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C H Bangma

Publications and source records attributed to C H Bangma.

At least 19 recordsLinked to original sources
PubMed2006

[The search for better markers for prostate cancer than prostate-specific antigen].

Prostate-specific antigen (PSA) is currently the most important biochemical marker for the diagnosis of prostate cancer. Because of the limited specificity of PSA, clinically irrelevant tumours and benign abnormalities are also detected that potentially lead to over-treatment and the accompanying physical and emotional burden for the patient. In addition, PSA is used as an indicator of progression or clinical response after treatment for prostate cancer, but the prognostic value of this marker is limited. Current studies are evaluating a number of alternative markers, such as PSA-related parameters, human kallikrein 2, osteoprotegerin and the gene DD3(PCA3), that may improve the specificity of current PSA-based diagnostics and the prognostic value of PSA.

Antigens, Neoplasm↗
PubMed2005

Effects of luminal oxalate or calcium oxalate on renal tubular cells in culture.

Oxalate or calcium oxalate crystal-induced tissue damage could be conducive to renal stone disease. We studied the response of renal proximal (LLC-PK1 and MDCK-II) and collecting (RCCD1 and MDCK-I) tubule cell lines to oxalate ions as well as to calcium oxalate monohydrate (COM) crystals. Cells grown on tissue culture plastic or permeable growth substrates were exposed to high (1 mM) and extremely high (5 and 10 mM) oxalate concentrations, or to a relatively large quantity of crystals (146 microg), after which cell morphology, prostaglandin E(2) (PGE(2)) secretion, [(3)H]thymidine incorporation, total cell numbers and various forms of cell death were studied. Morphological alterations, increased PGE(2) secretion, elevated levels of DNA synthesis and necrotic cell death were induced by extremely high, but not by high oxalate. Crystals were rapidly internalized by proximal tubular cells, which stimulated PGE(2) secretion and DNA synthesis and the release of crystal-containing necrotic cells from the monolayer. Crystals did not bind to, were not taken up by, and did not cause marked responses in collecting tubule cells. These results show that free oxalate is toxic only at supraphysiological concentrations and that calcium oxalate is toxic only to renal tubular cells that usually do not encounter crystals. Based on these results, it is unlikely that oxalate anions or calcium oxalate crystals are responsible for the tissue damage that may precede renal stone formation.

Animals↗
PubMed2005

Innovations in serum and urine markers in prostate cancer current European research in the P-Mark project.

An overview is given of serum and urine prostate cancer markers that are currently under investigation and subsequently the P-Mark project is introduced. There are many markers showing promise to overcome the limitations of prostate specific antigen (PSA). Eventually, these markers should be able to increase the specificity in diagnosis, differentiate between harmless and aggressive disease and identify progression towards androgen independence at an early stage. In the P-Mark project, several recently developed, promising markers will be evaluated using clinically well-defined biorepositories. Following successful evaluation, these markers will be validated on a sample set derived from two large, European, prostate cancer studies and used for the identification of special risk groups in the general population. In addition, novel markers will be identified in the same biorepositories by different mass spectrometry techniques.

Biomarkers, Tumor↗
PubMed2005

Virus specific immune responses after human neoadjuvant adenovirus-mediated suicide gene therapy for prostate cancer.

PURPOSE: Neoadjuvant gene therapy potentially improves the outcome of primary treatment of prostate cancer by radical prostatectomy in patients with high risk of recurrence. We conducted a Phase I escalating dose study with a replication-defective adenovirus expressing the herpes simplex virus-thymidine kinase gene (Adv-HSV-tk vector). The primary end point was toxicity, while the evaluation of the patients' cellular and humoral immune responses served as a secondary endpoint. MATERIAL AND METHODS: The Adv-HSV-tk vector was injected into the prostate in two doses (2x10(10) to 2x10(11) viral particles), followed by ganciclovir twice daily for 14 days and retropubic radical prostatectomy on day 21. Adenovirus-specific neutralizing, IgG and IgA antibodies were evaluated. Peripheral blood mononuclear cells (PBMC) were stimulated by Adv-HSV-tk and analysed for IFN-gamma production and 3H-thymidine incorporation. Prostate specimens were immunostained for B (CD20+) and for T (CD3+) lymphocytes. RESULTS: Toxicity was minor in all 8 patients treated. In the prostate, no virus related cytopathic effect could be observed. Dose-dependent infiltration of T and B lymphocytes in the whole prostate and in tumor areas was observed. Boosting of adenovirus-specific antibody responses was observed in 7 patients, and an increased adenovirus-specific PBMC proliferation and IFN-gamma production was seen after Adv-HSV-tk stimulation. CONCLUSION: Neo-adjuvant adenovirus-mediated cytotoxic gene therapy prior to prostatectomy for prostate cancer is feasible and safe in an outpatient setting for intraprostatic vector doses up to 2x10(11) viral particles. Activation of the immune system was observed. Application of higher vector doses may be considered.

