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A Prins

Publications and source records attributed to A Prins.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cardiovascular health check in the elderly in one general practice: does it offer new information and lead to interventions?

BACKGROUND: Prevention of cardiovascular disease in the elderly is becoming increasingly important. GPs are in a unique position to initiate preventive interventions in this age group. However, it is not clear which strategy a GP should follow to identify patients at increased cardiovascular risk-case finding or screening. OBJECTIVE: We aimed to assess the value of a single cardiovascular health check compared with a normal care case finding and to investigate the diagnostic or therapeutic consequences of detecting new cardiovascular risk indicators. METHODS: In 1991, 1002 persons aged 60 years and over, enlisted in one general practice, were invited. Of the 805 subjects who responded (80%), the cardiovascular risk profile was determined by a research physician. The proportion of newly detected cardiovascular risk indicators was the main outcome measure. A risk indicator was considered newly detected when it was not mentioned in the GP's summary of the patient record, which had been checked by the patient for its completeness. The patient records of participants with newly detected hypertension, diabetes or hypercholesterolaemia were systematically reviewed to detect diagnostic and therapeutic interventions by the GP. RESULTS: In 25.1% of the participants, one or more cardiovascular risk indicators were found which were previously unknown to the GP, including 38 (4.7%) cases of hypertension, 82 (10%) cases of isolated systolic hypertension, 14 (1.7%) cases of diabetes mellitus and 63 (7.8%) cases of hypercholesterolaemia. On the basis of these findings, the GP initiated therapeutic interventions in almost all subjects with newly detected diabetes. However, reports of newly detected hypertension or high cholesterol levels were usually not followed by an intervention. CONCLUSION: A single cardiovascular health check in the elderly can detect a considerable number of risk indicators that are unknown to a patient's GP. In most cases, however, the detection of hypertension or cholesterol > or = 6.5 mmol/l did not lead to interventions by the GP. More efforts are needed to ensure that the beneficial effects of these interventions are not limited to participants in clinical trials but can be extended to patients in general practice.

Aged↗
PubMed1999

Validity of American College of Rheumatology criteria for diagnosing hip osteoarthritis in primary care research.

OBJECTIVE: To study the validity of the American College of Rheumatology (ACR) criteria for hip osteoarthritis (OA) in patients receiving primary care. Three different sets of criteria are available, one with clinical symptoms only, and 2 with clinical symptoms and radiological signs combined. It is claimed that all 3 sets, separate from each other, can be used to diagnose hip OA for research purposes. METHODS: Consecutive patients (n = 227) aged 50 years or older, who had consulted a general practitioner for pain in the hip and had been referred for radiographic investigation of the hip, were recruited for a standardized history taking and physical investigation. The radiographs were evaluated according to a standardized protocol. The cross validity of the 3 different sets of ACR criteria was assessed by calculating the percentage agreement and the kappa between the separate sets. RESULTS: There was poor agreement between the set of clinical criteria and the 2 sets in which radiological signs were included (kappa 0.11 or lower). The 2 sets that included radiological signs showed high agreement (kappa 0.81-0.94, depending on cut off points for joint space narrowing). These sets also showed the highest agreement with the radiological OA defined as a Kellgren score 2 or more (kappa 0.13-0.48). CONCLUSION: The clinical ACR criteria showed no cross validity with the 2 other ACR criteria sets.

Female↗
PubMed1998

What is 'heavy'?

One of the work practices frequently taught to employees is to estimate the heaviness of load before it is actually handled. If it is 'heavy', then one should ask for help. However, limited information can be found in the ergonomics literature about what a person perceives as a 'heavy load'. This study was conducted on 20 male and 20 female workers in the package delivery industry to estimate the amounts of load that correspond to various levels of load heaviness (e.g. 'somewhat heavy'). Experienced employees were used for this purpose. The distribution of loads within each heaviness level was developed using fuzzy sets theory. The maximum load (i.e. 23 kg) defined by the US National Institute for Occupational Safety and Health represents a 'somewhat heavy' load based on the analysis of load distribution (corresponding to a 1.0 certainty factor). Also, the 40 kg considered in the 1981 NIOSH guidelines may be classified as a 'very heavy' load. A comparative analysis of the results of this study with norms established in prior research indicates that one should be more careful in the interpretation of statistical norms for human perception of load handling. A 'moderate' level of load heaviness (i.e. 14 kg) can be handled by 85% of the worker population.

