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Biomedical subjects

R Carpenter

Publications and source records attributed to R Carpenter.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1998

Hypertrophic cardiomyopathy in pregnancy. The use of two-dimensional and Doppler echocardiography during labor and delivery: a case report.

Hypertrophic cardiomyopathy (HCM) in pregnancy can result in a high incidence of maternal complications. Although echocardiography is frequently performed in pregnant women with HCM in order to confirm their hemodynamic classification, this modality has not been applied during labor and delivery in these patients. This case report documents the application of two-dimensional and Doppler echocardiography during labor and delivery in a 35-year-old woman with HCM.

Adult↗
PubMed1998

An audit of outcome including patient satisfaction with immediate breast reconstruction performed by breast surgeons.

Reconstruction of the female breast is becoming ever more frequently requested by patients after mastectomy for cancer. One of the least complex techniques is that of local tissue expansion with a permanent prosthesis. We present our experience and the clinical outcomes of the first 100 patients to have undergone surgery in the 4 years since the introduction of this method of breast reconstruction in our unit. A retrospective study was performed with a detailed questionnaire being sent to each patient for subjective assessment of satisfaction. Data were also collected on the rates of clinical infection of the prosthesis and the need for further surgery, including capsulotomy, nipple reconstruction and contralateral procedures. With 84% expressing their satisfaction at the final result, immediate breast reconstruction is both feasible and highly acceptable to the majority of patients.

Adult↗
PubMed1998

Orbital psuedotumour with intracranial extension. A case report.

Inflammatory pseudotumour of the orbit is an unusual condition of unknown aetiology which rarely extends beyond the orbit. To our knowledge 19 cases with intracranial extension have been reported, none of which involved the pituitary fossa or sphenoid sinus. Most required cytotoxic agents, surgery or radiotherapy in addition to corticosteroids. We present a case of orbital pseudotumour with extension into the pituitary fossa, sphenoid sinus and cavernous sinuses with vascular compression. Marked clinical improvement occurred on steroid therapy alone.

Adult↗
PubMed1997

Dual role for fimbriata in regulating floral homeotic genes and cell division in Antirrhinum.

The fimbriata (fim) gene of Antirrhinum affects both the identity and arrangement of organs within the flower, and encodes a protein with an F-box motif. We show that FIM associates with a family of proteins, termed FAPs (FIM-associated proteins), that are closely related to human and yeast Skp1 proteins. These proteins form complexes with F-box-containing partners to promote protein degradation and cell cycle progression. The fap genes are expressed in inflorescence and floral meristems in a pattern that incorporates the domain of fim expression, supporting an in vivo role for a FIM-FAP complex. Analysis of a series of novel fim alleles shows that fim plays a key role in the activation of organ identity genes. In addition, fim acts in the regions between floral organs to specify the correct positioning and maintenance of morphological boundaries. Taking these results together, we propose that FIM-FAP complexes affect both gene expression and cell division, perhaps by promoting selective degradation of regulatory proteins. This may provide a mechanism by which morphological boundaries can be aligned with domains of gene expression during floral development.

Amino Acid Sequence↗
PubMed1997

Inflorescence commitment and architecture in Arabidopsis.

Flowering plants exhibit one of two types of inflorescence architecture: indeterminate, in which the inflorescence grows indefinitely, or determinate, in which a terminal flower is produced. The indeterminate condition is thought to have evolved from the determinate many times, independently. In two mutants in distantly related species, terminal flower 1 in Arabidopsis and centroradialis in Antirrhinum, inflorescences that are normally indeterminate are converted to a determinate architecture. The Antirrhinum gene CENTRORADIALIS (CEN) and the Arabidopsis gene TERMINAL FLOWER 1 (TFL1) were shown to be homologous, which suggests that a common mechanism underlies indeterminacy in these plants. However, unlike CEN, TFL1 is also expressed during the vegetative phase, where it delays the commitment to inflorescence development and thus affects the timing of the formation of the inflorescence meristem as well as its identity.

Amino Acid Sequence↗
PubMed1997

Altered cell-matrix contact: a prerequisite for breast cancer metastasis?

