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Biomedical subjects

J de Jonge

Publications and source records attributed to J de Jonge.

16 recordsLinked to original sources
PubMed1999

The incorporation of different demand concepts in the job demand-control model: effects on health care professionals.

This paper reports a study of 212 health care professionals that focuses on job characteristics as predictors of employee health. By means of covariance structure modelling (LISREL 8) we tested the interactive assumptions of the Karasek (1979) Job Demand-Control (JD-C) Model [Karasek, R.A., Jr., 1979. Job demands, job decision latitude, and mental strain: implications for job redesign. Administrative Science Quarterly, 24, 285-307.] using three different concepts of job demands (i.e. psychological job demands, physical demands and emotional demands) in combination with a more focused measure of decision latitude (i.e. job autonomy) to predict employee health (i.e. job satisfaction, job involvement, emotional exhaustion and psychosomatic health complaints). Controlling for gender and age, the results partly support the JD-C hypotheses by finding three out of twelve assumed interaction effects. More specifically, different outcome variables are predicted by different combinations of job autonomy with the three kinds of job demands, respectively. In conclusion, although we refute the central hypotheses of the JD-C model to a large extent, the current (interactive) findings are quite illuminating and will be discussed in the context of their theoretical and practical implications. Researchers as well as practitioners have to broaden their perspective on 'job demands' in health care work and need to focus on different kinds of job demands to capture the complexity of this work setting.

Adult↗
PubMed1999

CD40 ligation prevents Trypanosoma cruzi infection through interleukin-12 upregulation.

Because of the critical role of the CD40-CD40 ligand (CD40L) pathway in the induction and effector phases of immune responses, we investigated the effects of CD40 ligation on the control of Trypanosoma cruzi infection. First, we observed that supernatants of murine spleen cells stimulated by CD40L-transfected 3T3 fibroblasts (3T3-CD40L transfectants) prevent the infection of mouse peritoneal macrophages (MPM) by T. cruzi. This phenomenon depends on de novo production of nitric oxide (NO) as it is prevented by the addition of N-nitro-L-arginine methyl ester, a NO synthase inhibitor. NO production requires interleukin (IL)-12-mediated gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) synthesis as demonstrated by inhibition experiments using neutralizing anti-IL-12, anti-IFN-gamma, and anti-TNF-alpha monoclonal antibodies (MAb). We found that an activating anti-CD40 MAb also directly stimulates IFN-gamma-activated MPM to produce NO and thereby to control T. cruzi infection. To determine the in vivo relevance of these in vitro findings, mice were injected with 3T3-CD40L transfectants or 3T3 control fibroblasts at the time of T. cruzi inoculation. We observed that in vivo CD40 ligation dramatically reduced both parasitemia and the mortality rate of T. cruzi-infected mice. A reduced parasitemia was still observed when the injection of 3T3-CD40L transfectants was delayed 8 days postinfection. It was abolished by injection of anti-IL-12 MAb. Taken together, these data establish that CD40 ligation facilitates the control of T. cruzi infection through a cascade involving IL-12, IFN-gamma, and NO.

3T3 Cells↗
PubMed1997

[Development and assessment of questionnaires].

This article describes the development and psychometric evaluation of self-report measurement instruments in (nursing) research. The aim of this study is to gain more insight into, and understanding of the use of such instruments. To be more specific, this paper deals with: (1) What is a self-report measurement instrument?; (2) How to develop such an instrument?; (3) What is its psychometric quality in terms of validity and reliability?; (4) How to analyze an instrument statistically?; (5) Which are the pros en cons of a self-report measurement instrument in general?; and (6) Where do we find examples of good measurement instruments? These six questions will be answered with the help of several practical research examples. The article concludes with a few suggestions for literature concerning existing measurement instruments and their psychometric qualities.

Evaluation Studies as Topic↗
PubMed1996

[Work and worker reactions in homes for the aged].

This article describes an investigation of relationships between work characteristics and worker reactions in three elderly homes of a Dutch foundation. Moreover, main effects as well as moderating effects of some relevant individual variables were studied. Variables were measured by means of questionnaires; 144 subjects from the caring and household departments took part in the study. From the results it appeared that social support, growth opportunities and work pressure are related to work satisfaction, work motivation and health complaints. The individual variables need for autonomy and coping strategies showed main effects as well as moderating- (buffer-) effects. On the basis of the findings practical consequences for the management of personnel and work have been formulated.

Adaptation, Psychological↗
PubMed1994

[Effect of work stress, autonomy and social support on the work experience of nurses and caregivers].

This paper describes a study on the relationship between job characteristics, health and well-being of health care professionals from various sectors (N = 249). More specific, we investigated the Demand-Control-Support Model (Johnson & Hall, 1988), using covariance structure modelling (LISREL 7). Although the data did not confirm the total model, we did found evidence with regard to some predicted relationships. Based on the present data, a revised model was presented. Finally, some practical implications were discussed.

Burnout, Professional↗
PubMed1993

Correction osteotomies of phalanges and metacarpals for rotational and angular malunion: a long-term follow-up and a review of the literature.

Correction osteotomies of nine phalanges and six metacarpals for rotational and angular malunion were performed in 15 patients ranging from 20 to 75 years of age and followed a mean period of 4.5 years, ranging from 1 to 11 years. Full correction of the preoperative deformity was achieved in 13 of the 15 patients (87%), bony union in 100%, and no loss of preoperative range of motion was observed, except in one patient who underwent additional arthrodesis. A high satisfaction rate was seen among 13 of the 15 patients. These results underline that osteotomies of phalanges and metacarpals for angular and rotational malunion can have significant functional benefits for the well-being of patients.

