Effectiveness of adjunctive stent implantation following directional coronary atherectomy for treatment of left anterior descending ostial stenosis

The aim of this study was to evaluate the acute and long-term angiographic and clinical results of optimal plaque debulking by means of directional coronary atherectomy (DCA) followed by stent implantation for treatment of left anterior descending (LAD) ostial stenosis. Eighty consecutive patients (66 men; aged 57 +/- 10 years) with angina pectoris, documented anterior myocardial ischemia, and de novo LAD ostial stenosis prospectively underwent DCA and stent deployment. They were evaluated angiographically after 6 months and clinically for up to 30 +/- 29 months. The primary success rate was 98%. The in-hospital complications were 1 death due to in-stent subacute thrombosis 7 days after the procedure, 1 non-Q-wave myocardial infarction, and 1 retrograde left main artery dissection. The angiographic binary restenosis rate was 14.5%, and the loss index was 0.38 +/- 0.35. The target lesion revascularization (TLR) rates at 6, 12, and 24 months were 6.0%, 14.5%, and 16.3%, respectively, and the combined event rates (death, nonfatal myocardial infarction, TLR) at the same times were 8.7%, 17.5%, and 21.2%, respectively. These results indicate that the combined approach of DCA and stent implantation is feasible and safe in patients with LAD ostial lesions, has a high success rate, a low incidence of restenosis, and a good long-term outcome.

Trends in coronary risk factors in the WHO MONICA project

BACKGROUND

The World Health Organization (WHO) MONICA Project was established to determine how trends in event rates for coronary heart disease (CHD) and, optionally, stroke were related to trends in classic coronary risk factors. Risk factors were therefore monitored over ten years across 38 populations from 21 countries in four continents (overall period covered: 1979-1996).

METHODS

A standard protocol was applied across participating centres, in at least two, and usually three, independent surveys conducted on random samples of the study populations, well separated within the 10-year study period.

RESULTS

Smoking rates decreased in most male populations (35-64 years) but in females the majority showed increases. Systolic blood pressure showed decreasing trends in the majority of centres in both sexes. Mean levels of cholesterol generally showed downward trends, which, although the changes were small, had large effects on risk. There was a trend of increasing body mass index (BMI) with half the female populations and two-thirds of the male populations showing a significant increase.

CONCLUSIONS

It is feasible to monitor the classic CHD risk factors in diverse populations through repeated surveys over a decade. In general, the risk factor trends are downwards in most populations but in particular, an increase in smoking in women in many populations and increasing BMI, especially in men, are worrying findings with significant public health implications.

Thrombogenic potential of human coronary atherosclerotic plaques

Higher levels of tissue factor (the initiator of blood coagulation) have been found in coronary atherosclerotic plaques of patients with unstable coronary artery disease, but it is not established whether they are associated with a different thrombotic response to in vivo plaque rupture. In 40 patients undergoing directional coronary atherectomy, prothrombin fragment 1 + 2, a marker of thrombin generation, was measured in intracoronary blood samples obtained proximally and distally to the coronary atherosclerotic plaque before and after the procedure. Before the procedure, plasma prothrombin fragment 1 + 2 levels were significantly increased across the lesion in patients with unstable, but not in those with stable, coronary disease (unstable, median increase, 0.37 nM; range, -0.35-1.16 nM) (stable, median increase, -0.065 nM; range, -0.58-1.06 nM) (P =.0021). After plaque removal, an increase in prothrombin fragment 1 + 2 across the lesion was observed only in patients with unstable coronary disease (unstable, median increase, 0.25 nM; range, -1.04-4.9 nM) (stable, 0.01 nM; range, -0.48-3.59 nM) (P =.036)]. There was a correlation between the tissue factor content of the plaque and the increase in thrombin generation across the lesion (rho = 0.33; P =.038). The higher tissue factor content found in plaques obtained from patients with unstable coronary disease was associated with a local increase in thrombin generation, thus suggesting a link with the in vivo thrombogenicity of the plaque.

Non-Hamiltonian equations of motion with a conserved energy

In 1980 Andersen introduced the use of "extended system" as a means of exploring by molecular dynamics simulation the phase space of a physical model according to a desired ensemble distribution different from the standard microcanonical function. Following his original work on constant pressure-constant enthalpy a large number of different equations of motion, not directly derivable from a Hamiltonian, have been proposed in recent years, the most notable of which is the so-called Nosé-Hoover formulation for "canonical" molecular dynamics simulation. Using a generalization of the symplectic form of the Hamilton equations of motion we show here that there is a unique general structure that underlies most, if not all the equations of motion for "extended systems." We establish a unifying formalism that allows one to identify and separately control the conserved quantity, usually known as the "total energy" of the system, and the phase-space compressibility. Moreover, we define a standard procedure to construct conservative non-Hamiltonian flows that sample the phase space according to a chosen distribution function [Tuckerman et al., Europhys. Lett. 45, 149 (1999)]. To illustrate the formalism we derive new equations of motion for two example cases. First we modify the equations of motion of the Nosé-Hoover thermostat applied to a one-dimensional harmonic oscillator, and we show how to overcome the ergodicity problem and obtain a canonical sampling of phase space without making recourse to additional degrees of freedom. Finally we recast an idea recently put forward by Marchi and Ballone [J. Chem. Phys. 110, 3697 (1999)] and derive a dynamical scheme for sampling phase space with arbitrary statistical biases, showing as an explicit application a demixing transition in a simple Lennard-Jones binary mixture.

Socio-occupational differences in acute myocardial infarction case-fatality and coronary care in a northern Italian population

AIMS

To appraise 28-day case-fatality of myocardial infarction (MI) among socio-occupational classes; to assess the consistency of the results for different degrees of MI severity; to explore if such differences are related to differences in management and treatment of the acute attack.

METHODS

All coronary events (n = 1077), registered in 1993-1994 among the 35-64 year old male residents in MONICA Area Brianza were investigated and classified into diagnostic categories according to MONICA criteria. For all cases standardized information on acute coronary care and interventions before and during hospitalization was collected. Classification of social classes was derived from the Erikson-Goldthorpe-Portocarero social class scheme, based on information on occupational characteristics widely available in European countries.

RESULTS

An increasing rate of case-fatality for decreasing levels of socio-occupational class was found. The social gradient resulted mainly from the higher incidence of out-of-hospital cardiac arrests. Treatment before and during the acute attack cannot explain the observed differences.

CONCLUSION

Combining these results with those obtained in other MONICA centres, it appears that further decreases in coronary mortality might be achieved through specific programmes addressed in particular to the reduction of out-of-hospital case-fatality in lower social classes.

Failed primary management of iatrogenic biliary injury: incidence and significance of concomitant hepatic arterial disruption

BACKGROUND

Vasculobiliary injury (VBI) is a well-recognized complication of laparoscopic cholecystectomy (LC). In patients with failed primary management of bile duct injury (BDI), an assessment of the hepatic arterial system may be important to determine the presence of VBI. This study was conducted to determine the incidence of VBI in patients with failed primary management of LC-related BDI and to establish a potential correlation between the level of BDI and the incidence of VBI.

METHODS

A retrospective review was conducted on 18 patients referred for failed primary management of LC-related BDI who underwent prospective arteriography as part of the preoperative work-up.

RESULTS

Of the 18 patients who sustained BDI, Bismuth level 4 lesions were found in 7 patients (39%), level 3 in 8 patients (44%), and level 2 in 3 patients (17%). VBI was identified on arteriography in 11 patients (61%). VBI was present in 71% of patients with level 4 lesions, 63% of patients with level 3 lesions, and 33% of patients with level 2 lesions. The time interval from primary management to its failure was longer in VBI than in BDI alone.

CONCLUSIONS

We have observed a high incidence of VBI in patients with failed primary management of LC-related BDI. Arterial disruption may affect the outcome of primary management of BDI.

Trends in coronary risk factors in the WHO MONICA project

BACKGROUND

The World Health Organization (WHO) MONICA Project was established to determine how trends in event rates for coronary heart disease (CHD) and, optionally, stroke were related to trends in classic coronary risk factors. Risk factors were therefore monitored over ten years across 38 populations from 21 countries in four continents (overall period covered: 1979-1996).

METHODS

A standard protocol was applied across participating centres, in at least two, and usually three, independent surveys conducted on random samples of the study populations, well separated within the 10-year study period.

