[Practice guidelines and accreditation: highlights from 50 years of quality management by the Dutch College of General Practitioners]. / Standaarden en praktijkaccreditering: hoogtepunten van 50 jaar kwaliteitsbeleid van het Nederlands Huisartsen Genootschap.

The Dutch College of General Practitioners (NHG) was established 50 years ago in response to the threatened position of general practitioners in The Netherlands. The NHG promotes quality care in general practice by aiding in the translation of scientific evidence into daily practice. The NHG practice guidelines form the core of its quality improvement programme, which comprises a cohesive package of continuing educational materials that support adoption in daily practice. The NHG practice accreditation programme is a new method for measuring and improving practice quality. This programme provides the basis for granting stamps of quality to general practices.

Prevalence of sensitization to the predatory mite Amblyseius cucumeris as a new occupational allergen in horticulture.

BACKGROUND: Protection against thrips, a common pest in bell pepper horticulture is effectively possible without pesticides by using the commercially available predatory mite Amblyzeius cucumeris (Ac). The prevalence of sensitization to Ac among exposed greenhouse employees and its clinical relevance was studied. METHODS: Four hundred and seventytwo employees were asked to fill in a questionnaire and were tested on location. Next to RAST, skin prick tests (SPTs) were performed with common inhalant allergens, the storage mite Tyrophagus putrescentiae (Tp) which serves as a temporary food source during the cultivation process and Ac. Furthermore, nasal challenge tests with Ac were carried out in 23 sensitized employees. RESULTS: SPTs positive to Ac were found in 109 employees (23%). Work-related symptoms were reported by 76.1%. Sensitization to Tp was found in 62 employees of whom 48 were also sensitized to Ac. Immunoglobulin (Ig)E-mediated allergy to inhalant allergens appeared to be an important risk factor for sensitization to Ac. Employees with rhinitis symptoms showed a significantly higher response to all Ac doses during the nasal challenge test compared with employees without rhinitis symptoms. CONCLUSIONS: The predatory mite Ac is a new occupational allergen in horticulture which can cause an IgE-mediated allergy in exposed employees. It is biologically active on the mucous membranes of the nose and therefore clinically relevant for the development of work-related symptoms.

The implementation of guidelines in The Netherlands.

A comprehensive system for quality improvement in General Practice has been developed in the Netherlands during the last decade. The basic principles of the quality system are discussed. Practice Guidelines are developed by GP's for GP's in a four step procedure. A range of methods and products based on the guidelines is produced to enhance the implementation of practice guidelines.

Nasal hyperreactivity.

Nasal hyperreactivity is an important feature of allergic and non-allergic rhinitis. This paper reviews the possible mechanisms behind hyperreactivity. Distinct mechanisms may play a role in allergic rhinitis--an inflammatory disease--and non-allergic rhinitis, mainly a non-inflammatory disease. In allergic rhinitis, particularly in perennial allergic rhinitis, there is a close connection between allergic response and non-specific hyperreactivity. In non-allergic rhinitis, a pathological entity comprising a heterogeneous series of diseases, understanding and measuring nasal hyperreactivity is much more difficult. A variety of methods to assess nasal hyperreactivity are available. Given the heterogeneity of mechanisms, the various patients groups and the lack of standardization in tests, it is not surprising that measurement of nasal hyperreactivity is not included in the diagnostic arsenal of the clinician.

Attributes of clinical guidelines that influence use of guidelines in general practice: observational study.

OBJECTIVE: To determine which attributes of clinical practice guidelines influence the use of guidelines in decision making in clinical practice. DESIGN: Observational study relating the use of 47 different recommendations from 10 national clinical guidelines to 12 different attributes of clinical guidelines-for example, evidence based, controversial, concrete. SETTING: General practice in the Netherlands. SUBJECTS: 61 general practitioners who made 12 880 decisions in their contacts with patients. MAIN OUTCOME MEASURES: Compliance of decisions with clinical guidelines according to the attribute of the guideline. RESULTS: Recommendations were followed in, on average, 61% (7915/12 880) of the decisions. Controversial recommendations were followed in 35% (886/2497) of decisions and non-controversial recommendations in 68% (7029/10 383) of decisions. Vague and non-specific recommendations were followed in 36% (826/2280) of decisions and clear recommendations in 67% (7089/10 600) of decisions. Recommendations that demanded a change in existing practice routines were followed in 44% (1278/2912) of decisions and those that did not in 67% (6637/9968) of decisions. Evidence based recommendations were used more than recommendations for practice that were not based on research evidence (71% (2745/3841) v 57% (5170/9039)). CONCLUSIONS: People and organisations setting evidence based clinical practice guidelines should take into account some of the other important attributes of effective recommendations for clinical practice.

