Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADENOFIBROMA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1985

Relationship of body-weight gain to longevity and to risk of development of nephropathy and neoplasia in Sprague-Dawley rats.

The relationship of weight gain to survival, risk of development of chronic progressive nephropathy and risk of development of various neoplasms has been studied in the control groups from two routine chronic toxicity studies in Sprague-Dawley rats. The groups comprised 100 CFY strain rats of each sex observed up to the age of 109 wk and 120 CD strain rats of each sex observed up to 111 wk of age (females) or 121 wk (males). The eventual incidence of tumours was found to be related to body weight at several ages. There was also a statistically significant association between high body weight at various ages and increased mortality, particularly in the CD strain and particularly in females. The 'heavy' rats proved to have an increased risk of developing both progressive nephropathy and certain tumours. This relationship was particularly marked for pituitary tumours in both sexes and for benign and malignant mammary tumours in females, and was significant irrespective of whether tumours coexisting with marked or severe progressive nephropathy were classified as fatal or incidental. There was also some evidence that increased body weight was positively associated with risk of islet-cell tumours and lipomatous tumours in males and fibromatous tumours in females. The observations illustrate how non-specific factors, such as those that affect body weight, may profoundly influence mortality and tumour incidence in chronic toxicity studies. The findings also highlight the difficulty of classifying particular neoplasms as incidental or fatal where other potentially life-threatening pathology (e.g. progressive nephropathy) is present.

Adenocarcinoma↗
PubMedDate not supplied

Frequency-dependent attenuation in breast tissue characterization.

The aim of this study is to establish whether an index derived from the slope of the frequency-dependent ultrasonic attenuation can provide quantitative information on normal and pathological breast tissue. Ultrasonic measurements were performed by using pulsed transmitted ultrasound in the frequency range 2-8 MHz. Thirty-three specimens were selected for their probable pathologic classification, by macroscopic observation, before ultrasonic study, and subsequently histologically classified. Ultrasonic results suggest the possibility that the examined specimens fall into four groups: (1) fat, fibroadenoma, giant fibroadenoma, infiltrating ductal carcinoma, medullary carcinoma; (2) infiltrating lobular carcinoma, tubular carcinoma, scirrhous carcinoma; (3) fibrosis; (4) fibrofatty tissue, fibrocystic disease. Correlative morphological studies indicate that the employed index can classify breast tissues on the basis of their cellular and fibrous composition and the inhomogeneity of their structure.

Adenocarcinoma↗
PubMed1988

Diagnostic value of different interpretative criteria in real-time sonography of the breast.

Use of breast sonography for clarification of pathological alterations in the breast is continuously increasing. It is known that cystic processes can be distinguished from solid processes with this method. The question of, to what extent, a prognosis of pathological relevance of such processes can be made, is of increased interest. This prognosis of pathological relevance is related to interpretative criteria which are not uniformly defined all over the world and which are also differently applied. The present investigation (evaluation of 755 sonographic focal findings) shows the rating value of each individual appraisal criterion and provides information on the certainty with which malignant and benign lesions in the breast can be distinguished. All interpretative criteria specified have a statistical significant difference (p less than 0.0001, 0.0044) in their rating pattern in malignant and benign processes. The criterion with the highest value is the wall contour. In principle, every sonographic focal finding should be examined with regard to its wall contour, the acoustic attitude of posterior wall, the internal echo pattern and the internal echogenicity. In the dynamic part of the investigation, alterations in the form and structure of the lesion must be registered. In our opinion there is a high probability of distinguishing malignant from benign processes by means of the mentioned criteria.

Adenofibroma↗
PubMed1988

Variation of transducer frequency output and receiver band-pass characteristics for improved detection and image characterization of solid breast masses.

