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J Wagenaar

Publications and source records attributed to J Wagenaar.

At least 19 recordsLinked to original sources
PubMed2006

Occupational asbestos exposure: how to deal with suspected mesothelioma cases--the Dutch approach.

INTRODUCTION: Patients with asbestos-related diseases, such as malignant mesothelioma (MM), are not uniformly treated in Europe when they apply for compensation. In The Netherlands, the Institute of Asbestos Victims (IAV) acts on behalf of patients with a malignant mesothelioma. In the majority of cases, the diagnosis is clear but in some, uncertainty remains. In these cases a specialist opinion of the Mesothelioma Group of the Dutch Thoracic Society (DTS) is required. The process of data handling and final outcome for these patients is discussed and compared with the situation in other European countries. MATERIALS AND METHODS: Dutch patients with a possible malignant mesothelioma and occupational exposure to asbestos presented their cases to the IAV. In 10% of the cases, pathological confirmation of a malignant mesothelioma could not be obtained. These cases were presented to the Mesothelioma Group to obtain a clinical diagnosis based on clinical reports, occupational history, X-ray examination and other factors. Each case was reviewed by three independent pulmonologists experienced in MM. The majority view was binding for acceptance or rejection of the diagnosis. RESULTS: In the period January 2000 until May 2005, the IAV received 1747 cases for compensation. In 161 cases no definitive diagnosis could be made on pathology and were presented to the Mesothelioma Group. Of these cases, 117 (73%) were considered to be compatible with the clinical diagnosis malignant pleural mesothelioma. Forty-four cases (27%) were rejected. In 75% of the cases (112 of 150), the conclusion of the three independent specialists was unanimous; in 11 cases one specialist refrained from a diagnosis. The median time from request to submission of the report was 34 days (range 1-185 days). CONCLUSIONS: Compared with other European countries, this approach, as determined by the IAV and Mesothelioma Group of the DTS, is an effective and rapid way to investigate claims of patients with a possible occupationally related malignant mesothelioma.

Aged↗
PubMed2005

A reconsideration of the Campylobacter dose-response relation.

As a major foodborne pathogen, Campylobacter jejuni receives much attention in quantitative risk assessment. To date, all dose-response assessments have been based on a single human feeding study which unfortunately provides incomplete and possibly biased information on the dose-response relation. An incident at a dairy farm, where several children from a school class became ill as a result of drinking raw milk contaminated with C. jejuni, appeared to show a very clear dose-response relation between the amount of milk consumed and the attack rate. This relation was very nearly exponentially shaped and, therefore, seemed to conflict with the rather slowly rising dose-response relation established in the feeding study. Here we show that both datasets can be reconciled when illness and infection are considered separately. This not only provides new information on the illness dose-response relation for Campylobacter, but also amends the infection dose-response relation because of their conditional dependence.

Adolescent↗
PubMed2004

Dengue: an arthropod-borne disease of global importance.

Dengue viruses cause a variable spectrum of disease that ranges from an undifferentiated fever to dengue fever to the potentially fatal dengue shock syndrome. Due to the increased incidence and geographical distribution of dengue in the last 50 years, dengue is becoming increasingly recognised as one of the world's major infectious diseases. This article will review clinical and diagnostic aspects of dengue virus infections. It also presents our current knowledge of the pathophysiology of severe dengue and addresses the importance of dengue virus infections in those travelling to parts of the world where dengue is endemic.

Animals↗
PubMed2000

Comparison of polymerase chain reaction assays with bacteriologic culture, immunofluorescence, and nucleic acid hybridization for detection of Leptospira borgpetersenii serovar hardjo in urine of cattle.

