, but respiratory compliance decreased. These changes lasted less than two hours. Oxygen requirements fell in 3 out of 4 infants. The changes in lung volume and compliance are explained in terms of changes in the shape of the static recoil pressure characteristics of the diseased lungs after treatment. Mechanisms behind the short duration are sought in mode of instillation, dosage, age at treatment, and severity of disease.

From a randomized multicenter trial with metoprolol in suspected acute myocardial infarction (n = 5778) we report on the outcome during a one-year follow-up in patients with confirmed infarction (n = 4106) in relation to whether or not they developed Q waves. Patients with Q waves had another pattern of risk factors, including lower age and a lower occurrence of previous infarction, angina pectoris, and congestive heart failure. After one year follow-up, 14.3% of the patients with Q waves had died versus 9.0% of those without Q waves (p less than 0.001). Reinfarction during the first year occurred in 8.2% of patients with Q waves and 12.5% of patients without Q waves (p less than 0.001). After one year, other morbidity aspects appeared relatively independent of the original presence of Q waves. In conclusion, during the first year after development of acute myocardial infarction the appearance of Q waves during the first three days is associated with a higher mortality and a lower reinfarction rate, whereas other morbidity aspects appear to be relatively independent of its presence.