Methyl methanesulfonate-induced hprt mutation spectra in the Chinese hamster cell line CHO9 and its xrcc1-deficient derivative EM-C11.

The Chinese hamster cell mutant EM-C11, which is hypersensitive to the cell killing effects of alkylating agents compared to its parental line CHO9, has been used to study the impact of base excision repair on the mutagenic effects of DNA methylation damage. This cell line has a defect in the xrcc1 gene. XRCC1 can interact with DNA polymerase-beta, thereby suppressing strand displacement, and DNA ligase III, both of which have been implicated in base excision repair. XRCC1 may, therefore, allow efficient ligation of single-strand breaks generated during base excision repair. Both EM-C11 and CHO9 cells were treated with methyl methanesulfonate (MMS), a DNA-methylating agent reacting predominantly with nitrogen atoms generating adducts which are substrates for the base excision repair pathway. EM-C11 cells are much more sensitive to the cytotoxic effects of MMS than CHO9: for EM-C11, the dose of MMS inducing 10% survival is 6-fold lower than that for CHO9. In contrast, mutation induction at the hprt locus following MMS is similar in EM-C11 and CHO9. Molecular analysis of hprt gene mutations showed that although the largest class of hprt mutations, both in EM-C11 and CHO9 cells, consisted of GC > AT transitions, most likely caused by O6-methylguanine, the size of this class was smaller in EM-C11. The fraction of deletion mutants in EM-C11, however, was twice as large as that found in CHO9 cells. These results suggest that reduced ligation efficiency of single-strand breaks generated during base excision repair, as result of a defect in XRCC1, may lead to the formation of deletions.

Effect of nucleotide excision repair on hprt gene mutations in rodent cells exposed to DNA ethylating agents.

The role of the nucleotide excision repair (NER) pathway in removal of DNA ethylation damage was investigated by means of hprt mutational spectra analysis in the NER-deficient Chinese hamster ovary cell line UV5, which lacks ERCC2/XPD, and in its parental cell line AA8. Both cell lines were exposed to ethyl methanesulfonate (EMS) or N-ethyl-N-nitrosourea (ENU). EMS gave a similar dose-dependent increase in hprt mutants in UV5 compared with AA8. In both cell lines EMS-induced mutations in the hprt coding region consisted almost exclusively of GC-->AT transitions, probably due to the direct miscoding lesion O6-ethylguanine. ENU, an agent that in addition to O6-ethylguanine also induces other O-alkylation products, was significantly more mutagenic in UV5 than in AA8. Mutational spectra analysis showed that the proportions of ENU-induced GC-->AT, AT-->TA and AT-->GC base pair changes were similar for both cell lines. ENU-induced DNA lesions that may be involved in GC-->AT transitions are O6-ethylguanine and O2-ethylcytosine, the latter being a chemically stable DNA lesion of which the miscoding properties and repair characteristics are largely unknown. ENU-induced AT-->TA transversions are probably caused by O2-ethylthymine, which mispairs with thymine. In AA8 thymines in ENU-induced AT-->TA transversions were exclusively located in the non-transcribed strand of the hprt gene, whereas in UV5 30% of these thymines were found in the transcribed strand. Together, these results indicate that O6-ethylguanine is a poor substrate for NER in rodent cells and that O2-ethylpyrimidines are preferentially removed from the transcribed strand of the hprt gene by NER.

[The role of the consulting physician in situations of active euthanasia]. / De rol van de consulent bij actieve levensbeëindiging in de thuissituatie.

The cases are reported of two patients, a man aged 69 with a metastasized bronchial carcinoma and a woman aged 65 with a frontotemporal glioblastoma no longer responding to irradiation. Both requested active euthanasia. In both cases, euthanasia was performed by injection, after a general practitioner from the same locum group had acted as consultant. The requirements of meticulousness in handling a request for active euthanasia are concerned with the request (which has to be voluntary, thoroughly considered and constant), the suffering (which has to be protracted, unbearable and incurable), consultation and the written report. The consulting or second physician in cases of active euthanasia confirms that the requirements of meticulousness have been met. In addition, the second physician may assist the general practitioner in the detection of factors that may impair correct decision-making by the doctor or the patient. The second physician will be aided in performing these tasks if he is a member of the same locum group as the treating physician. However, if he considers himself too involved, a physician outside the locum group should be available at all times.

