Complete structure of eclosion hormone of Manduca sexta

The locations of the three disulfide bonds of eclosion hormone (EH) isolated from Manduca sexta were assigned by sequence analysis of thermolysin fragments and by comparison of a key heterodimeric fragment to regiospecifically synthesized parallel and antiparallel isomers. We elucidated the complete structure of Manduca EH as a 62-residue peptide which has three disulfide bonds between Cys¹⁴-Cys³⁸, Cys¹⁸-Cys³⁴, and Cys²¹-Cys⁴⁹.     

Prevention of non-communicable diseases: Risk factors in youth: The North Karelia Youth Project (1984-88)

The North Karelia Youth Project is based on the results of previouspilot studies in North Karelia and forms part of the North Kareliaintegrated programme for non-communicable diseases prevention,co-ordinated by the WHO and conducted by the Finnish NationalPublic Health Institute. The project is designed to test thefeasibility and effects of a largescale health programme among12–16 year old schoolchildren. The educational programmeaims to prevent cigarette smoking and alcohol use mainly bytraining pupils to resist social pressures and by modifyingperceived social norms which may lead to smoking and alcoholuse. The dietary intervention aims to improve dietary habitsto decrease serum cholesterol and blood pressure level. Theprogramme also aims to promote positive decision-making andcoping skills and to increase social support for coping withstress. The study, which began in the autumn of 1984 provides a comprehensivethree-year programme for all seventh graders (ages 12–13)and succeeding age cohorts in North Karelia (24 schools) andin selected schools in the county of Kuopio (eight schools),including approximately 4 000 students in the first year and12 000 over the entire study period. Simultaneously successivemeasurements are implemented in all the intervention schoolsand in eight randomized reference schools, which will allowus to evaluate the programme and to test a number of hypothesesabout programme effects. The preventive programme is designedto make the best possible use of existing resources (teachers,parents, community) and will require only relatively modestnew expenditure so that, if proved effective, it can be continuedon a permanent basis. A baseline survey of the schools was carried out in the springof 1984 among ninth-graders. Twenty-four per cent of the boysand 18% of the girls reported smoking daily and 13% and 9% respectivelywere occasional smokers. About 20% had used alcohol during thepast week, 7% reported "passing out" because of drinking duringthe last year and 12% had been deeply drunk. The mean serumcholestrol level was 4.7 mmol/l and the mean blood pressure130/66 mmHg. At this baseline survey, the levels of these variableswere generally comparable in the different randomly assignedstudy groups, although there was a trend towards less smokingand alcohol use at baseline in the schools in North Kareliathan in those in the county of Kuopio.     

USING MULTIPLE DECREMENT MODELS TO ESTIMATE RISK AND MORBIDITY FROM SPECIFIC AIDS ILLNESSES

A simple non-parametric approach is developed to simultaneously estimate net incidence and morbidity time from specific AIDS illnesses in populations at high risk for death from these illnesses and other causes. The disease–death process has four-stages that can be recast as two sandwiching three-state multiple decrement processes. Non-parametric estimation of net incidence and morbidity time with error bounds are achieved from these sandwiching models through modification of methods from Aalen and Greenwood, and bootstrapping. An application to immunosuppressed HIV-1 infected homosexual men reveals that cytomegalovirus disease, Kaposi's sarcoma and Pneumocystis pneumonia are likely to occur and cause significant morbidity time.     

Claude Bernard (1813–1878)

The life and works of Claude Bernard (1813-1878) have been discussed with special reference to the importance of his researches in relation to modern anaesthesia and in commemoration of the centenary of his death.     

