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Biomedical subjects

A Meijer

Publications and source records attributed to A Meijer.

At least 19 recordsLinked to original sources
PubMed2000

A comparative study of the financing, provision and quality of care in nursing homes. The approach of four European countries: Belgium, Denmark, Germany and the Netherlands.

A comparative study of the financing, provision and quality of care in nursing homes. The approach of four European countries: Belgium, Denmark, Germany and the Netherlands As result of an increase in the numbers of frail elderly people, most European countries are facing problems with the financing and provision of services by nursing homes. At the same time, the expectations of quality of these services continue to rise. The main question investigated in this study was that of how countries approach the problems of financing and service provision by nursing homes and, at the same time, attempt to increase the quality levels in these institutions. The study was conducted in Belgium, Denmark, Germany and the Netherlands. A study was made of the relevant literature and questionnaires were sent to experts in each country. The four countries are addressing the problems of financing and sufficient service provision by controlling the use of nursing home services. In addition, financial problems are approached by extending co-payments, encouraging cheaper forms of care and putting pressure on nursing homes to operate at lower costs. Problems in the provision of care are addressed by applying more selective admission criteria and offering alternative forms of care outside the nursing home. As a result nursing home beds are used for those with the greatest care-dependency. Nursing home services are adjusted to rising quality expectations by offering a greater range of provision, decreasing the number of residents per room, improving comfort and improving the training of nursing staff. Another way to increase the quality of care is to separate the housing and service functions. Many nursing homes nowadays collaborate intensively with other facilities for the elderly to cope with all these problems and changes. The workload for nursing home staff has increased because of the increasing care-dependency of residents, the demand for higher quality of services and the financial problems.

Activities of Daily Living↗
PubMed2000

Diagnosis and management of inadvertently placed pacing and ICD leads in the left ventricle: a multicenter experience and review of the literature.

Three patients from different centers with pacemaker or ICD leads endocardially implanted in the left ventricle are described. All leads, two ventricular pacing leads and one ICD lead, were inserted through a patent foramen ovale or an atrial septum defect. The diagnosis was made 9 months, 14 months, and 16 years, respectively, after implantation. All patients had right bundle branch block configuration during ventricular pacing. Chest X ray was suggestive of a left-sided positioned lead except in the ICD patient. Diagnosis was confirmed with echocardiography in all patients. One patient with a ventricular pacing lead presented with a transient ischemic attack at 1-month postimplantation. During surgical repair of the atrial septum defect 14 months later, the lead was extracted and thrombus was attached to the lead despite therapy with aspirin. The other patients were asymptomatic without anticoagulation (9 months and 16 years after implant). No thrombus was present on the ICD lead at the time of the cardiac transplantation in one patient. We reviewed 27 patients with permanent leads described in the literature. Ten patients experienced thromboembolic complications, including three of ten patients on antiplatelet therapy. The lead was removed in six patients, anticoagulation with warfarin was effective for secondary prevention in the four remaining patients. In the asymptomatic patients, the lead was removed in five patients. In the remaining patients, 1 patient was on warfarin, 2 were on antiplatelet therapy, and in 3 patients the medication was unknown. After malposition was diagnosed, three additional patients were treated with warfarin. In conclusion, if timely removal of a malpositioned lead in the left ventricle is not preformed, lifelong anticoagulation with warfarin can be recommended as the first choice therapy and lead extraction reserved in case of failure or during concomitant surgery.

Adolescent↗
PubMed2000

Exchange of pacing or defibrillator leads following laser sheath extraction of non-functional leads in patients with ipsilateral obstructed venous access.

Occlusion of the subclavian or brachiocephalic vein in pacemaker or defibrillator patients prohibits ipsilateral implantation of new leads with standard techniques in the event of lead malfunction. Three patients are presented in whom laser sheath extraction of a non-functional lead was performed in order to recanalise the occluded vein and to secure a route for implantation of new leads. This technique avoids abandoning a useful subpectoral site for pacing or defibrillator therapy. The laser sheath does not affect normally functioning leads at the same site.

Adult↗
PubMed1999

Cardiogenic shock due to coronary narrowings one day after a MAZE III procedure.