Adenocarcinoma↗
PubMed2005

Prostate specific membrane antigen (PSMA) is a tissue-specific target for adenoviral transduction of prostate cancer in vitro.

BACKGROUND: Adenovirus binds to the coxsackievirus and adenovirus receptor (CAR) as a first step in the process of cellular infection. This dependence on CAR potentially limits the use of adenovirus in gene therapy, since CAR is expressed in many tissues of the body, and expression of CAR may be low or lost upon progression of certain tumors. These limitations may be overcome by transductional targeting of adenovirus towards other cell surface molecules. We have evaluated the pantumoral epithelial cell adhesion molecule (EpCAM) and prostate specific membrane antigen (PSMA) as possible targets for adenoviral transduction of prostate cancer cells. METHODS: Bispecific antibodies, constructed as conjugates between an anti-adenovirus fiber knob Fab' fragment and anti-EpCAM or anti-PSMA monoclonal antibodies, were incubated with an eGFP-expressing adenovirus to retarget this vector. A cell panel, that includes two prostate cancer cell lines and four non-prostate control lines, were infected with serial dilutions of the retargeted vector and specificity of infection was determined. RESULTS: Receptor-specific transduction was obtained for both EpCAM and PSMA. PSMA-retargeting was shown to be selective for the prostate cancer cell lines. CONCLUSIONS: PSMA serves as a tissue-specific target for adenoviral vectors and may be applicable for gene therapeutical treatment of prostate cancer.

Adenocarcinoma↗
PubMed2004

Bladder volume measurements with a limited number of fixed ultrasound beams.

Over the past 30 years, various ultrasonic methods have been suggested to measure bladder volume. Ultrasound (US) represents a noninvasive and simple way to assess such volumes. Bladder volumes are usually estimated from cross-sectional planes obtained with instruments using full imaging capabilities, but their accuracy remains limited. This study presents a simple ultrasonic technique that allows the assessment of bladder volume, using only five US beams distributed in a single sagittal plane at predetermined angles. Depending on the number of beams intercepting the bladder, the depth and the height of the bladder could be estimated, and the volume of urine then computed from an empirical formula. To check the validity of the approach, 110 different bladder volume measurements were performed using a 2-D scanning instrument. A total of 33 measurements were used to deduce the empirical formula, which was then used to estimate the volume for the other 77 scans. The computed volumes were compared with calibrated volume data available through voiding or catheterization. A mean error of 9.64% was found, with a relatively constant accuracy for the different volume ranges investigated. Based on this method, a prototype composed of five single-element transducers was developed and tested in clinical situations with 30 patients. The measurements led to a mean error of 70 mL +/- 60 mL with respect to the reference volume. Overall, this study demonstrated the reliability of the proposed method for bladder volume measurements.

Adult↗
PubMed2004

The value of (-7, -5)pro-prostate-specific antigen and human kallikrein-2 as serum markers for grading prostate cancer.

