Predictors of chronic posttraumatic stress symptoms following burn injury: results of a longitudinal study.

The authors' goal was to examine the course and predictors of posttraumatic stress symptoms among persons hospitalized for burns. A total of 301 participants completed self-report measures assessing peritraumatic mental state, anxiety related to pain, and posttraumatic stress symptoms. Twenty-six percent of the participants were suffering from posttraumatic stress symptoms at 2-3 weeks postburn and 15% of them at 12 months postburns. In general, a decrease in symptoms was observed over time, although a substantial part of the participants with acute stress symptoms suffers from chronic posttraumatic stress symptoms 1-year postburn. Symptoms were predicted by anxiety measures and objective factors, such as female gender, locus, and severity of injury.

Vagal cardiac control throughout the day: the relative importance of effort-reward imbalance and within-day measurements of mood, demand and satisfaction.

The effects of variables derived from a work stress theory (the effort-reward imbalance theory) on the power in the high frequency (HF_HRV) band of heart rate (0.14-0.40 Hz) throughout a work day, were determined using multilevel analysis. Explanatory variables were analysed at two levels: at the lowest level (within-day level), the effects of positive mood, negative mood, demand, satisfaction, demand-satisfaction ratio, and time of day were assessed. At the highest level (the subject level), the effects of sleep quality, effort, reward, effort-reward imbalance, need for control, type of work (profession), negative affectivity, gender and smoking on HF_HRV were assessed. Need for control has a negative effect on HF_HRV after controlling for time of day effects, i.e. subjects with a high need for control have a lower vagal control of the heart. In the long run, these subjects may be considered to be at increased health risk, because they have less of the health protective effects of vagal tone. The interaction between effort-reward imbalance and time of day has a positive effect on HF_HRV, i.e. the cardiac vagal control of subjects with a high effort-reward imbalance increases as the day progresses. It is discussed that this probably reflects reduced effort allocation, ensuing from disengagement from the work demands.

Cortisol secretion throughout the day, perceptions of the work environment, and negative affect.

The effects of explanatory variables derived from a work stress model (the effort-reward imbalance model) on salivary cortisol were assessed. A multilevel analysis was used to distinguish the effects of single occasion and multiple occasion measurements of work stress and effect on cortisol. The single (or cross-sectional) factors include Effort-Reward Imbalance (ERI), need for control, negative affect, and other enduring factors (type of occupation, gender, and smoking). The multiple occasion measurements include momentary negative mood, Momentary Demand-Satisfaction Ratio (MD-SR), sleep quality, work load (workday versus day off), at work (versus not being at the workplace), and lunch. The effect of time of day on cortisol was controlled for before the effects of these variables were determined. Momentary negative mood but not trait negative affect was positively associated with ambulatory measured cortisol. The variables from the work stress model--effort, reward, need for control, and the multiple occasion measurements of demand and satisfaction--did not affect cortisol. As could be expected, time of day had an effect on cortisol, but a hypothesised interaction with momentary negative mood was not found. Additionally, the results show that the time course of cortisol differs between individuals and that the effect of sleep quality on cortisol can vary from person to person. This points to the necessity of continued efforts to single out sources of individual variability. The finding that variables derived from the effort-reward imbalance model are not related with cortisol does not support the hypothesis that ERI leads to short-term changes in cortisol, indicating no relation with hypothalamic-pituitary-adrenal (HPA) axis activity. On the other hand, the present results invite further qualification of negative affect as a potential determinant of HPA activity, at least, as far as can be deduced from cortisol measurements.

Sensitive methods for determining subclasses of IgG anti-A and anti-B in sera of blood-group-O women with a blood-group-A or -B child.

The determination of the subclasses of IgG antibodies against blood groups A and B is important in order to improve our understanding and predict haemolytic disease of the newborn due to IgG anti-A or -B. We describe two techniques that circumvent the problem of the agglutination of A and B red cells by the corresponding IgG antibodies in saline: an antiglobulin consumption test and a modified solid-phase micro-immunofluorescence test. The results of the two techniques are compared with the results obtained in the indirect antiglobulin test beyond the saline agglutination titre in a microplate technique. The solid-phase micro-immunofluorescence test was the most sensitive for the determination of the subclasses of IgG anti-A and -B. Usually sera contained IgG2 anti-A, B in a higher titre than antibodies of other subclasses.

ABO and Rhesus phenotyping of fetal erythrocytes in the first trimester of pregnancy.

Determination of fetal red blood cell antigens in early pregnancy can be important in cases with a history of severe haemolytic disease of the newborn. From chorionic villus biopsies (CVB) between the 8th and 12th week of gestation a small number of fetal red blood cells was obtained, inevitably highly contaminated with maternal blood cells. Two techniques were used to demonstrate the minor (fetal) cell population with a blood group antigen differing from the major (maternal) cell population: a solid-phase microfluorescence technique (introduced in this paper) which was compared with the mixed agglutination technique. In series of artificial mixtures of erythrocytes it was shown that with the microfluorescence technique the ABO and Rhesus phenotypes of minor cell populations could be determined at a ratio of 1 in 4000 erythrocytes of the major population, making this technique 4 times as sensitive as the mixed agglutination technique. We further investigated the reliability of the microfluorescence technique to demonstrate antagonistic fetal blood groups in the first trimester of pregnancy. Of 18 women undergoing CVB prior to therapeutic abortion, blood group antagonism (ABO and Rhesus systems) was demonstrate in all 11 cases in which it was present. Therefore, it seems that CVB can be reliably used for the prenatal diagnosis of (recurrent) blood group antagonism.

Quantitative aspects of the destruction of red cells sensitized with IgG1 autoantibodies: an application of flow cytofluorometry.

The purpose of this study was to determine whether quantitative or qualitative factors are of major importance in the destruction of red cells sensitized with incomplete warm autoantibodies of subclass IgG1. To that end, the relative amount of igG1 antibody present on the red cells of patients with autoantibodies of this subclass only, was measured by means of continuous flow cytofluorometry. This method appeared to give an idea of the amount of antibody on red cells and was reproducible. The intensity of the fluorescence of patient's red cells, measured after incubation with a FITC-labelled anti-IgG1, was compared with the presence or absence of signs of increased haemolysis in vivo and the cytotoxic activity of normal monocytes towards these red cells in vitro. It appearedthat it was predominantly the amount of IgG1 autoantibody that determined whether or not these antibodies induced haemolysis in vivo or cytotoxicity of monocytes in vitro. This was also true with methyldopa-induced IgG1 autoantibodies.