Left Ventricular Outflow Tract Obstruction Following Mitral Valve Replacement with Carpentier-Edwards Prosthesis

Left ventricular outflow tract (LVOT) obstruction is a rare complication of mitral valve replacement. In this article, we describe three patients in whom left ventricular outflow tract obstruction occurred following Carpentier-Edwards porcine mitral valve replacement. All three patients presented with symptomatic mitral regurgitation (angiographic grade 3–4) requiring mitral valve replacement. Preoperatively there was no evidence of hypertrophic obstructive cardiomyopathy by physical exam, echocardiography, or by cardiac catheterization. At the time of surgery all three were shown to have severe mitral valve prolapse. The native anterior mitral leaflet was left intact and pledgeted to the mitral annulus. Following surgery a new systolic murmur was appreciated. Echocardiographic exam visualized obstruction of the left ventricular outflow tract by the prosthetic strut in two cases and by a flail anterior leaflet in one case. Continuous-wave Doppler measured a calculated peak gradient of 72 to 81 mmHg across the left ventricular outflow tract. In one case simultaneous Doppler and cardiac catheterization confirmed the diagnosis and severity of left ventricular outflow tract obstruction. Mechanisms of left ventricular outflow tract obstruction following Carpentier-Edwards porcine mitral valve replacement are discussed. These three cases highlight the importance of echo-Doppler techniques in understanding the mechanism of newly detected systolic murmurs following mitral valve replacement.     

Identifying the High Risk Patient with Coronary Artery Disease—Is Ejection Fraction All You Need?

Although the total number of deaths resulting from cardiovascular disease has decreased in the United States, the percentage of cardiac deaths that occur suddenly has increased. Over the past 10 years, a number of randomized clinical trials have evaluated the ability of antiarrhythmic therapy to reduce mortality in patients in patients with chronic coronary disease and abnormal left ventricular function that had not yet developed spontaneous sustained VT or VF. A majority of these trials have demonstrated that the implantable cardioverter-defibrillator (ICD) can reduce mortality compared to pharmacologic antiarrhythmic therapy, or no specific antiarrhythmic therapy. While, reduced left ventricular ejection fraction (EF) has been a major determinant for entry into these studies, in all but one case, it was not the sole entry requirement. These studies have demonstrated that a number of factors have prognostic significance, and therefore impact efficacy of the ICD. None of these studies was designed to evaluate the relative efficacy of various risk factors. Therefore, we lack adequate information today to determine the most cost-effective manner in which to assign use of ICDs for primary prevention. This article reviews the potential for using EF alone as a risk factor, as well as the efficacy of other variables for risk stratification.     

CORNEAL GRAFT SURVIVAL: A RETROSPECTIVE AUSTRALIAN STUDY

Four hundred and forty-eight consecutive corneal grafts are analysed and their survival calculated usin the actuarial life-table method. Overall survival at two years is 81 ± 4% and at five years is 65 ± 5%. Within diagnostic subgroups keratoconus has the best prognosis. Previous graft failure and recipient corneal vascularization are shown to have a negative effect on graft survival. Sex of patient, urgency of operation and use of combined procedures do not affect survival and second regrafts fare no worse than first regraits. The use of the actuarial life-table method of analysing graft survival is discussed and its importance emphasized.     

External Non-invasive Cardiac Pacing: A Comparative Hemodynamic Study of Two Techniques with Conventional Endocardial Pacing

Out-of-hospital therapy for cardiac arrest due to bradyarrhythmias or asystole is pharmacologic and the outcome is uniformly dismal. Optimal therapy for the latter disturbances may be artificial cardiac pacing, but conventional invasive pacing techniques are not employed or are of limited value in the out-of-hospital and emergency department setting. This investigation compared the hemodynamic effects of two techniques of non-invasive external pacing: 1) transcutaneous transthoracic pacing (TTP) and 2) tongue-to-epigastrium pacing (TEP), with conventional transvenous right ventricular endocardial pacing (RVEP) in a closed-chest, chronic heart block canine model. All techniques significantly increased (p less than .001) cardiac output (CO). However, CO and mean arterial pressure (MAP) measured during external pacing with either non-invasive technique were significantly greater than that during RVEP (p less than .001). TEP produced vigorous skeletal muscle stimulation and, in the canine model, it produced contraction resulting in impaired ventilation, hypoxemia, and a decrease in systemic vascular resistance. TTP in this model resulted in improved MAP and CO when compared with control and RVEP values and did not affect arterial or mixed venous blood gas values. Thus, this study demonstrates that noninvasive TTP is comparable to RVEP in its hemodynamic effects. TTP may offer definitive non-invasive therapy for a subset of victims of out-of-hospital cardiac arrest.