PubMed Health⌕ Search

Biomedical subjects

B Stenkvist

Publications and source records attributed to B Stenkvist.

At least 19 recordsLinked to original sources
PubMed1992

Appearance and detection of multiple copies of the mdr-1 gene in clinical samples of mammary carcinoma.

To examine the presence of multiple copies of the mdr-I gene in clinical tumor samples we have developed an approach where the cells are obtained by fine-needle biopsies and the number of gene copies determined by PCR. The temporal appearance of amplified mdr-I was examined in 20 breast-cancer patients with clinical stage-IV disease receiving endocrine treatment. Tumor samples were obtained every 2nd to 3rd month from the same tumor lesion. None of the initial samples from each patient contained multiple copies of mdr-I. Of 16 patients who showed increased tumor size, 4 developed multiple gene copies, showing that the event occurs without cytotoxic selection of cells with chemotherapy.

Aged↗
PubMed1992

Detection and temporal appearance of multiple copies of c-erb-B2 genes in advanced mammary carcinoma using fine needle biopsies and the polymerase chain reaction.

Aspiration of tumor cells by the fine-needle biopsy method yields only a small number of cells, which hampers conventional molecular analysis for the presence of multiple copies of oncogenes. We have therefore adopted the polymerase chain reaction (PCR) method to study semi-quantitatively the level of the c-erb-B2 gene in human breast tumor samples. Of 39 patients with mammary carcinoma, 7 (19%) contained multiple copies of c-erb-B2 genes, whereas only two samples failed to give informative data. Next the multiple copies of c-erb-B2 genes, whereas only two samples failed to give informative data. Next the temporal appearance of multiple gene copies was examined in 20 patients with clinical stage IV disease. Tumor samples were obtained every second to third month from the same tumor lesion of each patient. None of the initial samples from each patient contained multiple copies of c-erb-B2. Of 16 patients that showed progressive clinical disease, 5 developed multiple gene copies, showing that the event occurs in clinical stage IV disease.

Aged↗
PubMed1991

Amplification of oncogenes in mammary carcinoma shown by fine-needle biopsy.

A procedure that measures the amplification of oncogenes in human cancer cells is described. The cells were obtained by fine-needle biopsy to allow repeated sampling from individual metastases. A drawback was the low number of cells obtained, but this could be overcome by using a slot-blot hybridization technique to measure gene amplification. Two patients with mammary cancer (primary tumors or metastases), analyzed for the levels of amplification of the oncogene erb-B2, are described in detail. This technique is suitable for analyzing alterations occurring during cancer progression and for identifying subgroups of mammary cancer with different characteristics.

Aged↗
PubMed1991

Image analysis cytology for DNA determination in breast and prostate cancer.

Nuclear DNA distribution in fine-needle specimens from 112 breast carcinomas and 45 prostatic tumours was studied. The distributions were described statistically with five separate descriptors, namely mean deviation from 2C, percentage of cells exceeding 2.25C and 4.5C respectively, DNA index and entropy (a mathematical measure of degree of scatter of the DNA content of the nuclei). It was shown that information about DNA index only ('diploid' versus 'aneuploid') is too limited and the term 'diploid' even incorrect and misleading for description of human cancer cell populations. Merely an addition of the percentage of cells exceeding 2.25C allowed separation of a majority of the carcinoma specimens from specimens taken from normal tissue. Moreover, in carcinoma specimens 96% of the patients had between 1 and 100% of the cancer nuclei cell population exceeding 4.5C in contrast to all normal specimens, where this percentage was 0. Entropy was clearly correlated with percentage of Ki-67-positive cells, indicating that it contains information on both scatter of nuclear DNA content and proliferation. Plotting of the scatter (entropy) versus DNA index allowed separation of greater than 97% of the carcinoma specimens from specimens taken from normal individuals. With the use of all five descriptors of DNA distribution it was possible to separate all breast cancer specimens and all moderately and poorly differentiated prostate cancer specimens from normal specimens. The discrimination between well-differentiated prostate cancer and hyperplasia constituted a special problem in that it was not possible to confirm the diagnosis well-differentiated prostate cancer by objective measurements in 8% of the patients, even when all five descriptors were used for the analysis. None of the verified carcinoma specimens had a DNA distribution that was truly 'diploid' in the sense of the distributions of cancer nuclei and normal cell nuclei from the actual organ being quite similar.

Biopsy, Needle↗
PubMed1990

Cytological and DNA characteristics of hyperplasia/inflammation and cancer of the prostate.