OBJECTIVE: To assess the value of the precursor form (-7,5pro) of prostate-specific antigen (PSA) and human kallikrein-2 (hK2) for detecting and grading prostate cancer, as better serum markers with improved specificity are needed in men with lower ranges of total (t)PSA. PATIENTS AND METHODS: tPSA, free PSA (fPSA), the precursor (-7,5)proPSA and hK2 were measured in a subset of participants of the European Randomised Study of Screening of Prostate Cancer. In a pilot study, sera from 143 men biopsied but with no prostate cancer, 142 with BPH, and 146 with prostate cancer were analysed to determine the relative value of serum markers for differentiating between the groups. Then, in 141 men with prostate cancer who had a radical prostatectomy, these serum markers were related to the pathological grading to analyse their value as prognostic variables. RESULTS: Levels of (-7,5)proPSA, hK2 and fPSA could be used to distinguish between BPH and cancer, but proPSA and hK2, alone or combined, did not improve the specificity of fPSA for discriminating BPH and cancer. There was also no correlation between these serum markers and pathological tumour grade. CONCLUSION: The clinical effect of using (-7,5)proPSA or hK2 for detecting and grading prostate cancer remains limited.

Aged↗
PubMed2003

[Post mortem semen acquisition: not without 'informed consent'].

Recently, two requests for post-mortem semen acquisition were evaluated and rejected. The first request was from the wife of a man who died after the wedding night. In the second case, the wife requested that electroejaculation be done on a man who was brain dead because of a gunshot wound in the head. In both cases, the fact that there was no written consent from the men involved before they died was the deciding reason not to grant the requests. Written consent is legally and ethically seen as the final episode of a period in which persons have considered the consequences of the acquisition, storage and use of semen after the death of the husband.

Adult↗
PubMed2002

Different PSA assays lead to detection of prostate cancers with identical histological features.

OBJECTIVE: Because different PSA assays still show a wide inter-assay variation, we wondered what influence these discrepancies could have on the individual tumour characteristics of the cancers that each of these assays detect in a critical low PSA range. We analysed five different PSA assays in a biopsy simulation with PSA cut-offs of 3.0 and 4.0 ng/ml. MATERIALS AND METHODS: Randomly taken samples of 360 men with prostate cancer and 96 with benign prostatic disease from a screened population with PSA range of 1.0-6.0 ng/ml (Tandem-E) were investigated. In all cases the diagnosis was confirmed by sextant biopsies. One hundred and thirty-seven men (38%) underwent radical prostatectomy. Variability amongst assays was illustrated in terms of missed cancers and unnecessary biopsies, and in terms of pathologic features of detected cancers at both PSA cut-offs. RESULTS: Compared to Tandem-E, all assays, except Access, showed significant differences in PSA measurements. Furthermore, none of the assays discriminated significantly between benign and malignant prostatic disease (p>0.05). Tandem-E and Elecsys lead significantly more frequently to the detection of cancers at the cost of more unnecessary biopsies compared to the other assays. Yet, at both PSA cut-offs the proportion of cancers with a certain pathologic grade or stage that were detected by each assay were approximately the same. CONCLUSIONS: Our study shows that the use of different PSA assays only have consequences for the number, and not for the tumour characteristics of the prostate cancers that are detected. Thus, different PSA assays detect prostate cancers with the same tumour features.

Aged↗
PubMed2002

Validation of transrectal ultrasonographic volumetry for orthotopic prostate tumours in mice.

Orthotopic human prostate tumour models in athymic nude mice are regarded as being most suitable for fundamental and pre-clinical research on prostate cancer. The anatomic localization of the tumour in the pelvis, however, provides little possibility for monitoring tumour growth or regression. To assess time-related changes in orthotopic tumour volume, we applied transrectal ultrasonography (TRUS) to the murine prostate. This technique has the advantages of allowing accurate monitoring of tumours during therapeutic manipulations and a reduction of animal use due to a reduction of sacrificing endpoints. To validate the TRUS method, the mouse prostate reconstitution model, RM-9, and the prostate-specific antigen (PSA) producing human prostate cancer xenograft PC-346 were used. Volumetric calliper measurements were performed with a 30 MHz ultrasound probe designed for intra-arterial use in humans. Tumour weight, determined at various time-points, was found to be closely related to actual tumour weight (R = 0.99) and, in the PC-346 model, to the level of PSA in the plasma. Furthermore, the interobserver variation for TRUS was low for tumours above 50 mg. Thus, TRUS for murine prostate tumours proves to be an accurate, reproducible and sensitive method.

