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U Schenck

Publications and source records attributed to U Schenck.

At least 19 recordsLinked to original sources
PubMed2006

Free peritoneal tumour cells are an independent prognostic factor in curatively resected stage IB gastric carcinoma.

BACKGROUND: Several studies have shown that the cytological detection of free peritoneal tumour cells (FPTCs) in patients with gastric cancer indicates the presence of metastatic disease. The immunocytochemical detection of FPTCs, especially in early-stage tumours, has not been examined comprehensively. METHOD: Peritoneal lavage was performed in 351 patients before curative resection of a gastric carcinoma between 1987 and 2001, and an adequate sample was obtained from 346 patients. FPTCs were detected immunocytochemically using Ber-EP4 antibody. Median follow-up time was 70 months. RESULTS: FPTCs were detected in the lavage fluid of 74 patients (21.4 per cent) and correlated with increasing pathological tumour depth (pT) and lymph node (pN) status (P < 0.001). The 5-year overall survival of patients with FPTCs was significantly worse than that of patients without FPTCs (35 versus 71.9 per cent; P < 0.001). FPTCs were present in 14 (8.5 per cent) of 164 patients with stage IA or IB tumours. Although the detection of FPTCs had no prognostic significance for stage IA tumours, the presence of FPTCs in those with stage IB tumours was associated with a worse prognosis (P < 0.001). Multivariate analysis identified the presence of FPTCs as an independent prognostic factor in the whole cohort and in the stage IB subgroup. CONCLUSION: Detection of FPTCs is associated with poor prognosis even in patients with early-stage gastric cancer and should be used for risk-group stratification.

Adult↗
PubMed2006

Fine needle aspiration cytology: a survey of current European practice.

Fine needle aspiration cytology (FNAC) is practised widely throughout Europe. The majority of countries have dedicated cytopathologists as well as histopathologists practicing cytology. Despite this, FNAC is performed mostly by clinicians and radiologists except in the larger centres with dedicated staff with a special interest in cytopathology. The advent of One-Stop diagnostic services and image-guided procedures are prompting further development of FNAC clinics where cytopathologists take their own samples, issue reports in the same clinical session and take extra material for ancillary tests to complete the diagnosis. The volume of FNAC work varies accordingly; in dedicated centres FNAC represents up to 80% of the workload whilst, in the majority of countries, it represents one quarter or less. Hence, the rate of inadequate FNAC varies widely, depending on the local sampling policies and the organ, but does not exceed 25% in any of the countries. The most sampled organs are breast and thyroid, followed by lymph nodes. Most countries have dedicated training in cytopathology for pathology trainees, the duration varying between 6 months and 2 years of the total training time. This discussion, focusing on European practices, highlights the heterogeneity of FNAC activity but also its success in many centres where it is practiced to a high standard, particularly in breast, thyroid and lymph node pathology. The relatively high rate of inadequate material in some centres reflects local policies and calls for greater uniformity of FNAC practice, particularly specimen sampling. To achieve this, the future direction should concentrate on specialist training, to include performing as well as interpreting FNAC, as part of the curriculum. Current emphasis on web-based training may not provide first hand experience of the FNAC procedure and should be supplemented by attending FNAC clinics and developing the technique to its full potential.

Biopsy, Fine-Needle↗
PubMed2000

Cervical cancer screening in Germany.

Cervical cancer is one of the target cancers covered by the statutory German cancer screening programme which was introduced in West Germany in 1971 and expanded to the eastern part of the country in 1991. Women covered by statutory health insurance (over 90% of the female population) are eligible to receive an annual cervical examination including a Papanicolaou (PAP) smear beginning at age 20 years. Annual uptake currently slightly exceeds 50% of the eligible population. Shortly after implementation of the national screening programme in the early 1970s the incidence of invasive cervical cancer decreased moderately and the incidence of cervical carcinoma in situ increased substantially in the state of Saarland. These observations would be expected as a result of a cervical cancer screening programme with substantial uptake. Although quality assurance guidelines for cervical cancer screening have been adopted and updated since the inception of the screening programme, only minor changes have been made in the cross-sectional programme documentation. Implementation of population-based documentation and evaluation of screening activities is currently being developed for the German cancer screening programme in pilot studies implementing the European guidelines on the quality assurance of mammography screening. After demonstration of feasibility and effectiveness, improvements in the quality management of breast cancer screening will subsequently be applied to the cervical cancer screening programme.

Adult↗
PubMed2000

Restriction enzyme analysis of DNA methylation in "condensed" chromatin of Ha-ras-transformed NIH 3T3 cells.

