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Biomedical subjects

A Albert

Publications and source records attributed to A Albert.

At least 235 records · Page 13Linked to original sources
PubMed1986

Incidence and significance of pericardial effusion in acute myocardial infarction as determined by two-dimensional echocardiography.

To determine the incidence and clinical significance of pericardial effusion after acute myocardial infarction, two-dimensional echocardiography was serially performed in 66 consecutive patients. Pericardial effusion was observed in 17 (26%); the effusion was small in 13 patients, moderate in 3 and large with signs of cardiac tamponade in 1. In this patient, two-dimensional echocardiography strongly suggested myocardial rupture. The observation of pericardial effusion was not associated with age, sex, previous myocardial infarction, atrial fibrillation or treatment with heparin. It was more often a complication of anterior than of inferior acute infarction. Patients with pericardial effusion had higher peak levels of creatine kinase and lactic dehydrogenase and a higher wall motion score index. More patients with pericardial effusion had congestive heart failure or ventricular arrhythmias, developed a ventricular aneurysm or died within 1 year after their infarction. In conclusion, pericardial effusion is frequently visualized by two-dimensional echocardiography after acute myocardial infarction and its presence is associated with an increased occurrence of complications and cardiac death.

Aged↗
PubMed1986

Complementary role of thallium-201 scintigraphy to predischarge exercise electrocardiography for patients stratification after a first myocardial infarction.

The value of a predischarge exercise test combined with thallium-201 myocardial scintigraphy in detecting patients with severe multivessel disease (MVD) was studied in 58 consecutive patients discharged after a first acute myocardial infarction. Twelve electrocardiographic, clinical and scintigraphic variables were analysed. Angiography at one month revealed MVD (greater than 70% narrowing in vessels unrelated to infarction) in 26 patients (45%). ST segment depression of 1mm or greater, thallium defects in multiple vascular distributions (MVTL), and reversible thallium defects in a vascular distribution different from the infarct related vessel predicted patients at risk for MVD (predictive value respectively of 68%, 65% and 75%). The other variables were not significantly associated with the presence of MVD. Only ST segment depression and thallium defects in multiple vascular distributions emerged as independent predictors of MVD. Their combination yielded a 77% sensitivity and a 59% specificity for MVD. Combination of thallium imaging with the predischarge exercise ECG significantly improved the stratification provided by the exercise test alone (P less than 0.05). A positive thallium scan (MVTl defects) associated with a positive ECG (ST depression) carried a risk for MVD of 80% in the population studied. When both tests were negative, MVD was infrequent (risk 22%). Because improvement in the stratification of patients is not as clear as expected from studies performed at a later stage, it appears that exercise thallium scintigraphy at a submaximal level one or two weeks after infarction does not provide optimal information. Predischarge exercise thallium-201 scintigraphy, however, is superior to an exercise tolerance test alone in separating patients into those with high and low risk of MVD.

Electrocardiography↗
PubMed1986

Dynamic assessment of severity of illness in pediatric intensive care.

Severity of illness in 293 pediatric ICU patients was assessed by a daily estimate of ICU survival. The probability of nonsurvival was obtained by logistic regression analysis, using physiologic stability index (PSI) values from previous days as time-dependent covariates. Only PSI values from the previous 2 days gave statistically significant predictions of short-term (less than 24 h) outcome. When the prediction model derived from these data was tested prospectively on a separate set of 345 pediatric patients, there was excellent agreement between observed and predicted short-term mortality. Receiver operating characteristic curves for the 345 patients were statistically equivalent to those originally derived for the 293 patients, and this prediction model had significantly (p less than .025) more accuracy than prediction based on admission PSI. These results indicate that this model for daily risk assessment is statistically reliable and objective, as verified against eventual outcome. In the 345 patients, ICU mortality was predicted with 89% sensitivity and 91% specificity. This prediction model may be used to stratify patient groups for clinical studies, or identify very low-risk patients for potential early ICU discharge.

Child↗
PubMed1985

Derivation of a bioclinical prognostic index in severe head injury.