A study has been made of the correlation between objectively measured nuclear DNA content (by image analysis cytometry) and visual pathologic/cytologic diagnoses in hyperplasia/inflammation and well, moderately and poorly differentiated carcinomas of the prostate. The DNA measurement data were described by four statistical description methods--namely mean deviation from 2C, percentage greater than 4.25 C, DNA index and entropy. In 36% (5/14) of well differentiated and 13% (1/8) of moderately differentiated cancer it was not possible by objective measurement methods to demonstrate any difference between hyperplasia/inflammation and cancer. On the other hand one or more of the statistical descriptors was significantly different from hyperplasia/inflammation in all of those cancers visually diagnosed as poorly differentiated. The results underline the need for improvement of diagnostic criteria of prostate cancer--in particular well differentiated--in order to correctly understand the epidemiology (true incidence), survival and effects of treatment on the disease.

DNA↗
PubMed1990

Entropy as an algorithm for the statistical description of DNA cytometric data obtained by image analysis microscopy.

In an effort to obtain an additional statistical descriptor of DNA histograms we analysed a concept from mathematical information theory, called entropy, which describes the information content of histograms irrespective of parametric or non-parametric distributions. For this study, 32 fine-needle biopsies were analysed. It seems that the entropy of the DNA histogram is an extremely useful descriptor for the separation of distributions obtained from malignant tumours when compared with non-malignant lesions or normal controls.

Algorithms↗
PubMed1989

Cytophotometric estimation of cell proliferation in breast cancer. Correlation to the clinical course during long-term follow-up.

Tumours from 117 patients with breast cancer operated during a 5-month period 1975-1976 were investigated by absorbance scanning cytophotometry. The relations of these data to breast cancer recurrence and death during a follow-up period of 8.5 years were analysed using Cox's proportional hazards model. When individually tested, nodal status, grade of malignancy and high rates of proliferation, as indicated by cells in S-phase, were statistically significant predictors of the clinical outcome. The risk ratio associated with S-phase decreased significantly over time from primary treatment. No significant relation was found between DNA-ploidy or tumour size and the clinical course. In the multivariate analysis, based on 76 patients, nodal status alone was a significant prognostic factor.

Adult↗
PubMed1989

Analysis of machine-selected cells with an image analysis system in normal and abnormal cervical specimens.

An analysis has been performed of visual diagnostic criteria used in cervical cytology applied to machine selected cells in relation to automated classification based on variables, which can be recorded in an image system with automated cell search and segmentation, feature extraction and classification. A 98% accuracy could be obtained with the choice of the most ideal statistical methods for discrimination and the use of the most powerful variables recorded in the image system when compared with consensus of the visual diagnoses based on established cytological criteria for diagnosis of cancer and precancer of the cervix uteri. The most powerful discriminatory variables in the image system (of 17 recorded) for discrimination between normal and abnormal epithelial cells were, in addition to nuclear extinction, cytoplasmic extinction and cytoplasmic shape. It is concluded that the visual classification of cervical cells is highly accurate with experienced observers and that imaging microscopes can be trained to nearly equal this accuracy with appropriate statistical methods of discrimination. The problem of creating fully automated systems, however, also requires the inclusion of even more effective discriminatory variables and also the solution of such problems as automatic cell search, segmentation, artifact rejection, feature extraction, classification and electronic stability in order to become cost-effective.

Cervix Uteri↗
PubMed1979

Demonstration of protein AA in subcutaneous fat tissue obtained by fine needle biopsy.

Polarisation microscopy of material obtained by fine needle biopsy of subcutaneous tissue and stained with Congo red is a simple and reliable method for the diagnosis of systemic amyloidosis. It cannot, however, be used to differentiate histologically between different forms of amyloidosis. In the present study extracts of material obtained by fine needle biopsy of subcutaneous fat tissue from 13 patients were examined by double immunodiffusion with an antiserum against protein AA, a unique protein which forms a major part of the fibrils in secondary amyloidosis. Five of the patients showed amyloid deposits round the fat cells by conventional microscopy. In 3 of these, all with rheumatoid arthritis, protein AA was detected. Eight patients without amyloidosis and 2 with myelomatosis and amyloidosis showed no reaction with antiprotein AA antiserum. Thus the material obtained by fine needle biopsy of subcutaneous tissue could be used not only for the histological diagnosis of amyloidosis but also for a classification of systemic amyloidosis into secondary or primary based on the type of amyloid fibril protein involved.

