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Biomedical subjects

R Carpenter

Publications and source records attributed to R Carpenter.

At least 19 recordsLinked to original sources
PubMed1999

The significance of new densities and microcalcification in the second round of breast screening.

AIM: To assess the nature of new densities and microcalcifications in the second round of breast screening. MATERIALS AND METHODS: A total of 34 634 women were screened at our unit in the second round of the United Kingdom National Health Service Breast Screening Programme. Of those attending for the second time, 302 were recalled for further work-up of 311 new lesions. The lesions were divided into masses, microcalcifications, asymmetric densities and architectural distortions. Masses were classified according to margin and density, and microcalcifications according to morphology and distribution. RESULTS: Among women attending for the second time, the cancer detection rate was 0.45% (89 cancers). One hundred and eighty-eight new masses were identified: 53 well-defined (two malignant), 67 partially defined (six malignant), 54 ill-defined (18 malignant), and 14 spiculate (14 malignant). Well-defined masses were usually cysts, especially in women on hormone replacement therapy. Of 97 new microcalcifications, 71 were pleomorphic (28 malignant), 12 linear (one malignant), and 14 punctate (none malignant). Twenty-five new asymmetric densities were identified (five malignant). One of two architectural distortions was malignant. Malignancy was found in 21% of new masses, 30% of new microcalcification and 20% of asymmetric densities. CONCLUSION: Carcinoma was found in 24% of all new mammographic abnormalities appearing in a 3-year screening period. Spiculate and ill-defined masses, clustered pleomorphic microcalcification, and new asymmetric densities should be regarded with particular suspicion. The use of fine needle aspiration cytology in combination with imaging assessment may help to reduce the number of benign excisional biopsies for new mammographic lesions.

Biopsy, Needle↗
PubMed1999

Granulosa-theca cell tumour of the ovaries. A late metastasizing tumour.

Granulosa-theca cell tumours are ovarian neoplasms of low malignancy with hormone secreting potential, accounting for 2-3% of all ovarian cancers. They have an uncertain clinical course and a potential for late recurrence after surgical removal. Clinical features of a patient presenting with pulmonary metastases 21 years after removal of the primary tumour are described, along with a review of the management options.

Female↗
PubMed1998

The Antirrhinum ERG gene encodes a protein related to bacterial small GTPases and is required for embryonic viability.

Small GTPases have diverse roles in animals and yeast, including signal transduction, regulation of secretion, organisation of the cytoskeleton, and control of cell division. Similar GTPases have also been found in bacteria, such as the Escherichia coli GTPase ERA, which is involved in regulating metabolism and cell division [1,2]. Many small GTPases have been cloned from plants but their functional analysis has largely been limited to complementation of mutations in corresponding yeast genes, and antisense experiments which have implicated these proteins in processes such as root nodulation [3,4]. No mutations in plant GTPases have been reported, and thus their true importance in plant growth and development is unknown. Here we report the isolation of a gene from Antirrhinum majus encoding a protein from an entirely novel class of eukaryotic GTPases showing strongest similarity to the prokaryotic protein ERA. We have named this gene ERG (for ERA-related GTPase). The ERG gene is expressed in dividing or metabolically active cells. We generated a deletion allele of ERG by site-selected transposon mutagenesis and have shown that seeds containing embryos and endosperm homozygous for this deletion arrest soon after fertilisation. We conclude that ERG has a crucial role in plant growth and development, possibly by influencing mitochondrial division.

Amino Acid Sequence↗
PubMed1998

The significance of involved tumour bed biopsy following wide local excision of breast cancer.