RESULTS

Smoking rates decreased in most male populations (35-64 years) but in females the majority showed increases. Systolic blood pressure showed decreasing trends in the majority of centres in both sexes. Mean levels of cholesterol generally showed downward trends, which, although the changes were small, had large effects on risk. There was a trend of increasing body mass index (BMI) with half the female populations and two-thirds of the male populations showing a significant increase.

CONCLUSIONS

It is feasible to monitor the classic CHD risk factors in diverse populations through repeated surveys over a decade. In general, the risk factor trends are downwards in most populations but in particular, an increase in smoking in women in many populations and increasing BMI, especially in men, are worrying findings with significant public health implications.

Living donor liver transplantation for children with liver failure and concurrent multiple organ system failure

Liver transplantation for pediatric patients in liver failure and multiple organ system failure (MOSF) often results in poor patient survival. Progression of organ failure occurs while awaiting a cadaveric allograft. Therefore, we considered living donor liver transplantation (LDLT) in this critically ill group of children and report our initial results with comparison to a similar group who received cadaveric donation (CAD). A retrospective chart review was performed on all pediatric liver transplant recipients who met criteria for MOSF at the time of transplantation. Data collection involved pretransplantation patient profiles, as well as postoperative complications and patient survival. Eight patients in MOSF received living donor transplants and 11 patients received a cadaveric allograft. Mean wait time was 3.5 days in the LDLT group and 6.5 days in the CAD group. Pretransplantation patient profiles and postoperative complications were similar between groups. Mean cold ischemia times were 3.8 hours in the LDLT group and 7.9 hours in the CAD group (P = .0002). Thirty-day and 6-month survival rates of the LDLT group were 88% and 63% compared with 45% and 27% in the CAD group, respectively. Living donor transplant recipients in MOSF had decreased wait times to transplantation, as well as decreased cold ischemia times, compared with cadaveric transplant recipients. Patients in the LDLT group had markedly improved survival compared with the CAD group. Timely transplantation before worsening organ failure may account for these findings.

Surveillance of ischaemic heart disease: results from the Italian MONICA populations

BACKGROUND

The major objectives are to report on coronary event mortality, incidence and attack rates and changes over time observed in the Italian MONICA populations and to assess if trends are consistent when different disease definitions are considered. An analysis of diagnostic agreement between clinical and MONICA categories is presented in the context of developing a model for estimating disease incidence in a population, based on currently available data.

METHODS

Data were provided by the three Italian MONICA (MONItoring trends and determinants of CArdiovascular diseases) registers. The areas of Brianza and Friuli, both located in northern Italy, completed the 10-year period of registration. Data from the MONICA Latina area, located close to Rome, were limited to the first 3 years of registration. These data are used for assessing geographical differences in rates in the mid- 1980s and estimating the diagnostic agreement between International Classification of Diseases (ICD) codes and MONICA categories. Two diagnostic aggregates have been used: the standard MONICA diagnostic definition for myocardial infarction (MI), which includes non-fatal definite myocardial infarction and fatal coronary events, and the coronary event definition which includes, in addition, non-fatal possible myocardial infarctions.

RESULTS

From the mid-1980s to the mid-1990s, a considerable reduction in all-cause, cardiovascular and coronary mortality rates occurred in the monitored populations. Data from the MONICA registers confirm the accuracy of official reports of death rates and changes in Italy. Comparisons of time differences in attack and incidence rates of myocardial infarction and all coronary events indicate that the impact of the more severe manifestations of coronary heart diseases (fatal coronary event and acute MI) reduced during the period of observation, but when less severe events (minor myocardial infarction and angina pectoris) are considered, the overall impact of the disease on the population remained stable.

CONCLUSION

Epidemiological surveillance of coronary syndromes is relevant over this time period of impressive changes in prevention and treatment. Continuing restrictions in available resources necessitate the development of simplified registration systems.

[Identification of individuals with high coronary risk in the Italian population: indications of the Epidemiologic Cardiovascular Observatory]

BACKGROUND

The absolute global coronary risk has recently been introduced as an indicator of the incidence predicted by the main risk factors. It offers numerous options for the treatment of individuals at high risk. The identification of the absolute global coronary risk is produced through the application of functions obtained by longitudinal studies; their adequacy depends on the characteristics of the population from which they were estimated. The aim of this work was to evaluate the impact of the application of the absolute global coronary risk evaluation using the chart of risk proposed to the Italian physicians and to compare it with the results obtained from the application of other risk functions.

METHODS

The database of the Osservatorio Epidemiologico Cardiovascolare (OEC), consisting of men and women aged 35-74 years, has been considered as being representative of the Italian population. The individual risk has been computed using the functions and coefficients from the Framingham study, the PROCAM study and the Seven Countries Study-Italy. The prevalence of high risk factors has been estimated on the basis of the recommendations on coronary prevention of the Task Force of the European Societies.

RESULTS

The prevalence of high risk factors estimated by the Framingham function is 23.7% among men and 3.8% among women aged 35-74 years. In men aged 35-64 years, this estimated prevalence decreases from 14.2 to 8.7% when the Framingham function is adjusted using the mean value of the risk factors of the OEC, to 5.2% when the PROCAM function is applied, and to 1.1% when the function of the Seven Countries Study-Italy is employed.

CONCLUSIONS

The application of the risk function suggested to the Italian physicians implies that more than 2,700,000 men and more than 500,000 women aged 35-74 years are potential candidates for treatment with lipid-lowering drugs. The comparison between the use of different functions in the OEC sample produces high numerical differences. The over-evaluation of the individual at high risk implies significant human and social costs. It is therefore essential to determine risk functions and coefficients derived from recent Italian studies including all age groups, both sexes and taking into account the different geographic characteristics of our country.

Pancreas transplantation at Northwestern University

The collective advances made by many groups have significantly improved the results of pancreas transplantation. We have focused on the development of safe and effective immunotherapy, including a new protocol of rapid withdrawal of corticosteroids, the analysis of surgical technique of pancreas exocrine drainage on outcome and the role of SPK transplantation in patients with significant cardiovascular disease. We have found that multimodal immunotherapy including induction with tacrolimus-based maintenance combined with either MMF or sirolimus, with or without corticosteroids, resulted in excellent patient and graft survival rates with low rates of rejection. In this setting, enteric drainage was preferable to bladder drainage because of a lower rate of complications leading to hospital readmissions. Careful pretransplant screening for cardiovascular disease should be routinely performed for all SPK candidates. If successful coronary revascularization can be achieved, these patients can safely undergo SPK transplantation, with 5-year outcomes similar to those for recipients without coronary disease. Finally, we have observed that pancreas transplantation has an important ameliorating effect on hypertension that is independent of the method of pancreas exocrine drainage.

Alternative splicing of mGlu6 gene generates a truncated glutamate receptor in rat retina

A novel splice variant of metabotropic glutamate receptor type 6 (mGlu6 receptor) was identified by reverse transcription-polymerase chain reaction amplification and sequence analysis of rat retina cDNA. The new rat receptor isoform (mGlu6b receptor) is characterized by an additional exon of 88 nucleotides containing an inframe stop codon, thus predicting the expression of a truncated protein of 508 amino acids. In situ hybridization reveals mGlu6b receptor mRNA to be predominantly expressed in the outer part of the inner nuclear layer of rat retina, containing ON-bipolar cells. The mGlu6b protein would comprise the extracellular domain of the receptor containing the ligand-binding site, but would lack the transmembrane and intracellular portions, thus possibly acting as a retinal soluble receptor for glutamate.

Dynamics-function correlation in Cu, Zn superoxide dismutase: a spectroscopic and molecular dynamics simulation study

A single mutation (Val29-->Gly) at the subunit interface of a Cu, Zn superoxide dismutase dimer leads to a twofold increase in the second order catalytic rate, when compared to the native enzyme, without causing any modification of the structure or the electric field distribution. To check the role of dynamic processes in this catalytic enhancement, the flexibility of the dimeric protein at the subunit interface region has been probed by the phosphorescence and fluorescence properties of the unique tryptophan residue. Multiple spectroscopic data indicate that Trp83 experiences a very similar, and relatively hydrophobic, environment in both wild-type and mutant protein, whereas its mobility is distinctly more restrained in the latter. Molecular dynamics simulation confirms this result, and provides, at the molecular level, details of the dynamic change felt by tryptophan. Moreover, the simulation shows that the loops surrounding the active site are more flexible in the mutant than in the native enzyme, making the copper more accessible to the incoming substrate, and being thus responsible for the catalytic rate enhancement. Evidence for increased, dynamic copper accessibility also comes from faster copper removal in the mutant by a metal chelator. These results indicate that differences in dynamic, rather than structural, features of the two enzymes are responsible for the observed functional change.