Animals↗
PubMed2001

Transrectal ultrasound for monitoring murine orthotopic prostate tumor.

BACKGROUND: The mouse orthotopic prostate tumor model has been recognized as an ideal preclinical animal model simulating the anatomical and biological milieu of the prostate. In comparison with the subcutaneous tumor model, the only disadvantage of this model is the difficulty of chronological tumor growth monitoring. We have applied recent endoluminal ultrasound technology, transrectal ultrasonography (TRUS), to the monitoring of mouse orthotopic prostate tumors. METHODS: A 6 Fr. 20 MHz catheter-based radial scan probe was used and TRUS was performed without any prior preparation including anesthesia. Orthotopic tumors were initiated by inoculation of 5000 RM-9 cells into the dorsal prostate of 12-week-old C57BL/6 male mice. The tumor growth was monitored by TRUS from day 3 to day 21. In addition, TRUS was performed to detect tumor growth suppression after intraperitoneal administration of cis-diamminedichloroplatinum (CDDP). RESULTS: By ultrasound, tumors became detectable 7 days after tumor cell inoculation. TRUS images were clear and parallel to actual tumor growth. The tumor volume (X) calculated by TRUS correlated significantly with the actual tumor weight (Y) measured at autopsy; Y = 101.653 + 1.174X (R = 0.930, P < 0.001). Similarly, tumor growth suppression induced by CDDP was clearly detected by TRUS with reasonable accuracy. CONCLUSIONS: A high resolution TRUS allows simple and reliable monitoring of in situ tumor growth and growth suppression, making the mouse orthotopic prostate tumor model more efficient.

Animals↗
PubMed2001

Papillary necrosis associated with the HIV protease inhibitor indinavir.

The HIV protease inhibitor indinavir may cause nephrolithiasis and interstitial nephritis. The renal consequences of indinavir-associated nephrotoxicity are uncertain. We report a case of papillary necrosis in a patient treated with indinavir. An asymptomatic HIV-infected woman experienced right-sided renal colicky pain during treatment with indinavir. She passed a non-solid stone and continued indinavir treatment. Intravenous pyelogram performed 20 months later following an episode of left-sided colicky pain showed right-sided papillary necrosis. Indinavir-associated nephrolithiasis and chronic interstitial nephritis were the only possible causes identified in this patient. Physicians should be aware that indinavir nephrolithiasis may cause papillary necrosis.

Adult↗
PubMed2001

Combination gene therapy with adenoviral vector-mediated HSV-tk+GCV and IL-12 in an orthotopic mouse model for prostate cancer.

We previously demonstrated significant therapeutic activities associated with adenoviral vector-mediated Herpes Simplex Virus/thymidine kinase (AdHSV-tk) with ganciclovir (GCV) in situ gene therapy in the RM-1 orthotopic mouse prostate cancer model and interleukin-12 (AdmIL-12) in situ gene therapy in the RM-9 orthotopic mouse prostate model for prostate cancer. In both protocols, local cytotoxicity and activities against pre-established lung metastases were demonstrated. To test whether combined AdHSV-tk+GCV+IL-12 gene therapy would lead to enhanced therapeutic effects when compared to either treatment alone, we used RM-9 mouse prostate cancer cells in both orthotopic and pre-established lung metastases models of prostate cancer. Combined treatment with a single injection of optimal doses of AdHSV-tk+GCV or AdmIL-12 led to significantly increased suppression of orthotopic tumor growth. IL-12 gene therapy alone was more effective than AdHSV-tk+GCV in suppressing spontaneous lymph node metastases and pre-established lung metastases but combination gene therapy did not result in additional anti-metastatic activities. Combination gene therapy also did not achieve significantly better animal survival compared to AdHSV-tk+GCV or AdmIL-12 alone. Analysis of localized antitumor activities demonstrated that AdHSV-tk+GCV therapy induced higher levels of necrosis compared to AdmIL-12 or combination therapy. However, both treatments alone and combination therapy produced similar increases in apoptotic index. To address the possible mechanisms of locally co-operative cytotoxic activities, we analyzed the systemic natural killer (NK) response and the numbers of tumor-infiltrating immune cells using quantitative immunohistochemical analysis. AdHSV-tk+GCV therapy alone led to detectable increases in iNOS-positive cells, CD4+and CD8+T-cells and moderately increased numbers of F4/80 (macrophage selective)-positive cells within treated tumors. In contrast, AdmIL-12 elicited a highly robust pattern of tumor infiltration for all four of these immune cells that was in general mimicked by combination therapy. Further analysis of the accumulation of transforming growth factor-beta1 (TGF-beta1) immunohistochemical staining demonstrated that AdHSV-tk+GCV treatment, but not AdmIL-12 treatment, produced cancer cell-associated increases in this cytokine relative to control Ad-beta-gal injections. Interestingly, local injection with AdHSV-tk+GCV induced significant splenocyte-derived NK cell cytolytic activities with maximal response 7 days following treatment, whereas AdmIL-12 injection produced significantly higher NK activity with maximal response 2 days following injection. The combined treatment produced a higher systemic NK response over the 14-day treatment period. Depletion of NK cells in vivo demonstrated that this immunocyte subpopulation was responsible for early locally cytotoxic activities induced by AdHSV-tk+GCV but not AdmIL-12 and that NK activities were largely responsible for activities against pre-established metastases generated by both gene therapy protocols. Prostate Cancer and Prostatic Diseases (2001) 4, 44-55

