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C J Meijer

Publications and source records attributed to C J Meijer.

At least 91 records · Page 5Linked to original sources
PubMed2000

Analysis of genetic heterogeneity in Chlamydia trachomatis clinical isolates of serovars D, E, and F by amplified fragment length polymorphism.

Amplified fragment length polymorphism (AFLP) fingerprinting of clinical isolates of Chlamydia trachomatis serovars D, E, and F showed a low percentage of genetic heterogeneity, but clear differences were found. Isolates from index patients and partners had identical AFLP patterns and AFLP markers. Characterization of these AFLP markers could give more insight into the differences in virulence and clinical course of C. trachomatis infections.

Bacterial Outer Membrane Proteins↗
PubMed2000

Apolipoprotein H, a new mediator in the inflammatory changes ensuring in jeopardised human myocardium.

AIM: To investigate the presence of membrane "flip flop" in ischaemic human myocardium, we assessed depositions of apolipoprotein H (apoH; beta 2-glycoprotein 1) in ischaemic myocardium. Serum protein apoH can bind to negatively charged phospholipids and can also inhibit blood coagulation in vitro. We hypothesised that, because of its affinity for phosphatidyl serine, apoH might bind to "flip flopped" cells and would therefore be useful as a marker for membrane flip flop in vivo. METHODS: Myocardial tissue specimens were obtained from patients who had died within 14 days of acute myocardial infarction. RESULTS: Immunohistochemical analysis of these specimens revealed that apoH was selectively deposited in infarcted areas of human myocardium of at least one day's duration. Depositions of apoH were not found in non-ischaemic myocardial tissue samples obtained from patients who died from other (extracardial) causes. In vitro experiments with the human leukaemia T cell line Jurkat, subjected to apoptosis by etoposide, showed that apoH was bound to the membrane of apoptotic cells. However, these experiments also indicated that flip flop itself is not sufficient for apoH binding. In addition, Jurkat cells that bound apoH were positive for activated complement complexes, as was also found in the human heart. CONCLUSIONS: These results suggest that apoH is involved in the inflammatory processes that occur in ischaemic myocardium.

Apolipoproteins↗
PubMed2000

ALK expression in extranodal anaplastic large cell lymphoma favours systemic disease with (primary) nodal involvement and a good prognosis and occurs before dissemination.

AIMS: In anaplastic large cell lymphoma (ALCL), the site of origin has been described as an important prognostic factor. Recently, a fusion protein containing anaplastic lymphoma kinase (ALK) was described in systemic nodal ALCL, and shown to be associated with a good prognosis. The aims of this study were to investigate whether the presence of ALK protein differs between ALCL of different sites of origin; to determine whether ALK expression occurs before dissemination to other sites; and, finally, to investigate whether the site of origin remains a prognostic parameter in ALK negative ALCL. METHODS: ALK expression, as detected by immunohistochemistry using the monoclonal antibodies ALK1 and ALKc, was studied in 85 ALCLs from different sites of origin. In 22 patients, ALK expression was studied in multiple biopsies from different sites (including 13 skin, 16 lymph node, and nine other). Overall survival time was analysed using the Kaplan Meier method. RESULTS: ALK expression was found in 20 of 51 systemic ALCLs with (primary) nodal involvement. No ALK expression was found in 15 primary cutaneous, 14 gastrointestinal, and five nasal ALCLs. Multiple and subsequent biopsies of patients showed ALK expression to be identical to that seen in the primary diagnostic biopsy. Kaplan Meier survival curves showed that in ALK negative ALCLs originating from different sites, primary cutaneous cases are associated with an excellent overall survival, whereas the other cases show a comparable five years survival of less than 40%. CONCLUSIONS: If present, ALK expression favours systemic ALCL with (primary) nodal involvement, and can be used in differentiating between extranodal involvement of systemic (nodal) ALCL and primary extranodal ALCL. ALK is expressed consistently in multiple biopsies of a given patient, indicating that the chromosomal abnormality leading to aberrant ALK expression occurs before dissemination to other sites. Finally, in ALK negative non-cutaneous ALCLs, different sites of origin show comparable poor survival.

Adolescent↗
PubMed2000

PCR based high risk HPV testing is superior to neural network based screening for predicting incident CIN III in women with normal cytology and borderline changes.

