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Biomedical subjects

C J Heijnen

Publications and source records attributed to C J Heijnen.

At least 19 recordsLinked to original sources
PubMed2006

Disturbed in vitro adrenergic modulation of cytokine production in inflammatory bowel diseases in remission.

OBJECTIVE: Psychological stress has been implicated in the pathophysiology of both inflammatory and functional gastrointestinal (GI) diseases. The goal of this study was to address neuroendocrine modulation of cytokine production by peripheral blood cells in GI diseases. METHODS: We analyzed the in vitro effects of the beta-adrenergic agonist terbutaline and the glucocorticoid agonist dexamethasone on TNF-alpha and IL-10 production by LPS-stimulated monocytes in whole cell blood cultures in patients with inflammatory bowel diseases in remission (N=10), diarrhoea-predominant irritable bowel syndrome (IBS, N=12), patients with a recent gastroenteritis (post-infectious group, N=10), and healthy controls (N=15). RESULTS: In response to terbutaline, there was a significant increase in IL-10 production (concentration effect: p<0.05), which was diminished in IBD (group effect: p<0.01), comparable in IBS and controls, but enhanced in the post-infectious group (group x concentration effect: p<0.05). In contrast, terbutaline resulted in a concentration-dependent suppression of TNF-alpha production, which was comparable in all groups. Dexamethasone suppressed TNF-alpha production in a dose-dependent manner in all groups, but this effect was significantly more pronounced in post-infectious subjects (group effect: p<0.05). CONCLUSIONS: In IBD, disturbed adrenergic regulation of IL-10 could be part of the mechanism(s) underlying the modulation of disease activity by psychological stress. Diarrhoea-predominant IBS was not associated with altered adrenergic or glucocorticoid regulation of cytokine production by peripheral blood cells, whereas a recent history of gastroenteritis was associated with disturbed neuroendocrine modulation of cytokine production, which may play role in the pathophysiology of post-infectious IBS.

Adrenergic beta-Agonists↗
PubMed2006

Hydrogen peroxide impairs GRK2 translation via a calpain-dependent and cdk1-mediated pathway.

Oxidative mechanisms of injury are involved in many neurodegenerative diseases such as stroke, ischemia-reperfusion injury and multiple sclerosis. G protein-coupled receptor kinase 2 (GRK2) plays a key role in G protein-coupled receptor (GPCR) signaling modulation, and its expression levels are decreased after brain hypoxia/ischemia and reperfusion as well as in several inflammatory conditions. We report here that hydrogen peroxide downregulates GRK2 expression in C6 rat glioma cells. The hydrogen peroxide-induced decrease in GRK2 is prevented by a calpain protease inhibitor, but does not involve increased GRK2 degradation or changes in GRK2 mRNA level. Instead we show that hydrogen peroxide treatment impairs GRK2 translation in a process that requires Cdk1 activation and involves the mTOR pathway. This novel mechanism for the control of GRK2 expression in glial cells upon oxidative stress challenge may contribute to the modulation of GPCR signaling in different pathological conditions.

Animals↗
PubMed2006

Visceral pain and public speaking stress: neuroendocrine and immune cell responses in healthy subjects.

Whereas responses to psychological stressors are well-characterized, little is known regarding responses to painful visceral stimuli. We analyzed the emotional, cardiovascular, neuroendocrine, and cellular immune responses to painful rectal stimulation and psychological stress in healthy individuals. Eleven healthy subjects were studied in three conditions on separate days: painful rectal distension, public speaking stress, and rest. Blood was drawn for endocrinological and immunological analyses; heart rate and blood pressure were measured continuously; state anxiety was assessed with a questionnaire (STAI-S). Anxiety scores were highest in the rectal distension condition. This was evident following rectal distension (mean STAI-S scores: 44.2+/-3.5 post-distension vs. 36.6+/-3.8 post-speech, p<.05), but anxiety was also elevated at baseline (41.6+/-3.9 vs. 32+/-3.2 recovery, p<.01). This anticipatory effect was reflected by elevated baseline cortisol (p<.05) and baseline ACTH (p<.01) levels, as well as circulating lymphocytes and lymphocyte subsets, including decreased basal CD3+CD4+ cells (p<.05) and increased CD16+CD56+ cells (p=.06) compared to rest. Both public speech and rectal distension induced cardiovascular activation, but the effect was more pronounced following rectal distension (+63.8+/-9.4 mmHg in response to distension vs. +36.4+/-6.2 mmHg in response to speech for systolic BP, p<.05). Different response patterns were also observed in the distribution of circulating leukocytes and lymphocyte subsets, including CD16+CD56+ cells (p<.05). An acute visceral pain stimulus causes profound emotional, neuroendocrine, and immune cell responses, which are markedly affected by anticipatory anxiety. These findings may have implications for conditions associated with visceral hyperalgesia.