We investigated the problem of outcome prediction from seven risk factors in 40 severely head injured patients - 13 favorable and 27 unfavorable outcomes. By applying stepwise logistic discriminant analysis to the patients' data, we selected three significant risk variables: cerebrospinal fluid (CSF) CK-BB isoenzyme activity recorded on admission, severely raised intracranial pressure (more than 40 mmHg) and age, respectively. CSF CK-BB activity, which quantifies the initial neurological damage, proved to be the best prognostic factor. The presence of severe intracranial hypertension was always associated with a bad outcome, whereas its absence was not necessarily indicative of good prognosis. Finally, we combined the three selected variables into a single risk index, which allowed correct predictions in 92% of patients with favorable outcome and in 85% of patients with unfavorable outcome (total predictive efficiency 88%).

Adolescent↗
PubMed1985

The Salmonella/mammalian microsome mutagenicity test: comparison of human and rat livers as activating systems.

The mutagenicity of several test compounds was verified by the Salmonella/microsome mutagenicity test (Ames test), using both human liver and rat liver (untreated or pretreated with Aroclor 1254) S9 under identical experimental conditions. Aflatoxin B1, 3-methylcholanthrene, and cigarette-smoke condensate were less mutagenic in the presence of human-liver S9 than in the presence of rat-liver S9 (particularly after treatment with Aroclor 1254). The opposite was observed with 2-aminonanthracene and to a lesser degree with 2-aminofluorene; correlation studies indicate that the two compounds were activated by the same or by very similar enzymes, probably cytochrome P-450s. These results clearly indicate that human-liver S9, as an activating system, behaves differently than rat-liver S9; therefore, it may constitute a useful, additional tool for the study of mutagenicity and probably, carcinogenicity in man.

Animals↗
PubMed1985

Relative prognostic value of best motor response and brain stem reflexes in patients with severe head injury.

The object of this study was to determine whether the addition of information on brain stem reflexes improves the prognostic precision of the Glasgow coma scale for patients with severe head trauma. The study is based on 109 patients with a Glasgow coma score of 7 or less during the first 24 hours after injury. The average age was 23 years. The patients were classified into three groups according to their actual outcome after 6 months: dead, 44 patients; persistent vegetative state and severe disability, 13 patients; moderate disability and good recovery, 52 patients. We then compared, by means of multiple group logistic regression, the prognostic ability of motor responses alone using the Glasgow criteria and of brain stem reflexes via an original approach. We showed that the predictive capabilities of brain stem reflexes were greater than those of motor responses. Although closely related (r = 0.68), the use of these two parameters in a single scale, the Glasgow-Liege scale, improves the precision of prognosis, especially for those head trauma patients with initial and complete loss of consciousness. Age was also revealed to be an important factor for outcome prediction.

Adolescent↗
PubMed1985

Optimized determination of plasma prokallikrein on a Hitachi 705 analyser.

Manual determination of plasma prokallikrein using a chromogenic substrate is tedious. We describe the optimal conditions of enzymatic quantification by a fully automated method enabling rapid availability of the results and an easier estimation of this interesting compound in clinical chemistry.

Heparin↗
PubMed1985

Influence of oral contraceptives and pregnancy on constituents of the kallikrein-kininogen system in plasma.

We measured kininogens of low and high molecular mass along with prokallikrein activity in plasma of women with a normal menstrual cycle. We observed no difference between results for the follicular and luteal phases. We assayed the same constituents in women who were taking oral contraceptives (combined estroprogestative) and found that activity of prokallikrein and concentrations of low- and high-molecular-mass kininogens were significantly increased. Lastly, we studied the components of the kallikrein-kininogen system during pregnancy. We also observed a marked increase in their concentrations in plasma, despite a decrease in total proteins. Specifically, prokallikrein and kininogens increase continuously with gestational age, reaching their maxima around the eighth month of pregnancy. At that time, more than 50% of observed results fall outside the normal reference interval. Our observations are even more striking when prokallikrein and kininogens are expressed in units per gram of total proteins, to account for the hemodilution. After delivery, the concentrations of prokallikrein and low- and high-molecular-mass kininogens decline promptly, returning to normal within three days.

Adult↗
PubMed1985

Electrical activity and motility in the isoperistaltic side to side ileal reservoir.

