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Biomedical subjects

R J Diepersloot

Publications and source records attributed to R J Diepersloot.

At least 19 recordsLinked to original sources

Virulence factors of Escherichia coli isolated from urine of diabetic women with asymptomatic bacteriuria: correlation with clinical characteristics.

Since Escherichia coli isolated from compromised patients with symptomatic urinary tract infections (UTIs) express fewer virulence factors than those isolated from healthy controls, the question arises whether this is also the case for diabetic patients with asymptomatic bacteriuria (ASB). Polymerase chain reaction (PCR) assays were conducted on 111E. coli strains, isolated from the urine of diabetic women with ASB, using primers for the major subunit A and the G-adhesin (I, II, and III) of P fimbriae, type 1 fimbriae, S fimbriae, afimbrial adhesin, cytotoxic necrotizing factor (CNF), and aerobactin. Phenotypically, hemolysis, mannose-sensitive hemagglutination, mannose-resistant hemagglutination and O:K:H-serotypes were determined. Furthermore, we investigated the associations between virulence factors and patient characteristics (including deterioration of renal function). Type 1 fimbriae were the most prevalent virulence factor (86% by genotyping and 59% phenotypically). Except for a lower prevalence of known uropathogenic O-serotypes, we found the same number of virulence factors in our compromised patient group as listed in the literature in noncompromised patients with ASB. Certain virulence factors (type 1 and S fimbriae and CNF) of the causative E. coli correlated with the risk of a decline in renal function. In conclusion, the number of virulence factors in E. coli isolated from the urine of diabetic women with ASB are comparable with the results found in other (noncompromised) patients with ASB. Furthermore, certain virulence factors of E. coli might contribute to a decline in renal function.

Adult↗

Comparison of immulite with vidas for detection of infection in a low-prevalence population of pregnant women in The Netherlands.

A comparative evaluation of the Vidas system (bioMérieux, Marcy l'Etoile, France) and the Immulite System (Diagnostic Products Corporation) was performed using 500 prospectively collected serum samples. As part of a routine antenatal screening program, these samples were tested for hepatitis B surface antigen, and immunoglobulin G (IgG) and IgM antibodies to Toxoplasma gondii and rubella virus. The overall agreement between the two assay systems ranged from 98.0 to 99.8%. After discrepancy analysis the outcome in terms of relative sensitivity and specificity varied from 97.5 to 100%.

Animals↗

Antenatal screening for hepatitis B and antibodies to Toxoplasma gondii and rubella virus: evaluation of two commercial immunoassay systems.

A comparative evaluation of the Abbott AxSYM and DPC Immulite random-access analyzers was performed using 497 prospectively collected serum samples. These samples were sent to the laboratory for routine antenatal screening for hepatitis B surface antigen and immunoglobulin G (IgG) and IgM antibodies to Toxoplasma gondii and rubella virus. The overall agreement between the two assay systems ranged from 97.4 to 100%. After discrepancy analysis, the outcome in terms of sensitivity and specificity varied from 98.2 to 100% for all but one of the assays tested. The AxSYM rubella virus IgG assay tended to report protective or indeterminate antibody levels in 1% of the samples. This shortcoming might be overcome by raising the cutoff of the microparticle enzyme immunoassay system.

Animals↗

Comparison of a chemiluminescent immunoassay with two microparticle enzyme immunoassays for detection of hepatitis B virus surface antigen.

A comparative evaluation of the following commercial immunoassays for the detection of hepatitis B virus surface antigen (HBsAg) was performed: the Abbott AxSYM, Abbott IMx, and DPC IMMULITE assays. The specificity was 100% for all assays. Twelve samples were identified and were confirmed to be positive for HBsAg by all three methods. One additional sample was identified as reactive and was confirmed to be positive by the Abbott AxSYM assay only. Prior to confirmation testing the DPC IMMULITE assay produced significantly fewer false-positive results than the Abbott AxSYM assay (P < 0.05).

Adult↗

Procoagulant activity of endothelial cells after infection with respiratory viruses.

Influenza virus epidemics are associated with excess mortality due to cardiovascular diseases. There are several case reports of excessive coagulation during generalised influenza virus infection. In this study, we demonstrate the ability of respiratory viruses (influenza A, influenza B, parainfluenza-1, respiratory syncytial virus, adenovirus, cytomegalovirus) to infect lung fibroblasts and human umbilical vein endothelial cells in culture. All viral pathogens induced procoagulant activity in infected endothelial cells, as determined in a one-stage clotting assay, by causing an average 55% reduction in the clotting time. When factor VII deficient plasma was used clotting time was not reduced. The induction of procoagulant activity was associated with a 4- to 5-fold increase in the expression of tissue factor, as measured by the generation of factor Xa. Both experiments indicate that the procoagulant activity of endothelial cells in response to infection with respiratory viruses is caused by upregulation of the extrinsic pathway. Although both enveloped viruses and a non-enveloped virus (adenovirus) induced procoagulant activity in endothelial cells by stimulating tissue factor expression, the role of the viral envelope in the assembly of the prothrombinase complex remains uncertain. We conclude that both enveloped and non-enveloped respiratory viruses are capable of infecting cultured human endothelial cells and causing a shift from anticoagulant to procoagulant activity associated with the induction of tissue factor expression.