AIM: Following wide local excision of breast cancer approximately 25% of patients have residual disease in the tumour bed. The aim of this study was to determine whether positive bed biopsy correlated with either local recurrence or overall survival. METHOD: Following wide excision bed biopsies were taken at four separate sites from the tumour bed. Histopathological assessment of the bed biopsies was made and compared to features within the primary tumour. Patients were followed-up over a median period of 6.17 years and local recurrence and survival data documented. RESULTS: Two hundred and sixty-eight patients were included in the study and 63 had positive bed biopsies. In all, 85 patients had a recurrence of breast cancer and 69 died. Kaplan-Meier plots showed no evidence of a difference in survival between bed biopsy positive and negative patients. Bed biopsy positive patients were at greater risk of local recurrence. CONCLUSIONS: These findings suggest that positive bed biopsy is associated with an increase in local recurrence rates but has no effect on overall survival following wide excision of breast cancer.

Adult↗
PubMed1998

An audit of patient acceptance of one-stop diagnosis for symptomatic breast disease.

AIMS: The impetus for optimizing outpatient provision of breast-care services has come both from the patient and management in order to reduce anxiety and make full use of scarce resources. The one-stop diagnostic clinic for the investigation of symptomatic breast lesions is a relatively recent concept with well-known service benefits. However, acceptance to the patient has not been previously investigated. RESULTS: The results of this prospective audit demonstrate a high level of patient satisfaction with the multi-disciplinary, one-stop breast clinic.

Ambulatory Care↗
PubMed1998

Transcription of the prorenin gene in normal and diseased breast.

The angiotensin II type 1 (AT1) receptor is present in a wide variety of human and animal tissues, and is particularly abundant in epithelial cells. Because of this, and because it is known that tissue renin angiotensin systems (RASs) exist that have specific local functions, we investigated the expression and localisation of components of the RAS in normal and diseased breast tissue. Using a monoclonal antibody to the AT1 receptor, immunocytochemistry confirmed that the AT1 receptor was characteristically distributed in ductal epithelial cells in both normal and malignant tissue, and in most, although not all, cells in invasive tumours. Transcription of prorenin mRNA was studied by in situ hybridisation, using a DIG-ddUTP tail-labelled probe specific for the human prorenin gene. In normal tissue, and in cases of ductal carcinoma in situ, prorenin mRNA was distributed in myoepithelial cells and in a band of connective tissue cells completely surrounding the AT1-containing ductal epithelial cells. This prorenin transcribing tissue was disrupted and attenuated in invasive tumours, and in some of these, prorenin mRNA transcription could not be detected at all. Functions ascribed to the tissue RASs include regulation of mitosis and tissue modelling, as well as fluid and electrolyte transport. The results presented here strongly suggest the possibility that a tissue RAS may also be present in the breast, closely coupled to the provision of angiotensin II to the AT1 receptors in ductal epithelial cells. This mechanism is disrupted in cancer.

Breast Diseases↗
PubMed1998

99mTc-labelled SM3 in the preoperative evaluation of axillary lymph nodes and primary breast cancer with change detection statistical processing as an aid to tumour detection.

The extent of primary surgery for breast cancer could be tailored to the patient if previous information on the presence or absence of lymph node involvement could be reliably determined. Prospective radioimmunoscintigraphy in 29 patients with primary breast cancer that was found on screening has been undertaken with 555 MBq (15 mCi) 99mTc SM3, an Imperial Cancer Research Fund (ICRF) murine monoclonal antibody, 0.5 mg with images at 10 min and 22 h, and analysis using a change detection algorithm. Sites of significant change between the early and later images were displayed as a map of probabilities. Image-positive and -negative axillary lymph nodes were compared by histology in the 28 evaluable patients. The correct identification of the presence or absence of node involvement, even if impalpable, has been shown in 24 out of 28 patients (29 lymph node groups). Sensitivity was 90% (nine out of ten), specificity 84% (16 out of 19) and accuracy 86%. These results encourage further assessment of this technique.

Adult↗
PubMed1998

Control of floral homeotic gene expression and organ morphogenesis in Antirrhinum.