Adult↗
PubMed2005

Assessment of HPA-axis function in posttraumatic stress disorder: pharmacological and non-pharmacological challenge tests, a review.

Posttraumatic stress disorder (PTSD) is typically accompanied by acute and chronic alterations in the stress response. These alterations have mostly been described in individuals under baseline conditions, but several studies have also used a challenge model to further assess the role of the hypothalamic-pituitary-adrenal (HPA) axis in the stress response. This paper reviews common methodology and research findings on HPA function in PTSD, and discusses the pathophysiological mechanisms underlying these findings. We reviewed the literature and selected all English-language, human subject, data driven, pharmacological and non-pharmacological challenge studies pertaining to the HPA axis, and in vitro leukocyte glucocorticoid receptor studies in adult PTSD subjects. Studies using a non-pharmacological stress paradigm (cognitive stress, trauma reminders) to stimulate the HPA axis showed an exaggerated cortisol response in PTSD. The most widely used pharmacological challenge with consistent results was the low dose dexamethasone-suppression test (DST). These DST studies showed enhanced cortisol suppression in subjects with PTSD. Different hypotheses have been purported to explain the alterations in HPA axis functioning in PTSD. The results of the reviewed challenge tests, however, did not exclusively support one of the hypothesized mechanisms. Further research assessing hormones at all levels of the HPA axis at both baseline and at challenge conditions with a proper stratification of study population, will be necessary for a better understanding of stress-responsivity on the level of the HPA axis in PTSD.

Cognition↗
PubMed2004

Mechanical ventilation of healthy rats suppresses peripheral immune function.

This study was designed to investigate the possible effect of injurious mechanical ventilation on peripheral immune function of healthy rats. Three ventilation strategies were compared: 1) low peak inspiratory pressure (PIP)/positive end-expiratory pressure (PEEP); 2) high PIP/PEEP; and 3) high PIP/zero PEEP (ZEEP). As a reference group, healthy, nonventilated, sham-operated, anaesthetised rats were used. After 4 h, rats were sacrificed and macrophage inflammatory protein (MIP)-2 levels in lung and plasma were determined. Peripheral immune function was determined by measurement of splenic natural killer (NK) activity, mitogen-induced splenocyte proliferation and in vitro cytokine production. All immune measurements in the low PIP/PEEP group did not differ from the immune measurements in the reference group. High PIP strategies, irrespective of applied PEEP, enhanced MIP-2 levels in lung and plasma. NK cell activity, mitogen-induced splenocyte proliferation and MIP-2 and interleukin (IL)-10 production significantly decreased after high PIP/PEEP ventilation. In the high PIP/ZEEP-ventilated group, the decrease in splenocyte proliferation, MIP-2 and IL-10 production and NK cell activity was more pronounced and interferon-gamma production was also significantly lower than in the low PIP/PEEP group. These data show that high positive inspiratory pressure ventilation induces an inflammatory response in the lung, whereas at the same time the peripheral immune response is downregulated. Ventilator-induced peripheral immune suppression may contribute to poor outcome in acute respiratory distress syndrome patients.

Animals↗
PubMed2003

Short- and long-term effects of neonatal glucocorticoid therapy: is hydrocortisone an alternative to dexamethasone?

AIM: To compare short-term effects and neurodevelopmental outcome of neonatal glucocorticoid therapy between two centres. METHODS: A retrospective study was performed in two centres using a tapering course of either 5 to 1 mg kg(-1) hydrocortisone (HC; 22 d) or 0.5 to 0.1 mg kg(-1) dexamethasone (DEX; 21 d). In both centres glucocorticoid-treated infants and control patients were matched for gestational age, birthweight, severity of infant respiratory distress syndrome and periventricular-intraventricular haemorrhage. The following short-term glucocorticoid-induced effects were investigated in 25 HC-treated and 25 control patients in centre A, and in 23 DEX-treated and 23 control patients in centre B: oxygen dependency (inspiratory oxygen fraction), arterial pressure, blood glucose and urea concentrations, weight gain and head circumference before, during and after therapy (in treated infants), or at an interval comparable to treated infants (in control infants). Neurological outcome, psychomotor development and school performance at 5-7 y of age was evaluated in all groups. RESULTS: HC and DEX were equally potent in reducing oxygen dependency. Mean arterial pressure as well as blood glucose and urea concentrations were significantly increased during DEX, but not during HC treatment. Weight gain stopped during DEX therapy, but not during HC. Head circumference in both treatment groups was decreased after therapy compared with controls. Neonatally DEX-treated children needed special school education significantly more often (p < 0.01) than controls at 5-7 y of age. No differences between neonatally HC-treated children and controls on neurodevelopmental outcome were found at 5-7 y of age. CONCLUSION: Neonatal HC therapy has fewer short- and long-term adverse effects than neonatal DEX therapy.