Increased amounts of chromatin condensation (i.e., localized areas of high DNA density, or chromatin higher order packing state) have been described in NIH 3T3 cells transformed with the Ha-ras oncogene. The structural basis for this oncogene-mediated alteration in nuclear organization is unknown. Since DNA methylation is likely to be involved in regulating the nucleosomal level of DNA packaging, we studied the role of DNA methylation in higher-order chromatin organization induced by Ha-ras. CpG-methylated DNA content was estimated in "condensed" chromatin of Ha-ras-transformed NIH 3T3 cell lines which differ in ras expression and ras-induced metastatic ability but present approximately the same values of "condensed" chromatin areas. The question posed was that if DNA methylation were involved with the chromatin higher-order organization induced by Ha-ras in these cell lines, the methylated DNA density in the "condensed" chromatin would also be the same. The DNA evaluation was performed by video image analysis in Feulgen-stained cells previously subjected to treatment with Msp I and Hpa II restriction enzymes, which distinguish between methylated and non-methylated DNA. The amount of methylated CpG sequences not digested by Hpa II in "condensed" chromatin regions was found to vary in the studied ras-transformed cell lines. DNA CpG methylation status is thus suggested not to be involved with the higher order chromatin condensation induced by ras transformation in the mentioned NIH 3T3 cell lines.

3T3 Cells↗
PubMed2000

Cytological changes induced by intravesical bacillus Calmette-Guérin therapy for superficial bladder cancer.

To evaluate cytological changes of urothelial cells with intravesical instillation therapy of the bacillus Calmette-Guérin (BCG), cytological specimens of voided urine from patients with superficial bladder cancer (pTa and pT1) treated with intravesical BCG therapy were examined. The following three groups of patients who had no evidence of recurrence more than 2 years after the treatment were studied: groups 1 and 2, patients who were treated with BCG (n = 22) and epirubicin, a derivative of doxorubicin (n = 22), respectively, for prophylaxis of intravesical recurrence after transurethral resection (TUR); and group 3, patients receiving no intravesical therapy after TUR (n = 12). Sixteen cytological characteristics were studied before and after the treatment in each group. In group 1 patients translucent nuclei and prominent nucleoli, vacuolization of cytoplasm, and eosinophilic cytoplasmic inclusions were frequently observed in urothelial cells as well as an increase in granulocytes, especially within 3 months after BCG instillation therapy. In group 2 patients an increased nuclear/cytoplasmic ratio, hyperchromatic nuclei and prominent nucleoli of urothelial cells were transiently found within 1-2 months after intravesical epirubicin therapy. In group 3, translucent nuclei and prominent nucleoli of urothelial cells were found within 1-2 months after TUR. In conclusion, cytological changes induced by BCG therapy are nonspecific and reactive in nature, different from those due to chemotherapeutic agents and distinguishable from malignant changes of urothelial cells.

Administration, Intravesical↗
PubMed1999

Use of diagnostic categories in urinary cytology in comparison with the bladder tumour antigen (BTA) test in bladder cancer patients.

In recent years the use of diagnostic categories for extragenital cytology has increasingly been discussed as an approach to improve the quality of reports. Diagnostic categories reflect the adequacy of the materials for interpretation and the presence or absence of cancer cells. There is a tendency to add intermediate groups as qualifying probably malignant cases or findings associated with a serious cancer risk. Since 1971 we have added one of the following to the final diagnosis in all cases: unsatisfactory for cytological diagnosis, negative for cancer, repeat test suggested, suspicious of cancer, and positive for cancer. To evaluate whether diagnostic categories are useful for comparison of cytological results with those of an alternative test, cytological data were compared with the results of the Bard bladder tumour antigen (BTA) test in voided urine from 119 patients (76 with and 43 without bladder cancer). The diagnostic categories enabled us to calculate sensitivities and specificities of cytology based on different thresholds or decision levels. The BTA test had significantly higher sensitivity (79%) and lower specificity (60%) than urinary cytology with three different thresholds in cytology results (sensitivities: 16-43%, specificities: 81-100%). The present findings suggest that diagnostic categories improve comparison of cytologic results with those of alternative screening and diagnostic aids such as the BTA test.

Adolescent↗
PubMed1999

Immunocytochemically detected free peritoneal tumour cells (FPTC) are a strong prognostic factor in gastric carcinoma.