A MAZE III procedure was performed on a patient with a small body surface area. On the first postoperative day, the patient developed severe dysfunction of the left ventricle, due to significant narrowings of the right and circumflex coronary arteries in the areas that were cryoablated during the MAZE III procedure. The coronary narrowings were treated by percutaneous transluminal coronary angioplasty (PTCA). At discharge the coronary anatomy was normal again with an almost normal left ventricular function.

Adult↗
PubMed1999

Applying a contingency model of strategic decision making to the implementation of smoking bans: a case study.

A model of strategic decision making was applied to study the implementation of worksite smoking policy. This model assumes there is no best way of implementing smoking policies, but that 'the best way' depends on how decision making fits specific content and context factors. A case study at Wehkamp, a mail-order company, is presented to illustrate the usefulness of this model to understand how organizations implement smoking policies. Interview data were collected from representatives of Wehkamp, and pre- and post-ban survey data were collected from employees. After having failed to solve the smoking problem in a more democratic way, Wehkamp's top management choose a highly confrontational and decentralized decision-making approach to implement a complete smoking ban. This resulted in an effective smoking ban, but was to some extent at the cost of employees' satisfaction with the policy and with how the policy was implemented. The choice of implementation approach was contingent upon specific content and context factors, such as managers' perception of the problem, leadership style and legislation. More case studies from different types of companies are needed to better understand how organizational factors affect decision making about smoking bans and other health promotion innovations.

Adult↗
PubMed1999

Genomic relatedness of Chlamydia isolates determined by amplified fragment length polymorphism analysis.

The genomic relatedness of 19 Chlamydia pneumoniae isolates (17 from respiratory origin and 2 from atherosclerotic origin), 21 Chlamydia trachomatis isolates (all serovars from the human biovar, an isolate from the mouse biovar, and a porcine isolate), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and 1 Chlamydia pecorum isolate was studied by analyzing genomic amplified fragment length polymorphism (AFLP) fingerprints. The AFLP procedure was adapted from a previously developed method for characterization of clinical C. trachomatis isolates. The fingerprints of all C. pneumoniae isolates were nearly identical, clustering together at a Dice similarity of 92.6% (+/- 1.6% standard deviation). The fingerprints of the C. trachomatis isolates of human, mouse, and swine origin were clearly distinct from each other. The fingerprints of the isolates from the human biovar could be divided into at least 12 different types when the presence or absence of specific bands was taken into account. The C. psittaci fingerprints could be divided into a parakeet, a pigeon, and a feline type. The fingerprint of C. pecorum was clearly distinct from all others. Cluster analysis of selected isolates from all species revealed groups other than those based on sequence data from single genes (in particular, omp1 and rRNA genes) but was in agreement with available DNA-DNA hybridization data. In conclusion, cluster analysis of AFLP fingerprints of representatives of all species provided suggestions for a grouping of chlamydiae based on the analysis of the whole genome. Furthermore, genomic AFLP analysis showed that the genome of C. pneumoniae is highly conserved and that no differences exist between isolates of respiratory and atherosclerotic origins.

Animals↗
PubMed1999

Chlamydia pneumoniae in abdominal aortic aneurysms: abundance of membrane components in the absence of heat shock protein 60 and DNA.

In this article, we describe the results of a comparative study for the detection of Chlamydia pneumoniae in abdominal aortic aneurysm specimens of 19 patients through the use of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR), along with the detection of cytomegalovirus (CMV) and herpes simplex virus (HSV) by ICC and PCR. C pneumoniae-specific membrane protein was detected in specimens of all 19 (100%; 95% confidence interval [CI] 82% to 100%) and of 15 (79%; 95% CI 54% to 94%) patients with monoclonal antibodies RR-402 and TT-401, respectively. Chlamydial lipopolysaccharide was detected in specimens of 15 (79%; 95% CI 54% to 94%) patients when the results of 4 different monoclonal antibodies were combined. Surprisingly, chlamydial heat shock protein 60 was not detected in any of the specimens by ICC. Furthermore, C pneumoniae DNA was not detected by ISH when a C pneumoniae major outer membrane protein gene fragment was used as probe, nor was it reproducibly detected by PCR on extracted DNA. These results may be explained either by different kinetics of degradation of the different components of C pneumoniae after infection of the vessel wall or by the involvement of other Chlamydia-like microorganisms. Coexistence of C pneumoniae antigens and HSV antigens but not CMV antigens was observed in specimens from 10 of 18 (56%; 95% CI 31% to 78%) patients by ICC. CMV and HSV DNAs were not detected by PCR. In conclusion, we have demonstrated the presence of antigens of C pneumoniae in the absence of specific DNA in abdominal aortic aneurysms, suggesting persistence of the antigens rather than a persistent infection.