Adolescent↗
PubMed1998

Measuring morbidity of children in the community: a comparison of interview and diary data.

BACKGROUND: Little is known about the validity of estimates of morbidity experienced at home. METHODS: In the Dutch National Survey of Morbidity and Interventions in General Practice mothers of 1630 children answered a health interview and kept a health diary for 3 weeks (only the first 2 weeks were used). Children's symptoms were recorded during the interview using a check list and monitored in the health diary through open-ended questions. RESULTS: In the interview parents reported symptoms for 65% of their children and in the diary for 54% of children. Ear problems, colds, fever and weakness and anxiety were reported more often in the interview. Mother's mental health was assessed by the General Health Questionnaire; those scoring >4 were assessed as having impaired mental health and these parents reported symptoms for more children in the interview (81%) than in the diary (65%). For similar reference periods, the least educated mothers reported fewer children with symptoms in the diary (45%) than in the interview (66%). More highly educated mothers reported similarly in the diary (67%) and the interview (70%). CONCLUSION: Both data collection methods yield different estimates of community morbidity. Explanations such as telescoping, the seriousness of the symptoms, the amount of psychological distress of the respondent, forgetfulness and literacy limitations are discussed. We recommend that diaries should not be used in less educated populations.

Adolescent↗
PubMed1998

Validity and accuracy of interview and diary data on children's medical utilisation in The Netherlands.

STUDY OBJECTIVE: To assess the validity and accuracy of children's medical utilisation estimates from a health interview and diary and the possible consequences for morbidity estimates. The influence of recall bias and respondent characteristics on the reporting levels was also investigated. DESIGN: Validity study, with the medical record of the general practitioner (GP) as gold standard. In a health interview and three week diary estimates of medical utilisation of children were asked and compared with a GP's medical record. SETTING: General community and primary care centre in the Netherlands. PARTICIPANTS: Parents of 1,805 children and 161 GPs. MAIN RESULTS: The sensitivity of the interview (0.84) is higher than the diary (0.72), while specificity and kappa are higher in the diary (0.96; 0.64) than in the interview (0.91; 0.5-8). Recall bias, expressed as telescoping and heaping, is present in the interview data. Prevalence estimates of all morbidity are much higher in the interview, except for skin problems. Compared with a parental diary more consultations are reported exclusively by the GP for children from ethnic minorities (OR 1.6), jobless (OR 2.3), and less educated mothers (OR 2.6). CONCLUSIONS: Estimates of medical utilisation rates of children are critically influenced by the method of data collection used. Interviews are prone to introduce recall bias, while diaries should only be used in populations with an adequate level of literacy. It is recommended that medical records are used, as they produce most consistent estimates.

Child↗
PubMed1998

Comparison between two devices for measuring hip joint motions.

OBJECTIVE: To compare the reliability of measurements of hip motions obtained with two instruments, an electronic inclinometer and a two-arm goniometer, and to investigate whether the two instruments, and different body positions, produce the same measurement data. METHODS: Maximal active and passive hip movements were measured simultaneously with both instruments, in nine subjects during 10 consecutive measurements at short intervals. RESULTS: Intra-observer variability was lower with the inclinometer in measurements of passive hip rotations. The two instruments showed equal intra-observer variability for hip movements in general. The inclinometer showed lower inter-observer variability in the measurements of active internal rotation. More rotational movement was measured with the two-arm goniometer; more extension and flexion with the inclinometer. Also, more rotational movement was found in the prone position compared to sitting and supine positions. CONCLUSIONS: The inclinometer is more reliable in measurements of hip rotation. For hip movements in general the two-arm goniometer is just as accurate when used by only one observer. The two instruments, and some positions, are not interchangeable during consecutive measurements.

Adult↗
PubMed1998

Everyday symptoms in childhood: occurrence and general practitioner consultation rates.