We prospectively investigated the prognostic significance of free peritoneal tumour cells (FPTC) in a series of 118 patients with completely resected gastric carcinoma. Immunocytochemistry with the monoclonal antibody Ber-Ep4 was performed on cytospins from intraoperative peritoneal lavage specimens. Twenty-three patients (20%) had FPTC which was significantly correlated with pT and pN categories, stage, tumour size, lymphatic invasion, Laurèn and WHO classifications and perigastric adipose tissue metastases. The median survival time for all FPTC positive compared with negative patients was significantly shorter (11 compared with >72 months), with estimated 5-year survival rates of 8% vs. 60%. None of the patients with FPTC had an early gastric cancer. In advanced tumour subgroups without and with serosal invasion (n = 59 and 35), there were 19% and 34% with FPTC. Multivariate survival analysis showed nodal status, FPTC, mesenteric lymphangiosis, and lymph node metastasis to the compartment III to be independent prognostic factors with relative risks of 6.6, 4.5, 2.9 and 2.2 respectively. Recurrent disease occurred in 91% of FPTC-positive and in 38% of FPTC-negative patients. FPTC had a positive predictive value of 91% and a specificity of 97% for tumour recurrence. FPTC is a strong negative, independent prognostic indicator for survival in gastric carcinoma.

Adipose Tissue↗
PubMed1998

Distinct cytogenetic alterations in squamous intraepithelial lesions of the cervix revealed by laser-assisted microdissection and comparative genomic hybridization.

BACKGROUND: It has been established that comparative genomic hybridization (CGH) on Papanicolaou-stained cervical smears can be used to identify chromosomal imbalances. METHODS: In this study, the authors identified normal and dysplastic squamous epithelial cells cytologically, eliminated surrounding bacteria or leukocytes by a ultraviolet laser microbeam under microscopic control, and scraped out the cell groups of interest by a microdissection system. In 3 cases of squamous intraepithelial lesions (SIL), a total of 9 samples of dysplastic (n = 6) and nontumorous cells (n = 3) were investigated, each of them consisting of 3-40 cells. The DNA was amplified by degenerate oligonucleotide primed PCR (DOP-PCR) and used for CGH. RESULTS: Analyses of all nontumorous cell groups resulted in fluorescence ratio profiles that showed no deviation from the normal range, confirming that no methodologic artefacts have been produced. The CGH profiles from dysplastic cells, however, showed various chromosomal imbalances affecting six to nine different chromosomes. The most frequent gains in DNA were observed on chromosomes 1p, 2q, 4, and 5, whereas losses were found on chromosomes 6q and 13q. CONCLUSIONS: The results of this study demonstrate the feasibility and reliability of CGH on microdissected cell samples of routinely processed cervical smears. To the authors' knowledge, this is the first study reporting the use of CGH on cervical routine smears. This approach offers the opportunity to investigate sequence copy number changes in small, morphologically well-defined groups of dysplastic cells. It may, therefore, serve as a cytogenetic screening test for identifying chromosomal aberrations in precancerous lesions that are associated with a high risk for progression to invasive cancer.

Chromosome Aberrations↗
PubMed1998

Frequency of endocervical cells in cervical smears and hysterectomy rate of the patients.

In gynecologic cytology, different reporting schemes suggest mentioning the presence of endocervical cells or asking for a statement on adequacy. We were interested in the question whether our data could provide a possible basis for discussing a sampling technique with smear takers. At the time of writing, in all cases, both the presence of endocervical cells and hysterectomy are recorded in our laboratory information system. Most smears are taken with cotton swabs, but the sampling technique is often modified according to the clinical situation. In a series of 20,471 cervical/vaginal smears, 2,152 (10.5%) were taken from hysterectomy patients. Among the non-hysterectomy patients, endocervical cells were found in 65% of the cases. Typically, there was a lower frequency of endocervical cells in smears stemming from older women. The frequency decreased from a maximum of 75% in the age group of 40-44 years to 45% in the age group of 65-69 years. With regard to the smear takers, some differences were evident, with age distribution and frequency of hysterectomy being different among the smear takers. In a setting where many smears of hysterectomized patients are examined by cytology, good data quality is required to evaluate the sampling techniques of different smear takers. The age dependence of endocervical cell yield is confirmed. Different age distribution of the patients from different smear takers suggests that the percentage of smears showing endocervical cells cannot be considered an optimal estimator.

Adolescent↗
PubMed1997

Modeling, definition and applications of histogram features based on DNA values weighed by sine functions.