Blood Coagulation↗

Interleukin-6 production by endothelial cells after infection with influenza virus and cytomegalovirus.

Inflammation plays a role in the pathogenesis of cardiovascular diseases. Viruses may be a cause of chronic inflammation, and both influenza virus and CMV have been associated with cardiovascular diseases. IL-6, a proinflammatory cytokine with antiviral effects, has a pivotal role in the immune response, and under pathologic conditions, prohemostatic effects of IL-6 could lead to pathologic thrombosis and vascular plaque instability. To investigate this role of IL-6, we measured the production of IL-6 by human endothelial cells after infection with influenza virus and CMV. After infection with influenza virus or CMV, IL-6 release into the medium increased (1756.5+/-156.9 pg/mL vs 284.4+/-55.3 pg/mL; P < .001) for influenza-Infected compared with uninfected cells after 36 hours' incubation. Ultracentrifuged influenza virus supernatants, heat-inactivated virus, and purified hemagglutinin were not able to elicit IL-6 synthesis by human endothelial cells. These findings show that CMV and influenza virus are capable of modulating the in vitro production of IL-6, a cytokine involved in vascular inflammation, by human endothelial cells.

Cells, Cultured↗

Low prevalence of antibodies against the zoonotic agents Brucella abortus, Leptospira spp., Streptococcus suis serotype II, hantavirus, and lymphocytic choriomeningitis virus among veterinarians and pig farmers in the southern part of The Netherlands.

Serum samples from 102 veterinarians and 191 pig farmers from the southern part of the Netherlands were investigated for antibodies against Brucella abortus, Leptospira spp, Streptococcus suis serotype II, Hantavirus (HV), and lymphocytic choriomeningitis virus (LCMV). All samples were collected in 1993 and stored until this study was performed. The prevalence of antibodies against B.abortus in veterinarians (4.5%) was significantly higher (P = 0.01) than in pig farmers (0%). None of the veterinarians (0%) and only one pig farmer (0.5%) had antibodies against Leptospira spp. Furthermore, significantly (P = 0.015) more veterinarians (6%) than pig farmers (1%) had antibody titres against muramidase-released protein (MRP),a protein of pathogenic S. suis serotype II strains. None of the veterinarians and a total of 3 (1.6%) pig farmers had antibody titres against HV. The prevalence of antibodies against LCMV tended to be higher in pig farmers (2.6%) than in veterinarians (0%) (P = 0.10). It can be concluded that the prevalence of antibodies against the investigated zoonotic agents in veterinarians and pig farmers is low.

Agriculture↗

Influence of peroperative lavage solutions on peritoneal defence mechanisms in vitro.

OBJECTIVE: To find out the in vitro reaction of mesothelial cells and polymorphonuclear leucocytes (PMN) to incubation with seven commonly-used lavage solutions. DESIGN: Experimental study. SETTING: Laboratories, The Netherlands. MATERIAL: Cultured human peritoneal mesothelial cells and isolated PMN. INTERVENTION: Incubation of cells with clinically used lavage solutions (sodium chloride, Hartmann's solution, povidone-iodine, Dakin's solution, taurolidine, chlorhexidine, and hydrogen peroxide). MAIN OUTCOME MEASURES: Activation of monolayers of mesothelial cells and PMN measured by release of oxygen free radicals (chemiluminescence) and interleukin (IL)-8 concentrations and toxic effects measured by morphology, release of lactate dehydrogenase, failure of the restriction of the passage of inulin, and incorporation of propidium iodide. RESULTS: All solutions activated and killed mesothelial cells and PMN to some extent; the more concentrated the solution the greater the effect on these cells. CONCLUSION: Lavage solutions both poison and stimulate mesothelial cells and neutrophils, and some solutions are more potent than others.

Anti-Infective Agents, Local↗

[Clostridium difficile outbreak in surgical wards].