BACKGROUND: Fewer than 20% of all illnesses that occur in the home require the attention of a general practitioner (GP). Whether specific illnesses in children are more likely to need the attention of a GP is poorly understood, as is the influence of various other factors. Health diaries are the most suitable method of collecting comprehensive information about children's health problems at home and in general practice simultaneously. AIM: To investigate the occurrence of, and consultation rates for, specific symptoms in childhood in relation to age, sex, birth order, and place of residence of the child, and season of the year. METHOD: The parents of 1805 children kept a health diary over three weeks and recorded symptoms and consultation behaviour. The symptoms were later combined into illness episodes. RESULTS: Over three weeks, colds/flu (157/1000 children) and respiratory symptoms (114/1000 children) occurred most frequently. More young children (0-4 years) suffered from illness generally. Eleven per cent of all illness episodes required the attention of a GP. Consultation rates differed greatly according to symptoms. A GP was consulted most often for ear (36%) and skin (28%) problems, and least often for headaches (2%) and tiredness (1%). Regardless of symptoms, young children (0-4 years) were taken to a GP twice as often as older children (10-14 years). CONCLUSIONS: This study emphasizes the enormous amount of illness that occurs in children and the fact that more than 80% of all illnesses are dealt with by parents without reference to the professional health care system.

Adolescent↗
PubMed1997

Diphtheria toxin fused to granulocyte-macrophage colony-stimulating factor eliminates acute myeloid leukemia cells with the potential to initiate leukemia in immunodeficient mice, but spares normal hemopoietic stem cells.

We studied the cell kill induced by granulocyte-macrophage colony-stimulating factor (GM-CSF ) fused to Diphtheria Toxin (DT-GM-CSF ) in acute myeloid leukemia (AML) samples and in populations of normal primitive hemopoietic progenitor cells. AML samples from three patients were incubated in vitro with 100 ng/mL DT-GM-CSF for 48 hours, and AML cell kill was determined in a proliferation assay, a clonogenic assay colony-forming unit-AML (CFU-AML) and a quantitative long-term bone marrow (BM) culture ie, the leukemic-cobblestone area forming cell assay (L-CAFC). To measure an effect on cells with in vivo leukemia initiating potential DT-GM-CSF exposed AML cells were transplanted into immunodeficient mice. In two out of three samples it was shown that all AML subsets, including those with long-term abilities in vivo (severe combined immunodeficient mice) and in vitro (L-CAFC assay) were reduced in number by DT-GM-CSF. Cell kill induced by DT-GM-CSF could be prevented by coincubation with an excess of GM-CSF, demonstrating that sensitivity to DT-GM-CSF is specifically mediated by the GM-CSF receptor. Therefore, binding and internalization of GM-CSF probably occur in immature AML precursors of these two cases of AML. The third AML sample was not responsive to either GM-CSF or DT-GM-CSF. The number of committed progenitors of normal bone marrow (burst-forming unit-erythroid, colony-forming unit granulocyte- macrophage, and cobble stone area forming cell [CAFC] week 2) and also the number of cells with long-term repopulating ability, assayed as week 6 CAFC, were unchanged after exposure to DT-GM-CSF (100 ng/mL, 48 hours). These studies show that DT-GM-CSF may be used to eliminate myeloid leukemic cells with long-term potential in vitro and in immunodeficient mice, whereas normal hemopoietic stem cells are spared.

Acute Disease↗
PubMed1997

Withdrawal of long-term diuretic medication in elderly patients: a double blind randomised trial.

OBJECTIVES: About 20% of elderly people use long-term diuretic medication, but there is doubt whether prolonged diuretic medication on such a large scale is necessary. We performed a study to assess what proportion may successfully be withdrawn from diuretic therapy. DESIGN: Double blind randomised controlled trial with six month follow up. SETTING: General practice. SUBJECTS: 202 patients taking long-term diuretics without manifest heart failure or hypertension. INTERVENTIONS: Patients were allocated to either placebo (withdrawal group, n = 102) or continuation of diuretic treatment (control group, n = 100). MAIN OUTCOME MEASURE: Occurrence of clinical conditions requiring diuretic therapy based on fixed criteria. RESULTS: During follow up diuretic therapy was required in 50 patients in the withdrawal group and 13 in the control group (risk difference 36%; 95% confidence interval 22% to 50%). Heart failure was the most frequent cause of prescribing diuretic therapy (n = 25). Cessation of diuretic therapy caused a mean increase in systolic blood pressure of 13.5 (9.2 to 17.8) mm Hg and in diastolic pressure of 4.6 (1.9 to 7.3) mm Hg. CONCLUSION: Withdrawal of long-term diuretic treatment in elderly patients leads to symptoms of heart failure or increase in blood pressure to hypertensive values in most cases. Any attempt to withdraw diuretic therapy requires careful monitoring conditions, notably during the initial four weeks.