Nasal responsiveness to allergen and histamine in patients with perennial rhinitis with and without a late phase response.

BACKGROUND: In the lower airways an association has been found between early phase reaction (EPR), late phase reaction (LPR), and bronchial hyperreactivity. However, this association has not been shown for the upper airways in nasal pollen challenge studies. A study was undertaken to determine whether the EPR, LPR, and nasal hyperreactivity are related in perennial allergic rhinitis. METHODS: Twenty four patients with rhinitis who were allergic to house dust mite (HDM) were challenged with HDM extract. The nasal response was monitored by symptom scores and nasal lavages for up to 9.5 hours after challenge and concentrations of albumin, tryptase, and eosinophil cationic protein (ECP) in the lavage fluid were measured. Thirteen patients (defined as dual responders) had increased symptom scores between 3.5 and 9.5 hours compared with the baseline score. The other 11 patients (defined as early responders) showed an isolated EPR only. Nasal hyperreactivity was determined by nasal histamine challenge 24 hours later. RESULTS: Dual responders showed a significantly higher symptom score, albumin influx, and tryptase release during the EPR. During the late phase (3.5-9.5 hours) albumin influx was significantly increased at most time points and ECP release was significantly higher at 9.5 hours in the dual responder group. Dual responders showed a significantly stronger response to all doses of histamine. The area under the curve (AUC) of symptom scores during EPR and LPR and the AUC of the histamine dose response were significantly correlated (EPR-LPR: r = 0.49, p < 0.01; EPR-histamine: r = 0.75, p < 0.001; LPR-histamine: r = 0.66, p < 0.001). CONCLUSIONS: In patients with perennial allergic rhinitis the nasal responses to allergen and histamine are associated. Dual responders have an increased EPR, increased levels of mediators, and increased allergen-induced hyperreactivity.

Relationship between nasal hyperreactivity, mediators and eosinophils in patients with perennial allergic rhinitis and controls.

BACKGROUND: In perennial allergic rhinitis, patients are almost daily exposed to aeroallergens. This ongoing allergic reaction results in increased sensitivity to allergens and non-specific stimuli. It is generally known that inflammatory cells and mediators are involved in the pathogenesis of the allergic reaction. OBJECTIVES: To study the relationship between nasal hyperreactivity and nasal inflammation during natural allergen exposure. METHODS: In 48 patients with perennial allergic rhinitis and in 11 volunteers a nasal brush, a nasal lavage and a histamine challenge were performed. Nasal inflammation was estimated by the number of eosinophils, levels of albumin, tryptase, prostaglandin D2 (PGD2), eosinophil cationic protein (ECP) and leukotriene C4/D4/E4 (LTC4/D4/E4). RESULTS: In contrast to PGD2 and tryptase, eosinophils (1.9 vs 0%, P = 0.0023), LTC4/ D4/E4 (17.51 vs 1.43 pg/mL, P < 0.0001) and albumin (8.61 vs 2.37 mg/mL, P = 0.0008) were significantly increased in rhinitis patients as compared with controls. Patients also showed increased responses to nasal histamine challenge assessed using a composite symptom score (21.5 vs 4 points, P < 0.0001). The nasal response to histamine was weakly correlated with the total number of eosinophils in the cytospin (correlation coefficient r = 0.38, P = 0.009). CONCLUSION: Nasal hyperreactivity is correlated with the percentage of eosinophils in patients with perennial rhinitis. The patients' mediator profiles suggest that eosinophils are important in the ongoing allergic reaction and nasal hyperreactivity.

Nasal hyperreactivity and inflammation in allergic rhinitis.