A new approach has been used for ultrasound detection of small benign and malignant breast masses, namely, control of scattering in such a manner that a small mass can be easily recognized because of the effect of the scattering on the contrast between the mass and the surrounding normal tissue. Maintenance of good resolution as scattering is varied is an essential aspect of this approach. Image contrast is dependent on a number of instrumentation parameters but, in a fundamental sense, it is related to differences in the amount of scattering between a solid breast mass and the surrounding normal tissue. In the subject studies, modification of image contrast is accomplished by varying either the center frequency output of the transducer or the band-pass of the receiver. These approaches take advantage of differences in the frequency dependence of scattering coefficients of solid breast masses and normal tissue. A unique technique for varying center frequency without switching transducers was developed, namely, use of a wide bandwidth, co-polymer PVDF transducer, in combination with certain instrumentation conditions which allow the center frequency output of a single ultrasound transducer to vary over a relatively wide frequency range. Using this technique, an automatic B-mode ultrasound imaging breast instrument which allows emission of 3.5, 4.5, 6.5 and 11 MHz ultrasound frequencies from the same co-polymer transducer was used to examine patients with solid breast masses. Both a wide band-pass receiver, similar to that commonly used in clinical ultrasound systems and a tunable receiver (which allows variation of the band-pass from wide to narrow) was used with this automated system. Using the standard receiver system, it was found that there are advantages to having a range of transducer frequencies immediately available for breast examination. These include: (1) improved detection of masses located in highly attenuating regions of breast (by decreasing frequency); (2) availability of diagnostically relevant information at some one frequency which may not be apparent at other frequencies. Using the multiple frequency system and the standard receiver, it was found that the most appropriate examination frequencies for detection and diagnosis of fibroadenomas are higher frequencies (8 to 11 MHz). This is particularly true in the case of fibroadenomas in fatty breasts.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenofibroma↗
PubMed1989

Assessment of ultrasonic computed tomography in symptomatic breast patients by discriminant analysis.

From 95 subjects imaged with both speed of sound and attenuation ultrasonic computed tomography (UCT), quantitative analyses are presented on 40 cases where unequivocal correlating clinical diagnoses are available. Using four attenuation and speed of sound parameters from different regions of interest in the breast, a linear discriminator detects cancer with approximately 90% sensitivity and specificity. Increased confidence in the predictive power of this small study is given by a modern test of predictive power (jackknifing) and by the fact that diagnostic discrimination remains as high as 85% when only two parameters are employed--attenuation and speed of sound in the lesion minus those values in the remaining central mammary tissues. Speed of sound images appear particularly useful in older, fatty breasts where pulse echo ultrasound is particularly lacking. While UCT in the form studied here is not likely to receive wide clinical acceptance in the near future, a combined UCT/pulse echo system might find wide clinical utility if it can be sufficiently convenient and inexpensive.

Adenofibroma↗
PubMed1991

Continuous-wave and pulsed Doppler studies of the breast: clinical results and effect of transducer frequency.

Malignant growth requires a high metabolism. This allows the differentiation of lesions by Doppler measurements of their vascularisation. In this study of 224 patients with 45 malignancies (37 breast cancers and 8 local recurrences), 87% of the cases were correctly identified. Differentiation of palpable lesions was possible in 93%. The flow in normal breast arteries was studied as well as in carcinomas, comparing continuous-wave (CW) Doppler with frequencies at 4 and 8 MHz. To improve flow evaluations in nonpalpable lesions, pulsed Doppler was used at 3 MHz and color mapping systems at 5 MHz in another 37 patients. Color Doppler at 5 MHz identified 17 of the 21 malignancies; in all cases pulsed Doppler at 3 MHz failed.

Adenofibroma↗
PubMed1980

Lifespan carcinogenicity tests with native carrageenan in rats and hamsters.

Native carrageenan (Gelcarin), a widely used food additive, was tested for carcinogenicity in MRC rats and Syrian golden hamsters through lifespan studies. Three groups of 30 males and 30 females from these species received carrageenan at dose levels of either 5%, 2.5% or 0.5% in the diet daily for the animal's lifespan. A trend toward an increased incidence of benign mammary tumors in females and testicular neoplasms in males occurred at the median dose level (2.5%); however, the incidence of these tumors was not statistically significant. Hamsters did not develop neoplasms in response to treatment at any dose levels. From the results of this experiment, carrageenan demonstrated no carcinogenic effects in either species.

Adenofibroma↗
PubMed1985

Glutathione peroxidase, glutathione S-transferase and glutathione reductase activities in normal and neoplastic human breast tissue.

Glutathione peroxidase (GSH-Px), glutathione S-transferase (GSH-Tr) and glutathione reductase (GSSG-Rx) activities have been determined in normal and neoplastic human breast tissues. Large interindividual variations in the activities of all enzymes tested were found in both tumor and non-tumor specimens. In general a significant increase in the activities of the 3 enzymes was found in tumors, whereas in fibroadenoma they were as high as in healthy tissues. When a comparison was made between normal and neoplastic tissues of the same individual, GSH-Tr and GSSG-Rx activities were found to be higher in 15 and 11 cases, respectively, out of 17. GSG-Px activity was higher in all cases. From measurement of GSG-Px activity with both H202 and cumene hydroperoxide, it was deduced that human breast contains only the selenium-dependent form.