Aged↗
PubMed1997

Facilitated engraftment of human hematopoietic cells in severe combined immunodeficient mice following a single injection of Cl2MDP liposomes.

Transplantation of normal and malignant human hematopoietic cells into severe combined immunodeficient (SCID) mice allows for evaluation of long-term growth abilities of these cells and provides a preclinical model for therapeutic interventions. However, large numbers of cells are required for successful engraftment in preirradiated mice due to residual graft resistance, that may be mediated by cells from the mononuclear phagocytic system. Intravenous (i.v.) injection of liposomes containing dichloromethylene diphosphonate (Cl2MDP) may eliminate mouse macrophages in spleen and liver. In this study outgrowth of acute myeloid leukemia (AML) cells and umbilical cord blood (UCB) cells in SCID mice conditioned with a single i.v. injection of Cl2MDP liposomes in addition to sublethal total body irradiation (TBI) was compared to outgrowth of these cells in SCID mice that had received TBI alone. A two- to 10-fold increase in outgrowth of AML cells was observed in four cases of AML. Administration of 10(7) UCB cells reproducibly engrafted SCID mice that had been conditioned with Cl2MDP liposomes and TBI, whereas human cells were not detected in mice conditioned with TBI alone. As few as 2 x 10(4) purified CD34+ UCB cells engrafted in all mice treated with Cl2MDP liposomes. In SCID mice treated with macrophage depletion unexpected graft failures were not observed. Histological examination of the spleen showed that TBI and Cl2MDP liposomes i.v. resulted in a transient elimination of all macrophage subsets in the spleen, whereas TBI had a minor effect. Cl2MDP liposomes were easy to use and their application was not associated with appreciable side-effects. Cl2MDP liposome pretreatment in combination with TBI allows for reproducible outgrowth of high numbers of human hematopoietic cells in SCID mice.

Animals↗
PubMed1996

Fluorouracil selectively spares acute myeloid leukemia cells with long-term growth abilities in immunodeficient mice and in culture.

A subset of leukemic cells is assumed to maintain long-term growth of acute myeloid leukemia (AML) in vivo. Characterization of these AML progenitor cells may further define growth properties of human leukemia. In vitro incubations with 5-fluorouracil (5-FU) have been used for enrichment of normal primitive hematopoietic stem cells. By analogy to normal hematopoiesis, it was hypothesized that primitive leukemic stem cells might be kinetically more inactive than colony-forming cells (colony-forming units-AML [CFU-AML]). To examine this hypothesis, conditions were established for incubation with 5-FU that eliminated all CFU-AML. These conditions selected a 5-FU-resistant AML fraction that was evaluated for its capacity for long-term growth by transplantation into mice with severe combined immunodeficiency (SCID) and long-term culture in the quantitative cobblestone area-forming cell (CAFC) assay. Transplantation of the 5-FU-resistant fraction of four cases of AML into SCID mice resulted in growth of AML. Whereas no CFU-AML survived, 31% to 82% of primitive (week-6) CAFC were recovered from the 5-FU-treated cells. Hematopoietic cells proliferating in the CAFC assay were shown to be leukemic by cytologic, cytogenetic, or molecular analysis. The reduction of AML growth as determined by outgrowth of AML in SCID mice was in the same order of magnitude as the primitive (week-6) CAFC reduction. This indicates that both assays measure closely related cell populations and that the CAFC assay can be used to study long-term growth of AML. These results show a hierarchy of AML cells that includes 5-FU-resistant progenitors. These cells are characterized as primitive (week-6) CAFC and as leukemia-initiating cells in SCID mice.

Acute Disease↗
PubMed1996

Long-term leukemia-initiating capacity of a CD34-subpopulation of acute myeloid leukemia.

