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G P Vooys

Publications and source records attributed to G P Vooys.

At least 19 recordsLinked to original sources
PubMed1997

The effect of beta-carotene on sputum cytology in smokers: a preliminary study.

The use of biomarkers is a promising approach to the study of human cancer risk. Bronchial metaplasia in sputum cytology may be a marker for potential premalignancy that can be used for population studies. We recently performed a randomized, controlled trial in smokers on the effect of 14 weeks beta-carotene (20mg/day) on markers for DNA damage. We now have evaluated the application of sputum cytology in this study and performed a preliminary evaluation of the effect of beta-carotene. Of the 150 potential participants in this trial 75 were not eligible because they failed to produce sputum samples (n = 29), or because samples were unsatisfactory (n = 46). The eligible group was older (41 vs 37 years) and had smoked longer (23 vs 19 years), but had similar cigarette consumption (mean 21/day) and plasma cotinine levels. Metaplasia was graded in seven categories. Only 11 subjects (15%) showed minor or mild atypia on study entry. Agreement within and between observers was 95% within the same or an adjacent category. We observed no significant correlation between before and after treatment final metaplasia scores in either the beta-carotene (Spearman R = 0.18, P = 0.3) or placebo group (Spearman R = 0.17, P = 0.3). Initial metaplasia scores were somewhat higher in the beta-carotene group (n = 33) than in the placebo group (n = 42) (P = 0.06). Final metaplasia scores were similar in both groups (P = 0.69), and there was no decrease in metaplasia scores in the beta-carotene group (P = 0.75). This study indicates that sputum cytology may not yet be a readily applicable marker in studies of a healthy asymptomatic population, because many smokers do not spontaneously produce sputum, more severe lesions are rare, and variation over time in the minor lesions in large. Therefore, the preliminary evidence that beta-carotene has no influence should be interpreted with care.

Adult↗
PubMed1990

[Fine-needle biopsy of cold thyroid nodules].

In retrospect we analysed 175 fine needle aspiration biopsies, performed on 154 patients with a palpable, solitary, 'cold', thyroid nodule. In contrast to conventional diagnostic methods such as ultrasound and scintigraphy fine needle aspiration is a highly specific method for the detection of thyroid cancer. We found a significant difference in the frequency of thyroid carcinoma between patients operated because of cytological diagnosis and patients operated because of clinical suspicion of cancer, 44% and 20% respectively. We conclude that fine needle aspiration is a major step forward in the evaluation of solitary thyroid nodules.

Adolescent↗
PubMed1989

Quantitative immunohistologic and histomorphometric diagnostic criteria for Sjögren's syndrome.

Sjögren's syndrome (SS) is a chronic auto-immune exocrinopathy, especially affecting the lacrimal and salivary glands. The aim of this study is to improve the diagnostic possibilities of the sublabial salivary gland (SSG) biopsy. The SSG biopsies of 19 patients with SS and 65 healthy control subjects were used in a quantitative immunohistologic and histomorphometric study. Statistical analysis of the immunohistochemical data resulted in a diagnostic criterion, which is based on the percentages of IgA- and IgG-containing plasma cells. Statistical analysis of 3 immunohistologic and 6 histomorphometric features resulted in a combined immunohistologic and histomorphometric criterion, which is based on 2 immunohistologic parameters (the percentages IgA- and IgG-containing plasma cells) and 3 histomorphometric parameters (the volume percentages of acini, intralobular ducts and diffuse lymphoplasmacytic infiltrate). The immunohistologic diagnostic criterion has a specificity of 95.4%, a sensitivity of 100% and an overall percentage of misclassification of 3.6%. The combined diagnostic criterion has a specificity of 98.5%, a sensitivity of 100% and an overall percentages of misclassification of 1.2%. Furthermore it reduces the number of false positive diagnoses with a factor 6 from 9% to 1.5%.

Biopsy↗
PubMed1987

Renal hamartoma associated with renal cell (Grawitz) tumor: another indication that Grawitz tumors are carcinosarcomas.

We report a case of renal hamartoma (angiofibroma) which contained nests of renal cell (Grawitz) tumor and review the literature regarding this subject. We believe that the finding of Grawitz tumor cells within a mesodermal tumor supports our hypothesis that renal cell (Grawitz) tumors are of mixed (mesodermal and endodermal) origin, that is, they show at least one important biological characteristic of carcinosarcomas.

Carcinoma, Renal Cell↗
PubMed1986

Dynamics of human renal tumor colony growth in vitro.

Two-layer soft agar cultures from 26 patients with renal cell carcinoma, 21 renal primary lesions and 5 metastatic lesions, were evaluated for tumor colony formation using both dynamic growth curves and static single time point colony counting. Dynamic growth curves markedly increased the number of evaluable tumor cultures. There was no relationship between colony formation and TNM stage of the tumor or renal vein invasion. However, there was a significantly (p less than 0.02) higher rate of colony formation from younger (less than 50 y.) patients than from older patients. Only 2 of 5 tumors tested showed response to one or more cytostatic agents in vitro, both tumors showing response to Adriamycin and one to Cis-platin. Dynamic evaluation of tumor colony formation in soft agar may increase the clinical applicability of the human tumor cloning system both by increasing the number of evaluable cultures and by providing more information about the processes involved in tumor colony formation in vitro.