Anti-Inflammatory Agents↗
PubMed2002

Dynamics of mycobacterial HSP65-induced T-cell cytokine expression during oral tolerance induction in adjuvant arthritis.

OBJECTIVE: To investigate whether oral administration of mycobacterial heat-shock protein 65 (HSP65) during adjuvant arthritis (AA) induces regulatory cells and cytokines. METHODS: AA was induced in Lewis rats and from the time of disease onset HSP65 in the presence of soya bean trypsin inhibitor (STI) was administered orally every other day. The number of splenic CD4+CD25+ T cells and antigen-induced cytokine mRNA expression were determined. RESULTS: Oral treatment with HSP65/STI reduced AA symptoms. After one feeding of HSP65/STI, the number of CD4+CD25+ splenic T cells increased and HSP65-specific T cells expressed increased levels of interferon gamma and interleukin 10. After two feedings, the expression of interleukin-10 mRNA remained increased, whereas there was low expression of interferon gamma mRNA. The number of CD4+CD25+ splenic T cells remained increased. CONCLUSIONS: Oral treatment with HSP65/STI after AA onset reduces disease symptoms via dynamic changes in the number of CD4+CD25+ splenocytes and in antigen-induced cytokine production.

Administration, Oral↗
PubMed2002

Adrenaline-induced immunological changes are altered in patients with rheumatoid arthritis.

OBJECTIVE: To investigate whether in rheumatoid arthritis (RA) patients the immunological changes induced by adrenaline are different from healthy controls (HC). METHODS: Fifteen female RA patients and 14 HC were infused with 1 micro g/kg adrenaline over 20 min. Blood was drawn before, immediately after, and 1 h after the end of infusion. Lymphocyte subpopulations, cytokine production and natural killer cell cytotoxicity were determined. RESULTS: Subjects exhibited mild cardiovascular changes with no differences between patients and controls. CD16(+)CD56(+)CD3(-) NK cells increased by a factor of 5.7, CD3(+) T cells by 1.5, monocytes by 1.6 and PMN by 1.2 in both groups. The numbers of IL-8- and IL-10-producing monocytes were higher in patients and presented a larger increase after infusion. NK cytotoxic activity was higher in RA patients and increased after infusion in both groups. Activated monocytes and T cells were preferentially recruited in patients and controls. Values returned to baseline 1 h later. CONCLUSION: We describe an altered response to adrenaline in patients with RA with both pro- and anti-inflammatory effects. Additionally, activated T cells and monocytes recruited to the peripheral blood may influence disease activity.

Adult↗
PubMed2001

Local interferon-gamma levels during respiratory syncytial virus lower respiratory tract infection are associated with disease severity.

To investigate the role of cell-mediated immunity during respiratory syncytial virus (RSV) infection, interferon (IFN)-gamma and interleukin (IL)-10 levels in nasopharyngeal secretions were measured in infants with lower respiratory tract infection (LRTI) caused by RSV. A novel technique was used to measure in vivo cytokine levels in nasopharyngeal aspirates (NPAs). Cytokine levels in the NPAs of 17 mechanically ventilated infants and 43 nonventilated hospitalized infants were compared. As expected, mechanically ventilated infants were significantly younger than nonventilated infants (7 vs. 14 weeks). IFN-gamma levels were above the limit of detection in the NPAs of 3 (18%) mechanically ventilated infants and in the NPAs of 26 (60%) nonventilated infants. IL-10 levels in the NPAs of mechanically ventilated and nonventilated infants were comparable. It is hypothesized that maturation-related mechanisms have a key role in the development of RSV LRTI that results in mechanical ventilation.

Age Factors↗
PubMed2001

Adjuvant arthritis induces down-regulation of G protein-coupled receptor kinases in the immune system.