OBJECTIVE: To model new DNA histogram features that weigh DNA values with values of curves of a sine function and to show the definition and applications of such features. STUDY DESIGN: A simple example of a sine feature can be modeled to yield the value zero if all cells are diploid or polyploid, with values of 2c, 4c or 8c, and to yield the value 100 if all cells are aneuploid, with DNA values of 3c, 6c or 12c-e.g., cells that are probably from a malignant lesion or indicate proliferation. All other values are multiplied by the corresponding sine value. We folded the logarithmic DNA histogram with a sine curve with positive values only. RESULTS: Correlation with ploidy balance was -0.94, demonstrating the similarity of both features. The sine features, however, avoid cutpoints between diploid and aneuploid values and are therefore less influenced by minor mistakes in standardization of DNA histograms. We introduced deviation factors as variants; that led to higher sine values for higher c values. For breast carcinoma (N = 306) the sine values were spread from very low to very high values, whereas esophageal carcinomas (N = 125) were centered at a sine value of 50. In breast carcinoma the sine features also correlated with prognostic factors, including hormone receptor status. CONCLUSION: Description of DNA histogram features by graphic demonstration of their weight functions improves understanding of features. Since functions respect the cyclic events in proliferation and are not influenced by polyploidization.

Breast Neoplasms↗
PubMed1996

[Quality assurance in cytology by continuous registration of stage movement during microscopy work].

The discussion concerning the maximum workload of microscopical slides to be screened by doctors or cytotechnologists per unit of time has been activated in Germany by a "Guideline of the German Medical Association concerning quality assurance of cervical cytology". In this guideline the maximum workload is 8-10 cases per hour. To control the adherence to these guidelines we have monitored the screening process by using Axio-HOME-Microscopes to register the microscope stage coordinates every twenty milliseconds. In a series of 8653 slides screened by 5 cytotechnologists the average screening time was 3 1/2 minutes followed by an average intercase interval of 2 minutes. The distribution of the screening work over the day was presented in form of daily working profiles, allowing a control of workload limits. The results did not indicate, that the screening time per case vary with the time of the day and the day of the week. Since this approach to quality assurance seemed practical also for routine cytology, all working places of the cytotechnologists at the Cytological Institute of the Bavarian Cancer Society have been equipped with this set up for quality assurance.

Female↗
PubMed1996

Interlaboratory reproducibility in reporting inadequate cervical smears--a multicentre multinational study.

A set of 300 vaginal smears was interpreted by 13 cytologists from six European laboratories, who were requested to report inadequate and suboptimal smears. The set had been appropriately seeded to reach approximately 10% inadequate and 20% suboptimal smear frequency. According to the majority report, 230 smears were classified as adequate (76.7%), 43 as inadequate (14.3%), and 27 as suboptimal (9.0%). Agreement with the majority report ranged from 52% to 91% (average 78%). Kappa statistics for reporting inadequate smears showed a high level of agreement for five cytologists, and fair to good agreement for eight. In contrast, kappa statistics for reporting suboptimal smears showed fair to good agreement with the majority report only in five instances, whereas agreement was poor for eight cytologists. 'Inadequate smear' rates may be used to compare the quality of smears received in different laboratories, as there is a high level of agreement among cytologists as to what constitutes an inadequate smear. However, this is not true for "suboptimal smear" rates, and more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears: more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears.

Europe↗
PubMed1995

Modulation of ras transformation affecting chromatin supraorganization as assessed by image analysis.

Changes in chromatin supraorganization defined in terms of patterns of chromatin texture were studied by video image analysis in Feulgen-stained revertants of LTR-ras-transformed NIH 3T3 cells and in cell lines obtained by transfection of these revertants with sense and antisense constructs of the lysyl oxidase gene (also named Lox or "ras recision gene"). The objective was to determine whether changes in expression of the Lox gene, which have been assumed to modulate cell transformation by ras, could also affect the chromatin supraorganization changes known to be elicited in NIH 3T3 cells by ras transformation. The image analysis results revealed that, although a nuclear phenotype visually similar to the most frequent one (III) in ras-transformed NIH 3T3 cells also appeared in the revertant, it contained a remarkably less tight chromatin packing state. This situation was also found in the revertant transfected with the sense construct of the Lox gene, but in the revertant transfected with the Lox antisense constructs the chromatin texture of the III phenotype was equal to or close to that of the ras-transformed cells. With regard to the nuclear phenotype characterized by abundant loosely packed chromatin and less represented in the transformed cell lines (I'), changes in the various cell lines, although detectable, were not as drastic as those reported for the III phenotype. The enhancement in chromatin condensation of the type III nuclei, which affects euchromatin, is probably associated with a limited transcription of the genome. Although the image analysis results are mostly in agreement with previously published data on the molecular biology and tumorigenicity of the same cell lines, it appears that the phenomenon of chromatin condensation once established in NIH 3T3 cells by LTR-ras transformation could not be totally reverted by simply affecting Lox expression.

