Biomedical subjects

A J van Dijk

Publications and source records attributed to A J van Dijk.

15 recordsLinked to original sources

PubMed2007

Role of human leucocyte antigen DQ in the presentation of T cell epitopes in the major cow's milk allergen alphas1-casein.

BACKGROUND: Little is known about the association between human leucocyte antigen (HLA) and cow's milk allergy (CMA). The aim of the present study was to determine the HLA restriction of T cell clones (TCCs) specific to alphas1-casein, the most abundant milk protein, and to study possible HLA class II allele associations with CMA. METHODS: alphas1-Casein-specific TCCs were derived from 6 children with CMA, 9 atopic children without CMA and 5 non-atopic children. T cell epitope specificity was defined by stimulation with overlapping peptides, spanning the alphas1-casein molecule. HLA restriction was determined in proliferation assays using antibodies blocking either HLA-DP, HLA-DQ or HLA-DR. HLA genotyping was performed in 32 subjects with CMA, 23 atopic and 22 non-atopic individuals. RESULTS: Ten TCCs were restricted to HLA-DQ, 6 TCCs to HLA-DR and 4 TCCs to HLA-DP. The sequence in alphas1-casein that was most immunogenic to T cells from children with CMA contained T cell epitopes restricted to DQB1*0201, DPB1*0401 and DRB1*1501. The DQB1*0501 allele frequency was lower in children with CMA than in non-atopic children, but this difference could not be confirmed in an additional group of subjects with and without CMA. CONCLUSIONS: HLA-DQ plays a substantial role in the presentation of T cell epitopes in alphas1-casein. However, HLA class II allele frequencies do not show major differences between cow's milk allergic, atopic and non-atopic subjects. T cell epitopes in the most immunogenic region are presented by various abundantly present HLA genotypes. Therefore, this sequence may be a suitable target for peptide immunotherapy.

Adolescent↗

PubMed2006

Acid-base balance of umbilical artery blood of liveborn piglets at birth and its relation with factors affecting delivery of individual piglets.

In the limited number of studies that reported on the relation between factors affecting birth of individual piglets and acid-base balance values at birth, predominantly simple correlation coefficients have been used. The aim of the present study was to analyse the relation between factors affecting delivery of individual liveborn piglets and acid-base balance values (pH, PCO(2) , HCO(3)(-) and BE(ecf)) at birth. In total 201 piglets originating from 44 litters were used for the collection of blood samples from the umbilical artery immediately after birth, preferably in the period of apnea. Blood samples were analysed with the iStat Portable Clinical Analyser. Significantly lower pH, HCO(3)(-), BE(ecf) and significantly higher PCO(2) levels were found in posteriorly presented piglets, independently of the condition of the umbilical cord, birth weight and cumulative birth interval/rank. Independently of presentation, birth weight and rank, piglets born with ruptured umbilical cords showed significantly lower pH values. Next to that, increasing birth weights resulted in increasing HCO(3)(-) and BE(ecf) values at birth, independently of presentation, condition of the umbilical cord and cumulative birth interval/rank. Both an increase in cumulative birth interval and in rank was associated with a significant decrease of pH, HCO(3)(-), BE(ecf) and increase of PCO(2) levels in umbilical cord blood at birth. Together these results demonstrate for the first time that a clear relation exists between (factors affecting) the progress of delivery and acid-base balance values in a polytocous species like the pig.

Acid-Base Equilibrium↗

PubMed2005

Factors affecting duration of the expulsive stage of parturition and piglet birth intervals in sows with uncomplicated, spontaneous farrowings.

Modern pig farming is still confronted with high perinatal piglet losses which are mainly contributed to factors associated with the progress of piglet expulsion. Therefore the aim of this study was to identify sow- and piglet factors affecting the duration of the expulsive stage of farrowing and piglet birth intervals in spontaneous farrowing sows originating from five different breeds. In total 211 litters were investigated. Breed affected duration of the expulsive stage significantly: the shortest duration was found in Large White x Meishan F2 crossbred litters and the longest duration in Dutch Landrace litters. No effect of parity on the duration of the expulsive stage was found. An increase in littersize (P<0.01), an increase in number of stillborn piglets per litter (P<0.05) and a decrease of gestation length (P<0.05, independently of littersize) all resulted in an increased duration of the expulsive stage of farrowing. A curvilinear relationship between birth interval and rank (relative position in the birth order) of the piglets was found. Besides that, piglet birth intervals increased with an increasing birth weight (P<0.001). Stillborn (P<0.01) and posteriorly presented (P<0.05) piglets were delivered after significantly longer birth intervals than liveborn and anteriorly presented piglets. The results on sow- and piglet factors affecting duration of the expulsive stage and piglet birth intervals obtained in this study contribute to an increased insight into (patho) physiological aspects of perinatal mortality in pigs.

