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Biomedical subjects

Dirk De Bacquer

Publications and source records attributed to Dirk De Bacquer.

47 records · Page 3Linked to original sources

Factors influencing the decline in endothelial cell density after corneal allograft rejection.

PURPOSE: Corneal allograft rejection is one of the major causes of transplant failure. The purpose of the current study was to examine the decline in endothelial cell density (ECD) in patients experiencing allograft rejection, by comparing this decline with the normal evolution in patients who undergo penetrating keratoplasty (PKP) and to identify possible factors predictive of this endothelial cell loss after corneal allograft rejection. METHODS: In a case-control study of 45 corneas that underwent corneal allograft rejection, specular microscopy photographs taken within the shortest time preceding the onset of rejection and after the resolution of the rejection were analyzed. RESULTS: The observed percentage loss of ECD in 21 (47%) corneas was not significantly greater than expected. A second group of 13 (29%) corneas showed a decline in ECD that was significantly greater than expected. Finally there were 11 corneas (24%) in which endothelial cells were no longer observable. The only two risk factors that reached statistical significance after multiple logistic regression analysis were a delay in diagnosis (a delay of >1 day yielded an odds ratio of 10.40; P=0.02) and a recipient age of more than 60 years (odds ratio, 6.95; P=0.04). CONCLUSIONS: Corneal allograft rejection does not necessarily cause a higher than expected endothelial cell loss; almost half of the patients in this study showed a decline in ECD that is comparable to the decline in patients who undergo PKP and have an uneventful follow-up. The most important variable influencing the extent of endothelial cells loss is a delay in diagnosis and treatment.

Adolescent↗

Nosocomial bacteremia caused by antibiotic-resistant gram-negative bacteria in critically ill patients: clinical outcome and length of hospitalization.

Population characteristics and outcomes were retrospectively compared for critically ill patients with nosocomial bacteremia caused by antibiotic-susceptible (AB-S; n=208) or antibiotic-resistant (AB-R; n=120) gram-negative bacteria. No significant differences in severity of illness and comorbidity factors were seen between groups. Patients with bacteremia caused by AB-R strains had a longer hospitalization before the onset of the bacteremia. The in-hospital mortality for patients with bacteremia caused by AB-S strains was 41.8%; for patients infected with AB-R strains, it was 45.0% (P=.576). A multivariate survival analysis demonstrated that older age (P=.009), a high-risk source of bacteremia (abdominal and lower respiratory tract; P=.031), and a high acute physiology and chronic health evaluation II-related expected mortality (P=.032) were independently associated with in-hospital mortality (P<.05). Antibiotic resistance in nosocomial bacteremia caused by gram-negative bacteria does not adversely affect the outcome for critically ill patients.

Bacteremia↗

Discriminative value of serum amyloid A and other acute-phase proteins for coronary heart disease.

We studied the value of serum amyloid A (SAA), a first-class acute-phase protein, as a marker for coronary heart disease (CHD) in a middle-aged male population. In a working population of 16307 men (age, 35-59 years), 446 cases had a history of CHD or prominent Q:QS waves on electrocardiogram. For each case, two matched controls were investigated. SAA, measured by immunonephelometry, was correlated with other acute-phase proteins, cardiovascular risk factors, and infectious serology markers. SAA concentrations were significantly higher in the cases than in controls (P<0.05) and correlated with serum C-reactive protein (CRP) (r=0.61), plasma fibrinogen (r=0.39), serum haptoglobin (r=0.26), and body mass index (r=0.13) (P<0.001). Serum CRP is a better marker for CHD than SAA, which showed discriminative power only in a univariate model comparing highest versus lowest tertile (odds ratio, 1.39; 95% confidence interval, 1.03-1.87). Neither SAA nor other acute-phase proteins correlated with Chlamydia pneumoniae immunoglobulin (Ig)G, Helicobacter pylori IgG and IgA, and cytomegalovirus IgG. In conclusion, although SAA has a discriminative value for CHD, serum CRP is to be preferred as a first-class acute-phase reactant for detection of the disease.

Acute-Phase Proteins↗

The importance of plasma apolipoprotein E concentration in addition to its common polymorphism on inter-individual variation in lipid levels: results from Apo Europe.