Adult↗
PubMed1985

Cell DNA content--correlation with clonogenicity in the human tumour cloning system (HTCS).

Thirty-six ovarian and renal-cell tumours were analyzed by flow cytometry (FCM) for DNA content and in parallel were assayed for colony formation in a human tumour cloning system (HTCS). While 15/19 (79%) tumours with an abnormal (aneuploid) DNA stemline formed colonies in the HTCS, only 2/17 (12%) of diploid tumours formed colonies. All samples contained tumour cells as assessed by routine cytological examination. The capacity to form colonies in the HTCS was not correlated in these tumours with grade or stage of disease or tumour type. The level of aneuploidy expressed as the FCM DNA index did not correlate with the cloning efficiency in HTCS. These findings suggest that tumour growth in the HTCS reflects a biologically important potential, related in at least some tumours to an abnormal DNA stemline.

Carcinoma, Renal Cell↗
PubMed1985

Repeated urine cell culture in soft agar: potential role in follow-up of patients with transitional cell carcinoma.

To evaluate the persistence of cells with clonogenic properties in patients being treated for transitional cell carcinoma, 272 urine samples were collected from 75 patients and cultured in a double layer soft agar "cloning" system. The development of colonies was evaluated with growth curves based on repeated colony counting with an Omnicon automated colony counter at regular time intervals. Forty-eight patients had at least one evaluable culture. Comparing the results of colony development in culture with the clinical evaluation of the patients, 9 patients had a histologically proven recurrence preceded or accompanied by tumor colony growth in urine culture. One patient had tumor recurrence with growth negative urine culture (false negative). Fifteen patients have had growth negative urine culture with a negative follow-up (mean 19.5 months). Twenty-one patients have had growth positive urine cell cultures with no recurrence in their follow-up (mean 18.7 months). Although the follow-up times are at present relatively short, the present study suggests that repeated soft agar urine culture of patients with low-grade, low-stage bladder carcinoma may provide a means for identifying those patients at a higher risk for recurrence/progression of their disease.

Agar↗
PubMed1985

Automated counting of human tumour colonies in the Courtenay-Mills assay system.

A procedure for using the Omnicon automated image analysis system for counting colonies grown from a human tumour cell line (COLO 205) in the Courtenay-Mills assay is described. This involves the transfer of the agar medium from culture tubes into petri dishes. Comparisons of observer and instrument counts were done on a blinded basis. Run-to-run correlation coefficient was 0.996 for automated counting and the inter-observer correlation coefficient was 0.984. Both assessments showed a linear relationship between the number of cells plated and the number of colonies grown. Automated colony counting is fast, reliable and provides additional information on colony size distribution, not obtainable with manual counting. This automated procedure will greatly facilitate in vitro drug sensitivity evaluation.

Autoanalysis↗
PubMed1985

Time course of ovarian tumour growth in soft agar culture.

Single time point assessment is usually employed in the Human Tumour Cloning System as the only parameter for in vitro growth. This does not seem to give a fair expression of the dynamic biological properties of tumour growth and time dependent effects, e.g. of cytotoxic drugs. We studied the time course of colony formation in temporal growth patterns (TGPs) and compared this method of growth evaluation with conventional single time point assessment in 57 samples of ovarian tumour cultures in the HTCS. A first advantage of the use of TGPs is that more cultures become evaluable, as this assessment over time can detect a rise in the number of colonies in dishes where colony-like clumps have initially been seeded. Thus only 28 of the cultures were evaluable for single time point assessment, whereas 57 were available for TGP evaluation. Growth was more often seen at TGP evaluation (14/57) than at single day assessment (8/57). Evaluation of growth over the course of time potentially allows detection of sensitivity to drugs. Furthermore TGPs reflect the dynamics of biological growth. These features cannot be studied in single time point assessment.

Agar↗
PubMed1983

Interferons and bronchogenic carcinoma in juvenile laryngeal papillomatosis.

A squamous cell carcinoma of the bronchus developed in a patient during the course of juvenile laryngeal papillomatosis. This patient had received interferon treatment, which caused regression of the papillomas, but apparently had no influence on the progression of the bronchogenic squamous cell carcinoma. This suggests that interferons have an antiviral effect, but not an antitumor effect in the dosage used. No radiation therapy had been given in the past and no other carcinogenic factors are obvious. However, human papilloma viruses, which cause juvenile laryngeal papillomatosis, have been incriminated in the genesis of squamous cell carcinomas.

Adolescent↗
PubMed1983

Soft-agar cultures of transitional cell carcinoma colonies from urine, irrigation fluids and tumor samples.