Time trends of major coronary risk factors in a northern Italian population (1986–1994). How remarkable are socioeconomic differences in an industrialized low CHD incidence country?

BACKGROUND

The goals are to estimate time trends (1986-1994) of major coronary risk factors in an industrialized low CHD incidence population and to assess education class (EC) differences in risk factor prevalence and in time trends.

METHODS

Three population surveys were conducted in 1986-1987, 1989-1990 and 1993- 1994 on independent and two-stage age- and gender-stratified random samples (1906 men and 1941 women) of 35-64 year old residents of Brianza, an affluent region of northern Italy. The protocol for data collection, clinical measurements and biochemical determinations adhered to the WHO MONICA manual and underwent repeated quality control assessments. EC were identified according to gender- and 5-year birth-cohort specific tertiles.

RESULTS

In the initial, middle and final surveys 1258, 1259 and 1330 subjects were enrolled, corresponding to participation rates of 70.1%, 70.3% and 74.3%, respectively. Over the 8-year period, in men systolic blood pressure and smoking habits declined, body mass index and serum total cholesterol increased. In women systolic blood pressure showed a constant reduction, total cholesterol and BMI increased and the prevalence of smokers remained stable. Overall inverse associations with EC were found for body mass index, for prevalence of cigarette smokers in men and for systolic blood pressure in women. Decreases in blood pressure were more evident in the lowest EC. Cigarette smoking was on the decline in the higher EC in men. BMI and total cholesterol increased in all EC with the notable exception of the 'low' EC in women.

CONCLUSIONS

Favourable changes of the risk factor profile in the low socio-economic classes may have contributed to reduce CHD rates in this population. Specific policies oriented to lowest socio-economic classes are needed to continue to combat the smoking epidemic.

Models to assess nitrogen losses in pediatric patients on chronic peritoneal dialysis

To develop models to estimate nitrogen (N) losses of children on chronic peritoneal dialysis (CPD) from easily measurable indexes and laboratory tests, we measured the N content and all nitrogenous compounds in dialysate (D), urine (U), and feces over 3 days in 19 pediatric patients on CPD. Total measured N losses (TNm) were 5.56+/-2.26 g/day (69.9+/-11.1% in dialysate, 16.3+/-10.6% in urine, and 13.6+/-4.6% in feces). Correlation coefficients between measured dialysate and urinary N losses and the single nitrogenous compounds indicated values of over 0.9 only for urea in dialysate and urine; fecal N losses correlated well with body surface area (BSA). Taking into account these correlations, we developed a univariate additive model and three multivariate models to predict total estimated N losses (TNe). The best prediction of TNm was obtained with model 3, which considered not only urea output in dialysate and urine but also dialysate protein loss and BSA: TNe (g/day)=0.03+/-1.138 UN urea+0.99 DN urea+1.18 BSA+0.965 DN protein. A confirmatory analysis performed on a second group of 23 pediatric patients on CPD, using all four models, showed a higher percentage of studies with a relative difference between TNm and TNe less than 10% for model 3 than for the other models. Thus, N losses of pediatric patients on CPD can be estimated from measured urea and protein losses in dialysate and urea loss in urine, together with BSA.

[Occupational aging and cardiovascular diseases]

A short review of occupational aging and cardiovascular disease is presented. Coronary and stroke events are typical diseases of aging, in which rare monogenic disorders and common polymorphisms interact with environmental factors. Among these factors, particular attention has been given to social and occupational organizations. Cardiovascular mortality apparently increases with heavy industrialization processes and lower socioeconomic and educational status. Similar data are now available for incidence and case fatality. Since traditional risk factors--e.g., cholesterol, blood pressure and smoking--follow the same pattern, but with a weaker association than expected, observational and preventive studies are considering risk possibilities beyond such factors. Job demand/job decision latitude is the most widely used paradigm to evaluate specific organizational risk at work. A few cohort or population studied and many cross-sectional studies have shown an independent and inverse relationship between decreasing control of the job, coronary disease and blood pressure levels. While such results need further confirmation, they suggest the need for more accurate research on the adverse or mutually protective influences of long-lasting adaptation processes required by prevailing work organization.

[The assessment of the coronary risk in a work setting. The results of the SEMM study and the outlook for prevention in Italy. Surveillance of Employees Municipality of Milan]

BACKGROUND

The goals of the present report are to assess the differences in distribution of traditional coronary risk factors in a work setting, aimed at identifying specific groups at risk and to compare mean values of such risk factors and of an overall risk score of the entire working sample with the results observed in the third WHO-MONICA population survey carried out in northern Italy (Area Brianza).

METHODS

In the SEMM study 7872 employees (2601 men and 5271 women) were enrolled between 1992 and 1996. The third MONICA survey in Brianza was carried out on an age- and gender-stratified random sample of 831 men and 884 women in 1993-1994, selected from the 25-64-year-old residents of five municipalities, representative of the study population. In both studies coronary risk factors were measured according to the MONICA protocol, adopting standardized methods.

RESULTS

In comparison with the MONICA population sample, the entire working group showed lower mean levels of blood pressure and total cholesterol, higher prevalence of current cigarette smokers and lower mean levels of HDL cholesterol, in both gender groups. Prevalence of overweight subjects was higher among men in the working group, but the opposite pattern was detected in women. The overall risk score, calculated using the coefficients of a proportional hazard survival equation estimated in a large collaborative Italian follow-up study, resulted lower in the working sample, in both gender groups. This result may be attributed to a selection bias known in occupational epidemiology as "healthy worker effect". In contrast to this finding, the prevalence of smokers, in particular among women, was higher in the employed sample, indicating that working stress conditions may play some role.

CONCLUSIONS

In order to extend the assessment of cardiovascular risk factors as well as prevention activities in work settings, some advantages are highlighted: the high participation rates, the feasibility to adopt standardized protocols, and easier and cheap procedures for censoring in follow-up studies. Moreover, due to the recently adopted legislation in Italy which increases the number of working categories to be included in periodic clinical examinations, prevention activities in work settings to contrast the epidemic of widespread chronic diseases, like cardiovascular diseases, are encouraged. This will also allow for the investigation of individual variations over time of coronary risk factors.

Estimation of contribution of changes in classic risk factors to trends in coronary-event rates across the WHO MONICA Project populations

BACKGROUND

From the mid-1980s to mid-1990s, the WHO MONICA Project monitored coronary events and classic risk factors for coronary heart disease (CHD) in 38 populations from 21 countries. We assessed the extent to which changes in these risk factors explain the variation in the trends in coronary-event rates across the populations.

METHODS

In men and women aged 35-64 years, non-fatal myocardial infarction and coronary deaths were registered continuously to assess trends in rates of coronary events. We carried out population surveys to estimate trends in risk factors. Trends in event rates were regressed on trends in risk score and in individual risk factors.

FINDINGS

Smoking rates decreased in most male populations but trends were mixed in women; mean blood pressures and cholesterol concentrations decreased, bodymass index increased, and overall risk scores and coronary-event rates decreased. The model of trends in 10-year coronary-event rates against risk scores and single risk factors showed a poor fit, but this was improved with a 4-year time lag for coronary events. The explanatory power of the analyses was limited by imprecision of the estimates and homogeneity of trends in the study populations.

INTERPRETATION

Changes in the classic risk factors seem to partly explain the variation in population trends in CHD. Residual variance is attributable to difficulties in measurement and analysis, including time lag, and to factors that were not included, such as medical interventions. The results support prevention policies based on the classic risk factors but suggest potential for prevention beyond these.