Interindividual variation in the concentration of plasma lipids which are associated with coronary artery disease (CAD) risk is determined by a combination of genetic and environmental factors. This study investigates the effects of apoE genotype and plasma concentration on cholesterol and triglycerides (TG) levels in subjects from five countries: Finland, France, Northern Ireland, Portugal, and Spain. Age and sex significantly influenced serum cholesterol, TG and apoE concentrations. The age effect differs in males and females. The allele frequencies of the apoE gene, one of the most widely studied CAD susceptibility genes, were determined: the epsilon2 allele frequency and the apoE concentration showed a north-south increasing gradient while the epsilon4 allele frequency showed the reverse. ApoE plays an important role in lipid metabolism. Total cholesterol and TG concentrations were significantly dependent on apoE genotype in both sexes. These differences in lipids between genotypes were more pronounced when plasma apoE concentrations were taken into account.

Adult↗

Cross-sectional study of the ophthalmological effects of carbon disulfide in Chinese viscose workers.

This article presents cross-sectional investigation results of ophthalmological effects for the occupational exposure to carbon disulfide of workers at a large viscose fibre factory in the middle part of China. The total of 271 exposed subjects (191 males, 80 females) and 133 workers (93 males, 40 females) not exposed to any toxic agent in the working environment underwent ophthalmological examination. The self-administered questionnaire collected data on the medical history and ophthalmological complaints during the past three months. The ophthalmologic examination included routine examination for retinal capillary anomalies and and color vision with the FM 100-Hue test method. Nearly all subjects did not use respirators, smocks or aprons, gloves or other personal protective devices during work time. The average personal CS2 exposure level in the present study was 13.7-20.05 mg/m3. The FM 100-Hue test results showed that the total error scores of the exposed group, whether male or female, were higher than that of the control, the discrimination of the green and blue zones was also impaired significantly. A fundus examination showed no retinal capillary anomalies or other serious ophthalmological symptoms that may be related to effects of CS2. In conclusion, color vision was disturbed in workers exposed to CS2, at levels below the present threshold value. Reduced color discrimination may be attributed to long-term carbon disulfide exposure and suggests that health surveillance of workers exposed to carbon disulfide should include the FM 100-Hue Test as a sensitive and easy method.

Adult↗

Expression of the multidrug transporter P-glycoprotein is highly correlated with clinical outcome in childhood acute lymphoblastic leukemia: results of a long-term prospective study.

The improved cure rate in childhood ALL may be attributed largely to the effective multidrug regimens currently applied in well-designed clinical trials. However, in a minority of patients with ALL, chemotherapy failure remains a leading cause of cancer related death, most probably due to cellular drug resistance. The better-known mechanism of such resistance is mediated by P-glycoprotein (P-gp). In a long term prospective study (mean time of follow-up: 65 months) the multidrug efflux pump P-gp was examined immunocytochemically in leukemic cells of 102 protocol-treated children with de novo acute lymphoblastic leukemia (ALL) and of 37 children with relapsed ALL. Fourteen percent expressed P-gp at initial diagnosis and 35% were P-gp positive at relapse. The patients being P-gp positive at initial diagnosis had a higher rate of leukemic relapse than the P-gp negative patients (P = 0.02). In the relapsing patients, those who were P-gp positive had a 2.18-fold greater risk for leukemic death than those who were P-gp negative. Paired analysis on diagnostic and relapsed samples from 20 patients did not support the hypothesis of P-gp mediated expression being a chemotherapy induced phenomenon. The cumulative event free survival for de novo ALL patients was significantly higher in the P-gp negative patient group. Multivariate analysis showed that P-gp expression is independent of other known risk factors. In conclusion we strongly advise that tests for P-gp in leukemic blasts should be conducted for every child with ALL, since this parameter selects a subgroup of patients with increased risk for leukemic relapse.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Comparison of occupational exposure to carbon disulphide in a viscose rayon factory before and after technical adjustments.