OBJECTIVE: To compare sensitivity and specificity of various polymerase chain reaction (PCR) assays for detection of Leptospira borgpetersenii serovar hardjo in bovine urine and to compare results of the optimal PCR assay with results of immunofluorescence, nucleic acid hybridization, and bacteriologic culture. ANIMALS: 6 heifers. PROCEDURE: Heifers were exposed to serovar hardjo type hardjo-bovis by conjunctival instillation of 10(6) leptospires on 3 successive days. Urine samples were collected before and after infection. Sensitivity and specificity of 5 PCR assays were compared, to determine the optimal assay for use with bovine urine samples. The optimal PCR assay was then compared with results of bacteriologic culture, nucleic acid hybridization, and immunofluorescence. RESULTS: A PCR assay with the best combination of specificity (100%) and sensitivity (91%) was selected for comparison with the other diagnostic tests. Sensitivity for nucleic acid hybridization was 55%, whereas sensitivity for bacteriologic culture and immunofluorescence was 89 to 93%. CONCLUSIONS AND CLINICAL RELEVANCE: Bacteriologic culture, PCR, and immunofluorescence were sensitive for detection of L borgpetersenii serovar hardjo type hardjo-bovis in urine specimens of cattle, but a single technique was not the most sensitive for each animal tested. Therefore, the use of 2 techniques in combination is warranted for maximal sensitivity for diagnosis.

Animals↗
PubMed1999

High-resolution genotyping of Campylobacter strains isolated from poultry and humans with amplified fragment length polymorphism fingerprinting.

For epidemiological studies of Campylobacter infections, molecular typing methods that can differentiate campylobacters at the strain level are needed. In this study we used a recently developed genotyping method, amplified fragment length polymorphism (AFLP), which is based on selective amplification of restriction fragments of chromosomal DNA, for genetic typing of Campylobacter jejuni and Campylobacter coli strains derived from humans and poultry. We developed an automated AFLP fingerprinting method in which restriction endonucleases HindIII and HhaI were used in combination with one set of selective PCR primers. This method resulted in evenly distributed band patterns for amplified fragments ranging from 50 to 500 bp long. The discriminatory power of AFLP was assessed with a C. jejuni strain, an isogenic flagellin mutant, and distinct C. jejuni strains having known pulsed-field gel electrophoresis and fla PCR-restriction fragment length polymorphism genotypes. Unrelated C. jejuni strains produced heterogeneous patterns, whereas genetically related strains produced similar AFLP patterns. Twenty-five Campylobacter strains obtained from poultry farms in The Netherlands grouped in three C. jejuni clusters that were separate from a C. coli cluster. The band patterns of 10 C. jejuni strains isolated from humans were heterogeneous, and most of these strains grouped with poultry strains. Our results show that AFLP analysis can distinguish genetically unrelated strains from genetically related strains of Campylobacter species. However, desirable genetically related strains can be differentiated by using other genotyping methods. We concluded that automated AFLP analysis is an attractive tool which can be used as a primary method for subtyping large numbers of Campylobacter strains and is extremely useful for epidemiological investigations.

Animals↗
PubMed1994

Cellular and humoral immune responses in dogs experimentally and naturally infected with Leishmania infantum.

In this paper we describe a number of immunological parameters for dogs with a chronic Leishmania infantum infection which exhibit patterns of progressive disease or apparent resistance. The outcome of infection was assessed by isolation of parasites, serum antibody titers to Leishmania antigen, and development of clinical signs of leishmaniasis. Our studies show that 3 years after experimental infection, asymptomatic or resistant dogs responded to L. infantum antigen both in lymphocyte proliferation assays in vitro and in delayed-type hypersensitivity reaction, whereas no serum antibodies to parasite antigen were shown. In contrast, symptomatic or susceptible animals failed to respond to parasite antigen in cell-mediated assays both in vitro and in vivo and showed considerably higher serum antibodies to leishmanial antigens. In addition, significantly higher level of interleukin 2 (IL-2) and tumor necrosis factor were found in supernatants from stimulated peripheral mononuclear cells from asymptomatic dogs compared with those from symptomatic and control uninfected dogs. IL-6 production did not vary significantly among the groups studied. Finally, we observed similar results with a group of mixed-breed dogs with natural Leishmania infections also grouped as asymptomatic or symptomatic on the basis of clinical signs of canine visceral leishmaniasis. These results demonstrate that serum antibody titers, antigen-specific proliferative responses, delayed-type hypersensitivity skin reactions, and IL-2 and tumor necrosis factor production by peripheral mononuclear cells can be used as markers of disease progression.