How to program rate responsive pacemakers

Because oxygen uptake (VO2) increases linearly with heart rate during exercise, the oxygen pulse reserve (OPR) method (VO2 reserve divided by heart rate reserve) may provide a valid guide for rate responsive parameter tailoring. Using custom-made software (Pacing Rate Profile Software [PRPS]) it is possible to predict the exercise pacing rate profile with significant accuracy, according to the patient's functional class when ergospirometry apparatus is not available for a cardiopulmonary stress test (CPX). PRPS for Windows is based on the OPR method and some known workload/metabolic cost of exercise relationships during effort. The present study had two aims; first, to evaluate the reliability of PRPS in accurately predicting pacing rate profiles; and second, the suitability of activity and metabolic rate responsive sensors in supplying pacing rates sufficiently near to those predicted using CPX or PRPS. To test the reliability of PRPS we studied 244 patients, NYHA Class I-II, under two different stress test protocols. In one, the bicycle protocol (25 W, 2-minute steps), we tested 137 normal patients (94 men and 43 women, mean age 67 +/- 15 years). Sixty-eight of these were simultaneously CPX tested. PRPS predicted pacing rates were matched against the patients' sinus rhythms or their theoretical CPX measured VO2 heart rates (OPR method). Linear regression analysis was highly significant (r = 0.93 and r = 0.97, respectively). The other, the treadmill protocol, consisted of three different protocols. (1) Speed Incremental Treadmill Stress Test (SITST): 57 patients underwent CPX (33 men and 24 women, mean age 67 +/- 15 years, NYHA Class I-II). All had been pacemaker implanted for SSS and/or advanced atrioventricular block (AVB). PRPS pacing rates were matched against CPX VO2 OPR calculated heart rates (r = 0.93), (linear regression analysis). (2) CAEP: 30 patients underwent CPX (26 men and 4 women, mean age 61 +/- 11 years, NYHA Class I-II). Thirteen of them had been pacemaker implanted for SSS and/or advanced AVB. In all 30 patients the PRPS rates were matched against CPX VO2 calculated rates (r = 0.90). In the 17 normal nonimplanted patients, the PRPS rates were also matched against sinus rhythms, (r = 0.80). (3) Weber: 20 patients underwent CPX (16 men and 4 women, mean age 68 +/- 8 years, NYHA Class I-II). As above, in six normal nonimplanted patients, statistical analysis between PRPS rates and sinus rhythms was performed (r = 0.89). The comparison between PRPS theoretical pacing rates and VO2 predicted rates in all 20 patients was also statistically significant (r = 0.93). Finally, to test the reliability of PRPS also in NYHA Class III-IV patients, we tested 22 implanted patients (15 men and 7 women, mean age 70 +/- 9 years) and compared PRPS predicted rates against VO2 CPX measured rates (r = 0.92). To determine if the wide variety of RR pacers were able to supply pacing rates near to those predicted, whether by means of CPX or PRPS, we studied a total of 89 patients: 49 of these (26 men and 23 women, mean age 66 +/- 12 years) had been implanted with activity sensors; 12 patients (11 men and one woman, mean age 70 +/- 7 years) had been implanted with metabolic sensors, and finally 28 patients (19 men and 9 women, mean age 70 +/- 12 years) had been implanted with dual sensors (activity + QT or minute ventilation). Linear regression analysis showed r = 0.93 for activity sensors, r = 0.94 for metabolic sensors, and r = 0.92 for dual sensor. In conclusion, when rate responsive pacing causes symptoms or functional impairment, physicians must provide a personalized rate response tailoring derived from precise, simple physiological testing. OPR is an easy physiological method for tailoring rate response settings, suitable for activity and metabolic sensors. When ergospirometry apparatus is not available, PRPS can successfully replace CPX testing for tailoring.

Adult respiratory distress syndrome due to pulmonary and extrapulmonary causes: CT, clinical, and functional correlations

PURPOSE

To assess the differences in CT appearance between adult respiratory distress syndrome due to pulmonary disease (ARDSP) and that due to extrapulmonary disease (ARDSEXP) and determine whether the variable appearances of ARDS are due, in part, to the initial pulmonary and systemic causes.

MATERIALS AND METHODS

Thirty-three patients, 22 with ARDSP and 11 with ARDSEXP, underwent helical CT shortly after intubation. Two readers evaluated images for the type, extent, and distribution of pulmonary opacities; secondary findings; and correlation with survival and physiologic parameters.

RESULTS

In both ARDSP and ARDSEXP, approximately 80% of the lung was abnormal. In ARDSP, ground-glass opacification and consolidation were equally prevalent, whereas in ARDSEXP ground-glass opacification was dominant. Ground-glass opacification was evenly distributed, whereas consolidation tended to be dorsal and caudal. ARDSP often caused asymmetric consolidation, whereas ARDSEXP caused symmetric ground-glass opacification. Air bronchograms were almost universal. Pleural effusions were present in one-half of the patients, and Kerley B lines and pneumatoceles were uncommon. Lung consolidation correlated with the ratio of mean partial pressure of arterial oxygen to fraction of inspired oxygen, shunt fraction, and pulmonary arterial pressure. The patients who died tended to have more consolidation and asymmetric disease.

CONCLUSION

ARDSP tends to be asymmetric, with a mix of consolidation and ground-glass opacification, whereas ARDSEXP has predominantly symmetric ground-glass opacification. In both groups, pleural effusions and air bronchograms are common, and Kerley B lines and pneumatoceles are uncommon.

Prothrombotic genetic risk factors in young survivors of myocardial infarction

It has long been thought that an individual thrombotic tendency increases the risk of myocardial infarction, especially in young adults. Several "prothrombotic" genetic factors that may influence the individual thrombotic risk have been identified. To investigate the association between the risk of myocardial infarction at a young age and genetic factors thought to be associated with an increased tendency to thrombosis (the polymorphisms 4G/5G of the PAI-1 gene, PIA1/PIA2 of the platelet glycoprotein IIIa, C3550T of the platelet glycoprotein Ib gene, G10976A of the factor VII gene, C677T of the methylenetetrahydrofolate reductase gene, G1691A of the factor V gene, and G20210A of the prothrombin gene), we performed a case-control study evaluating 200 survivors (185 men, 15 women) of myocardial infarction who had experienced the event before the age of 45 years and 200 healthy subjects with a negative exercise test, individually matched for sex, age, and geographic origin with the cases. The presence of the PIA2 polymorphic allele was the only prothrombotic genetic factor associated with the risk of myocardial infarction at a young age. The odds ratio for carriers of the PIA2 allele compared with those of the PIA1 allele was 1.84 (95% confidence intervals (CI) 1.12 to 3.03). There was a significant interaction between the presence of the PIA2 allele and smoking: with their simultaneous presence, 46% (95% confidence intervals 11% to 81%) of premature myocardial infarctions were attributable to the interaction between the two factors. In conclusion, carrying the PIA2 polymorphic allele of platelet glycoprotein IIIa was the only genetic prothrombotic factor associated with the risk of developing myocardial infarction at a young age. The clinical expression of this genetic predisposition seems to be enhanced by smoking.

Antithrombotic therapy of unstable angina and non-Q-wave myocardial infarction

Unstable angina and non-Q-wave myocardial infarction still represent an unsolved problem for clinicians, owing to their unpredictable evolution and high incidence of coronary events in the follow-up. Traditional antithrombotic agents, unfractionated heparin and aspirin, have been proved to be highly effective, but show some important limitations. New potent antithrombotic therapy have been studied to improve their efficacy, with encouraging results. Among these drugs, low molecular weight heparins (for subcutaneous administration) and inhibitors of platelet glycoprotein receptor IIb/IIIa (for intravenous, and possibly oral, administration) are the most promising and are now under extensive investigation.

Isolation and cloning of multipotential stem cells from the embryonic human CNS and establishment of transplantable human neural stem cell lines by epigenetic stimulation

Stem cells that can give rise to neurons, astroglia, and oligodendroglia have been found in the developing and adult central nervous system (CNS) of rodents. Yet, their existence within the human brain has not been documented, and the isolation and characterization of multipotent embryonic human neural stem cells have proven difficult to accomplish. We show that the developing human CNS embodies multipotent precursors that differ from their murine counterpart in that they require simultaneous, synergistic stimulation by both epidermal and fibroblast growth factor-2 to exhibit critical stem cell characteristics. Clonal analysis demonstrates that human C NS stem cells are multipotent and differentiate spontaneously into neurons, astrocytes, and oligodendrocytes when growth factors are removed. Subcloning and population analysis show their extensive self-renewal capacity and functional stability, their ability to maintain a steady growth profile, their multipotency, and a constant potential for neuronal differentiation for more than 2 years. The neurons generated by human stem cells over this period of time are electrophysiologically active. These cells are also cryopreservable. Finally, we demonstrate that the neuronal and glial progeny of long-term cultured human CNS stem cells can effectively survive transplantation into the lesioned striatum of adult rats. Tumor formation is not observed, even in immunodeficient hosts. Hence, as a consequence of their inherent biology, human CNS stem cells can establish stable, transplantable cell lines by epigenetic stimulation. These lines represent a renewable source of neurons and glia and may significantly facilitate research on human neurogenesis and the development of clinical neural transplantation.