Soft-agar cultures of transitional cell carcinoma from urine, irrigation fluid and transurethral resection solid tumor specimens show good colony growth. Growth of tumor colonies produced from urine was adequate to evaluate the presence of a viable tumor, since 12 of 18 noninfected cultures showed growth. The number of colonies produced was adequate to evaluate the sensitivity or resistance to chemotherapy agents in only 3 of 18 cultures. For irrigation fluid, similar results were obtained: 9 of 17 noninfected cultures showed growth, while only 3 of 17 were adequate for drug-sensitivity evaluation. For the evaluation of sensitivity or resistance, tumor cell suspensions were most appropriate, 7 of 25 noninfected cultures showed 30 or more colonies/dish, whereas 17 of 25 showed growth. With the possibility of obtaining growth of tumor cells derived from urine, a prospective study is proposed to define the value of repeated urine cultures in monitoring the status of the urothelium of patients treated for transitional cell carcinoma.

Agar↗
PubMed1983

Scanning electron microscopy of exfoliative cervical cytology.

The cervical epithelium was studied in 2260 cells with the consecutive LM-SEM method. The purpose of the study was to describe as many cell types as possible and compare these results with the literature. Cells should be related to two diagnoses: that of the individual cell, and that of the tissue from which it originates. Micro-ridges with bars cover the luminal side of normal intermediate and superficial cells. Microvilli with grooves cover the basal side. Microvilli and microridges are intermeshing. Parallel-running plicae form side-to-side junctions. Regional differences on the same cell side were mainly found on normal cells. Metaplasia has some characteristic features. Dysplasia and carcinoma in situ show a continuous process of surface alterations to round cells with irregular microvilli and holes. Malignant cells show many bizarre forms. A quantitative, prospective study on SEM parameters, will be needed to establish prognostic SEM criteria with a high malignancy index.

Biopsy↗
PubMed1981

Cell surface morphology in epithelial malignancy and its precursor lesions.

The cell surface organization of cancer cells is of potentially great significance, as it may not only allow (early) diagnosis, but as it may also harbour markers for refined prognosis (degree of oncogenetic and metastatic potential), and targets for selective cancer (chemo- and immuno) therapy. With these aspects in mind, the present review deals with SEM work done on (pre-) malignant cells, both in vivo and in vitro, and in animal models. Attention, however, is focused on human cancer cells. Cancer cells in vitro may lose many of their original malignant characteristics, and show adaptations to culture conditions. Many other factors have been shown to influence cell surface morphology, such as cell cycle, cell contacts, and preparations technique. Cancer cells differ in their surface morphology from normal cells, and have an extra ordinary amount of surface activity. Human malignant epithelial cells show abundant long. pleomorphic microvilli, especially those present in effusions. In squamous epithelium (bladder, cervix) microridge system present on normal superficial cells are progressively replaced by microvilli which increase in number and degree of pleomorphism during experimental and clinical oncogenesis. The question of whether or not the appearance of long. Pleomorphic microvilli reflects an irreversible alteration of the epithelium, and thus provides an early marker of irreversible neoplastic transformation is considered and assessed on the basis of our work with (pre-) malignant cells of the human uterine cervix. Although SEM has contributed significantly to the description of oncogenesis, up to now it has no early diagnostic, prognostic or therapeutic significance.

Carcinoma, Squamous Cell↗
PubMed1980

Field test results using the BioPEPR cervical smear prescreening system.

BioPEPR is a cathode ray tube scanning device that has been developed for the prescreening of cervical smears. Cervical samples are collected in suspension, syringed, counted and spread across a microscope slide. Feulgen-Thionine with Congo Red is used as the staining procedure. Fields of 6 X 8 mm are scanned at 1 mu resolution, using an intermediate photographic step. Morphologic parameters of the cells are measured, as called for by a hierarchical decision strategy. Analysis speed is currently about 4 min per smear; improvements of at least a factor of four are expected. A field test of BioPEPR is being undertaken in cooperation with a local population screening program. In the study two smears are made from each woman; the first is prepared according to the Papanicolaou technique while the second is prepared and stained according to the BioPEPR methods. In addition to smears from the population screening program a number of possibly abnormal smears are obtained from several gynecological clinics. To date approximately 3500 "second" smears have been analyzed by the BioPEPR system. The results show a missed positive rate on the order of a few percent (no missed positives were more severe than a slight dysplasia), and a false alarm rate of about 24%. A further analysis of the age distribution of the false alarm rate shows that a large proportion came from women above the age of 50; the false alarm rate is about 20% for women under the age of 50.

Adult↗
PubMed1980

Ovarian pregnancy: a morphologic description.

This case report presents a "true" ovarian pregnancy in a women using a Dalkon shield. The gestational sac was implanted in the ovary close to the corpus luteum and contained a normally developed embryo of Carnegie Stage 11. A morphologic description of the embryo is given. The importance of a morphologic description of the conceptus in cases of ovarian pregnancy is discussed.

Adult↗