BACKGROUND/AIMS: To improve the accuracy of conventional cytology in cervical cancer screening, high risk human papillomavirus (HPV) testing and neural network based screening have been developed. This study assessed the power of both techniques to detect women at risk of developing incident CIN III; that is, CIN III detected during the follow up of women with normal cytology and borderline nuclear changes. METHODS: A cohort of 2250 women, 34-54 years of age, who attended population based cervical cancer screening from 1988 to 1991 and had normal smears or borderline nuclear changes was followed. All smears were tested for high risk HPV and the smears were rescreened using neural network based screening. The value of neural network based screening for predicting incident CIN III during a mean follow up period of 6.4 years was compared with that of high risk HPV testing. In addition, morphological markers presumed to be related to HPV were correlated with HPV status. RESULTS: Thirteen (0.6%) women had incident CIN III. Both high risk HPV positivity and abnormal cytology were associated with an increased risk for incident CIN III (odds ratio, 240 and 22, respectively) and high risk HPV positivity was associated with abnormal cytology. The sensitivity of high risk HPV testing for predicting incident CIN III was much higher than that of neural network based screening (92% and 46%, respectively). None of the morphological markers assessed, including koilocytosis, was correlated with high risk HPV status. CONCLUSION: High risk HPV testing is superior to neural network based screening in identifying women at risk of developing CIN III. For women with normal cytology and borderline changes and a negative high risk HPV test, the screening interval can be considerably prolonged.

Adult↗
PubMed2000

Low diagnostic accuracy of selective screening criteria for asymptomatic Chlamydia trachomatis infections in the general population.

OBJECTIVES: To develop and validate selective screening criteria for asymptomatic Chlamydia trachomatis infections in the general population. METHODS: 11,505 people, aged 15-40 years, registered in 16 general practices in Amsterdam were invited to return by mail a home obtained first void urine sample and a questionnaire. Participants were randomly allocated into a development group (75%) or a validation group (25%). C trachomatis infection was determined by the ligase chain reaction. In the development group a set of criteria was identified by means of stepwise logistic regression analysis. The diagnostic accuracy (area under the ROC curve; AUC) and sensitivity, and the corresponding percentage of people selected for screening were calculated. The criteria developed in this study were applied to the validation group. RESULTS: The prevalence of asymptomatic C trachomatis infections among men was found to be 2.4% (1.7-3.0), and among women 2.8% (2.2-3.4). Screening men, based on Surinam/Antillean origin and painful micturition, yielded an AUC of 0.58 (0.55-0.60). Screening women, based on Surinam/Antillean origin, new sex partner in the previous 2 months, and unmarried/not cohabiting, yielded an AUC of 0.67 (0.65-0.69). Application of the criteria for men to the validation group yielded an AUC of 0.53 (0.48-0.57); by screening 10% of the men, 15% of the cases were detected. The AUC of the criteria for women in the validation group was 0.58 (0.54-0.61); by screening 51% of the women, 63% of the cases were detected. CONCLUSION: The prevalence of asymptomatic C trachomatis infections in Amsterdam is less than 3%. No suitable selective screening criteria for the general population could be identified.

Adolescent↗
PubMed2000

Malignancy-associated changes in breast tissue detected by image cytometry.

In several tissues, nuclear differences have been described in normal-appearing cells from patients with invasive carcinomas compared to cases without invasive carcinoma, a phenomenon known as malignancy-associated changes (MACs). The aim of this study was to determine the presence of malignancy-associated changes in breast tissue. Image cytometry was performed on Feulgen stained tissue sections of patients with usual ductal hyperplasia with (n = 30) or without (n = 41) adjacent invasive breast carcinoma. Nuclear features of normal-appearing cells as well as of usual ductal hyperplastic cells were separately compared between the two groups. Many features of normal-appearing epithelial cells were significantly different between cases with and without invasive cancer. Significant differences were also found by measuring ductal hyperplastic nuclei instead of normal-appearing nuclei. Cases with or without cancer could be distinguished with a classification accuracy of 80% by discriminant analysis using 2 nuclear features derived from ductal hyperplastic cells. In conclusion, image cytometry on breast tissue sections shows that malignancy-associated changes can be found in normal as well as in usual ductal hyperplastic breast cells. This could be clinically relevant for the detection of occult breast cancer, for the prediction of risk in these lesions, and to monitor the effect of chemopreventive agents.

Breast↗
PubMed2000

EORTC classification for primary cutaneous lymphomas: a comparison with the R.E.A.L. Classification and the proposed WHO Classification.