Aged↗
PubMed1998

Detection of microorganisms in vessel wall specimens of the abdominal aorta: development of a PCR assay in the absence of a gold standard.

A procedure in which the "Invitrogen Easy-DNA" kit was followed by a silica-based method for the isolation of DNA was developed for extraction of PCR-inhibitor-free DNA from up to 300 mg of human vessel wall tissue. Optimally designed PCR assays were developed for the detection of at least one infected cell in this amount of tissue. Details of the procedure are given for the detection of DNA of Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus type 1 and type 2 in human vessel walls. The procedure can serve as a reference method or as a gold standard when a high-performance method is needed.

Aorta, Abdominal↗
PubMed1998

Learning curve characteristics of pacing lead extraction with a laser sheath.

The learning curve characteristics of lead extraction with a laser sheath were examined in 19 patients. Forty-two leads were removed: five leads were removed by traction alone, five required a femoral approach as a primary procedure and a laser sheath was used in 32 lead extraction attempts. Primary laser success was achieved in 26 attempts (81%). A femoral approach was successfully applied as a back-up procedure in five of the failures. Overall, 26% of the leads were removed by the femoral approach. The overall success rate was 98% (41 of 42 leads). No variables related to the patients, leads, or extraction techniques were significantly related to failure of laser sheath extraction. There was a distinct learning curve with all but one failure occurring in the first half of our cases. All failures occurred with leads implanted from the right subclavian vein. In four, a sharply angled curve at the subclavian vein-superior vena cava junction could not be passed with the laser sheath. The ability to smooth this curve improved the results during the learning curve. All procedures were performed in the operating room for safety reasons. This precaution was lifesaving in a case of acute tamponade after laser extraction of an atrial lead. In another case the left internal mammary artery was torn after laser sheath extraction, causing the formation of a false aneurysm. New pacing leads were introduced in nine patients during the same procedure. The mean procedure time was 255 +/- 110 min. reflecting the complexity of these procedures.

Clinical Competence↗
PubMed1997

Species identification of Chlamydia isolates by analyzing restriction fragment length polymorphism of the 16S-23S rRNA spacer region.

The genetic diversity of the 16S-23S rRNA spacer region of 12 Chlamydia pneumoniae isolates, 7 Chlamydia trachomatis isolates (human biovars: the trachoma serovars B and C, the urogenital serovars D, E, and F, and the lymphogranuloma venereum serovar L2; and a mouse biovar), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and one Chlamydia pecorum isolate was studied. The 16S-23S rRNA spacer region was amplified by PCR and digested with the restriction enzymes MseI, PstI, AluI, BglII, NlaIV, and BclI. All 26 isolates could be amplified by using one genus-specific primer pair, yielding an amplicon with a size of 803 bp. The analytical sensitivity of the PCR assay was < or = 100 inclusion-forming units per reaction. Digestion with MseI or AluI made it possible to differentiate the four species from each other, the C. trachomatis human biovars from the mouse biovar, and the C. psittaci avian isolates from the feline isolate. The MseI profiles were more distinct than the AluI profiles. Phylogenetic analysis of the results for all enzymes combined supported the current classification of four Chlamydia species: C. pneumoniae, C. trachomatis, C. psittaci, and C. pecorum. Phylogenetic analysis also suggested subdivision of isolates of C. trachomatis and C. psittaci into subgroups that coincide with their host range. In conclusion, we have developed an easy and rapid method for species and subspecies identification of Chlamydia based on restriction fragment length polymorphism analysis of the 16S-23S rRNA spacer region.