The objective of this follow-up study was to verify the efficacy of the technical adjustments gradually introduced in departments of a viscose rayon factory from 1989 onward. Personal exposure to carbon disulphide was assessed by means of personal monitoring through active sampling. Six job titles in three departments of the factory were sampled. Geometric means were calculated and used as estimates of time-weighted average (TWA) concentrations. The results from the present study were compared with similar measurements from a previous study in the same factory. Due to organizational changes, only three job titles (spinner, first spinner, and viscose preparator) could be compared directly. Two new job titles were identified, although tasks performed in these two job titles already existed. The measurements from one job title could not be compared, due to a substantial reorganization and automation of the tasks carried out in the department. The comparison before and after technical improvements shows that personal exposure of spinner and first spinner has been substantially reduced. Even the geometric means of measurements outside the fresh air mask are below the TWA-TLV (Threshold Limit Value). Despite the difficulties in comparing the results from the two studies, it is concluded that the technical measures reduced up to tenfold personal exposure to carbon disulphide and personal protection reduced it further by a factor two.

Air Pollution, Indoor↗

The pursuit of secondary prevention targets in Czech coronary patients. A comparison of EuroAspire I and II surveys.

BACKGROUND: Definite evidence has been established, that coronary patients benefit from appropriate secondary prevention measures, as recommended by the European and National Guidelines. EuroAspire I (1995) and EuroAspire II (1999) were surveys aimed to evaluate the state of the implementation of guidelines into the every-day medical practice in several European countries, including Czech Republic. We wondered to what extent the practice in secondary prevention of Czech physicians, since the guidelines were published, changed during 5 years, to pursue the targets. METHODS: We compared two surveys, undertaken in the same geographical areas of the Czech Republic. Consecutive patients, males and females, less than 71 years of age were indentified following acute coronary event or revascularisation procedure and were interviewed and examined at least 6 months after hospitalization. RESULTS: The Czech surveys included 331 patients in EuroAspire I and 410 in EuroAspire II. In EuroAspire II, the total number of smokers decreased in males, but increased in females. The patients were more obese, had higher glucose levels as well, while blood pressure, total and LDL cholesterol and triacylglycerols were lower, than in EuroAspire I. Corresponding changes also occurred in the prevalence of hypertension and hyperlipidaemias by definitions. There was a significant increase in the use of betablockers, ACE inhibitors and hypolipidemic drugs, mainly statins. In conclusion, in spite that the compliance with the recommendations for secondary prevention improved, achievement of targets remained rather unsatisfactory, likewise in other European countries.

Chi-Square Distribution↗

Cytomegalovirus infection: an occupational hazard to kindergarten teachers working with children aged 2.5-6 years.

The aims of the study were to evaluate the occupational risk of cytomegalovirus (CMV) infection in kindergarten teachers working with children aged 2.5-6 years, and to determine occupational risk factors within the occupation of kindergarten teaching. A cross-sectional seroprevalence study was conducted in 211 kindergarten teachers and 283 administrative workers. Relevant confounding factors were considered. Overall seropositivity rates ranged from 16.4% in childless women to 33.7% in women with one child or more. Raising own children was the major risk factor for CMV seropositivity: adjusted OR 2.25. Kindergarten teaching showed to have a significantly increased CMV seropositivity rate: adjusted OR 1.54. Among kindergarten teachers, washing hands at school, number and age of the pupils, and seniority had no significant influence on seropositivity. The results indicated an increased risk of CMV infection in kindergarten teachers and an insufficiency of hygienic measures to prevent seropositivity.

Adult↗

Diabetes mellitus in middle-aged people is associated with increased sick leave: the BELSTRESS study.

In a prospective study of the association between self-reported diabetes mellitus and sick leave from work, 21,149 men and women, aged 35-59 years, participated. Prevalence of diabetes was obtained by questionnaire. Sick leave was prospectively obtained from departments of human resources in the year after the baseline survey. Outcome variables related to duration of sick leave, repetitive absences, and long absences of at least seven consecutive days. In gender-specific multivariate analyses the relation between diabetes and sick leave was studied independent of age, body mass index, physical activity, alcohol intake, education, job title, and smoking habit. Prevalence rates of self reported diabetes were 2.8% and 2.2% in men and women, respectively. For each outcome variable a significant association between diabetes and sick leave was observed. Significant associations were found between diabetes and duration of sick leave and repetitive absences in men. In women a similar trend was observed for duration, and a significant association was found for repetitive absences.

Adult↗