The development of reproductive organs in Antirrhinum depends on the expression of an organ identity gene, plena, in the central domain of the floral meristem. To investigate the mechanism by which plena is regulated, we have characterised three mutants in which the pattern of plena expression is altered. In polypetala mutants, expression of plena is greatly reduced, resulting in a proliferation of petals in place of reproductive organs. In addition, polypetala mutants exhibit an altered pattern of floral organ initiation, quite unlike that seen in loss-of-function plena mutants. This suggests that polypetala normally has two roles in flower development: regulation of plena and control of organ primordia formation. In fistulata mutants, plena is ectopically expressed in the distal domain of petal primordia, resulting in the production of anther-like tissue in place of petal lobes. Flowers of fistulata mutants also show a reduced rate of petal lobe growth, even in a plena mutant background. This implies that fistulata normally has two roles in the distal domain of petal primordia: inhibition of plena expression and promotion of lobe growth. A weak allele of the floral meristem identity gene, floricaula, greatly enhances the effect of fistulata on plena expression, showing that floricaula also plays a role in repression of plena in outer whorls. Taken together, these results show that genes involved in plena regulation have additional roles in the formation of organs, perhaps reflecting underlying mechanisms for coupling homeotic gene expression to morphogenesis.

Base Sequence↗
PubMed1998

A common mechanism controls the life cycle and architecture of plants.

The overall aerial architecture of flowering plants depends on a group of meristematic cells in the shoot apex. We demonstrate that the Arabidopsis TERMINAL FLOWER 1 gene has a unified effect on the rate of progression of the shoot apex through different developmental phases. In transgenic Arabidopsis plants which ectopically express TERMINAL FLOWER 1, both the vegetative and reproductive phases are greatly extended. As a consequence, these plants exhibit dramatic changes in their overall morphology, producing an enlarged vegetative rosette of leaves, followed by a highly branched inflorescence which eventually forms normal flowers. Activity of the floral meristem identity genes LEAFY and APETALA 1 is not directly inhibited by TERMINAL FLOWER 1, but their upregulation is markedly delayed compared to wild-type controls. These phenotypic and molecular effects complement those observed in the tfl1 mutant, where all phases are shortened. The results suggest that TERMINAL FLOWER 1 participates in a common mechanism underlying major shoot apical phase transitions, rather than there being unrelated mechanisms which regulate each specific transition during the life cycle.

Arabidopsis↗
PubMed1998

Design, testing, and results of an outcomes-managed approach to patients requiring prolonged mechanical ventilation.

BACKGROUND: Outcomes management that uses critical pathways may decrease costs while improving outcomes for patients who require prolonged mechanical ventilation. OBJECTIVE: To study the efficacy of an outcomes-managed approach to weaning patients from prolonged (more than 3 days) mechanical ventilation. METHODS: A method of multidisciplinary care delivery was designed that included an outcomes manager, a care pathway for patients receiving mechanical ventilation, and weaning protocols. Data collection consisted of three parts: a retrospective review of 124 patients who required prolonged ventilation during a 1-year period before implementation of the care model, a 6-month prospective study in which 91 patients were alternately assigned by month to an outcomes-managed approach or a non-outcomes-managed approach, and a 6-month prospective study of 90 patients in which an outcomes-managed approach without alternate-month assignment was used. RESULTS: Outcomes management had no significant effect on total duration of mechanical ventilation or length of stay in the hospital, days of mechanical ventilation without tracheostomy, days of mechanical ventilation with tracheostomy, or outcome (weaned, withdrawal from mechanical ventilation, death, or transfer without weaning). However, duration of mechanical ventilation was 1.3 days shorter, length of stay in the hospital was 2.1 days shorter, and the cost per case was $ 3341 less for patients in the outcomes-managed group than for patients in the non-outcomes-managed group. CONCLUSION: Outcomes-managed care did not have a significant effect on duration of ventilation, length of stay in the hospital, or outcome in patients receiving long-term mechanical ventilation.

Adult↗