Adult↗
PubMed1991

Severe reductions in transcripts for cytochrome c oxidase during erythropoiesis in vitro do not lead to inactive mitochondria in reticulocytes.

At some stage during erythroid cell differentiation proliferation of the cell stops and its organelles are removed and degraded. We wanted to know how mitochondrial function correlated with the synthesis of products necessary for functional mitochondria. We studied the time course of the presence of a nuclear and a mitochondrial transcript for the mitochondrial enzyme cytochrome c oxidase as well as that of the enzyme activity itself in differentiating murine splenic erythroid progenitors (erythroid colony-forming units, CFU-E) in vitro. Whereas the amount of total RNA as well as the transcripts for subunits II and IV of cytochrome c oxidase (COX II and COX IV) per cell decreased to low levels, the amount of globin mRNA increased from zero in CFU-E (t = 0) to high levels in late erythroblasts (21 h). Thus, RNA synthesis as such was not inhibited. The cytochrome c oxidase activity also declined. In the total culture, total RNA as well as the mRNAs for COX II and IV decreased after 7 h. The enzyme activity increased until 21 h and decreased after that. The early decrease of the transcripts, followed after a lag phase of 14 h by a decrease in enzyme activity, ultimately does not result in inactive mitochondria in the reticulocyte stage, as was shown with a mitochondria-specific fluorescent probe.

Animals↗
PubMed1990

Intracerebral hematomas during anticoagulant treatment.

We retrospectively studied 79 patients from three centers who suffered an intracerebral hemorrhage during treatment with anticoagulants and compared them with 84 patients from one center who suffered a spontaneous intracerebral hemorrhage without anticoagulant treatment. Mortality after 30 days was slightly higher in patients with anticoagulant treatment (67%) than in those without (55%), and the proportion of patients who attained moderate or complete recovery was slightly smaller in the treated group (22% and 36%, respectively); neither difference was statistically significant. Volume of the supratentorial hematoma was measured from computed tomograms in 70% of the patients in both groups and was significantly greater in the 55 patients treated with anticoagulants than in the 59 patients not so treated. Volume was not related to the degree of anticoagulation. Based on the total number of patients treated with anticoagulants in the Heerlen region, we conclude that for patients older than 50 years of age the risk of intracerebral hemorrhage during anticoagulant treatment is increased approximately eightfold but is unrelated to the degree of anticoagulation. Our results suggest that intracerebral hemorrhage is more frequent and more extensive in patients treated with anticoagulants but that once it has occurred in such patients intracerebral hemorrhage is not significantly more serious than in untreated patients.

Adult↗
PubMed1989

The natural history of the Guillain-Barré syndrome in 18 children and 50 adults.

Plasma exchange (PE) is indicated in adult patients with a severe Guillain-Barré syndrome (GBS). For children this has not been proven. If the disease runs a milder course in children, the problems experienced with PE might outweight the benefit. In order to evaluate the need for such a specific treatment in children, we compared the severity of the disease between 18 children and 50 adults; no significant differences were found. The mean duration of hospitalisation of all children was 84 days, four children needed artificial ventilation for a mean of 21.5 days and two children died. We conclude therefore that PE is indicated in children with a severe GBS. The final decision, however, depends also on the practical feasibility of the procedure.

Adolescent↗
PubMed1988

Ataxia telangiectasia in a brother and sister at older age.

In general ataxia telangiectasia is a disease of childhood leading to severe ataxia in the first decade and death in adolescence. We present a brother and a sister with the characteristic features of ataxia telangiectasia at the age of 43 and 44. They are still in reasonable good health, despite their relative old age. This unusual manifestation of ataxia telangiectasia will be discussed with emphasis on clinical and genetic aspects.

Adult↗
PubMed1983

Metabolic aspects and viability of heparin/CPDA-1-stored red cell concentrate as a by-product of a high-yield factor VIII production method.

As a by-product of a new high-yield method of production of freeze-dried factor VIII, red cell concentrate (RCC) containing a small amount of heparin besides CPDA-1 was studied. Compared to CPDA-1 stored RCC no difference was found in hematology parameters and 2,3-DPG levels during 28 days storage. Although still in the normal range for transfusion, ATP levels were significantly lower compared to CPDA-1-stored RCC after 30 days shelf life. A survival study with 51Cr-labelled red cells showed good recovery and normal red cell half-life. Rapid transfusion of heparin/CPDA-1 RCC in 6 volunteers did not have any effect on aPTT. Heparin could not be detected in posttransfusion plasma samples.

2,3-Diphosphoglycerate↗
PubMed1980

Hard-tissue resorption and deposition after endodontic instrumentation.

Hard-tissue resorption and deposition following endodontic instrumentation were studied histologically in forty-one monkey teeth after 2, 7, and 42 days. No medicaments and no root canal filling materials were used. The number and length of lacunae and areas of resorption of the root canal wall, the root surface, and the lamina dura were counted and measured. Resorption, stimulated by instrumentation, was observed after 7 days at all sites. Resorption was slight at the root canal wall and at the root surface and was significantly more severe than normal osteoclastic replacement in the adjacent lamina dura. After 42 days the reaction had subsided at the three sites, but none of the tissue had returned to normal. Inflammatory reaction due to infection of the root canal appeared to enhance resorption after 42 days at the root canal wall and the lamina dura, but this was not observed at the root surface.

Alveolar Process↗