Search PubMed⌕ Search

Biomedical subjects

J de Jonge

Publications and source records attributed to J de Jonge.

At least 19 recordsLinked to original sources
PubMed2000

Importance of portal flow diversion in experimental auxiliary partial orthotopic liver transplantation.

BACKGROUND: Auxiliary partial orthotopic liver transplantation (APOLT) has successfully been performed in patients with noncirrhotic metabolic diseases. It remains, however, unclear if intervention in the portal venous inflow is necessary to ensure adequate portal blood flow to graft and host liver. In this experimental study we evaluate the hepatic flow during APOLT. METHODS: Left lateral/medial segmental grafts were transplanted from beagle to dalmatian dogs. Vascular structures were anastomosed end-to-end. The effect of diversion of the portal flow was studied in three groups: in the ligation group (n=3) the host portal vein was tied off, the free flow group (n=6) had random flow to both livers. In the banding group (n=11) the host portal vein was banded with a adjustable strapband to restore the pretransplantation flow distribution. RESULTS: After reperfusion the blood flow through the common portal vein decreased from 49 to 36 ml/kg/min (P<0.03) in all animals. Flow through the left portal vein decreased from 26 to 5 ml/kg/min (P<0.0001). Banding restored the flow in the left portal vein to 12 ml/kg/min, although the flow in the free-flow group remained 4 ml/kg/min. In the ligation group the total portal flow was forced toward the graft leading to the highest perfusion: 24 ml/kg/min (P<0.005). Adverse effect of this ligation was the development of portal hypertension. CONCLUSIONS: This experimental study confirms that diversion of the portal flow is necessary for adequate graft perfusion in APOLT. Banding can restore the pretransplantation flow distribution, without compromising the flow in the common portal vein.

Animals↗
PubMed2000

Job strain, effort-reward imbalance and employee well-being: a large-scale cross-sectional study.

This study investigated the effects of the Job Demand-Control (JD-C) Model and the Effort-Reward Imbalance (ERI) Model on employee well-being. A cross-sectional survey was conducted comprising a large representative sample of 11,636 employed Dutch men and women. Logistic regression analyses were used. Controlling for job sector, demographic characteristics (including educational level) and managerial position, employees reporting high job demands (i.e. psychological and physical demands) and low job control had elevated risks of emotional exhaustion, psychosomatic and physical health complaints and job dissatisfaction (odds ratios ranged from 2.89 to 10.94). Odds ratios were generally higher in employees reporting both high (psychological and physical) efforts and low rewards (i.e. poor salary, job insecurity and low work support): they ranged from 3.23 to 15.43. Furthermore, overcommitted people had higher risks of poor well-being due to a high effort-low reward mismatch (ORs: 3.57-20.81) than their less committed counterparts (ORs: 3.01-12.71). Finally, high efforts and low occupational rewards were stronger predictors of poor well-being than low job control when both job stress models were simultaneously adjusted. In conclusion, our findings show independent cumulative effects of both the JD-C Model and the ERI Model on employee well-being and are not significantly different in men and women as well as in young and old people. In particular, high (psychological and physical) efforts and low rewards adversely affected employee well-being. Preliminary findings also indicate excess risks of poor well-being in overcommitted persons suffering from high cost--low gain conditions at work.

Adolescent↗
PubMed2000

Linear and nonlinear relations between psychosocial job characteristics, subjective outcomes, and sickness absence: baseline results from SMASH. Study on Musculoskeletal Disorders, Absenteeism, Stress, and Health.

This study investigates the demand-control-support (DCS) model by (a) using a more focused measure of job control, (b) testing for interactive and nonlinear relationships, and (c) further extending the model to the prediction of an objective outcome measure (i.e., company-administrated sickness absence). Hypotheses were tested in a heterogeneous sample of 1,739 employees from a 3-year prospective cohort study called SMASH (Study on Musculoskeletal Disorders, Absenteeism, Stress, and Health). Baseline results showed that a linear additive model was superior for job satisfaction, psychosomatic health complaints, and sickness absence, whereas a curvilinear model was superior for emotional exhaustion and depression. It is concluded that, first, there was no evidence of interactive effects. Second, it seems sensible to pay more attention to curvilinear relationships in future research. Finally, the DCS model was not supported using a more objective outcome measure.

Adolescent↗
PubMed1999

Directing portal flow is essential for graft survival in auxiliary partial heterotopic liver transplantation in the dog.

BACKGROUND/PURPOSE: Auxiliary liver transplantation is an attractive alternative for orthotopic liver transplantation in patients with certain inborn errors of metabolism of the liver in which complete resection of the liver is unnecessary or even contraindicated. Because in these diseases portal hypertension is mostly absent, finding a balance in portal blood distribution between native liver and graft is complicated. The objective of this study was to investigate requirements for long-term (180 days) graft survival in auxiliary partial heterotopic liver transplantation (APHLT) in a dog model. METHODS: A metabolic defect was corrected in 26 dalmation dogs with a 60% beagle heterotopic auxiliary liver graft. Four groups of different portal inflow were studied. In the ligation group the portal vein to the host liver was ligated. In the split-flow group graft and host liver received separate portal inflow. In the banding group the distribution of the portal flow was regulated with an adjustable strapband and in the free-flow group the portal blood was allowed to flow randomly to host or graft liver. RESULTS: Metabolic correction increased in all groups after transplantation from 0.19 +/- 0.02 to 0.70 +/- 0.05 (P< .0001) but remained significantly better in the ligation and split-flow groups (graft survival, 135 +/- 27 and 144 +/- 31 days). In the banding group metabolic correction decreased significantly after 70 days, and although the grafts kept some function for 155 +/- 14 days, in 4 of 6 dogs portal thrombosis was found. In the free-flow group, competition for the portal blood led to reduced correction within 12 days and total loss of function in 96 +/- 14 days. Graft function also was assessed with technetium (Tc) 99m dimethyl-iminodiacetic acid uptake. A good linear association between HIDA uptake and metabolic correction was observed (r = 0.74; P < .0005). Grafts that contributed more than 15% to the total uptake of HIDA showed biochemical correction. This indicates a critical graft mass of about 15% to 20% of the hepatocyte volume to correct this metabolic defect. CONCLUSION: Auxiliary partial heterotopic liver transplantation can be a valuable alternative treatment for inborn errors of hepatic metabolism if the native liver and the graft receive separate portal blood inflow.

Animals↗
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↗