G protein-coupled receptors (GPCR) play a crucial role in the regulation of the immune response by, e.g., chemokines, PGs, and beta(2)-adrenergic agonists. The responsiveness of these GPCRs is turned off by the family of G protein-coupled receptor kinases (GRK1-6). These kinases act by phosphorylating the GPCR in an agonist-dependent manner, resulting in homologous desensitization of the receptor. Although GRKs are widely expressed throughout the body, leukocytes express relatively high levels of GRKs, in particular GRK2, -3, and -6. We investigated whether in vivo the inflammatory disease adjuvant arthritis (AA) induces changes in GRK expression and function in the immune system. In addition, we analyzed whether the systemic effects of AA also involve changes in GRKs in nonimmune organs. At the peak of the inflammatory process, we observed a profound down-regulation of GRK2, -3, and -6 in splenocytes and mesenteric lymph node cells from AA rats. Interestingly, no changes in GRK were observed in thymocytes and in nonimmune organs such as heart and pituitary. During the remission phase of AA, GRK levels in spleen and mesenteric lymph nodes are returning to baseline levels. The decrease in GRK2 at the peak of AA is restricted to CD45RA(+) B cells and CD4(+) T cells, and was not observed in CD8(+) T cells. In conclusion, we demonstrate in this study, for the first time, that an inflammatory process in vivo induces a tissue-specific down-regulation of GRKs in the immune system.

Animals↗
PubMed2001

Neonatal dexamethasone treatment induces long-lasting changes in T-cell receptor vbeta repertoire in rats.

Glucocorticoids are frequently administered for the prevention of chronic lung disease in infants with respiratory distress syndrome. However, neonatal treatment may have consequences for immune functioning in the long-term. Here we demonstrate that neonatal glucocorticoid treatment has long-lasting effects on mRNA expression of several Vbeta genes within the CD4 and CD8 T cell subset in rats. Changes in the peripheral T cell Vbeta repertoire may be a consequence of altered intrathymic selection events in which corticosterone plays an important role. Indeed, here we show that neonatal glucocorticoid treatment affects corticosterone production by thymic epithelial cells during neonatal life. In conclusion, changes in T cell Vbeta repertoire after neonatal glucocorticoid treatment may contribute to altered immune reactivity in later life.

Age Factors↗
PubMed2001

Neonatal glucocorticoids and the developing brain: short-term treatment with life-long consequences?

Although synthetic glucocorticoids are frequently used in hospital for the prevention of chronic lung disease in premature infants, major concern has arisen about the possible long-term consequences of these treatments. Animal research provides evidence for the idea that neonatal glucocorticoid treatment enhances susceptibility to autoimmune disease in adult life. Altered functioning of the hypothalamo-pituitary-adrenal axis, and/or changes at higher brain levels might underlie alterations in disease susceptibility.

Animals↗
PubMed2001

Systemic lupus erythematosus and rheumatoid arthritis patients differ from healthy controls in their cytokine pattern after stress exposure.

OBJECTIVE: To study whether patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) differ from healthy individuals in their immune responses to acute psychological stress. METHODS: The phenotype and function of peripheral blood lymphocytes were analysed before and after stress exposure in patients and healthy subjects. RESULTS: Natural killer (NK) cell numbers increased transiently in all groups under stress. NK activity, however, increased in healthy controls only. We observed a stress-induced increase in interleukin (IL)-4-producing (IL-4(+)) cells in SLE patients only, whereas interferon (IFN) gamma(+) cell numbers increased due to stress in all three groups. An analysis of supernatants from phytohaemagglutinin (PHA) cultures revealed increased IFN gamma and IL-10 levels in healthy subjects but not in SLE or RA patients after stress exposure. CONCLUSIONS: These data demonstrate that RA and SLE patients differ in their immune response to stress from healthy controls. Changes in cytokine patterns might be responsible for stress-induced exacerbation of disease activity in RA and SLE patients.

Adult↗
PubMed2001

Psychological adjustment of adolescent girls with chronic fatigue syndrome.

