Validation of risk-based quality control techniques: a case study from the automotive industry.

Quality control is an outstanding area of production management. The effectiveness of applied quality control methods strongly depends on the performance of the measurement system. Many researchers aimed to analyze the effect of measurement errors on conformity or process control and proposed solutions to treat measurement uncertainty. Although both risk-based conformity control and process control solutions have been designed, verification and validation of these methods have not been provided through laboratory experiments. This paper proposes a case study from the automotive industry regarding the application of risk-based conformity control and risk-based control charts. Acceptance intervals and control limits are optimized to minimize the loss associated with incorrect decisions. The optimization is conducted assuming two scenarios: first, the process and measurement errors are simulated, and second, all data points are measured in the laboratory. This study verifies the applicability of risk-based approaches to real industrial problems and compares the results obtained by simulations and experiments, providing information about the achievable cost reduction opportunities granted by simulations.

[Plasma homocysteine levels in patients with ischemic heart disease]. / A plazma-homociszteinszint vizsgálata ischaemiás szívbetegekben.

In the latest years it became clear that beside traditional cardiovascular risk factors the high plasma homocysteine level increases the risk of atherosclerotic diseases too. Metaanalysis of 27 papers found that 10% of population's coronary risk is attributable to homocysteine and a 5 mumol/l increase in its plasma level elevates the coronary risk by as much as 0.5 mumol/l cholesterol increase. Recent studies have shown an inverse relation between the levels of plasma homocysteine and that of folic acid, vitamin B6, vitamin B12. The latters are cofactors and substrates of the homocysteine and methionin metabolism. The plasma total cholesterol, HDL-cholesterol, triglyceride, lipoprotein(a), Apo A1, Apo B and homocysteine concentrations were examined in 39 patients suffering from coronary artery disease treated in the Cardiac Rehabilitation Department of our hospital. Twenty of them were treated by folic acid and vitamin B6 for a three week period. The mean (+/- SD) plasma homocysteine concentration was 15.60 +/- 6.14 mumol/l. In the treated subgroup the mean (+/- SD) plasma homocysteine concentration was 17.3 +/- 7.00 mumol/l, the mean (+/- SD) plasma folic acid level was 8.58 +/- 4.6 mumol/l. After the three week treatment period (folic acid and vitamin B6) the plasma homocysteine level decreased by 26.5% (p = 0.012), that of folic acid increased by 68.7% (p = 0.002). From the plasma lipids the level of total- and LDL-cholesterol decreased significantly (6.7% and 10.4%, P < 0.05), caused by the strict diet during hospital treatment. As for the genetic polymorphism of the V677 gen of the metylenetetrahydrofolate-reductase (MTHFR) enzyme there was a significant correlation with homocysteine level (r = 0.436, p = 0.010), and a negative, but not significant correlation with the folic acid level (r = -0.354).

[Significance of contractile reserve in the assessment of cardiac diseases]. / A kontraktilis rezerv értéke a szívbetegségek megítélésében.

One of the most important question in the revascularization of patients with impaired left ventricular function caused by coronary heart disease is the proper differentiation of necrotic myocardium and the region with the possibility of functional recovery. An improving in myocardial performance causes better survival in patients undergone revascularization. Preoperative assessment of segmental or global contractile reserve as a marker of myocardial viability by various methods in suitable to predict the improvement expected after procedure. It is useful in selection of the patients in whom the restoration of coronary blood flow takes a beneficial effect in their survival and quality of life. Authors based on relevant data summarize the methods in the evaluation of contractile reserve and its usefulness in clinical decision making of various heart diseases.

[The effects of statins on stroke and cardiovascular incidence in randomized, placebo-controlled trials with clinical endpoints]. / Stroke és cardiovascularis hatások a statinokkal végzett klinikai végpontú, randomizált, kontrollos vizsgálatokban.

In the mortality statistics behind the coronary heart disease and cancer the stroke is the third leading cause of death. The risk factors of stroke and coronary heart disease are similar, but in a recent meta-analysis (Prospective Studies Collaboration) on 450,000 patients from 45 studies didn't find close correlation between the occurrence of stroke and the cholesterol level. In the Multiple Risk Factor Intervention Trial the incidence of haemorrhagic and non-haemorrhagic stroke was analysed separately and a significant correlation has been found between the high cholesterol level and occurrence of the non-haemorrhagic stroke. The great statin trials in a large scale of patients' groups (different cholesterol and risk levels at the inclusion) beside the decline of coronary events proved a decrease in stroke incidence too. The mechanism of action of the statins on stroke is not known: beside the cholesterol lowering effect the so called pleiotropic effects (plaque stabilisation, improvement of endothelial dysfunction and antithrombotic properties) and a direct effect on vascular tone could get importance. The fact that statins could improve the incidence of coronary events with 24-34%, that of stroke with 10-31%, suggests, that this drugs has to be used more frequently in the clinical practice.