In ten rabbits, electrical activity and motility were measured in a side to side isoperistaltic ileal reservoir of 10 centimeters up to three months postoperatively and compared with normal ileum in three rabbits in the control group. Synchronous short spike wave complexes appeared across the reservoir anastomosis early postoperatively; however, they were not associated with propulsive peristaltic waves. Long intense spike wave complexes were associated with propulsive peristaltic waves in the rabbit ileum. These complexes appeared within two weeks postoperatively; however, they were initially asynchronous across the anastomosis. Within three months postoperatively, these complexes became synchronous across the anastomosis, indicating near normal propulsive function in the reservoir.

Action Potentials↗
PubMed1985

Pulmonary pathology associated with hypertonic central venous fluid administration.

In a rabbit model, a variety of hyperalimentation solutions have been shown to have an adverse effect on the right atrium, pulmonary artery and pulmonary parenchyma when infused for one week into the right atrium. High concentrations of dextrose combined with amino acids produced the greatest morbidity and mortality. No clear relation exists between pH or osmolarity and toxicity. The pulmonary injury seen in this model may explain the occasional development of pulmonary hypertension in patients receiving long term total parenteral nutrition.

Animals↗
PubMed1985

Human kininogens of low and high molecular mass: quantification by radioimmunoassay and determination of reference values.

Kininogens of low and high molecular mass, highly purified from human plasma, were used to raise antisera in rabbits. To obtain immunologically intact tracers, we labeled the kininogens by the lodogen method, followed by double chromatography, first on Sephadex G50 and then on Sephadex G200 for high-molecular-mass kininogen or on G100 for low-molecular-mass kininogen. Both assays are sensitive, accurate, and reproducible. On an equimolar basis, the high-molecular-mass kininogen cross reacted completely in the determination of low-molecular-mass analyte. Moreover, the radioimmunoassay for the former was highly specific. After optimizing the time and temperature of incubation to provide rapid and reliable results, we determined 95% reference intervals from a large sample of healthy subjects (250 men, 200 women): 109-272 and 69-116 mg/L for the low- and high-molecular-mass kininogens, respectively.

Adult↗
PubMed1985

In utero supplemental fetal feeding in an animal model: effects on fetal growth and development.

That the fetus swallows amniotic fluid and has the capability of intestinal absorption of protein and carbohydrate is known, but its significance in fetal nutrition is not clear. We have infused nutrient solutions of dextrose and amino acids intra-amniotically in a chronic third-trimester fetal rabbit model and examined the effects on fetal growth and development. Over a 5-day period, 26 fetal rabbits received graded doses of dextrose in water with or without amino acids infused continuously into the amniotic space. At the time of delivery, fetal body, liver, and brain weight, crown-rump length, and brain protein content were significantly higher in the infused rabbits than in noninfused controls. Amniotic fluid, serum, and gastric content glucose levels were significantly higher in infused fetuses. There was a linear relationship between nonprotein calories administered and fetal growth within the infused group. No toxicity of infusates in the fetus was noted, although technical complications relating to the infusion apparatus were common. We conclude that third-trimester intra-amniotic infusion of nutrient solutions enhances fetal growth in this rabbit model. We speculate that this technique may be of value in the antenatal treatment of growth-retarded fetuses.

Amino Acids↗
PubMed1984

Fibrinogen and fibrin interaction with concanavalin A dimer and its influence on coagulation.

Concanavalin A dimer interacts with fibrinogen and soluble fibrin at pH 5.2 Analysis of the binding data shows that there are in both cases four binding sites per molecule and that the dissociation constant does not change by removal of fibrinopeptides A and B. Ultracentrifugal studies show that no aggregates of fibrinogen or fibrin are formed through concanavalin A binding and that up to four molecules of concanavalin A dimer can bind to one molecule of fibrinogen or fibrin. These results imply that the four carbohydrate chains in the molecule are accessible to concanavalin A dimer. There is a diminution in the coagulation of fibrinogen by thrombin at low relative lectin concentrations and an increase at high concentrations. However, the lectin always favours the aggregation of fibrin monomers and does not have any inhibitory effect on the release of fibrinopeptides. We conclude that the electric charge in the neighbourhood of the carbohydrate in both chains, B beta and gamma plays an important role in the attraction between monomeric fibrin and fibrinogen-monomeric fibrin. The different effect of concanavalin A on the coagulation, depending on the relative concentration of the lectin, would be the result of the screening of this electric charge favouring either the interaction of fibrinogen-monomeric fibrin or the polymerization of monomeric fibrin.

Blood Coagulation↗