The history of allergic disease goes back to 1819, when Bostock described his own 'periodical affection of the eyes and chest', which he called 'summer catarrh'. Since they thought it was produced by the effluvium of new hay, this condition was also called hay fever. Later, in 1873, Blackley established that pollen played an important role in the causation of hay fever. Nowadays, the definition of allergy is 'An untoward physiologic event mediated by a variety of different immunologic reactions'. In this review, the term allergy will be restricted to the IgE-dependent reactions. The most important clinical manifestations of IgE-dependent reactions are allergic conjunctivitis, allergic rhinitis, allergic asthma and atopic dermatitis. However, this review will be restricted to allergic rhinitis. The histopathological features of allergic inflammation involve an increase in blood flow and vascular permeability, leading to plasma exudation and the formation of oedema. In addition, a cascade of events occurs which involves a variety of inflammatory cells. These inflammatory cells migrate under the influence of chemotactic agents to the site of injury and induce the process of repair. Several types of inflammatory cells have been implicated in the pathogenesis of allergic rhinitis. After specific or nonspecific stimuli, inflammatory mediators are generated from cells normally found in the nose, such as mast cells, antigen-presenting cells and epithelial cells (primary effector cells) and from cells recruited into the nose, such as basophils, eosinophils, lymphocytes, platelets and neutrophils (secondary effector cells). This review describes the identification of each of the inflammatory cells and their mediators which play a role in the perennial allergic processes in the nose of rhinitis patients.

Effect of intranasal fluticasone proprionate on the immediate and late allergic reaction and nasal hyperreactivity in patients with a house dust mite allergy.

BACKGROUND: Patients with perennial allergic rhinitis develop nasal symptoms not only after allergen exposure, but generally also after non-specific stimuli. OBJECTIVE: To evaluate the effect of 2 week's treatment with fluticasone propionate aqueous nasal spray (FPANS) on the nasal clinical response, inflammatory mediators and nasal hyperreactivity. METHODS: Twenty-four rhinitis patients allergic to house dust mite (HDM), participated in a double-blind, placebo-controlled crossover study. After 2 week's treatment with placebo or 200 micrograms FPANS twice daily, patients were challenged with HDM extract. Symptoms were recorded and nasal lavages were collected for up to 9.5 h after challenge. Nasal hyperreactivity was determined by histamine challenge 24 h later. RESULTS: Because of a carry-over effect for the immediate symptom score, for this variable only the data from the first treatment period were used. FPANS treatment resulted in a significant decrease of nasal symptoms with 70%, 69% and 63% after 100, 1000 and 10,000 Biological Units (BU)/mL of HDM extract respectively. Active treatment resulted in a 76% decrease of the late-phase symptoms. FPANS treatment significantly reduced albumin influx after HDM 1000 BU/mL with 62% and tended to reduce tryptase release after HDM 1000 BU/mL (P = 0.0629). During the late phase FPANS treatment reduced albumin influx with 67% and eosinophil cationic protein (ECP) release with 83%. No effect of FPANS was seen on histamine levels. FPANS significantly decreased histamine-induced symptom score with 34%, secretion with 32% and sneezes with 41%. CONCLUSION: FPANS significantly inhibits the immediate and late allergic response, and nasal hyperreactivity, probably by suppressing mast cells and eosinophils in the nasal mucosa.

Allergy to bumblebee venom. I. Occupational anaphylaxis to bumblebee venom: diagnosis and treatment.

We describe six patients with severe occasional anaphylaxis, caused by stings of bumblebees. Sensitization to bumblebee venom was confirmed by intracutaneous tests and RAST with purified bumblebee venom. Three patients changed their occupation and will probably not be stung by bumblebees in the future. The other patients started immunotherapy with newly purified bumblebee venom extract. After 1 year of treatment, no severe side-effects had occurred and clinical benefit in two patients could be demonstrated, as both skin sensitivity or serum IgE to bumblebee venom had decreased. Moreover, both patients were unresponsive to in-hospital sting challenge.

Mechanisms and biomarkers of genotoxicity. Molecular dosimetry of chemical mutagens.

The relevance of the use of DNA adduct frequencies as a parameter for the extent of mutation induction by monofunctional alkylating agents was investigated in cultured Chinese hamster cells and in rat skin fibroblasts treated in vivo with the test chemicals. The nature of the biologically significant DNA adducts was investigated by DNA sequence analysis of mutations induced at the hypoxanthine-guanine phophoribosyltransferase (hprt) gene. The results show that under conditions where O6-alkylguanine is a persistent DNA lesion more than 50% of the mutations are GC to AT transitions indicating that the frequency of O6-alkylguanine is a good parameter for mutation induction. However, in target cells which are able to remove alkyl groups from the O6 position of guanine, alkylating agents with a low nucleophilic selectivity (e.g. N-ethyl-N-nitrosourea (ENU) and N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG)) exert most of their mutagenic activity most likely via the induction of O2-ethylthymine.

Nitric oxide metabolites in nasal lavage fluid of patients with house dust mite allergy.