OBJECTIVE: To evaluate the clinical consequences of a hospital outbreak of Clostridium difficile infections in the Netherlands. DESIGN: Descriptive. SETTING: Diakonessen Hospital Utrecht, the Netherlands. METHODS: In the period from 1 August 1995 to 1 September 1996 C. difficile infections were recorded (gastrointestinal symptoms after use of antibiotics and findings at C. difficile toxin assay in faeces, or sigmoidoscopy). The monthly incidence of infections increased to 5 patients in December 1995; at that time strict hygienic measures were implemented and perioperative antimicrobial prophylaxis was adjusted. Data on the clinical course were collected retrospectively from the records of the patients involved. RESULTS: In 20 patients, admitted for various reasons to the surgical wards, hospital stay was complicated by a C. difficile infection. The mean age was 70 years. Eleven patients presented with diarrhoea, eight patients had nausea and vomiting as well. Diagnosis was confirmed by C. difficile toxin determination in most patients (n = 15). Despite antibiotic treatment in 19 patients, recurrences were seen in five patients (25%) and five patients died (25%). The monthly incidence declined to 0-1 per month. CONCLUSION: C. difficile infections in surgical patients carry a significant morbidity and mortality. Preventive hygienic measures are important to control spread of the infection.

Aged↗

Chlamydia trachomatis infection of human mesothelial cells alters proinflammatory, procoagulant, and fibrinolytic responses.

In this study we demonstrate the capability of Chlamydia trachomatis to infect cultured human mesothelial cell (MC) monolayers and to induce the production of the proinflammatory cytokines interleukin 1beta (IL-1beta) and IL-8. Seventy-two hours after initial infection, both the procoagulant activity of MC and the activity of the fibrinolytic inhibitor (plasminogen activator inhibitor 1) in the supernatants were enhanced. These findings support the hypothesis that provoked proinflammatory responses contribute to the development of complications after chlamydial infection.

Chlamydia trachomatis↗

Multicenter evaluation of the Amplicor Enterovirus PCR test with cerebrospinal fluid from patients with aseptic meningitis. The European Union Concerted Action on Viral Meningitis and Encephalitis.

The Amplicor Enterovirus PCR test was compared with viral culture for the detection of enteroviruses in cerebrospinal fluid (CSF) specimens. In a multicenter study in which nine laboratories participated, a total of 476 CSF specimens were collected from patients with suspected aseptic meningitis. Sixty-eight samples were positive by PCR (14.4%), whereas 49 samples were positive by culture (10.4%), demonstrating that the Amplicor Enterovirus PCR test was significantly more sensitive than culture (P < 0.001). After discrepancy analysis the sensitivity and specificity of the Amplicor Enterovirus PCR test obtained by using viral culture as the "gold standard" were 85.7 and 93.9%, respectively. Our results with the CSF specimens collected in different countries demonstrate that the Amplicor test is capable of detecting a large variety of enterovirus serotypes and epidemiologically unrelated isolates in CSF specimens from patients with aseptic meningitis. The Amplicor Enterovirus PCR test is a rapid assay which can be routinely performed with CSF samples and is an important improvement for the rapid diagnosis of enteroviral meningitis.

Cerebrospinal Fluid↗

Tissue concentrations after a single-dose, orally administered ofloxacin in patients with diabetic foot infections.

We studied the penetration of orally administered ofloxacin at the site of diabetes-related foot infections in patients with a planned debridement of the lesion. A total of nine patients received 800 mg of oral ofloxacin 120 to 150 minutes before surgery. During surgery, vital margin tissue and a serum sample were obtained. Serum and tissue concentrations of ofloxacin were measured. From seven patients sufficient amounts of tissue were obtained. Mean serum concentration was 7.0+/-3.5 mg/liter; mean tissue concentrations was 11.5+/-8.4 mg/kg. Mean serum and tissue concentrations exceed the minimal inhibitory concentration90 (MIC90) of commonly involved pathogens. This indicates that orally administered ofloxacin can be an effective treatment for infected diabetic foot lesions.

Administration, Oral↗

Piperacillin/tazobactam therapy for diabetic foot infection.

In this study, 29 patients were hospitalized with a diabetic foot infection and were treated with piperacillin/tazobactam. Of these 23 patients who were evaluated for efficacy of treatment, 22 patients improved or were clinically cured. In seven patients (30%), there was persistence of one of the baseline pathogens. Adverse events were reported in 15 patients (58%), three of which were serious. Piperacillin/tazobactam may be useful as monotherapy in diabetic foot infection giving an adequate clinical response and the level of side effects equivalent to those of other broad-spectrum antibiotics.

Adult↗

Patients with diabetes mellitus and atherosclerosis; a role for cytomegalovirus?