Bacterial Typing Techniques↗
PubMed1996

Reocclusion: the flip side of coronary thrombolysis.

Since the introduction of thrombolytic therapy for acute myocardial infarction, the incidence of coronary artery reocclusion has been intensively studied. Also, the prediction and diagnosis of reocclusion by angiographic and clinical variables, as well its invasive and pharmacologic prevention, have gained much attention. By angiographic definition, reocclusion requires three angiographic observations: one with an occluded artery, one with a reperfused artery and a third for the assessment of subsequent occlusion (true reocclusion). Since the introduction of early intravenous reperfusion therapy, most studies use only two angiograms: one with a patent and one with a nonpatent infarct-related artery. A search for all published reocclusion studies revealed 61 studies (6,061 patients) with at least two angiograms. The median time interval between the first angiogram after thrombolysis and the second was 16 days (range 0.1 to 365). Reocclusion was observed in 666 (11%) of 6,061 cases. Interestingly, the 28 true reocclusion studies showed an incidence of reocclusion of 16 +/- 10% (mean +/- SD), and the 33 studies with only two angiograms 10 +/- 8% (p=0.04), suggesting that proven initial occlusion of the infarct-related artery is a risk factor for reocclusion after successful thrombolysis. The other predictors for reocclusion are probably severity of residual stenosis of the infarct-related artery after thrombolysis and perhaps the flow state after lysis. Reocclusion is most frequently seen in the early weeks after thrombolysis. The clinical course in patients with reocclusion is more complicated than in those without this complication. Left ventricular contractile recovery after thrombolysis is hampered by reocclusion. Routine invasive strategies have not been proven effective against reocclusion. In the prevention of reocclusion, both antiplatelet and antithrombin strategies have been tested, including hirudin and hirulog, but the safety of these agents in thrombolysis is still questionable. Thus, reocclusion after thrombolysis is an early phenomenon and is more frequent after proven initial occlusion of the infarct-related artery. Reocclusion can be predicted by angiography after thrombolysis. Because reocclusion is detrimental, strategies to prevent it should be developed and carried out after thrombolytic therapy for acute myocardial infarction as soon as they are deemed safe.

Antithrombins↗
PubMed1996

An Angiographic Study of Intracoronary Streptokinase versus Intravenous Tissue Plasminogen Activator After Failed Coronary Thrombolysis with Intravenous Streptokinase.

Objective: The medical treatment of failed intravenous streptokinase in patients with acute transmural myocardial infarction using angiographic endpoints. Design: Prospective open angiographic comparison of intracoronary streptokinase with intravenous tissue plasminogen activator. Setting: Single center study in a tertiary institution. Subjects: Eighty-five patients with acute myocardial infarction within 4 hours after symptom onset. Treatment regimens: The subjects received 1.5 million U intravenous streptokinase. Coronary angiography within 48 hours (median 19 hours) showed infarct-related vessel patency in 65 patients (76%). In the catheterization laboratory the 20 patients (24%) with failed intravenous streptokinase received repeat thrombolysis immediately after angiography. The first 10 patients with failed intravenous streptokinase received intracoronary streptokinase at a dose of 4000 U/min in the occluded infarct-related artery for a maximum of 1 hour. The subsequent 10 pati ents received high-dose front-loaded intravenous tissue plasminogen activator (100 mg in 1 hour). Results: In none of the patients receiving repeat streptokinase was reperfusion obtained. In 6 of 10 (60%) of the patients receiving tissue plasminogen activator, reperfusion was seen within 60 minutes (p < 0.005 vs. intracoronary streptokinase). One patient (5%) died and two refused follow-up angiography. Seventeen (88%) patients underwent angiography 3 months later according to the protocol. Two patients showed a persistently reperfused infarct-related artery, three reoccluded, four spontaneously reperfused, and eight had a persistently occluded infarct-related artery. The left ventricular ejection fraction was slightly higher at 3 months, and there were no differences between the patients with open vessels (increase +7.7 +/- 5.8%) and those with persistently occluded vessels (increase +5.8 +/- 6.8%). Conclusions: Repeat thrombolysis after failed intravenous streptokinase ca n be achieved with front-loaded intravenous tissue plasminogen activator but not with intracoronary streptokinase. Although patient numbers are small and repeat thrombolysis was performed rather late, this study leads the way to affordable optimization of thrombolysis, which needs large-scale testing.