Animals↗
PubMed1993

[Gastrostomy instead of gastric intubation for stomach decompression after large urologic operations].

In 31 patients who had undergone extensive intraabdominal urological surgery, a gastrostomy was performed for gastric decompression instead of introduction of a nasogastric tube. There were no complications during the procedure. All patients tolerated the gastrostomy well. Two were fed through the gastrotomy. We conclude, that gastrostomy is a safe method of gastric decompression.

Aged↗
PubMed1988

Intravesical and intradermal Bacillus Calmette-Guérin application. A phase I study to the toxicity of a Dutch Bacillus Calmette-Guérin preparation in patients with superficial bladder cancer.

In 30 patients toxic side effects of Bacillus Calmette-Guérin (BCG) were evaluated after intradermal and intravesical administration. The BCG preparation (BCG-RIVM) was produced in a homogeneously dispersed culture yielding a relatively high number of culturable particles per milligram dry weight BCG. All patients had a history of recurrent multiple noninvasive superficial transitional cell carcinoma of the bladder, and were previously unsuccessfully treated with intravesical chemotherapy (epodyl and/or adriamycin). BCG-RIVM (1 X 10(9) culturable particles) was instilled in the bladder, in combination with intradermal BCG-RIVM (8 X 10(7) culturable particles) administration once a week for 6 consecutive weeks. BCG was applied intradermally by a multiple-puncture technique. During and after therapy, subjective and objective side effects and toxicity were registered. Hematology and blood chemistry, including hepatic and renal function, was monitored. Only minor toxicity and/or side effects were observed during therapy and for a period of 6 months after treatment. After a period of 7 days no significant amount of BCG bacteria could be detected in the urine of 24 investigated patients.

Administration, Intravesical↗
PubMed1981

Distinct enzymatic responses in mice exposed to a range of low doses of ozone.

Short-term exposure of mice to low O3 doses, as defined by the product of concentration and exposure time (ct), was observed to induce alterations in two enzyme systems: first, that leading to changes in hepatic reduced ascorbic acid (RAA) content, and second to changes in plasma creatine phosphokinase (CPK) activity. RAA alterations were noticed immediately, 30 min and 120 min after termination of the exposure period, whereas CPK showed alterations immediately and 15 min after termination of the exposure. Later determinations, i.e., 24 hr after O3 exposure for RAA and 30 min after 03 exposure for CPK, revealed no significant differences when compared to control animals. Although differences in sensitivity existed, the dose response curves for both systems were more or less similar, showing a short decrease for the initial very low O3 doses, followed by a profound rise and a gradual decrease to control levels for subsequent ct doses. Exceptions were the 30 min curve for RAA and the immediate curve for CPK in so far as that both showed an additional depression. Neither plasma histamine nor plasma lactic acid dehydrogenase (LDH3) were observed to be altered by the range of O3 doses employed. These findings were explained on the basis of adaptation of the organism to a potentially noxious O3 stimulus by enhanced metabolic processes: a weak stimulus leading to only a small adjustment, and stronger stimuli to elevated enzyme activity as well. With increasing doses of O3 this elevation in enzyme activity was found to be gradually diminished, possibly due to a steadily growing demand, leaving the overshoot becoming continually smaller until a balanced state is achieved.

Air↗
PubMed1975

Vasectomy in prostatic surgery.

A prospective study was conducted to evaluate the usefulness of vasectomy in prostatic surgery. The results showed that vasectomy does not reduce the incidence of epididymitis. Since vasectomy is not without disadvantages (such as sterility, some prolongation of the operation and the possible occurrence of complications) vasectomy as a routine in prostatic surgery is not indicated.

Epididymitis↗