3T3 Cells↗
PubMed1994

Quantitative evaluation of AgNOR in liver cells by high-resolution image cytometry.

This study is aimed at determining the relationship between polyploidy and the amount of nucleolar organiser region (AgNOR) positive dots or aggregates using high resolution image analysis. Liver imprints from mice in which hepatocyte polyploidy is very well documented and related to variation in nuclear area were used as a model for this investigation. A technical variant of the AgNOR method using a Triton X-100 treatment was developed for removal of some proteins from the cytoplasm, which produced a clearer and cleaner background. Feulgen-stained preparations were used to detect the association of various ploidy degrees with their respective values of nuclear area and to subsequently furnish a basis for the association of the nuclear areas in AgNOR-stained cell preparations with different ploidy levels. A high correlation between nuclear and AgNOR-stained areas was revealed and was demonstrated to be much higher than the correlation between nuclear area and the number of AgNOR positive dots or aggregates. The use of two different thresholds for segmentation of the grey levels of the AgNOR-stained material demonstrated the importance of the appropriate decision to obtain the best results to be associated with polyploidy in terms of the real biological event involved, the nuclear area being in this case correlated to Feulgen-DNA values.

Animals↗
PubMed1994

High resolution image-cytometric differentiation of hormone sensitive and hormone insensitive prostatic carcinomas.

Until the present it was not possible to predict hormone sensitivity of prostatic carcinoma. Based on studies correlating image cytometric results of hormone receptor negative and hormone receptor positive breast carcinomas, the present study aims at separating responders and non-responders to hormone therapy in metastatic prostatic carcinoma. From May-Grünwald-Giemsa stained slides of fine needle aspirates of 23 patients with metastasizing prostatic carcinoma about 100 nuclei per slide were taken by TV camera for image-cytometric processing. One thousand and twenty-two nuclei came from 10 patients who showed tumour regression for at least 36 months and who all survived for more than 5 years. One thousand three hundred and thirty-two nuclei were from prostatic aspirates of patients who showed a continuous tumour progression despite receiving hormone therapy. All patients of the latter group died within 5 years. A correct classification of the patient groups of responders and non-responders was possible in 19-21 of 23 cases by means of high resolution image analysis including nuclear structural features. It was found that even simple planimetric features, like the nuclear perimeter, or densitometric features, such as the total nuclear extinction, differed markedly between the two groups. The data show that nuclei from hormone sensitive prostatic carcinoma are distinct from those of non-sensitive ones in the present series. The interpretation of results must take into account that the very strict criteria for hormone sensitivity leads to a highly selected patient group. The application of the method to an unselected patient group can be presumed to yield a higher rate of false classifications.

Azure Stains↗
PubMed1993

Leukotriene B4 and C4 production in isolated rat gastric mucosal cells.

Dispersed rat gastric mucosal cells (F0) were separated into five fractions (F1-F5) by counterflow elutriation, with F1 representing the smallest and F5 the largest cell diameters. In F0-F5, leukotriene B4 (LTB4) release in response to 10(-5) M calcium ionophore A-23187 was 7.68 +/- 1.26, 51.6 +/- 10.8, 72.4 +/- 10.4, 7.1 +/- 0.7, 5.7 +/- 0.6, and 11.6 +/- 3.4 pg.10(6) cells-1 x 30 min-1. In the identical fractions, sulfidopeptide release in response to A-23187 was 200.6 +/- 20.5, 1,116.0 +/- 166.6, 1,309.4 +/- 163.2, 189.8 +/- 25.8, 108.0 +/- 18.0, and 158.4 +/- 54.0 pg.10(6) cells-1 x 30 min-1. High-pressure liquid chromatography verified the radioimmunologically determined LTB4 and identified LTC4 as the only sulfidopeptide LT released. LT release from F2 cells in response to A-23187 was time and dose dependent, reaching maximal stimulation at 10(-5) M A-23187. This response was blocked by the dual inhibitor of cyclooxygenase and lipoxygenases, BW755C (2 x 10(-5)-2 x 10(-4) M), by the selective 5-lipoxygenase inhibitor L-651,392 (10(-7)-10(-5) M), and by MK-886 (10(-9)-10(-7) M), which blocks translocation of 5-lipoxygenase. The postreceptor stimuli dibutyryl adenosine 3',5'-cyclic monophosphate, forskolin, 12-O-tetradecanoyl-phorbol-13-acetate, and oleyl-acetyl-glycerol failed to induce LT release. However, 10(-4) M arachidonic acid increased basal LT release up to eightfold and increased A-23187-stimulated LT release by an additional 30%.(ABSTRACT TRUNCATED AT 250 WORDS)

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