[Effect of enalapril on restrictive type diastolic filling disorder in severe congestive heart failure]. / Enalapril hatása restriktív típusú diastolés telödési zavarral járó súlyos szívelégtelenségben.

Authors investigated the effect of enalapril (10-20 mg daily) on twenty-nine patients with chronic heart failure in NYHA III-IV stadium who's ejection fraction value was under 40% and had restrictive type of diastolic filling abnormality. Parameters of left ventricular function were measured by echocardiography and the basal data were compared to data detected at the time of 3 and 6 months control. A beneficial effect of enalapril was found on functional cardiac status (reduction in NYHA score), on systolic function (augmentation in ejection fraction and mean mitral anulus motion amplitude). Parallel with the previous parameters in the severity of restrictive diastolic filling alterations (reducing the value of pathologically high E/A ratio and an increasing in deceleration time of early diastolic filling wave) a countable decrease was observed. Authors emphasize the favourable effect of angiotensin converting enzyme inhibitors on chronic heart failure caused by different reasons independently of its severity. The source of drug action is reduction of the preload and afterload as well as keeping under control the harmful ventricular remodelling based on impediment of myocardial angiotensin system.

[The role and significance of sagittal abdominal diameter in the determination of adipose tissue distribution]. / Mesto i znacaj sagitalnog abdominalnog dijametra u detekciji distribucije masnog tkiva.

Up-to-now trials have pointed out the importance of determining the type of obesity because the central type of obesity is joined with glucose tolerance disturbance, hyperinsulinemia and insulin resistance. The sagittal abdominal diameter proved to be the method of choice in routine clinical practice for visceral fat tissue detection. We examined a group of 60 females in whom, apart from standard measures (body weight, height, body mass index, perimeters of waist and hips), the sagittal abdominal diameter was measured by means of specially constructed caliper (Holtain Kahn Abdominal Caliper). Gathered parameters were compared with the results of an examination performed on 30 healthy females of normal body weight (control group). Results show a statistically significant higher sagittal abdominal diameter in females with central type of obesity in comparison to the control group, which points to greater quantity of visceral fat tissue in this type of obesity.

[Motion of the mitral anulus and suitability of the motion amplitude for determination of left ventricular function in Q-type myocardial infarct]. / A mitralis anulus mozgása és mozgási amplitudójának alkalmassága a bal kamra funkció megítélésére acut Q-típusú myocardialis infarctusban.

Cardiac apex hardly changes its location during the time of cardiac cycle, but the mitral anulus--representing cardiac base--has a systolic descent toward the apex and in diastole moves to the left atrium. The whole amplitude of mitral anulus motion is so useful indicator of left ventricular systolic function as ejection fraction derived from enddiastolic and endsystolic parameters. Mitral anulus motion amplitude easy to measure noninvasively by echocardiography. Authors examined 110 patients with their first, Q-type acute myocardial infarction 7-10 days after the onset of symptoms. In the same time ejection fraction value was assessed by radionuclide ventriculography. Data of ejection fraction and mitral anulus motion amplitude were compared. Their conclusions: 1. mitral anulus motion amplitude well correlated with left ventricular ejection fraction 2. patients had a decreased mitral anulus motion amplitude at the site of infarction 3. investigation of mitral anulus motion amplitude is an useful and easy to make method to assess of systolic function of left ventricle in acute myocardial infarction.

[Acute myocardial infarction mortality in a hospital department during the last decades]. / Az acut myocardialis infarctus halálozásának alakulása osztályunkon az utóbbi évtizedekben.

Authors surveyed the data of 2677 patients with acute myocardial infarction treated in cardiological department between 1970 and 1993. Activity of Coronary Care Unit (has been working from 1974) reduced the earlier hospital mortality in general internal medicine possibilities with 50%. Main cause of this reduction was the temporal electrotherapy of cardiac arrhythmias. Since the middle of last decade the goal of has been generally introduced combined therapy (beta-blockers, intravenous nitrates, acetyl-salicic acid, thrombolytics) is to reduce the mass of damaged myocardium and hereby increasing the ratio of survival. They reduced the hospital mortality around 10% with consistent application of this therapy. According to the authors application of thrombolytic therapy has basic importance in management of myocardial infarction, but they could not treat a lot of patients with streptokinase in consequence of too long prehospital time period and not properly controlled hypertension. The proportion of systemic thrombolytic therapy on their patients is almost a quarter of them. It would be very important to increase this beneficial ratio with reducing the time of patients decision to turn to health care and applying systemic thrombolytic therapy more than six hours after the onset of symptoms of myocardial infarction.