Animals↗

PubMed2002

[Spray-dried plasma in diets for weaned piglets: influence on growth and underlying mechanisms].

Spray-dried animal plasma (SDAP) is a by-product of slaughter plants. The plasma obtained from slaughtered pigs or ruminants is spray-dried and used for the production of human foodstuffs and animal feeds. SDAP added to the diet of weaned piglets has considerable positive effects on the growth performance of piglets. In a meta-analysis, it was calculated from 68 comparisons between SDAP-containing diets and control diets that the SDAP-induced change in average daily gain (ADG) and average daily feed intake (ADFI) in the first 2 weeks after weaning was +26.8% and +24.5%, respectively. Two experiments demonstrated that dietary SDAP can reduce post-weaning diarrhoea. The aim of the research described in this thesis was to learn more about the mechanisms underlying the growth- and health-promoting properties of SDAP in the diet of weaned piglets. Results showed that dietary SDPP has positive effects on the post-weaning growth performance and health of piglets. These effects are more pronounced in piglets kept under suboptimal conditions and/or high infection pressure, and in piglets fed on diets lacking anti-microbial growth promoters. SDAP acts by influencing the gastrointestinal microflora: it appears to affect pathogenic bacteria rather than exert a general anti-bacterial effect leading to nutrient sparing, as has been described for anti-microbial growth promoters. SDAP has great potential as treatment for immuno-compromised mammals, such as neonates, and for animals in which antibiotic treatment is not possible, for instance when there is a ban against antibiotics or when multi-resistant bacteria are involved.

Animal Feed↗

PubMed2001

Small intestinal morphology in weaned piglets fed a diet containing spray-dried porcine plasma.

The hypothesis tested in this study was that the reported beneficial effects of spray-dried porcine plasma (SDPP) on piglet post-weaning performance and health are associated with a trophic effect on small intestinal mucosa. At 24 days of age, the piglets of seven sows were assigned to one of three treatment groups. One group continued to be suckled. The other two groups were weaned and offered a diet containing either 15 per cent SDPP or casein. From each treatment group, one piglet was anaesthetised and samples were taken from the small intestinal wall at 26, 28 and 31 days of age. There were no significant effects of SDPP versus casein on villus length. On average, there was less mitotic activity in the SDPP -fed piglets than in those fed casein on days 4 and 7 after weaning. As less mitotic activity leads to less immature enterocytes, this may provide a mechanism for the reported beneficial effects of SDPP on performance and health.

Animal Feed↗

PubMed2001

In vitro evidence for differential involvement of CTGF, TGFbeta, and PDGF-BB in mesangial response to injury.

BACKGROUND: Connective tissue growth factor (CTGF) is a profibrotic growth factor, which is upregulated in wound healing and renal fibrosis, including anti-Thy-1.1 nephritis. The kinetics of CTGF mRNA expression in anti-Thy-1.1 nephritis suggested that CTGF regulation might contribute to glomerular response to injury downstream of transforming growth factor-beta (TGFbeta). In anti-Thy-1.1 nephritis the initial damage is followed by mesangial repair and limited sclerosis, which involves mesangial cell (MC) activation (alpha-smooth-muscle actin (alphaSMA) expression), proliferation, migration, and extracellular matrix production. The present in vitro study addresses the possible role of CTGF in these different aspects of mesangial response to injury, and how CTGF activity might relate to effects of TGFbeta and platelet-derived growth factor-BB (PDGF-BB). METHODS AND RESULTS: Immunostaining and ELISA showed that alphaSMA expression and transformation of MC into myofibroblast-like cells was induced by TGFbeta, but not affected by PDGF-BB, CTGF, or neutralizing anti-CTGF antibodies. [(3)H]thymidine incorporation and Ki67 staining demonstrated that, unlike PDGF-BB, neither CTGF nor TGFbeta induced the proliferation of MC. In contrast, both CTGF and TGFbeta induced MC migration, as evidenced by approximation of wound edges in scrape-wounded, non-proliferating rat MC monolayers. In addition, fibronectin expression was upregulated by both CTGF and TGFbeta, as measured by dot-blot analysis. Anti-CTGF completely blocked the effect of added CTGF. Moreover, anti-CTGF significantly reduced TGFbeta-induced increase in fibronectin. CONCLUSION: It thus appears that CTGF is specifically involved in a subset of the adaptive changes of MC involved in mesangial repair and sclerosis, which makes it an interesting candidate target for future intervention strategies.