Adipose Tissue↗
PubMed1979

Analysis of reproducibility of subjective grading systems for breast carcinoma.

The inter- and intra-observer reproducibility of three grading systems for breast cancer has been analysed: those of the World Health Organisation, of Black, and of Hartveit. In addition, the components forming the basis of these grading systems were analysed separately with regard to reproducibility and interrelationship. In this analysis, degree of differentiation was also included as a parameter. The grading systems of WHO and of Black gave a stratification of the material into three categories of tumours, but that of Hartveit did not. All three systems had a low inter- and intra-observer reproducibility. Truncated component analysis indicated that the grading systems of WHO and of Black are closely related to each other and to the 'nuclear lobulation' component of Hartveit's system. The components 'pleomorphism', 'mitotic frequency', and 'hyperchromasia' of the WHO system were closely interrelated. Descriptors such as 'differentiation' and 'tubule formation' were interrelated but acted in a different direction from the others.

Breast Neoplasms↗
PubMed1979

High resolution segmentation of cervical cells.

A major problem in the automation of cervical cytology screening is the segmentation of cell images. This paper presents the present status of the work on that problem at the University of Uppsala. A dual resolution system is used. Suspect malignant cells are located at 4 mu resolution. Each such cell is rescanned at 0.5 mu resolution at two different wavelengths, 530 and 570 nm. The nucleus and the cytoplasm are isolated each by two independent methods. For the nucleus adaptive thresholding in the histogram of the 570 nm image and a contouring in a radially transformed version of that image is used. For the cytoplasm a two dimensional thresholding in the 2D histogram and a contouring in a radially transformed version of the 530 nm image is used. If the two nuclear masks agree the surrounding area is checked for disturbing objects. If also the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the segmentation is thus three categories; free cells, free nuclei and rejected objects. The shape of the objects belonging to the former two categories is checked and irregularly shaped ones are rejected as probably consisting of several overlapping nuclei. Cells passing also this test are classified as normal or malignant. The experience from using this algorithm is discussed and areas for further research are pointed out.

Cell Nucleus↗
PubMed1979

Nasocytologic examination of wood industry workers.

To establish a methodology for field examination for early diagnosis of ethmoidal cancer in workers in the furniture industry, two methods were compared, namely nasal rinsing and direct sample-taking from the middle meatus. The latter method proved superior, resulting in a high number of cylinder cells. This method was tried out in a field survey of 715 furniture workers. No tumours of precancerous changes were revealed. The investigation continues, by exposing the Syrian golden hamster to wood-dust and using, amongst other methods, quantitative nuclear morphometry for evaluation.

Cytodiagnosis↗
PubMed1979

Bronchial carcinoma. I. A prospective five year study on an unselected carcinoma population in a Swedish county.

No prospective clinical investigations of unselected total materials of bronchial carcinoma have been reported. The clinical profile of 273 patients with histologically verified bronchial carcinoma from a Swedish county during 1971-1976 is presented. The difficulties in making valid comparisons with other literature reports makes it necessary to describe in detail the total material. Such a description is given in the present paper. In order to avoid different selection mechanisms an attempt was made to collect an almost total material. No patients were lost in the follow-up. Autopsy was performed in 95% of the deceased patients. The distribution of the histological WHO groups in the total material was: 44% group I, 18% group II, 29% group III and 9% group IV. The material was used for randomized investigations of radiotherapy, chemotherapy and placebo treatment in inoperable patients with the purpose of studying the quality of survival in addition to survival time. For the measurement of the quality of survival the Carlens vitagram index was used (Carlens et al. 1970). The influence of a general health survey with mass miniature chest X-ray was also studied, since such a survey was performed in the region of the study. The expected 5-year survival is estimated to be 7%. Only 20 patients with resectional therapy without known signs of metastases are expected to survive. Nine (45%) of these patients were discovered by mass miniature chest X-ray and thus for a limited number of patients the detection by the general health survey gives a better prognosis.

Adult↗
PubMed1978

Reproductive history and risk of breast cancer: a case-control study in an unselected Swedish population.

Variables in reproductive histories were studied in 179 consecutively detected, unselected breast cancer patients and age-matched controls selected from a computerized population register. The comparison between patients and controls showed no significant difference in age at meanarche, age at first birth, age at menopause or number of children. A subdivision into pre- and post-menopausal women yielded no further information. These results are at variance with most earlier reports, possible because the controls here were selected from the whole female population instead of hospitalized patients. Our data do not support the view that it is possible to define groups at high risk for breast cancer on the basis of productive histories.

Adult↗