Primary cutaneous lymphomas differ significantly from their nodal equivalents in clinical behaviour and prognosis, and often require a different therapeutic approach. Since currently used classification systems for non-Hodgkin lymphomas do not or insufficiently recognize the special character of these lymphomas, primary cutaneous lymphomas are not uncommonly diagnosed incorrectly, and/or treated inappropriately with unnecessarily aggressive therapies. For that reason the Cutaneous Lymphoma Group of the European Organization for Research and Treatment of Cancer (EORTC) has recently proposed a separate classification for the group of primary cutaneous lymphomas. The EORTC Classification is consistently based on a combination of clinical, histological, immunophenotypical and genetic criteria, and includes well-defined and recognizable disease entities. It contains a limited number of cutaneous T-cell lymphomas and cutaneous B-cell lymphomas, which comprise more than 95% of all primary cutaneous lymphomas. The clinical significance of this classification has been validated by long-term follow-up data of more than 800 patients with a primary cutaneous lymphoma. The basic principles of the EORTC Classification will be presented, and current controversies between the EORTC Classification on the one hand, and the R.E.A.L. Classification and the proposed WHO Classification on the other will be discussed.

Europe↗
PubMed2000

Epidemiology of human papillomavirus infection.

Anogenital human papillomavirus (HPV) infection is a sexually transmitted disease (STD) that typically follows a self-limiting transient course for both sexes. The HPV incidences and prevalences vary greatly, because they reflect the sexual activity of the individuals studied and of the population they are in contact with. Higher prevalences are seen in young, sexually active groups and in high-risk areas for cervical and penile cancer, e.g. in Colombia. There has also been an increasing trend with time in Western Europe, paralleling the spread of other STDs and changes in sexual behavior. Penile intraepithelial neoplasia is usually positive for high-risk HPV DNA, mostly of type 16, whereas only approximately 50% of invasive penile cancers are positive for HPV DNA. This is similar to the role of high-risk HPV in vulvar carcinoma, where the attributable proportion is also approximately 40-50%. Moreover, in both sites similar histologic types of squamous cell carcinoma, i.e. the basoloid and basaloid/warty types, are mainly associated with high-risk HPV types. The studies performed so far have indicated that HPV has an etiological role in penile cancer, although the attributable proportion may be only approximately 40-50%.

Carcinoma, Squamous Cell↗
PubMed2000

Morphological features of epithelial abnormalities and precancerous lesions of the penis.

There is a heterogenous spectrum of abnormalities and atypical lesions in the penile epithelium. The terminology used to designate precursor lesions is variable but squamous intraepithelial lesions of low and high grade or penile intraepithelial neoplasia I, II and III are the recommended terms. Other probable precursor lesions are squamous hyperplasia and bowenoid papulosis. Low- and high-grade squamous intraepithelial lesions may be classified into squamous or simplex, the most frequent types, or warty (condylomatous) and basaloid. There is a striking morphological correspondence between precancerous lesions of the penis and their respective invasive lesions. The presence of two groups of lesions in the precancerous as well as invasive carcinomas, the squamous typical and the warty basaloid, is consistent with the bimodal hypothesis of the existence of non-HPV (the typical squamous) and HPV-related (warty or basaloid) tumors.

Carcinoma in Situ↗
PubMed1999

Aberrant expression of MUC1 mucin in ductal hyperplasia and ductal carcinoma In situ of the breast.

MUC1 mucin is a high molecular weight transmembrane glycoprotein expressed on the apical cell surface of normal glandular epithelia. In many human adenocarcinomas, this protein is up-regulated and/or underglycosylated, and its expression changes from apical to the entire cell membrane. It is thought that entire cell membrane expression of MUC1 reduces cell-cell and cell-extracellular matrix interactions and therefore may facilitate invasive growth and development of metastases. In this study, we determined immunohistochemically the expression of normal and underglycosylated MUC1 in normal breast tissue (n = 8) and in a spectrum of breast lesions, including usual ductal hyperplasia (n = 23), atypical ductal hyperplasia (n = 7), and ductal carcinoma in situ (DCIS) (n = 22). We used 4 monoclonal antibodies; 115D8 is directed to a glycopeptide, the other 3 to the peptide core of the molecule, of which 139H2 is not affected by the degree of glycosylation of MUC1, whereas SM3 and VU-4-H5 stain only underglycosylated forms. All cases showed apical positivity for 115D8 and 139H2. Entire cell membrane expression of fully (normal) glycosylated MUC1 was mainly found in DCIS lesions. Apical staining of SM3 was found in 38% of normal cases and 60% of the ductal lesions with no difference between the different subgroups. Apical staining of VU-4-H5 was found more often in DCIS (27%) than in normal tissue or ductal hyperplasia (3%). Membrane expression of underglycosylated MUC1 was found only in poorly differentiated DCIS. In conclusion, aberrant expression of MUC1, i.e., on the entire cell membrane and/or underglycosylated forms, can be found in ductal hyperplasia with atypia and especially in DCIS of the breast. This finding implies that these lesions with aberrant expression are at higher risk for developing subsequent invasive breast carcinoma.