Acute myeloid leukemia (AML) proliferation in vivo is maintained by a small fraction of progenitor cells. These cells have been assumed to express an immature phenotype and to produce most colony-forming units (CFU-AML). For one case of AML (French-American-British [FAB] M1, normal cytogenetics), we examined the capacity of the CD34+ (25% of unseparated AML cells) and CD34- fractions to initiate leukemia in severe combined immunodeficient (SCID) mice. In addition, the production of CFU-AML and nucleated cells (NC) of these subsets was investigated in long-term bone marrow culture (LTBMC). The frequencies of cobblestone area-forming cells (CAFC) were also estimated; early appearing cobblestone areas (CAs) are indicative of relatively mature progenitors and late CAs represent the progeny of primitive progenitors. In mice transplanted with CD34- (98% pure) or CD34+ (98% pure) grafts, similar AML cell growth was seen throughout an observation period of 106 days. The capacity to establish long-term growth from the CD34- cells was confirmed by renewed outgrowth after retransplantation. In vitro, the CD34- fraction contained both immature and mature CAFCs and produced high numbers of CFU-AML and NC in LTBMC. The CD34+ fraction produced only small numbers of CFU-AML, NC, and mature CAFCs. Therefore, the expression of CD34 and the content of CFU-AML were not associated with long-term growth of AML. However, similar frequencies of primitive CAFCs were observed in both fractions. Thus, both CD34- and CD34+ subsets of this AML sample contained immature progenitors with the capacity to initiate long-term AML growth as characterized in vivo (in SCID mice) as well as in vitro (in CAFC assay), indicating asynchrony between functional and immunophenotypical maturation of AML progenitor cell compartments.

Animals↗
PubMed1995

Rotterdam general practitioners report (ROHAPRO): a computerised network of general practices in Rotterdam, The Netherlands. Rotterdam's HuisArtsen Project.

STUDY OBJECTIVE: Dutch public health services are charged with collective preventive care for the population--care that should, by law, be based on epidemiological data. General practices potentially offer important data for this purpose, particularly since more and more use a computer. This study aimed to assess whether it is possible to obtain useful epidemiological data from this source. DESIGN: In 1990, the Rotterdam Municipal Health Service, in collaboration with the Erasmus University Rotterdam, started a computerised sentinel practice network. The main features of this and a specific small investigation are described. SETTING: The following institutions cooperate in the network: Municipal Health Service Rotterdam Area; Departments of General Practice and of Medical Informatics, Erasmus University Rotterdam; Rotterdam District Association of General Practitioners. PATIENTS: Data are currently collected from 20 general practitioners and > 40,000 patients. In a specific project, the distribution of cardiovascular risk factors in different ethnic groups was compared. MAIN RESULTS: It was possible to build up a regional epidemiological registration system in this manner. In the cardiovascular project we found striking differences between ethnic groups. The risk profile for Turkish men, in particular, was less favourable. The health service also uses the system to improve cooperation between public health and primary health care (for example, in cervical screening, influenza vaccination). CONCLUSION: Computerised general practices offer great possibilities for research and for preventive activities in which public health care and general practitioners can cooperate.

Adult↗
PubMed1995

Conditions for engraftment of human acute myeloid leukemia (AML) in SCID mice.

Transplantation of human AML into severe combined immunodeficient (SCID) mice provides a useful experimental model but graft failures have been reported. We investigated the influence of a number of factors on the outgrowth of AML in the SCID mouse bone marrow (BM). The transplantation route and total body irradiation (TBI) were examined using the cell line HL-60 as a model for AML. The role of graft size and recombinant human IL-3 (IL-3) were investigated with patient samples of AML cells. Intravenous transplantation was demonstrated to be superior to intraperitoneal transplantation. Pretransplant conditioning resulted in a dose-dependent increase of AML growth in the SCID mouse. Cell dose titrations ranging from 3 x 10(7) - 3.6 x 10(5) AML cells i.v. per mouse revealed a minimum of 1.1 x 10(6) required for reproducible engraftment. Earlier and more extensive infiltration by human AML cells was seen following injection of greater cell numbers. IL-3 given post-transplantation SCID mouse recipients, promoted AML growth in three cases, whereas a fourth AML cell specimen also grew without support of IL-3. In vitro growth factor responsiveness of AML cells to IL-3 did not predict IL-3 dependence of AML growth in vivo.