Journal Article↗
PubMed1996

Reflectance pulse oximetry at the forehead of newborns: the influence of varying pressure on the probe.

OBJECTIVE: Transmission pulse oximetry (TPO) is not a practical method of intrapartum fetal monitoring of arterial oxygen saturation. Reflectance pulse oximetry (RPO) requires a sensor applied to the skin of the fetal head and may be a useful technique. During labor, various degrees of pressure will be exerted on the RPO sensor. Previous studies have shown that moderate pressure on the sensor can improve the RPO signal. At increasing pressure, however, blood flow underneath the sensor will be occluded. This study examines the influence of pressure applied to the RPO sensor on the signal from the forehead of healthy newborns as a model for the fetal situation. METHODS: After institutional approval, 12 healthy newborns were studied. The RPO probe was placed at the forehead. Pressure on the probe was increased stepwise from 0 to 80 mmHg, and the effect on the ratio between the relative changes of the red and infrared light intensities (R/IR, inversely related to oxygen saturation) and pulse sizes was evaluated. Additionally, the effect of firm pressure (> 150 mmHg) on the probe was evaluated. RESULTS: R/IR values remained virtually unchanged when pressure onto the probe was increased from 0 to 80 mmHg, although the standard deviation slightly decreased. The pulse size increased as pressure on the probe increased. During firm pressure on the probe (> 150 mmHg), plethysmographic signals remained detectable, but R/IR values markedly increased. CONCLUSIONS: In newborns, mild to moderate pressure on the probe has little influence on the RPO signal at the forehead. Even during firm pressure, RPO can be used to obtain pulsatile signals, that presumably derive from tissue underneath the skull, such as the cerebral circulation.

Fetal Monitoring↗
PubMed1996

A microcarrier culture method for the production of large quantities of viable Chlamydia pneumoniae.

We studied the propagation of Chlamydia pneumoniae strain TW-183 in HEp2 cells grown on microcarrier beads. Infection of the cells in microcarrier culture was optimized by addition of 7.5% polyethylene glycol 4000 (PEG4000) during adsorption. The yield in microcarrier culture was similar to that of microtitre-plate culture using centrifugation-assisted infection (120 x 10(6) and 225 x 10(6) bacteria/10(6) HEp2 cells respectively), as was the burst size (505 and 449 bacteria produced/infecting bacterium respectively). However, up to 64% savings in labour time and 27% saving in culture medium were achieved if the microcarrier culture method was used instead of the microtitre-plate culture method. The optimal yield of viable bacteria could only be achieved at a narrow range of multiplicities of infection (0.24 - 1.14 inclusion-forming units/cell), independent of the mode of infection (centrifugation-assisted infection of PEG4000-facilitated infection by adsorption) and independent of incubation temperature (35 degrees C or 37 degrees C). The yield of microcarrier cultures was the same at an incubation temperature of 35 degrees C or 37 degrees C in contrast to an increased production at 35 degrees C in the microtitre-plate culture method using centrifugation-assisted infection. In conclusion, the microcarrier culture method is useful to produce large quantities of viable Chlamydia pneumoniae economically.

Chlamydophila pneumoniae↗
PubMed1996

Sequence analysis of deletion mutations at the HPRT locus of human T-lymphocytes: association of a palindromic structure with a breakpoint cluster in exon 2.