OBJECTIVE: To examine psychosocial problems and adaptation of adolescent girls with chronic fatigue syndrome (CFS). METHODOLOGY: Thirty-six adolescent girls with CFS (mean age: 15.2 years; mean syndrome duration: 19.7 months) who fulfilled the criteria of the Centers for Disease Control and Prevention were examined by interviews regarding premorbid problems and by questionnaires regarding psychosocial functioning and distress, psychological attitudes, and coping resources. Data were compared with normative data. RESULTS: Of the adolescents, 86.1% reported 1 or more premorbid problems (58.3% physical, 38.9% psychological, and 52.8% familial). Normal adjustment was reported for psychosocial self-esteem, social abilities, and attentional abilities. High adjustment to adult social standards of behavior was found, but low perceived competence in specific adolescent domains, such as athletic ability, romance, and participation in recreational activities. The girls reported predominantly internalizing problems. Normal achievement motivation, no debilitating fear of failure, and high internal locus of control were observed. Palliative reaction patterns and optimism were predominantly used as coping strategies. CONCLUSIONS: The large number of premorbid problems suggests a possible contributing factor to the onset of the syndrome, although there were no reference data of healthy adolescents. In distinct domains of psychosocial adjustment, the adolescent girls with CFS showed strengths such as adequate self-esteem and scholastic and social abilities, and weaknesses such as low competence in adolescent-specific tasks and internalizing distress, which may partly be explained by syndrome-specific somatic complaints. The use of optimistic and palliative reaction patterns as coping strategies in this patient group indicates that the patients with CFS seem to retain an active and positive outlook on life, which may result in a rather adequate psychological adaptation to the syndrome, but also in maintenance of the syndrome by exceeding the physical limits brought about by the CFS. Our results on adjustment and coping strategies may be helpful to implement (individual) rehabilitation programs.

Adaptation, Psychological↗
PubMed2000

Neonatal dexamethasone treatment increases susceptibility to experimental autoimmune disease in adult rats.

Major concern has emerged about the possible long term adverse effects of glucocorticoid treatment, which is frequently used for the prevention of chronic lung disease in preterm infants. Here we show that neonatal glucocorticoid treatment of rats increases the severity (p< or = 0.01) and incidence (p< or =0.01) of the inflammatory autoimmune disease experimental autoimmune encephalomyelitis in adult life. In search of possible mechanisms responsible for the increased susceptibility to experimental autoimmune encephalomyelitis, we investigated the reactivity of the hypothalamo-pituitary-adrenal axis and of immune cells in adult rats after neonatal glucocorticoid treatment. We observed that neonatal glucocorticoid treatment reduces the corticosterone response after an LPS challenge in adult rats (p< or =0.001). Interestingly, LPS-stimulated macrophages of glucocorticoid-treated rats produce less TNF-alpha and IL-1beta in adult life than control rats (p<0.05). In addition, splenocytes obtained from adult rats express increased mRNA levels of the proinflammatory cytokines IFN-gamma (p<0.01) and TNF-beta (p<0.05) after neonatal glucocorticoid treatment. Apparently, neonatal glucocorticoid treatment has permanent programming effects on endocrine as well as immune functioning in adult life. In view of the frequent clinical application of glucocorticoids to preterm infants, our data demonstrate that neonatal glucocorticoid treatment may be a risk factor for the development of (auto)immune disease in man.

Aging↗
PubMed2000

Stress induces increases in IL-6 production by leucocytes of patients with the chronic inflammatory disease juvenile rheumatoid arthritis: a putative role for alpha(1)-adrenergic receptors.

Juvenile rheumatoid arthritis (JRA) is characterized by chronic inflammation of the joints. In the present study we demonstrate that exposure of JRA patients to a noradrenergic stressor (cold pressor test) results in enhanced LPS-induced IL-6 production by peripheral blood cells of these patients. Healthy, age-matched controls had the same rise in norepinephrine, but do not respond with changes in IL-6 production after exposure to the cold pressor test. Moreover, PBMC of patients with JRA express mRNA encoding alpha(1)-adrenergic receptors (AR), predominantly of the alpha(1d)-AR subtype. In contrast, we could not detect mRNA encoding for alpha(1)-AR in PBMC of healthy controls. The results of this study suggest that expression of alpha(1)-AR mRNA in PBMC during chronic inflammation is associated with altered responses of the immune system to stress.

Acute Disease↗
PubMed2000

Noradrenaline induces phosphorylation of ERK-2 in human peripheral blood mononuclear cells after induction of alpha(1)-adrenergic receptors.

alpha(1)-Adrenergic receptors (ARs) are not expressed by peripheral blood mononuclear cells (PBMCs) of healthy human individuals. However, in the present study we show that alpha(1)-ARs can be induced in lymphocytes after culturing with either the mitogen PHA or the glucocorticoid dexamethasone. Moreover, incubation of these activated PBMCs with noradrenaline (NA) results in enhanced phosphorylation of ERK-2, a kinase involved in the activation of many immune functions. Similar induction of alpha(1)-AR mRNA with concomitant NA-induced activation of ERK-2 occurs in monocytes after culture with LPS. Our results demonstrate that functional alpha(1)-ARs can be induced on PBMCs and that these alpha(1)-ARs mediate NA-induced activation of ERK-2.

Adrenergic alpha-1 Receptor Antagonists↗