Diabetic patients are known to have an impaired immune response to viral antigens and a high incidence of atherosclerosis. This study was initiated to evaluate the association between cytomegalovirus infection and atherosclerosis in patients with diabetes mellitus. Patients with diabetes mellitus type 1 and 2 (> 5 years) with (group A) and without (group B) clinical signs of atherosclerosis were included. Cytomegalovirus cultures were obtained, serum was screened for CMV-antibodies and CMV-IgG and CMV-IgM titers were determined. Cytomegalovirus antibodies were detected more often in diabetic patients with atherosclerosis compared to patients without atherosclerosis (70.7 vs. 45.2%, P = 0.018. In female patients the prevalence of CMV-antibodies was 89.5 vs. 40.0% (P = 0.0037). CMV IgG titers were twice as high in group A compared to group B. Cytomegalovirus was cultured from four urine samples and two throat swabs in group B and in one urine and one throat swab in group A. The prevalence of cytomegalovirus antibodies was higher in diabetic patients with atherosclerosis compared to diabetic patients without atherosclerosis. This difference was most striking in the female population. CMV-IgG titers were twice as high in the atherosclerosis group. These data suggest that cytomegalovirus may play a role in the development of clinical atherosclerosis in patients with diabetes mellitus.

Antibodies, Viral↗

High seroprevalence of Helicobacter pylori in diabetes mellitus patients.

To assess the prevalence of Helicobacter pylori in diabetes mellitus, a serological test used to detect antibodies to H. Pylori in patients with diabetes mellitus. Within six months, 45 insulin-dependent, 98 non-insulin-dependent, and a control group of 159 outpatients were enrolled in this study. The age adjusted seroprevalence rate of Helicobacter pylori were determined using a commercial anti-Helicobacter pylori IgC and IgA ELISA (Bio-Rad). The prevalence rates increased with age in all age groups until 60-70 years. In diabetic patients, the frequency of Helicobacter pylori infection was higher than control subjects in nearly all age groups, reaching significance in three age categories of NIDDM patients and in one age category in IDDM patients. This higher seroprevalence could not be explained by differences in socioeconomic status or use of antibiotics.

Adult↗

[Large variation in the treatment of foot infections in diabetic patients in The Netherlands].

OBJECTIVE: To determine the treatment of foot infections in patients with diabetes mellitus and the implementation of the Dutch consensus guidelines. DESIGN: Questionnaire. SETTING: Nationwide. METHOD: To 180 internists and paediatricians were sent a letter explaining the objective of the survey and a questionnaire. After two months an identical questionnaire was sent, with the request to return it when the first questionnaire had not been returned yet. RESULTS: Seventy-three questionnaires (40%) were returned of which 63 were evaluable. The main reason for hospitalisation was the threat of limb loss (90%). Most patients presenting with superficial wound infections were treated with local surgical procedures (90%); however, 16% of the responders considered hospitalisation indicated. If osteomyelitis was present 81% of the responders would hospitalize the patient. Antibiotic treatment was instituted by 93%. In all, 11 different antibiotics were used. Of antibiotic combinations the combination of penicillin and lincomycin was used most frequently and the recommended combination of aminoglycoside and lincomycin least. The main reason for using a combination of antibiotics was presence of polymicrobial flora (93%). CONCLUSION: We conclude that treatment of diabetic foot is still very diverse in spite of the consensus guidelines.

Anti-Bacterial Agents↗

A hospital outbreak of penicillin-resistant pneumococci in The Netherlands.

Respiratory infections with penicillin resistant pneumococci constitute an increasing health care problem. This paper describes the nosocomial spread of penicillin resistant pneumococci (PRP) on a pulmonary ward. During an eight-month period, minimal inhibitory concentrations (MICs) for penicillin and several other antibiotics were performed on all Streptococcus pneumoniae isolates that were shown to be penicillin resistant by a screening assay. The personal data and case history of all patients with penicillin resistant pneumococci were evaluated. Penicillin Resistant Pneumococci were cultured from 18 patients, 16 men (mean age 74 +/- 8 yrs) and 2 women (aged 54 and 60 yrs). Chronic obstructive pulmonary disease was diagnosed in 16 patients, 10 of which had an additional underlying disease (2 diabetes mellitus, 2 heart failure, 2 malignancy). Prior to culture of Penicillin Resistant Pneumococci, 11 out of 18 patients were treated with antibiotics, a beta-lactam in most instances. Ten out of 18 patients died during or shortly after hospitalization. The death of one patient seems to be directly related to infection with Penicillin Resistant Pneumococci. The five Penicillin Resistant Pneumococci isolates available for serotyping were all type 9. The minimal inhibitory concentrations for penicillin varied from 0.5 to 2.0 mg.l-1. High minimal inhibitory concentrations were also noted for cefixime (all over 4.0 mg.l-1) and ceftriaxone (0.5-1.0 mg.l-1). It is concluded that penicillin resistant pneumococci can spread rapidly among old and debilitated patients. Thus, patients with this infection should be barrier nursed.

Aged↗