Journal Article↗
PubMed2001

Discordant performance of assays for free and total prostate-specific antigen in relation to the early detection of prostate cancer.

OBJECTIVE: To assess the value of applying rigid threshold values in interpreting prostate specific antigen (PSA) results, by selecting and comparing five current methods for measuring free and total PSA. MATERIALS AND METHODS: Samples taken from an ongoing screening study for prostate cancer (total PSA by Tandem-E assay, 17 334 participants; biopsy criterion a PSA of 3.0 microg/L, 4 464 men) from men with a total PSA of 1.0-6.0 microg/L were measured for free and total PSA using the Access, Immulite, Elecsys and Prostatus analysis kits, in two patient groups, i.e. with prostate cancer or no evidence of disease. RESULTS: Both patient groups had equal means for total PSA but not for free PSA. In all, 360 samples from men with cancer and 96 from men with no evidence of disease were analysed. All methods applied to both groups deviated statistically significantly from the Tandem-E result for total PSA, except for the Access kit. There was a close correlation among all the methods (correlation coefficients of 0.89-0.97). There were very discordant results for the combination of the Tandem-E vs Prostatus (8% difference), representing 315 participants at a threshold of 3.0 microg/L. For free PSA (free/total PSA) the situation was worse, with extreme differences of 32% and 36% for both patient groups (Elecsys vs Access). CONCLUSIONS: Depending on the threshold value applied as an indication for biopsy, when using the total PSA alone or combined with the free/total PSA, care is needed in interpreting patient groups because of the discordance among PSA assays.

Biopsy↗
PubMed2000

Blood and serum substances for markers of prostate cancer.

Serummarkers for prostate carcinoma are widely applied for the purpose of early detection of cancer and the differentiation between benign and malignant disease, for the pre-treatment staging of detected prostatic cancers, and for the monitoring of prostate cancer after curative or palliative therapies. This review illustrates the limitations of current markers for prostatic disease in blood en serum. It gives an overview of what is known about PSA and its isoforms, hK2, PSMA, and PSCA, and discusses, based on this information, in what direction current research is developing in order to improve these markers.

Antigens, Neoplasm↗
PubMed2000

[Mass screening for detection of prostatic carcinoma].

Active screening has been advocated around the world with reference to the favorable results of breast cancer screening. The risk of overdiagnosis and subsequent overtreatment by aggressive therapies fuels the arguments against screening. The value of early detection of prostate cancer in asymptomatic stages remains to be determined. There is a lack of pretreatment prognostic factors in order to distinguish those cancers which are life threatening from those which will have a relatively benign or even asymptomatic course. The benefit of prostate cancer screening, in terms of reducing disease-specific mortality and improvement of quality of life, can probably only be proven by a randomized study. Such studies are ongoing in the USA, Canada, and Europe.

Biomarkers, Tumor↗