Antibodies, Monoclonal↗
PubMed1999

Relation of human papillomavirus status to cervical lesions and consequences for cervical-cancer screening: a prospective study.

BACKGROUND: A relation has been established between infection with high-risk types of human papillomavirus and development of cervical cancer. We investigated a role for testing for human papillomavirus as part of cervical-cancer screening. METHODS: We monitored by cytology, colposcopy, and testing for high-risk human papillomavirus 353 women referred to gynaecologists with mild to moderate and severe dyskaryosis. The median follow-up time was 33 months. At the last visit we took biopsy samples. Our primary endpoint was clinical progression, defined as cervical intraepithelial neoplasia (CIN) 3, covering three or more cervical quadrants on colposcopy, or a cervical-smear result of suspected cervical cancer. FINDINGS: 33 women reached clinical progression. All had persistent infection with high-risk human papillomavirus. The cumulative 6-year incidence of clinical progression among these women was 40% (95% CI 21-59). In women with end histology CIN 3, 98 (95%) of 103 had persistent infection with high-risk human papillomavirus from baseline. Among women with mild to moderate dyskaryosis at baseline, a second test for human papillomavirus at 6 months predicted end histology CIN 3 better than a second cervical smear. INTERPRETATION: Persistent infection with high-risk human papillomavirus is necessary for development and maintenance of CIN 3. All women with severe dyskaryosis should be referred to gynaecologists, whereas women with mild to moderate dyskaryosis should be referred only after a second positive test for high-risk human papillomavirus at 6 months.

Adolescent↗
PubMed1999

Adverse effects of activated cytotoxic T lymphocytes on the clinical outcome of nodal anaplastic large cell lymphoma.

Systemic (nodal) anaplastic large cell lymphoma (ALCL) is a subgroup of T-cell non-Hodgkin's lymphomas with a relatively favorable clinical outcome. Part of systemic ALCLs harbor a genetic aberration (usually the t(2;5)(p23;q35) translocation) containing the anaplastic lymphoma kinase (ALK) gene at 2p23, which results in aberrant expression of the ALK protein. Recently, we have shown that the presence of high percentages of activated cytotoxic T lymphocytes (CTLs) in tumor biopsy specimens of Hodgkin's disease (HD) is associated with a poor prognosis. In the present study, we investigated the prognostic value of percentages of activated CTLs in combination with ALK expression in primary nodal ALCL. Primary nodal biopsies of 42 patients with ALCL were investigated for the percentage of activated CTLs (quantified using Q-PRODIT) and the expression of ALK by immunohistochemistry using monoclonal antibodies (MoAbs) directed against T-cell antigen granzyme B (GrB) and ALK, respectively. These parameters were evaluated for their predictive value regarding progression-free and overall survival time. The presence of a high percentage of activated CTLs (ie, >/=15%) was found to be an unfavorable prognostic marker. In combination with a lack of ALK expression, it was possible to identify a group of patients with a very poor prognosis. In this group, 13 of 16 patients died within 2 years as a result of the disease. Of the remaining 26 patients, only three (all ALK negative) died (P <.0001). Furthermore, the percentage of activated CTLs combined with ALK status appeared to be of stronger prognostic value than the International Prognostic Index (IPI). We conclude that a high percentage of activated CTLs present in biopsy material of patients with primary nodal ALCL is a strong indicator for an unfavorable clinical outcome. The combination of ALK expression and percentage of activated CTLs appears to be more sensitive than the IPI in identifying a group of patients with a highly unfavorable clinical outcome who may be eligible for alternative (high dose) therapy schemes.

Anaplastic Lymphoma Kinase↗
PubMed1999

[Systematic home screening for Chlamydia trachomatis infections of asymptomatic men and women in family practice by means of mail-in urine samples].