Adenofibroma↗
PubMed1987

Estrogen receptor in dissociated and cultured human breast fibroadenoma epithelial cells.

Estrogen binding was measured by a whole cell receptor assay in epithelial cells isolated from 20 premenopausal patients with breast fibroadenomas. A high affinity specific binding for estrogens was detected in the epithelial cells isolated from all 20 fibroadenomas. A relationship between estrogen binding and the phase in the menstrual cycle of the patient has been observed. Cell culture experiments using serum-free medium have also shown that estrogen binding can be augmented by cortisol.

Adenofibroma↗
PubMed1991

Low-frequency electromagnetic radiation enhances the induction of rat mammary tumors by nitrosomethyl urea.

Low-frequency electromagnetic fields enhance the induction of mammary gland tumors in rats using nitrosomethyl urea. The incidence of tumors depended on the duration of exposure to static (dc) and variable (ac) magnetic fields. Variable magnetic fields induced mammary gland cancer much more frequently than static ones. Apart from increasing the incidence of mammary gland tumors, household low-frequency electromagnetic fields reduced the mean latent period of tumor development and led to predominance of malignant tumors in the exposed animals as compared to controls. Mammary gland tumors developed rarely under the effect of static or variable magnetic fields per se, without preliminary administration of a carcinogen. Household low-frequency electromagnetic fields may potentially present an oncogenic hazard for animals and humans.

Adenocarcinoma↗
PubMed1993

Differentiation of benign from malignant breast masses by time-intensity evaluation of contrast enhanced MRI.

Using gadolinium-DTPA enhanced MRI we analyzed the enhancement characteristics of palpable breast masses in 23 patients--10 cancers and 13 benign lesions. The most specific finding for separating benign from malignant lesions was a ratio of maximum intensity change divided by the time interval during which this first occurred. Designated ranges of this ratio were specific for benign disease and sensitive for malignancy in this small patient group. Three of eight fibroadenomas exhibited enhancement patterns indistinguishable from cancer.

Adenofibroma↗
PubMedDate not supplied

Breast lesion discrimination using statistical analysis and shape measures on magnetic resonance imagery.

Magnetic resonance images of intact human breast tissue are evaluated using statistical measures and shape analysis. In this paper, the Mahalanobis distance measurement and a related F-statistical value demonstrate that breast lesions are statistically separable from normal breast tissue. The minimum set of parameters to provide first order statistical separability between fibroadenomas, cysts, and carcinomas are T1-weighted, T2-weighted, and Dixon opposed pulse sequences. Tumor shape is quantified by development of a compactness measure and a spatial frequency analysis of the lesion boundary. Malignant lesions are shown to be separable from benign lesions based on quantitative shape measures.

Adenofibroma↗
PubMed1990

Extracellular matrix proteins and their receptors in the normal, hyperplastic and neoplastic breast.

We studied by immunohistochemistry, the distribution of tenascin (Ten), cellular fibronectin (cFn), laminin and certain pertinent extracellular matrix protein receptors in normal human female breast, variants of fibrocystic disease (FCD), benign tumors, and ductal and lobular carcinomas. Monoclonal antibodies (mAb) to Ten, extradomain A containing cFn (EDAcFn), A and B chains of laminin, and beta-1 (beta-1) and different alpha subunits of intergrins were used. In in-situ ductal and lobular carcinomas, laminin staining had focal gaps, Ten-immunoreactivity displayed periductal or periacinar bands, and cFn showed broad and intense periductal staining; strong reactions for beta-1 and alpha-6 were noted in the basal cytoplasm of non-neoplastic myoepithelial cells while few tumor cells stained weakly. In infiltrating ductal and lobular carcinomas (IDC, ILC), laminin reactivity was weak, uneven or absent around neoplastic clusters whereas stromal staining for Ten and cFn was extensive and strong. In most IDC, moderate beta-1 and alpha-6 staining involved variable subpopulations; one mucinous carcinoma stained strongly and diffusely. In 20-40% of cells in ILC, beta-1 and alpha-6 were localized in delicate, ramified cytoplasmic processes. Indirect immunofluorescence studies with mAbs to other alpha-integrin subunits suggest that in various breast carcinomas only alpha-3 is expressed in tumor cells and that the vessels contained alpha-1 integrin. As compared with the normal breast, FCD and benign tumors, reactivity for Ten and cFn is increased in breast carcinomas while laminin is attenuated and decreased or absent; yet, Ten cannot be regarded as a carcinoma marker since it can be detected in benign tumors, FCD, and even in the normal breast.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenofibroma↗