To study the structure and mechanism of deletion mutation in human somatic cells in vivo, we have identified and sequenced the breakpoints of 16 independent deletions at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in human T-lymphocytes. Seven deletions were found in exon 2, three in each of exon 3 and 6, and one in each of intron 3, exon 8 and exon 9. Most of the deletions seemed to result from non-homologous recombination, possibly by a slippage-misalignment mechanism between short repeat sequences. Putative secondary DNA structures, possibly acting as intermediates in the deletion formation, were identified in several mutants. Six of the seven exon 2 deletions had a breakpoint within a 12 bp region (in the 5' end of exon 2) which contains a 9 nucleotide palindrome (AACCAGGTT) and is preceded by a TGA direct repeat tract. One of the mutants had two deletions in tandem, separated by the palindrome. Another mutant, in which 23 bp containing the palindromic sequence was deleted, had an additional base (C) inserted between the breakpoints forming a direct repeat (gACGAC) in the deletion junction. Taken together with previously reported deletion mutations at the HPRT locus, these results suggest that the deletion cluster in the 5' part of HPRT exon 2 in T-cells in vivo is promoted by the 9 nucleotide palindrome sequence and the TGA repeat tract. The former may act as a stabilizer in a putative intermediate structure, and the latter may induce slippage and misalignment during replication.

Base Sequence↗
PubMed1995

Adverse long-term effects of reocclusion after coronary thrombolysis.

OBJECTIVES: This study sought to assess the long-term clinical consequences of reocclusion after coronary thrombolysis. BACKGROUND: After acute myocardial infarction successfully treated with thrombolysis, reocclusion occurs in approximately 30% of patients and leads to poorer in-hospital outcome. However, the long-term effects of reocclusion are unknown. METHODS: Three hundred patients with no history of coronary surgery and with a patent infarct-related artery at coronary angiography within 48 h after thrombolysis were enrolled in the Antithrombotics in the Prevention of Reocclusion in Coronary Thrombolysis (APRICOT) trial. At a mean (+/- SD) of 77 +/- 23 days after thrombolysis, 248 patients (87%) underwent follow-up angiography. Reocclusion was observed in 71 (29%) of 248 patients. To compare outcome between 71 patients with and 177 without reocclusion an analysis of event-free survival, defined as a clinical course without death, reinfarction and revascularization, was performed. RESULTS: Over a 3-year follow-up period, event-free survival was significantly better in patients without reocclusion: At 1 year it was 63% for patients with and 83% for those without reocclusion (p < 0.001). In the first year, two or more cardiac-related events occurred in 24% of patients with and 6% of those without reocclusion (p < 0.001). Patients with reocclusion had a markedly higher reinfarction and revascularization rate. At 1 year the reinfarction rate was 23% for patients with and 5% for those without reocclusion (p < 0.001). CONCLUSIONS: This analysis shows the adverse influence of reocclusion on long-term clinical outcome in relation to reinfarction and need for revascularization. To further optimize prognosis after thrombolysis, prevention of reocclusion should become a main priority. Future research should focus on the criteria and timing of elective revascularization procedures in the prevention of coronary reocclusion.

Aged↗
PubMed1995

Reflectance pulse oximetry at the forehead improves by pressure on the probe.

In this study, we investigated the possibility of improving reflectance (back-scatter) pulse oximetry measurements by pressure applied to the probe. Optimal signal detection, with the probe applied to an easily accessible location, is important to prevent erroneous oxygen saturation readouts. At the foreheads of 10 healthy adult volunteers, the effects of pressure applied onto the reflectance pulse oximeter probe were studied. Distances between the LEDs (660 nm and 940 nm) and the three photodiodes in the sensor were 4 mm, 7 mm, and 10 mm. For each detector, recordings were evaluated regarding red-to-infrared (R/IR) ratios and pulse sizes in relation to the stepwise increased pressure applied to the probe. R/IR variability decreased with applied pressures between 60 and 120 mm Hg. These findings are partly attributed to a corresponding increase in red and infrared pulse sizes at the detectors, which results in an improved signal-to-noise ratio. It is thought that pressure onto the oximeter sensor forces venous blood out of the tissues underneath the sensor. Consequently, the disturbing influence of pulsating and non-pulsating venous blood is reduced. Moreover, the increased difference in vessel diameter between diastole and systole and the corresponding difference in light absorption and an increase in flow velocities, causes an increase in pulse size with increasing pressure on the probe. Pressure applied to the probe may be useful in increasing the accuracy of reflectance pulse oximetry.

Adult↗