Actins↗

PubMed2001

Identification of human ccn2 (connective tissue growth factor) promoter polymorphisms.

BACKGROUND: Connective tissue growth factor (CCN2; CTGF) is a newly identified growth factor, which is involved in the regulation of wound repair and fibrosis. Because there is variation among individuals with respect to tissue response to injury, genetic factors might be involved in the final outcome of tissue repair or scarring. For example, polymorphisms in the promoter region of genes, such as those encoding transforming growth factor beta1 (TGF-beta1), interleukin 10 (IL-10), and tumour necrosis factor alpha (TNF-alpha), influence transcriptional responses and are thought to contribute to the dysregulation of these genes in pathological conditions. AIM: To investigate whether the promoter region of the ccn2 (ctgf) gene contains polymorphic sequences that might account for differential expression. MATERIALS/METHODS: Seventy seven human DNA samples were sequenced-45 were from healthy controls and 32 were from patients with ischaemic heart disease (IHD)-using M13 tailed sequence specific ccn2 (ctgf) primers for amplification of a 600 bp fragment upstream of the transcription start site. Amplicons were bidirectionally sequenced with a dye primer M13 forward and reverse sequencing kit. RESULTS: A C to G substitution was identified at position -132 in one of the patients with IHD. Moreover, in five of the 32 patients with IHD and in six of the 45 healthy controls, a G to C polymorphism was found at position -447. These substitutions at -132 and -447 are thought to lie within predicted binding domains for the transcription factors Pbx-1 and MZF1, respectively. In addition, insertions at position -43 (G), -47 (C), -71 (G) and a C to T substitution at position -198 were found in all DNA samples compared with the published ccn2 (ctgf) promoter sequence. These corrections do not involve sequences predicted to function as transcription factor binding sites. CONCLUSION: Sequence analysis of the ccn2 (ctgf) promoter of 77 human DNA samples has revealed corrections and polymorphic sites. The latter lie within putative regulatory elements.

Alleles↗

PubMed2000

Quality of life assessment: its integration in rehabilitation care through a model of daily living.

To integrate quality of life assessment with rehabilitation care, some correspondence is required between the concepts of quality of life and of rehabilitation. A notion of quality of life is presented in which quality is conceived as degree of goodness, and life as daily living. Rehabilitation is considered both a process of adaptation and assistance to that process. These notions of quality of life and of rehabilitation can together be operationalized through a model of daily living. An individual's appraisal of his own situation in relation to adaptation can be explained, assuming a hierarchy of internal standards. Explaining appraisal by others requires external standards. Both types of appraisal are important grounds for decisions regarding assistance. In addition, general ideas on justification of rehabilitation as assistance may influence such decisions. The model integrates both objective and subjective appraisal and ideas on justification into rehabilitation, thereby offering opportunities for theoretical underpinning of the practice.

Activities of Daily Living↗

PubMed1998

Predictors of health status and life satisfaction in spinal cord injury.

OBJECTIVE: To analyze relationships between injury-related variables, demographic variables, functional health status, and life satisfaction of people with spinal cord injury (SCI). DESIGN: Cross-sectional survey. SETTING: A community in the Netherlands. SUBJECTS: Three hundred eighteen people with SCI, aged 18 to 65 years. Mean age was 39.4 years and mean time after injury was 3.6 years. MAIN OUTCOME MEASURES: Health status was measured with the SIP68. Its six scales were aggregated to three dimensions, measuring physical, psychologic, and social functioning. Life satisfaction was measured with the Life Satisfaction Questionnaire. Data were analyzed by path analysis using LISREL V8. RESULTS: Obtained scores showed that respondents suffered from serious limitations in physical functioning and social functioning, had only a few limitations in psychologic functioning, and were satisfied with their lives in general and with most life domains. Physical functioning was accurately predicted by injury-related variables, but psychologic functioning was not. Next to level and completeness of the injury, the number of secondary complications turned out to be a predictor of functional health. In a path model that had a close fit with the data, injury-related variables were related to health status but not to life satisfaction. Social functioning (-.48), marital status (-.38), psychologic functioning (-.19), and age (-.16) were significant predictors of life satisfaction (total R2=.44). CONCLUSIONS: This study points out the high prevalence of secondary complications and their importance to the health status of people with SCI. Level of social and psychologic functioning are more important predictors of life satisfaction than the seriousness of the injury.