BACKGROUND: The role of nitric oxide in the early and late phase of the allergic process was investigated in patients with allergic rhinitis against house dust mite and the effect of fluticasone propionate aqueous nasal spray was determined. METHODS: Production of nitric oxide (measured as nitrite+nitrate) in vivo in nasal mucosa was examined in 24 patients with rhinitis allergic to the house dust mite. In a double blind placebo controlled crossover study fluticasone propionate 200 micrograms aqueous nasal spray was administered twice daily for two weeks. In response to provocation with house dust mite extract (after four basal nasal lavages) nasal lavages were performed every hour for 9.5 hours by washing the nose with saline. In addition, a similar lavage protocol was performed in healthy volunteers with or without challenge with phosphate buffered saline. RESULTS: Nitric oxide is present in nasal lavage fluid in detectable amounts (range 10-50 microM), the level gradually increasing with time in both patients and controls after a decrease during the four basal lavages. Treatment with fluticasone propionate aqueous nasal spray did not affect initial basal production of nitric oxide nor production following provocation with house dust mite extract. CONCLUSIONS: Production of nitric oxide in nasal mucosa determined in sequential nasal washings is not affected by therapeutic doses of intranasal steroids.

Molecular analysis of ethyl methanesulfonate-induced mutations at the hprt gene in the ethyl methanesulfonate-sensitive Chinese hamster cell line EM-C11 and its parental line CHO9.

The Chinese hamster cell line EM-C11 has been shown to be 5 times more sensitive than its parental line CHO9, but not hypermutable, after treatment with ethyl methanesulfonate. Ethyl methanesulfonate-induced mutational spectra were determined at the hprt locus to investigate whether the same adducts are responsible for mutation induction in both cell lines. The mutational spectra for EM-C11 and CHO9 show an important difference. GC-->AT transitions were found in both cell lines at similar frequencies; however, the spectrum of CHO9 contains a class of AT-->GC transitions, which seems to be replaced by a group of deletions in EM-C11. Since the ethyl methanesulfonate-induced mutation frequency for both lines is the same at equal exposure, it is hypothesized that the lesions leading to AT-->GC transitions in CHO9 are responsible for the deletions in EM-C11. This phenomenon might be explained if the responsible adduct(s) in CHO9 is bypassed resulting in replication errors, while blocking DNA synthesis in EM-C11 causing the observed increase in cell death. In surviving EM-C11 cells, DNA strand exchanges might have occurred at the position of stalled replication forks, leading to gross molecular changes. The adduct probably responsible for the AT-->GC transitions in CHO9 and the deletions in EM-C11 is 3-ethyladenine.

Asynchrony between pronuclear development and protein synthetic changes in zygotes of the mouse derived from oocytes aged postovulation in vivo and fertilized in vivo.

The pattern of proteins synthesized by one-cell embryos derived from unaged oocytes and oocytes aged postovulation in vivo was analyzed by means of 35S-methionine labeling and gel electrophoresis. The oocytes were obtained after ovulation induction by an injection of luteinizing hormone-releasing hormone (LHRH) at proestrus or after a superovulation procedure. The analysis was performed in unfertilized aged and unaged secondary oocytes and in zygotes derived from them. The patterns of proteins synthesized by secondary oocytes from all experimental groups were very similar: The oocytes showed a predominant synthesis of 35 kDa proteins. Zygotes from aged as well as unaged LHRH-induced oocytes also showed a predominant synthesis of one group of polypeptides with a relative molecular weight of about 35 kDa. The proteins of the 35 kDa protein complex migrated in an upper (u), middle (m), or lower (l) band in 10% polyacrylamide sodium dodecyl sulfate (SDS) gels. The u- and m-band 35 kDa proteins were shown to be synthesized by secondary oocytes. Early pronuclear zygotes from unaged LHRH-induced oocytes synthesized u- and m- but no l-band 35 kDa proteins. In contrast, part (38%, n = 47) of the early pronuclear zygotes from aged LHRH-induced oocytes did synthesize the l-band 35 kDa proteins. Late pronuclear zygotes (LPZ) from aged as well as unaged oocytes synthesized predominantly the l-band 35 kDa proteins. However, although only 5.8% (n = 51) of LPZ from unaged oocytes synthesize m- and l-band 35 kDa proteins, these bands of proteins are present in 25% (n = 24) of the LPZ from aged oocytes.(ABSTRACT TRUNCATED AT 250 WORDS)