Acute Disease↗
PubMed1995

Accuracy of an oscillometric automatic blood pressure device: the Omron HEM403C.

The purpose of this study was to assess the accuracy of the Omron HEM403C blood pressure (BP) device and to study whether this accuracy was affected by subject-related factors such as BP level and age. A comparison was made with a Hawksley random zero sphygmomanometer. BP was measured with both meters connected to one arm-cuff by means of a T-connector. To assess the level of agreement of the Omron HEM403C with the random zero meter, BP was measured in 212 subjects. Systolic and diastolic readings with the Omron HEM403C were on average 1 mmHg (s.d. 9, 95% CI 0.4-2.2) and 4 mm Hg (s.d. 8, 95% CI 3.6-5.1) respectively, higher than those with the random zero meter. The Omron HEM403C underestimated SBP compared with the random zero at higher SBP levels and overestimated SBP at lower SBP levels. The Omron meter overestimated the diastolic pressure at all DBP levels and the diastolic difference was not related to the DBP level. A multiple linear regression analysis demonstrated that the SBP level and not age was the factor that independently influenced the systolic difference between the meters. According to the criteria of the British Hypertension Society the Omron HEM403C is accurate enough to be recommended for those clinical and research purposes that are in need of automatic measurements.

Adolescent↗
PubMed1994

Potential indirect anti-inflammatory effects of IL-4. Stimulation of human monocytes, macrophages, and endothelial cells by IL-4 increases aminopeptidase-N activity (CD13; EC 3.4.11.2).

IL-4 up-regulates various monocytic properties that are associated with pro-inflammatory functions. Paradoxically, IL-4 may also act as an anti-inflammatory agent by down-regulating the production of several inflammatory mediators. As the activity of some mediators has recently been shown to be regulated by peptidases, we examined whether IL-4 was able to modulate the expression of a cell membrane-associated peptidase, aminopeptidase-N (CD13). IL-4 caused a dose-dependent increase in the expression of CD13 Ag on highly purified human blood monocytes. Maximal expression was observed around 48 h of culture. This IL-4-induced increase was completely blocked by anti-IL-4 antiserum. Furthermore, the increase in surface expression was preceded by increased mRNA levels of CD13, which was maximal around 24 h of culture. We also observed that CD13-mediated leucine-aminopeptidase activity of monocytes was induced by IL-4. Other CD13-expressing cells were also sensitive to IL-4, as CD13 Ag expression and CD13 mRNA levels were up-regulated in human alveolar macrophages and endothelial cells upon IL-4 treatment. The increased expression of cell membrane aminopeptidase-N represents a potentially increased cellular ability to inactivate inflammatory mediators. Therefore, these findings represent further evidence of IL-4-mediated anti-inflammatory actions. We postulate that up-regulation of aminopeptidase-N expression may be an indirect mechanism of IL-4 to modulate the action of bioactive peptides. This mechanism may underlie, at least partially, the anti-inflammatory effects of IL-4 in vivo.

Aminopeptidases↗
PubMed1993

Prevalence of hearing impairment and hearing complaints in older adults: a study in general practice.

In one general practice, 660 people aged 60 years or over were screened by means of pure tone audiometry and a specific questionnaire to assess the prevalence of hearing impairment and hearing complaints. Hearing impairment was defined as an average loss of 35 dB or more in the 1, 2 and 4 kHz frequencies in one or both ears. In total, 37.4% (95% CI, 33.3-41.1%) of the participants was hearing impaired. The prevalence was higher in men (55.1%) than in women (44.9%) and clearly increased with age in both sexes. The prevalence of hearing complaints in terms of hearing difficulties and/or tinnitus, was 37.3% (95% CI, 33.6-41.0%), and increased with age, especially in women. Of the subjects with hearing impairment, 64.4% reported hearing complaints. Of the subjects without hearing impairment, 21.1% experienced hearing complaints. This study suggests that screening older adults with relatively simple methods, may identify a large proportion of men and women in general practice with hearing problems. Providing information to both patients and general practitioners about the possibilities of hearing improvement is a crucial step in making people become more aware of hearing problems. This could ultimately lead to improvement of the quality of life of older men and women with hearing problems.

Age Factors↗