Changes in estimated coronary risk in the 1980s: data from 38 populations in the WHO MONICA Project. World Health Organization. Monitoring trends and determinants in cardiovascular diseases

The World Health Organization (WHO) MONICA Project is a 10-year study monitoring trends and determinants of cardiovascular disease in geographically defined populations. Data were collected from over 100,000 randomly selected participants in two risk factor surveys conducted approximately 5 years apart in 38 populations using standardized protocols. The net effects of changes in the risk factor levels were estimated using risk scores derived from longitudinal studies in the Nordic countries. The prevalence of cigarette smoking decreased among men in most populations, but the trends for women varied. The prevalence of hypertension declined in two-thirds of the populations. Changes in the prevalence of raised total cholesterol were small but highly correlated between the genders (r = 0.8). The prevalence of obesity increased in three-quarters of the populations for men and in more than half of the populations for women. In almost half of the populations there were statistically significant declines in the estimated coronary risk for both men and women, although for Beijing the risk score increased significantly for both genders. The net effect of the changes in the risk factor levels in the 1980s in most of the study populations of the WHO MONICA Project is that the rates of coronary disease are predicted to decline in the 1990s.

Ambulatory blood pressure in air traffic controllers

Conflicting reports exist as to whether air traffic controllers (ATC) have an increase in blood pressure (BP) and prevalence of hypertension because of the stressful nature of their job. We have addressed the issue in male ATC working at the Linate airport of Milan. A total of 80 ATC participated, and the 24 h blood pressure monitoring was obtained during two working shifts separated by one night of rest. Blood pressure was measured conventionally and by 24 h ambulatory monitoring; data were compared with those of an age matched male sample three times as large, selected from the data of the Studio delle Pressioni Ambulatoriali delle Loro Associazioni (PAMELA), ie, a large sample representative of the population of the nearby town of Monza. Treated hypertensive subjects were excluded from both groups. Conventional diastolic BP and heart rate were similar in ATC and controls, whereas conventional systolic BP was significantly greater in the former than in the latter group. No difference, however, was seen between ATC and controls as far as ambulatory BP and heart rate were concerned; namely, 24 h, day, and night average systolic BP, and diastolic BP and heart rate were similar in the two groups. Thus daily life BP is not increased in ATC. This may result from the fact that, being a highly selected group with suitable training, these subjects adequately cope with the stress inherent to the job.

A model of cost-outcome analysis for assistive technology

During the CERTAIN study (research carried out in 1994-96 within the Technology Initiative for Disabled and Elderly (TIDE) programme of the European Union), a number of real life case studies of provision of assistive technology to disabled persons were investigated in order to assess the applicability of socio-economic principles, methods and techniques already available from Health Care Technology Assessment studies. A retrospective study on cost, effectiveness and utility resulting from the implementation of assistive technology was carried out over a sample of disabled persons who had adopted technical aids before the start of the project. The sample was selected in such a way to include different pathologies (steady or progressive), impairments, ages, technology and social environment. Each case was described by considering all clinical, technical and social aspects; a common structure for case reporting was developed and tested; attempts were carried out to apply and refine concept and tools derived from health technology assessment studies; on the grounds of such experience a decision support model was elaborated for the choice between different alternatives in order to maximize the client's quality of life while making efficient use of scarce resources. A computer implementation of such a model was also developed, along with a mathematical structure of cost analysis. Within a national research programme such findings were further exploited, leading to the development of a prototype cost-outcome instrument designed for use in clinical practice in the provision of assistive technology to individual cases.

[Changes in the treatment of cardiac emergencies and their influence on fatalities. Data from the MONICA Project, Brianza Area]

BACKGROUND

During the last decade, clinical trials consistently modified the therapeutic approach to coronary disease, and particularly to acute myocardial infarction. However, the magnitude of the contribution to the observed reduction in case fatality rates due the therapeutic improvement is still being debated.

OBJECTIVES

To determine the real degree of implementation of the "suggested treatments" on clinical practice, and to evaluate their global effect on coronary mortality.

METHODS

Analysis of the type of administered treatment in two consecutive series of acute coronary events, observed during the year 1986 (500 events) and 1989 (907 events), registered by the MONICA Project-Brianza Area. We evaluated: pre-coronary times; type of hospitalization; type of treatment before, during and after the event; occurrence of cardiac arrest and cardiopulmonary resuscitation both in and out of hospital; global and specific fatality rates at 28 days.

RESULTS

In the study period, overall coronary fatality rates changed from 29.4 to 23.6% (19% decrease-p < 0.05), fatality of confirmed AMI changed from 16.4 to 8.3% (49.4% decrease-p < 0.005); specific fatality for out of hospital cardiac arrest was unchanged (99%). Pre-coronary times were unmodified in the two periods of observation: hospitalization < 1 hr. in 20%, < 6 hr. in 50%, > 24 hr. in 10% of events. The percentage of cases admitted in CCU changed from 47.4 to 54.8% (from 71.6 to 86.4% of patients with confirmed AMI-p < 0.025). Thrombolysis in confirmed AMI changed from 29.3 to 43.2% (p < 0.001); antiplatelets treatment changed from 19.7 to 81.9% (p < 0.001); the use of betablockers went from 16.6 to 44% (p < 0.001) while the use of other agents was unmodified. Coronary arteriography and revascularization procedures continue to play a marginal role.

CONCLUSIONS

The MONICA registry experience shows that very important changes occurred in the treatment of coronary emergencies, particularly in the acute phase of myocardial infarction, suggesting that in our area, standardization of the therapeutic protocols might be responsible for the observed reduction of coronary fatality even though the advantages were observed only in hospitalized patients.

Job strain and ambulatory blood pressure levels in a population-based employed sample of men from northern Italy

OBJECTIVES

The purpose of this cross-sectional study was to examine the associations between categories of perceived job strain and blood pressure, measured by clinical and ambulatory devices on a population-based sample of employed men in northern Italy.

METHODS

The study included 527 employed normotensive or mild hypertensive nonmedicated men enrolled in an age-gender stratified random sample of 821 25- to 64-year-old residents of the city of Monza (in the vicinity of Milan). The job-strain categories were classified according to the traditional quadrant-term approach and also a new approach based on the comparison of extreme tertile categories in order to enhance contrasts. Clinical blood pressure was measured according to the standardized MONICA procedure; 24-h, work, leisure, and nighttime blood pressure values were obtained with an ambulatory device. Disparities, calculated as differences between clinical and ambulatory measurements, were also analyzed.

RESULTS

Among normotensive working men the highest mean for systolic blood pressure was found in the high-strain group, and progressively lower values were found in the passive, active and low-strain categories. These patterns were observed for both the clinical and ambulatory measurements. Among the mild hypertensive subjects, lower mean values for ambulatory systolic and diastolic blood pressure were found in the passive and high job-strain categories when the tertile term approach was adopted. The passive group also showed the highest mean difference between the clinical and ambulatory measurements; this finding indicates that they may be more susceptible to alarm reactions.

CONCLUSIONS

The results indicate that job strain affects blood pressure in population-based samples and the effect is consistent across sociocultural contexts.

Comparison of dobutamine stress echocardiography with dipyridamole stress echocardiography for detection of viable myocardium after myocardial infarction treated with thrombolysis

OBJECTIVE

To compare the ability of dobutamine and dipyridamole stress echocardiography to detect functional recovery of stunned but viable myocardial regions early after acute myocardial infarction, and to predict late functional recovery of the reperfusion salvaged myocardium within the infarct area.

METHODS

Within 10 d of acute myocardial infarction, 51 patients--30 anterior and 21 inferior, 44 Q wave and seven non-Q-wave infarction--were submitted to a dobutamine echocardiography test at low dose (5-10 micrograms/kg/min over 5 min) and high dose (20-40 micrograms/kg/min over 3 min) and to dipyridamole echocardiography test (0.56 mg/kg over 4 min + 0.28 mg/kg over 2 min) on different days and in random order, after interruption of any vasoactive drug. Resting echocardiography was repeated at two months in 41 of 51 patients (80%). Regional wall motion of the left ventricle was analysed in a semiquantitative manner on a 14-segment model. Viability was defined as improvement of one grade or more of at least two basally asynergic segments in the infarcted area.

