Biomedical subjects

K Stepniewska

Publications and source records attributed to K Stepniewska.

5 recordsLinked to original sources

PubMed1994

Neurological and cognitive impairment in long-term survivors of small cell lung cancer.

Despite its effectiveness in reducing the rate of brain metastases, the role of prophylactic cranial irradiation (PCI) in the management of small cell lung cancer (SCLC) remains controversial because of concern about radiation-induced neurological morbidity. In order to evaluate morbidity and its impact on quality of life 64 patients surviving > or = 2 years in remission were recalled for assessment. 52 had received PCI. Most of the patients were well: 95% had performance status < or = 1 and nine out of 37 neurological examinations were abnormal. On neuropsychometric testing, only 19% of patients performed at the level expected for their age and intellectual ability on all four tests used. Fifty-four per cent of patients were impaired on two or more of the tests, suggesting a significant degree of measurable cognitive dysfunction. The number of patients who had not received PCI was insufficient for comparative analysis with the number who had, but among those treated with PCI, patients receiving 8 Gy in 1 fraction appeared less impaired than those receiving higher radiation doses in multiple fractions. The study showed that neuropsychometric testing is acceptable to patients, can be administered by non-psychologists in the clinic and is sensitive to otherwise undetected deficits of cognitive function in this patient population. Prospective evaluation of PCI should include neuropsychometric testing.

Adult↗

PubMed1993

Beta-2 microglobulin: a prognostic factor in diffuse aggressive non-Hodgkin's lymphomas.

beta-2 microglobulin levels were measured in stored serum taken at presentation from 262 patients treated with combination chemotherapy for Kiel classification high-grade lymphoma at a single centre over a 15 year period. A significant association was found between elevated levels and advanced (Ann Arbor stage III or IV) disease or hepatic infiltration, but not with other sites of extranodal involvement or bulky disease. Patients with normal levels at presentation had a 70% remission rate with treatment compared to 37% of those with elevated levels (P < 0.001). With median follow up of 6 years duration of remission was significantly greater in patients with normal beta-2 microglobulin at presentation (plateau at 70%, compared to median remission of 19 months in those with raised levels, P < 0.001). Survival overall was also better in the group with normal levels (actuarial median 9 years compared to 1 year, P < 0.001). Multivariate analyses including treatment type, age, sex, B symptoms, stage, bulk, albumin, sodium, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase and beta-2 microglobulin, placed beta-2 microglobulin among the three most influential independent variables for prediction of response rate, duration of remission and overall survival.

Adolescent↗

PubMed1992

Angiogenesis, assessed by platelet/endothelial cell adhesion molecule antibodies, as indicator of node metastases and survival in breast cancer.

Animal models suggest a role for new vessel formation (angiogenesis) in tumours with metastatic potential, and there is some evidence that this is true for human tumours. What is needed is a sensitive and specific label for endothelial cells, and one candidate would be a monoclonal antibody to platelet/endothelial cell adhesion molecule (PECAM). We have counted microvessels in 103 primary breast cancers using the JC70 antibody to PECAM (or CD31). We compared our findings with various pathological indicators (lymph node status and tumour grade, size, and type and markers (oestrogen receptor, and c-erbB-2 expression and detection of mutant p53). Tumours showed significantly higher vascularisation than normal breast tissue and the number of blood vessels/mm2 was significantly associated with node metastasis. Only 2 out of 50 tumours with 99 vessel/mm2 or less were node positive whereas 31 out of 39 tumours with counts above 140/mm2 were positive (p < 0.0001). Tumour size and grade also correlated with node metastasis and vascularisation also increased with the size of the primary and with poor differentiation. However, within each subgroup of size or differentiation tumours without node involvement had much lower vascular counts, and multivariate analysis showed that vascular count alone explains the association of size and grade with node metastasis. Other markers, conventional or novel, did not correlate with vascularisation. Even with the short follow-up in this series, vascular counts correlated with early death. These results suggest that angiogenesis is closely linked to metastasis, that it is acquired at a critical density of vessels, and that this process occurs as tumours enlarge or become more poorly differentiated. Counting of newly formed microvessels stained with endothelium-specific antibodies may prove to be a useful tool in the early detection of metastatic potential and in the selection of patients for whom anti-angiogenesis drugs might be beneficial.

Antigens, Differentiation, Myelomonocytic↗

PubMed1992

Visual impact of adaptive speckle reduction on US B-mode images.

Adaptive speckle reduction, which is designed to improve image contrast, dramatically alters the familiar appearance of the ultrasonographic B-mode scan. The acceptability to radiologists of this alternative method of display was assessed. Four experienced radiologists selected B-mode scans from 83 liver and 71 breast examinations and graded the change in diagnostically important features after adaptive speckle reduction. There was no loss of important anatomic detail in the smoothed images and a net reduction in image artifacts. Removal of speckle noise improved definition of lesion margins in 38.3% of cases and enhanced visibility of metastases in 35.4% of liver studies and 7.7% of breast lesions. In 42.1% of cases, the textural information in the image was judged to be enhanced. Image information in general was said to be better seen in 49.5% of cases. The preliminary radiologic experience with speckle-reduced B-mode echograms is favorable and does not indicate generation of any substantial image artifacts.

Breast Neoplasms↗

PubMedDate not supplied

Some practical issues in binary data analysis.

Three topics motivated by practical problems where the response variable is binary are described and illustrated. When a number of different explanatory variables are measured on each individual, a parsimonious model may be needed to predict the response of a future patient, or in selecting the variables that any treatment effect must be adjusted for. Some variable selection procedures used in conjunction with fitting logistic regression models are summarized and their performance investigated using a simulation study. A study to compare two devices for delivering anaesthetic gas to patients during surgery is then described, in which the response variable is the incidence of post-operative sore throat. In this study, the allocation of patient to device was non-random and a method for analysing these data that takes account of this aspect of the data is illustrated. In studies to compare different forms of contraceptive, the extent of regularity in the menstrual bleeding cycle is an important consideration for the acceptability of a contraceptive. Diary data on the menstrual bleeding pattern are therefore routinely collected. A method of summarizing the cyclic behaviour in the diary data for a particular woman is described, and extended to allow comparisons to be made between groups of women on different types of contraceptive. The approach is illustrated using a database made available by the World Health Organization.

Computer Simulation↗