Adolescent↗

PubMed1998

Outcome of strategy training in stroke patients with apraxia: a phase II study.

OBJECTIVE: Evaluation of a therapy programme for stroke patients with apraxia. The programme is based on teaching patients strategies to compensate for the presence of apraxia. This programme was designed for assessment and treatment by occupational therapists. DESIGN: The outcome was studied in a pre-post test design. Measurements were conducted at baseline and 12 weeks later. SUBJECTS: Thirty-three stroke patients with apraxia were treated at occupational therapy departments n general hospitals, rehabilitation centres and nursing homes. MAIN OUTCOME MEASURES: The following measurements were conducted: an apraxia test, a motor functioning test, observation of activities of daily living (ADL), Barthel Index, and an ADL questionnaire for the therapist and the patient. RESULTS: The patients showed large improvements in ADL functioning on all measures and small improvements on the apraxia test and the motor functioning test. The effect sizes for the disabilities, ranging from 0.92 to 1.06, were large compared to the effect sizes for apraxia (0.34) and motor functioning (0.19). The significant effect of treatment is also seen when individual improvement and subjective improvement are considered. Measured with the Barthel Index for instance, 71% of the patients improved. CONCLUSIONS: These results suggest that the programme seems to be successful in teaching patients compensatory strategies that enable them to function more independently, despite the lasting presence of apraxia.

Activities of Daily Living↗

PubMed1997

B7-1 (CD80) as target for immunotoxin therapy for Hodgkin's disease.

In this preclinical study, the potential applicability of an anti-B7-1 immunotoxin (IT) for the treatment of Hodgkin's disease (HD) was investigated. Immunohistochemical analysis demonstrated strong expression of B7-1 on Hodgkin and Reed-Sternberg (R-S) cells and clear expression on dendritic cells, macrophages and some B-cells in tissues, but not on other tissue cells. Flow cytometric analysis demonstrated that B7-1 was expressed on a few monocytes, but not on CD34+ cells from bone marrow, resting T- or B-cells from peripheral blood or epithelial and endothelial cell lines. An anti-B7-1 immunotoxin containing the anti-B7-1 monoclonal antibody (MAb) B7-24 and saporin as toxin moiety was constructed and showed an affinity similar to that shown by the native MAb. It exhibited strong cytotoxicity against the B7-1+ B-cell line Raji (IC50 10(-11) M), R-S cell lines HDLM2, KM/H2 and L428 and also against a B7-1-transfected epithelial cell line, A431, whose parental line lacks expression of B7-1. In clonogenic assays with Raji cells or KM/H2 cells, a 3- or 4-log kill, respectively, was observed. No cytotoxicity was found against the B7-1- epithelial and endothelial cell lines or against haematopoietic progenitor cells. In conclusion, an anti-B7-1 immunotoxin was developed that had good cytotoxicity against R-S cell lines and that may be used in the elimination of R-S cells in vivo. A concomitant elimination of activated antigen-presenting cells may avoid development of antitoxin and anti-mouse Ig responses and allow repeated administration.

Antibodies, Monoclonal↗

PubMed1997

Services for spinal cord injured: availability and satisfaction.

This article discusses service delivery for Spinal Cord Injured (SCI) in the Netherlands. In this wealthy country, almost everyone has access to domestic adaptations and other equipment, regardless of income and with low, or without user contributions. However, satisfaction with this system of its products is rarely examined. Subjects in this research are 318 SCI individuals between 18 and 65 years of age, living in the community at a mean time of 3.6 years after injury. Availability of accessible housing, domestic adaptations, wheelchairs and outdoor transportation is investigated. Satisfaction with available services and satisfaction with service delivery procedures is measured by self-developed questionnaires. Relationships between these satisfaction scores and measures for functional health status (SIP68) and life satisfaction (LSQ) are analyzed. The presence of domestic adaptations is high, and 78.3% said their houses were sufficiently adapted at the time of the interview. Wheelchairs were generally available and most respondents had more than one. However, many users had complaints about their wheelchairs: 35.9% about their manual wheelchairs and 47.5% about their electric wheelchairs. Public transport was rarely used, 51.1% of respondents had an adapted car. Having an adapted car was significantly related to the ability to drive independently. Satisfaction with available services was acceptable, but satisfaction with service delivery procedures was very low. Satisfaction with available services did have a significant relationship with functional health status when the influence of the type of injury was taken into account. Satisfaction with available services also had a significant relationship with life satisfaction, after the influence of functional health status was taken into account. Further research on this topic is recommended.