RESULTS

Regional functional recovery was detected by low dose dobutamine in 38/51 patients (75%) and in 147/308 (48%) of basally asynergic segments, compared to 25/51 patients (49%; P < 0.001) and 78/308 segments (25%; P < 0.001) only identified by dipyridamole. Late spontaneous functional recovery was detected in 24/41 patients (59%) and in 78/254 basally asynergic segments (31%). The sensitivity of dobutamine and dipyridamole echocardiography for predicting spontaneous functional recovery was 72% and 51% respectively (P < 0.001), specificity 68% and 82% (P < 0.001), positive predictive value 50% and 56%, and negative predictive value 85% and 79%.

CONCLUSIONS

In comparison with dipyridamole in patients with thrombolysed myocardial infarction, dobutamine induces regional functional recovery. This suggests that dobutamine is more sensitive in showing the presence of viable myocardium within the infarct zone, though it has a lower specificity in predicting delayed spontaneous functional recovery of non-contractile but still viable areas.

[Validation of the Italian version of the Kjellberg and Iwanowski's Mood Scale]

Two questionnaires were administered to evaluate stress risk factors in 1652 employees of the Milan Town Council (772 Social Service personnel and 880 administrative staff). The study was focused on cardiovascular diseases. The Mopsy questionnaire is a selection of scales selected by the World Health Organization for international multicenter studies on cardiovascular morbidity, while the Mood Scale of Kjellberg & Iwanowski (1989) is a brief scale translated from Swedish used to measure "actual" stress and arousal state in neurotoxicology. The aim of the present study was to validate the Italian version of the Mood Scale for its possible use in health surveillance and research on stress and arousal changes at work. Appropriate statistical data analyses were applied to study the construct validity (factor analysis), concurrent validity (correlations with the Mopsy scale) and internal consistency (Cronbach alpha). The data confirm the Swedish results on the Mood Scale factor analysis. A good face and construct validity and a good internal consistency were observed. Nevertheless, the Mood Scale does not allow collection of demographic, anamnestic and personal data as does the Mopsy questionnaire.

Bacteriological studies of liver parenchyma in controls and in patients with gallstones or common bile duct stones with or without acute cholangitis

BACKGROUND/AIMS

The presence of aerobic and/or anaerobic bacteria in the liver parenchyma, gallbladder bile, and common bile duct was investigated.

MATERIALS AND METHODS

There were 15 control subjects, 32 cases with symptomatic gallstones, 16 patients with common bile duct stones without acute cholangitis and 8 cases with common bile duct stones with an acute suppurative cholangitis.

RESULTS

No bacteria were isolated in controls. The percentage of positive cultures in liver parenchyma increased in proportion to the severity of the biliary tract disease. There was no clear correlation between normal and altered hepatic histology and the presence or absence of bacteria except in patients with acute cholangitis.

CONCLUSIONS

When biliary tract obstruction is present, the biliary tract is more vulnerable to invasion of bacteria and therefore increases the chance of spread into the liver parenchyma.

Reliability of body fat distribution measurements. The ARIC Study baseline cohort results. Atherosclerosis Risk in Communities Study

OBJECTIVE

To estimate the reliability of skinfold and girth measurements, and ratios involving these measurements, commonly used in epidemiological and clinical studies as measures of body fat distribution.

DESIGN

Repeated measurements of body fat distribution measures were scheduled on randomly selected participants at the baseline clinical examination of the ARIC Cohort Study, by the same or by different technicians.

SETTING

Probability sample of 45-65 year old residents selected from four US communities.

MEASUREMENTS

Subscapular and triceps skinfolds were taken twice using a Lange caliper on standardized right-side locations. Waist and hip girths were measured using an anthropometric tape applied at the level of umbilicus and of the maximal protrusion of the gluteal muscles, respectively. Repeated measurements were taken 1-2 h apart.

RESULTS

Inter-technician measurements of triceps skinfolds, subscapular skinfolds, waist girth, hip girth, and waist/hip ratio each had high reliability (R > 0.91). The reliability coefficient for triceps/subscapular ratio (R = 0.81) was somewhat lower. For skinfold measures, intra-observer coefficient of variations are lower than the ones observed in previous studies, and inter-technician coefficient of variations are comparable.

CONCLUSIONS

These results confirm previous findings which indicate that the reliability of girth measurements is greater than for skinfold measurements. As a consequence, the waist to hip ratio is less affected by measurement error than the skinfold ratio. Moreover, the expected gain in reliability from using the average of two skinfold measures, taken in succession, was not realized, indicating that when measurements are taken in rapid succession by the same technician, statistical independence between measures is questionable.

Trends of smoking habits in northern Italy (1986-1990). The WHO MONICA Project in Area Brianza, Italy. MONICA Area Brianza Research Group

The trends of age-gender specific prevalence of self-reported smoking habits are presented, observed in two population surveys, performed in 1986-87 and 1989-90 in Area Biranza, a northern Italian industrialized district where a WHO MONICA Centre is located. Methods were internationally standardized to obtain comparable data on two independent random samples, each composed of 1,600 subjects, age-sex stratified and extracted from the 25-64 year old residents. A closed question interview was administered to identify smoking condition (smoker, past-smoker, occasional smoker, never smoker), number of cigarettes consumed per day and attained educational level, categorized in compulsory school and post-compulsory school. Serum thiocyanate was measured as a validation index, using a cutpoint of > 100 mumol l-1 to detect false negatives. Trends in smoking prevalence are analyzed taking into account influences of education in the presence of an anti-smoking policy that was started in Italy toward the end of the eighties. Self-reported data, confirmed by serum thiocyanate, show a consistent decline of smokers among males (from 48 to 41%), more evident in younger age groups. In females, smoking prevalence is stable (23-24%), although thiocyanate levels in the whole samples indicate a slight but significant tendency to decrease. Education demonstrates positive influences against smoking, particularly in younger male classes. In females a crossover effect is observable: in the second survey youngest group, education results protective against smoking; the contrary is true in the older groups. Our data, detailing what was initially recognized in previous Italian surveys, may be useful to specify the directions of future preventive actions.

[Evaluation of the socioeconomic status in epidemiological surveys: hypotheses of research in the Brianza area MONICA project]

Socio-economic status (SES) has been reported as a causative factor of increasing health inequalities in industrialized countries. The phenomenon has been particularly investigated for job related diseases, including cardiovascular disease and risk. The group of occupational medicine specialists in the world wide MONItoring program of CARdiovascular disease (WHO-MONICA Project) is now producing a number of hypotheses about the application of internationally defined criteria and tools for SES evaluation in the Italian area of the Project, Area Brianza. After a short review of some main conceptual and methodological problems, a proposal is presented of an SES index, derived from the pooled data of two population surveys carried out in this area. From a randomized sample of 3200 residents, 25-64 years old, stratified by sex and age decade, 1731 subjects, 594 females and 1137 males, employed at the time of the screening were extracted. Four variables were considered: age, education, occupational level and job-strain (according to the Karasek-Theorell model) by which each subject was classified in three levels--high, medium, low--of education and occupation, whose combination was used to obtain as many levels of socio-economic status. This a method of building an SES index is based on a sequence of approximations following two essential criteria: limitation of the variables to be surveyed, through standardized procedures; ability to identify the "low" SES category, presumably more at risk for disease.

The leucine-responsive regulatory protein of Escherichia coli negatively regulates transcription of ompC and micF and positively regulates translation of ompF

The two major porins of Escherichia coli K-12 strains, OmpC and OmpF, are inversely regulated with respect to one another. The expression of OmpC and OmpF has been shown to be influenced by the leucine-responsive regulatory protein (Lrp): two-dimensional gel electrophoresis of proteins from strains with and strains without a functional Lrp protein revealed that OmpC expression is increased in an lrp strain, while OmpF expression is decreased. In agreement with these findings, we now present evidence that transcriptional (operon) fusions of lacZ+ to ompC and micF are negatively regulated by Lrp. Lrp binds specifically to the intergenic region between micF and ompC, as indicated by mobility shift assays and by DNase I footprinting. The expression of an ompF'-lacZ+ gene (translational) fusion is increased 3.7-fold in an lrp+ background compared with an lrp background, but expression of an ompF-lacZ+ operon fusion is not. Studies of in vivo expression of the outer membrane porins during growth on glucose minimal medium showed that the OmpF/OmpC ratio is higher in lrp+ strains than it is in isogenic lrp strains. The effect of Lrp was not seen in a strain containing a deletion of micF. Our studies suggest that the positive effect of Lrp on OmpF expression stems from a negative effect of Lrp on the expression of micF, an antisense RNA that inhibits ompF translation.