OBJECTIVE: To determine the prevalence and determinants of Chlamydia trachomatis (CT) infections among asymptomatic men and women in general practice. To determine participation rates in a systematic screening programme in general practice, using home obtained mailed urine samples. DESIGN: Cross-sectional study. METHODS: In 15 general practices in Amsterdam, the Netherlands, a sample of 11,005 persons (5541 women and 5464 men), aged 15-40 were invited to send in a urine sample and a completed questionnaire by mail. The urine samples were tested using the ligase chain reaction for DNA amplification. Patients diagnosed with CT were treated and partner notification was performed. RESULTS: 33% of invited males (1809/5464) and 50% of females (2751/5541) sent in the study material. Older patients participated more frequently than younger patients. Participation rates among persons with a Dutch background were higher than rates among persons from other ethnic groups. In 42 men and 79 women a CT infection was identified (2.3% and 2.9% respectively). Infections were more prevalent in patients from Surinam and the Dutch Antilles and in the age category 21-25 years. Type of health insurance as a proxy measure of socioeconomic status was not an indicator of infection. CONCLUSION: The participation in this systematic screening using mail-sent urine samples was 33% in men and 50% in women. The CT prevalences among asymptomatic men and women were 2.3% and 2.9% respectively.

Adolescent↗
PubMed1999

Variants of squamous cell carcinoma of the anal canal and perianal skin and their relation to human papillomaviruses.

High-risk types of human papillomaviruses (hrHPVs) may be a necessary cause in cervical cancer and in some subtype of anal, vulvar, and penile cancers. Large studies aimed at characterizing hrHPV-associated and non-hrHPV-associated subtypes of anal carcinomas are, however, lacking. We searched for human papillomavirus type 16 and 13 other hrHPVs in tumor tissue by PCR and performed a systematic histological evaluation of specimens from 386 patients with anal cancer (86% invasive; 302 women and 84 men). Cancers in women and homosexual men were more often hrHPV positive (P < 0.01) and located in the anal canal (P < or = 0.01) than were cancers in heterosexual men. In both women and men, anal canal cancers contained hrHPV clearly more often than did perianal skin cancers, and increasing hrHPV positivity was seen with higher localization in the anal canal. Indeed, 95 and 83% of cancers involving the anal canal in women and men, respectively, were hrHPV positive versus 80 and 28% of perianal skin cancers (P-trend < 0.001). Basaloid feature, adjacent anal intraepithelial neoplasia, poor or absent keratinization, and a predominance of small or medium neoplastic cells were all strongly positively associated with hrHPV status. Like cancer of the uterine cervix, the development of cancer of the anal canal may require infection with hrHPV, whereas a dual etiology of perianal skin cancers bears parallels to vulvar and penile cancers.

Age Factors↗
PubMed1999

Active specific immunotherapy for stage II and stage III human colon cancer: a randomised trial.

BACKGROUND: Colon cancer is curable by surgery, but cure rate depends on the extent of disease. We investigated whether adjuvant active specific immunotherapy (ASI) with an autologous tumour cell-BCG vaccine with surgical resection was more beneficial than resection alone in stage II and III colon cancer. METHODS: In a prospective randomised trial, 254 patients with colon cancer were randomly assigned postoperative ASI or no adjuvant treatment. ASI was three weekly vaccinations starting 4 weeks after surgery, with a booster vaccination at 6 months with 10(7) irradiated autologous tumour cells. The first vaccinations contained 10(7) BCG organisms. We followed up patients for time to recurrence, and recurrence-free and overall survival. Analysis was by intention to treat. FINDINGS: The 5.3 year median follow-up (range 8 months to 8 years 11 months) showed 44% (95% CI 7-66) risk reduction for recurrence in the recurrence-free period in all patients receiving ASI (p=0.023). Overall, there were 40 recurrences in the control group and 25 in the ASI group. Analysis by stage showed no significant benefit of ASI in stage III disease. The major impact of ASI was seen in patients with stage II disease, with a significantly longer recurrence-free period (p=0.011) and 61% (18-81) risk reduction for recurrences. Recurrence-free survival was significantly longer with ASI (42% risk reduction for recurrence or death [0-68], p=0.032) and there was a trend towards improved overall survival. INTERPRETATION: ASI gave significant clinical benefit in surgically resected patients with stage II colon cancer. ASI has minimal adverse reactions and should be considered in the management of stage II colon cancer.

Adjuvants, Immunologic↗