Activities of Daily Living↗

PubMed1995

[Dutch interview version of the Barthel Index evaluated in patients with spinal cord injuries].

OBJECTIVE: Clinimetric evaluation of a Dutch questionnaire version of the Barthel Index (BI). DESIGN: Survey. SETTING: Eight Dutch rehabilitation centres. METHODS: Interviews with 318 spinal cord injured (SCI) patients living in the community, who were between 18 and 65 years of age at the time of the interview and who were admitted for the first time after injury to a specialized rehabilitation unit between 1986 and 1992. Validity, reliability and discriminant validity of the BI were determined. RESULTS: This Dutch questionnaire version of the BI had good reliability (Cronbach's alpha: 0.87; all item-total correlations > or = 0.30). In case of persons with a complete SCI a strong and statistically significant relationship was found between BI score and the level of the lesion (Spearman-Brown correlation: 0.69; p < 0.0001). Patients with more serious lesions had significantly higher BI scores than patients with less serious lesions. CONCLUSIONS: This Dutch questionnaire version of the BI was a sufficiently reliable and valid measure for assessing ability to cope in activities of daily living. Further research should be done on the test-retest reliability and responsiveness of this BI version.

Activities of Daily Living↗

PubMed1995

CD8 T cell activation after intravenous administration of CD3 x CD19 bispecific antibody in patients with non-Hodgkin lymphoma.

A bispecific antibody directed to T and B cells (CD3 x CD19 bsAb) was daily infused intravenously in escalating doses from 10 micrograms up to 5 mg in three patients with chemotherapy-resistant non-Hodgkin lymphoma; in this way we aimed to activate T cells to kill the malignant B cells. Only limited toxicity was observed, consisting of moderate fever preceded by chills or shivers and mild thrombocytopenia. No human anti-(mouse Ig) antibodies were found. Pharmacokinetics showed a t1/2 of 10.5 h with peak levels of 200-300 ng/ml after infusion of 2.5 mg bsAb. bsAb in serum was functionally active in vitro. After bsAb infusion a rise in serum tumour necrosis factor alpha was observed, accompanied by an increase in soluble CD8 and to some extent in soluble interleukin-2 receptor (IL-2R), but not in interferon gamma. IL-4 or soluble CD4. No evidence was found for monocyte activation (no increases in IL-6, IL-8 or IL-1 beta in serum). No gross changes in histology or number of IL-2R+, CD4+ or CD8+ cells were found in the lymph nodes after therapy, but one patient showed activated CD8+ T cells within the tumour nodules. In conclusion, after intravenously administered CD3 x CD19 bsAb only moderate toxicity was found, probably due to CD8+ T cell activation and cytokine release, without CD4+ T cell activation.

Adult↗

PubMed1988

[Somatotropin: endocrinological aspects].

Bovine somatotropin (BST) is a polypeptide hormone produced by the pituitary gland. Its release is regulated by hypothalamic hormones such as the Growth Hormone Releasing Factor (GRF) and the Somatotropin Release Inhibiting Factor (SRIF). Unlike somatotropin, GRF en SRIF are not species-specific. Somatotropin is released into the blood, and then bound to receptors which are present in various tissues but not in those of the mammary gland. Binding of somatotropin to receptors of hepatocytes results in the synthesis of somatomedins which are mediators of somatotropin. Receptors for somatomedins were recently found to be present in mammary gland tissue. The release of somatotropin is pulsatile and is influenced by steroids, genetic factors, nutrition and pregnancy. The effect of BST is dependent on its average concentration in the plasma and not on a particular pattern in this concentration. The effect of administration of BST prior to peak lactation is variable, but subsequently continuous to be positive. It therefore is advisable to start treatment after day 90. In the future, administration of recombinant-BST will be performed through slow-release preparations.

Animals↗