Hemodynamics of volume loading compared with dobutamine in severe right ventricular infarction

To compare the hemodynamic effect of volume loading with that of dobutamine infusion in severe ischemic right ventricular (RV) dysfunction, 11 patients with inferior and RV infarction complicated by low cardiac output syndrome and important hemodynamic derangement (systolic blood pressure < 100 mm Hg, cardiac index < 2.0 liters/min/m2, right atrial pressure > 10 mm Hg) were prospectively studied within 48 hours of symptom onset. After right heart catheterization, volume loading (mean 400 ml saline solution) and dobutamine infusion (5 and 10 micrograms/kg/min over 10 minutes) were performed according to a randomized, crossover design. Volume loading resulted in increased right atrial (from 15 +/- 2 to 19 +/- 3 mm Hg, p < 0.05) and pulmonary capillary (from 15 +/- 2 to 19 +/- 3 mm Hg, p < 0.05) pressures, without increasing cardiac index, heart rate, aortic pressure, or right and left ventricular stroke work index. Dobutamine (5 micrograms/kg/min) increased cardiac index (from 1.5 +/- 0.3 to 1.9 +/- 0.5 liters/min/m2, p < 0.05), incrementing both heart rate (from 61 +/- 12 to 70 +/- 13 beats/min, p < 0.05) and stroke volume index (from 25 +/- 6 to 27 +/- 5 ml/beat/m2, p < 0.05), as well as right (from 1.4 +/- 1.6 to 2.3 +/- 2.2 g.m/m2, p < 0.05) and left (from 21 +/- 7 to 27 +/- 10 g.m/m2, p < 0.05) stroke work indexes; right and left ventricular filling pressures did not decrease. Dobutamine (10 micrograms/kg/min) significantly improved myocardial performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodynamic effects of glyceryl trinitrate during continuous 24 hour infusion in patients with heart failure

OBJECTIVE

To investigate whether the susceptibility to tolerance to glyceryl trinitrate is similar in different vascular beds in patients with chronic heart failure.

PATIENTS

Twenty patients with heart failure underwent a continuous infusion of glyceryl trinitrate over 24 hours followed by administration of N-acetylcysteine (5 g intravenously) in a bolus.

MAIN OUTCOME MEASURES

Haemodynamic measurements under control conditions, at peak titration of glyceryl trinitrate at 24 hours, and after N-acetylcysteine; plasma renin activity and packed cell volume.

RESULTS

After 24 hours of infusion the acute reduction in right atrial pressure had largely waned, while pulmonary vascular resistance remained improved and systemic resistance, which was not reduced at peak titration, significantly decreased with respect to control conditions. The effects of N-acetylcysteine and hormonal responses were different in patients who did and did not develop tolerance to glyceryl trinitrate.

CONCLUSIONS

The haemodynamic profile of glyceryl trinitrate changed substantially during the study from a predominantly venodilator action at peak titration to a predominantly arteriolar dilatation after 24 hours of infusion. The different effects of N-acetylcysteine and the different hormonal responses confirm the multifactorial pathogenesis of tolerance to glyceryl trinitrate.

[Minor injuries: little known aspects of occupational accidents]

This paper is aimed at describing and characterizing occupational injuries which do not receive compensation (minor injuries), and at evaluating the differences between compensated and non compensated injuries with reference to type and site of the lesion. Data were collected in a car manufacturing plant and covered the period 1984-1991. Information regarding all kinds of occupational accidents were extracted, following a standardized procedure, from different paper forms compiled by health personnel within the factory (physicians and nurses). Due to the large amount of information registered, a sampling scheme was adopted which considered the same three months every two years, previously selected to cover the entire observation period (1984-85, 1987-88, 1990-91). In addition, to evaluate che adequacy of the sampling procedures for the compensated injuries only, the resulting sampled distributions of the relevant variables were compared with the totality of the injuries. 7,299 events occurred in the sampled months, which corresponded to 652.59 occupational accidents per million hours worked: 8.97% of them caused absence from work lasting more than three days (compensated cases), 3.59% caused a less than three workday loss (LTTWL cases), and the great majority (87.44%) did not cause any absence from work (first aid cases). The frequency index of the total number of accidents did not change over time, but the three categories of injuries did change: for example, first aid cases had their maximum frequency during the middle period (with a peak of 93.21% in March 1987) and their minimum during the last period (73.28% in June 1991). An opposite pattern occurred for accidents which caused absence from work. Type and site of the lesions differed among the three categories of occupational accidents. For example, cuts/lacerations were observed in 48% of first aid cases, 30% of compensated cases, and 15% of LTTWL cases. On the contrary, injuries due to extraneous bodies and contusions which were the most frequent category for LTTWL cases with, respectively, 28% and 25% of the cases, represented only 10% and 13% of first aid cases. With respect to the site of the lesion, hands had the highest frequency index both for first aid (56%) and compensated (39%) cases, and eyes were most affected (36%) among LTTWL cases. With respect to compensated injuries, a notable correspondence of the distributions of the relevant variables between the sample and the whole population was evident, also when considering separate individual subperiods.(ABSTRACT TRUNCATED AT 400 WORDS)

[Variations over time in the accident rate in an automobile manufacturing plant]

This paper describes some characteristics of occupational injuries occurring in a car manufacturing plant during the period 1984-1991. Data regarding all kinds of injuries (not only those which received compensation) were extracted from records compiled by health personnel within the factory according to a sampling scheme that considered the same three months every two years. In addition, all injuries which caused absence from work lasting more than three days were evaluated (without sampling). To compute frequency indexes, the number of hours worked each month/year were obtained. Roughly 650 occupational injuries per million hours worked occurred in the whole population without appreciable changes over time: about 90% of the events did not cause absence from work. For two-thirds of the injuries that caused absence from work, the absence lasted more than three days. More than 50% of the injuries involved the hands; the eyes and arms followed with lower percentages. Cuts/lacerations comprised 45% of all injuries, followed by contusions and foreign bodies. Over time, the frequency index of foreign bodies in the eyes diminished, whereas muscular disorders increased, mainly in the last period. Compensated injuries were particularly elevated in the final period and lowest in the middle: this pattern is attributable only to events with temporary consequences. The increase in the incidence of injuries in the last period was observed in all categories of duration of absence but the decrease of incidence in the middle period concerned only events with shorter duration (less than fourteen days' absence). These trends can be partially attributed to the changes in health management within the factory (recognition and first aid) which occurred in the time period considered. Some combinations of site and type of lesion (i.e., foreign bodies in the eyes) showed a decrease over time both for index of frequency and mean duration of absence; others had a particular pattern: decrease in frequency and increase in mean duration of absence in the middle period, followed by an opposite pattern in the last period (i.e., cuts/lacerations of the hands); some others showed a decrease both for frequency and duration of absence (sprains/strains of the vertebral column muscles).

[The echo-dobutamine and echo-dipyridamole tests in assessing vital myocardium and residual ischemia in myocardial infarct after thrombolysis]

The aim of the study was to compare the ability of dobutamine and dipyridamole echocardiography to detect stunned but viable myocardium early after acute myocardial infarction, to predict spontaneous functional recovery of the reperfused myocardium at 2 months and to detect myocardial ischemia in the infarcted area. Within 10 days from acute myocardial infarction, 47 patients, 29 anterior and 18 inferior, 41 Q-wave and 6 non Q-wave infarctions, underwent dobutamine echocardiography test at low-dose (5-10 mcg/kg/min over 5 min) and high-dose (20-40 mgc/kg/min over 3 min) and to dipyridamole echocardiography test (0.56 mg/kg over 4 min + 0.28 mg/kg over 2 min) in different days and in random order, after interruption of any vasoactive drug. Resting echocardiography was repeated at 2 months in 38/47 patients. Regional wall motion analysis was performed in a qualitative manner on a 14-segment model; viability was defined as improvement of 1 grade or more of at least 2 basally asynergic segments in the infarcted area. Ischemia was defined as an improvement followed by significant deterioration of contractility of the infarcted segments or deterioration of the infarcted area. All patients underwent coronary arteriography within 1 month from admission. Viability was detected by low-dose dobutamine in 34/47 patients (72%) and in 131/297 (44%) of basally asynergic segments compared to only 21/47 patients (45%) and in 66/297 segments (22%) detected by dipyridamole; myocardial ischemia was induced by dobutamine in 64% of patients compared to 36% by dipyridamole. Late spontaneous functional recovery was detected in 21/38 patients (57%) and in 70/244 (29%) of asynergic segments. Sensitivity of dobutamine and dipyridamole echocardiography for predicting spontaneous functional recovery was 70% and 46% specificity 69% and 83%, positive predictive value 48% and 52%, negative predictive value 85% and 79% respectively. Dobutamine correctly identified the presence of a significant stenosis of the infarct-related artery in 74% of cases compared with 43% of dipyridamole; specificity for detecting stenosis was 67% for dobutamine and 83% for dipyridamole. In conclusion, in patients with thrombolyzed myocardial infarction dobutamine echocardiography detects viable myocardium with late spontaneous recovery in a greater proportion of patients and segments than dipyridamole; dobutamine has a higher sensitivity but a lower specificity compared to dipyridamole for identifying a residual stenosis of the infarct-related artery that may jeopardize myocardium in the area at risk.