[Lipid status in extreme obesity]. / Lipidski status u ekstremnoj gojaznosti.

50 extremely obese women < 35 years of age (their height 164 cm, weight 107 kg, BMI 40) were analyzed in this paper. Following lipidic and lipoprotein parameters were determined: total triglycerides, total HDL-, LDL-cholesterol, electrophoresis of serum's lipoproteins, and in the third of patients the level of apoproteins. AI, AII and B. In all patients the level of glycemia on an empty stomach was determined. Gathered results were compared with those of the control group which consisted of 32 metabolically healthy women of corresponding age. On the basis of gathered results it can be concluded that in extremely obese women the level of numerous atherogenic lipidic fractions such as total triglycerides, total cholesterol, LDL-cholesterol and apoprotein B was statistically significantly increased, while the level of protective HDL-cholesterol was statistically significantly decreased. Results of this investigation point to the common connection between obesity and disorder of metabolism considering lipids and lipoproteins which result in increased incidence of cardiovascular diseases in obese persons.

An attempt to evaluate the risk factors related to coronary heart disease in Hungary.

Using questionnaires, the authors evaluated the risk of coronary heart disease in different groups of Hungarian society. Among physicians, teachers, factory workers and agricultural workers, the latter seem to be at the highest risk. On the basis of these results obtained in a population of 363 agricultural employees, a detailed risk factor analysis was made. These results were compared with those of the Framingham Offspring Study. Hungarians show alarmingly often a high blood cholesterol level, hypertension, smoking and obesity (the latter factor in women). The more frequent occurrence of the three main risk factors (high blood cholesterol, hypertension, smoking) in young Hungarians is concordant with the fact that the incidence of myocardial infarction in young people in Hungary is one of the highest in the world. The frequency of a positive parental history and obesity in men is lower in the Hungarian population than in the American one. The risk of coronary heart disease in the examined Hungarian population is considered high. The authors have launched a preventive programme.

Tumor cell implantation with the use of Gelaspon gelatin sponge disc.

Myelomonocytic leukemia (My) mesoblastic nephroma (Ne) and hepatocellular carcinoma (He) cells were implanted under the renal capsule of F344, Long-Evans (LE) and BDIX rats. Gelaspon sponge discs were used in the implantation procedure, which were resorbed within a few days. The tumor cells, which were located on the surface of these discs could then attach themselves to the renal capsule and thus grow. There was a correlation between the number of tumor cells and the difference between the two kidney masses. The correlation was linear between 10(4) and 10(6) cells, thus the method proved to be a simple, fast and quantitative model in experimental cancer prevention and therapy.

Reactivity of mouse ascitic fluids containing monoclonal antibodies directed against adenovirus hexon.

Thirty-two mouse hybridoma ascites were produced, containing hexon specific monoclonal antibodies, using crystallized hexons of human adenovirus type 1 as immunizing and selecting antigen. The reactivity of the ascitic fluids was tested with hexon preparations of 11 different human adenovirus species (serological types) belonging to 4 different subgenera by ELISA and passive haemagglutination (HA) methods. By these methods the 32 hybridoma antibodies showed 4 and 12 distinct reactivity patterns (type of cross-reactions) respectively. In the positive cases significant differences could be detected in the titres of the hybridoma antibodies in both ELISA and HA. It can be assumed that adenovirus type 1 hexon-related epitopes are present on a number of heterologous hexons in characteristic (interspecies) combinations for the given heterologous hexon and that a gradient of relationship may exist among the antigenic structures of hexons of the different adenovirus species.

Characterization of adenovirus hexon epitopes by monoclonal antibodies.

Three-thousand hybridoma clones were produced using crystallized hexon of human adenovirus type 1 for immunization. ELISA revealed 69 homospecific antibody producing clones. The monoclonals were reactive with both crystallized and non-crystallized purified soluble hexon preparations, as well as with the hexons derived from purified virions. Hexon preparations of 10 different human adenovirus species (members of 4 different subgenera) were used for the characterization of 33 monoclonal antibodies. ELISA and passive haemagglutination (HA) tests revealed 6 and 15 distinct reactivity patterns (RP) i.e. intertype cross-reaction of a given antibody with the panel of test-antigens, respectively. Four of these RP-s were identical by both techniques. Significant quantitative differences existed between extinction values in ELISA and HA-titres. The results indicate the presence of identical epitopes as well as epitypic relationships among the hexons. The common epitopes and the epitypic relationship seem to be characterized by 16 different interspecies specificities under the experimental conditions, which are independent of subgenus boundaries and are demonstrable in different combinations on the hexons of adenovirus species belonging either to the same or to different subgenera.