[Echocardiography-dobutamine test in the short-term evaluation of the results of coronary angioplasty]

BACKGROUND

Coronary angioplasty is commonly performed as a means of coronary revascularization, but at present no method has proven to be of definite value in assessing the functional result of a given angiographic procedure.

OBJECTIVES

The purpose of this study was to evaluate whether dobutamine stress echocardiography can detect a reversal of ischemia-induced left ventricular regional wall motion abnormalities 15 days after an angiographically successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

25 patients underwent dobutamine stress echocardiography 24-48 hours before and 15 days after an elective angiographically successful PTCA. Twelve out of 25 patients (48%) suffered from a previous myocardial infarction. Symptomatic myocardial ischemia was documented before PTCA in 18/25 patients (72%) and asymptomatic ischemia in 7/25 (28%). Dobutamine was infused utilizing incremental steps of 5 mcg/kg/min over 3 minutes, up to a maximal dose of 40 mcg/kg/min. Echocardiographic images were stored on video tape and analyzed in a qualitative manner by two independent and experienced cardiologists without knowledge of the angiographic data. An asynergy score (from 0 = normal to 3 = dyskinesia) was calculated using a 14-segment left ventricular model in basal conditions and at peak stress, before and after PTCA. All tests were performed taking the patients off the antianginal therapy.

RESULTS

One-vessel coronary artery disease was present in 18/25 (72%) patients, and two-vessel disease in 7/25 (28%) four of these 7 patients underwent PTCA on both involved vessels; mean diameter of the stenosis was 91 +/- 6% before PTCA, and was reduced to 22 +/- 8% after PTCA. Dobutamine stress echocardiography induced wall motion abnormalities in 24/25 patients before and in 4/25 after PTCA; the frequency of dobutamine-induced wall motion abnormalities significantly decreased from 96% to 12% before and after angioplasty (p < .01). All patients developed regional wall motion abnormalities in the region supplied by the dilated vessel. Wall motion score at peak dobutamine infusion improved from 8.5 +/- 4.8 before PTCA to 2.6 +/- 4.9 after PTCA (p < .001). There was a significant increase in the rate-pressure product achieved during the test after PTCA (21300 +/- 400 bts/min.mmHg) compared to the test performed before PTCA (19000 +/- 500 bts/min.mmHg) (p < .05). Dobutamine induced angina in 6/25 patients (24%) and ST-segment changes in 19/25 patients (76%) before PTCA, whereas angina occurred only once after PTCA and ST-segment changes 6 times only after PTCA. No major side effects occurred during dobutamine infusion both before and after PTCA.

CONCLUSIONS

Our study indicates that dobutamine stress echocardiography is a feasible and safe method that accurately demonstrates an early improvement in stress-induced regional left ventricular dysfunction after an angiographically successful coronary angioplasty.

Dobutamine stress echocardiography for assessment of myocardial viability and ischemia in acute myocardial infarction treated with thrombolysis

To evaluate the role of dobutamine echocardiography for early assessment of myocardial viability and ischemia in acute myocardial infarction (MI), 59 patients with thrombolyzed acute MI underwent low- (5-10 micrograms/kg/min, 8 patients) and high-dose (20-40 micrograms/kg/min, 51 patients) dobutamine echocardiography at a mean of 8 +/- 4 days after acute MI. Myocardial viability in the infarct zone was documented in 43 of 59 (73%) patients (group 1), in whom mean asynergy score index decreased from 1.6 +/- 0.3 at baseline to 1.3 +/- 0.2 (p < 0.001), after low-dose dobutamine. No viability was present in 16 of 59 (27%) patients (group 2). At follow-up, recovery of regional contractile function was observed in group 1 (asynergy score index decreased from 1.6 +/- 0.3 to 1.4 +/- 0.3; p < 0.001), but not in group 2 patients. Sensitivity, specificity, and negative and positive predictive values of low-dose dobutamine echocardiography in predicting spontaneous recovery of function were 79%, 68%, 50%, and 89%, respectively. Of the 51 patients who underwent high-dose dobutamine, 26 of 36 (72%) group 1 patients showed a deterioration of contractility in the infarct zone indicative of myocardial ischemia compared with only 1 of 15 (7%) group 2 patients. At follow-up, recovery of regional function was greater in patients with no evidence of myocardial ischemia at high doses than in those with an ischemic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of dobutamine stress echocardiography, dipyridamole stress echocardiography and exercise stress testing for diagnosis of coronary artery disease

To compare the value of dobutamine and dipyridamole stress echocardiography with exercise stress testing for the diagnosis of coronary artery disease (CAD), 80 patients with chest pain of suspected myocardial ischemic origin (57 with CAD and 23 without significant CAD) underwent dobutamine stress echocardiography (5 to 40 micrograms/kg/min), dipyridamole echocardiography (0.84 mg/kg over 10 minutes) and bicycle exercise electrocardiography after discontinuation of antianginal treatment. Dobutamine echocardiography and exercise testing revealed a higher overall sensitivity than dipyridamole echocardiography (79 vs 60%, p < 0.005; 77 vs 60%, p < 0.05, respectively); this finding was due to a higher dobutamine and exercise sensitivity in 1-vessel CAD (62 vs 33%, p < 0.05 for both tests), whereas sensitivity of the 3 tests was similar in multivessel CAD. Dobutamine and dipyridamole showed a higher specificity than exercise (83 vs 43%, p < 0.01; 96 vs 43%, p < 0.005, respectively). Diagnostic accuracy of dobutamine echocardiography was higher than that of exercise (80 vs 67%, p < 0.05), whereas the difference with dipyridamole (80 vs 70%) was not significant. In the tests that yielded positive results, double product during exercise was significantly higher than that during dobutamine and dipyridamole echocardiography. No major complications occurred during the tests, but adverse effects were more frequent during dobutamine testing. Thus, dobutamine echocardiography may be superior to dipyridamole echocardiography and exercise electrocardiography for the diagnosis of CAD.

Effects of cyproterone acetate on the reproductive tract and pituitary-gonadal axis of the golden hamster

The effects of cyproterone acetate (CA) on the reproductive tract and serum levels of gonadotropins and testosterone in male golden hamsters exposed to long days, were studied. The daily injection of CA at 100 mg kg-1 body weight during 8 weeks reduced sperm count, both in caput and cauda epididymidis. The weight of epididymis and seminal vesicles were also reduced, while testicular weight and histology were not affected. Serum levels of testosterone and LH were increased 3.6 and 1.8 fold, respectively, above controls, while FSH was not affected by the treatment with CA. The absence of an inhibitory action of CA on the testis could be explained through an increase in LH stimulation, thus suggesting that in the golden hamster CA is devoid of progestagenic partial effects.

Heparin infusion facilitates ex vivo spontaneous platelet aggregation in patients with acute myocardial infarction who have undergone thrombolytic therapy

We investigated ex vivo spontaneous platelet aggregation (SPA) in platelet-rich plasma in 37 patients with acute myocardial infarction. It occurred in about 50% of subjects receiving heparin after streptokinase treatment, while it rarely took place in patients who did not receive either streptokinase or heparin and in those treated with streptokinase alone. The study of patients receiving heparin for deep vein thrombosis suggested that SPA may derived from adenosine diphosphate released from platelets during sample handling. We suggest that heparin infusion may facilitate ex vivo platelet activation and that this mechanism is operative in patients with acute myocardial infarction who have undergone thrombolytic therapy.