The integrins are receptors that regulate interaction between epithelial cells and the extracellular matrix. Previous studies have shown that a reduction in the expression of the alpha2beta1, alpha3beta1, alpha6beta1, alpha(v)beta1 and alpha(v)beta5 integrins in primary breast cancer is associated with positive nodal status. In order to assess the functional significance of altered integrin expression, primary breast cancer cells were derived from individual patients with known tumour characteristics using immunomagnetic separation. Purified human fibronectin, vitronectin, laminin and type IV collagen were used to represent the principal extracellular matrix proteins in an in vitro adhesion assay. Primary breast cancer cells from lymph node-positive patients were significantly less adhesive to each of the matrix proteins studied (P<0.001, Mann-Whitney U-test). Matrix adhesion of primary breast cancer cells from node-negative patients was inhibited by appropriate integrin monoclonal antibodies (P<0.001, paired Wilcoxon test). Adhesion to fibronectin, vitronectin and laminin, but not type IV collagen, was influenced by the inhibitor arginine-glycine-aspartate, suggesting that breast cancer cell recognition of collagen IV is mediated through alternative epitopes. Weak matrix adhesion correlated with loss of integrin expression in tissue sections from corresponding patients assessed using immunohistochemistry. This study demonstrates a link between altered integrin expression and function in primary breast cancers predisposed to metastasize.

Adult↗
PubMed1996

Origin of floral asymmetry in Antirrhinum.

Dorsoventral asymmetry in flowers is thought to have evolved many times from a radially symmetrical ancestral condition. The first gene controlling floral asymmetry, cycloidea in Antirrhinum, has been isolated. The cycloidea gene is expressed at a very early stage in dorsal regions of floral meristems, where it affects growth rate and primordium initiation. Expression continues through to later stages in dorsal primordia to affect the asymmetry, size and cell types of petals and stamens.

Alleles↗
PubMed1996

Control of inflorescence architecture in Antirrhinum.

Flowering plants exhibit two types of inflorescence architecture: determinate and indeterminate. The centroradialis mutation causes the normally indeterminate inflorescence of Antirrhinum to terminate in a flower. We show that centroradialis is expressed in the inflorescence apex a few days after floral induction, and interacts with the floral-meristem-identity gene floricaula to regulate flower position and morphology. The protein CEN is similar to animal proteins that associate with lipids and GTP-binding proteins. We propose a model for how different inflorescence structures may arise through the action and evolution of centroradialis.

Amino Acid Sequence↗
PubMed1996

Growth enhancement of implanted human colorectal cancer cells by the addition of fibroblasts in vivo.

The effect of fibroblasts on the growth of HT29 human colorectal cancer cells was used to study stromal modulation of tumour growth dynamics. Fibroblasts were isolated from rat livers, 1, 2.5 and 4 days after two-thirds partial hepatectomy and from normal livers. Cells harvested 2.5 and 4 days after hepatectomy ('fast' fibroblasts) had a significantly faster growth rate in vitro than those harvested on day 1 or those from normal livers (P < 0.02). The fibroblasts were inoculated with HT29 colorectal cancer cells into nude mice. Controls received cancer cells with or without a fibroblast cell line (C3H10T 1/2). At 3 weeks both tumour take and growth (size) were significantly greater in the group inoculated with cancer cells and 'fast' fibroblasts than in the other groups (tumour take 100 versus 42-75 per cent, P < 0.03; median tumour size 3.5 versus 0.3-0.4 g, P < 0.02). In conclusion, tumour growth is enhanced by fibroblasts, especially by those derived from actively regenerating liver. It is suggested that the stimulation is not only mechanical but may also involve a humoral mechanism.

Animals↗
PubMed1996

Integrin expression in breast cancer cytology: a novel predictor of axillary metastasis.

The integrins are heterodimeric transmembrane receptors of varying alpha and beta subunits that modulate cell adhesion to each other and to the extracellular matrix. Loss of integrin expression on primary breast cancer frozen sections measured by immunohistochemistry may be related to the presence of axillary metastasis. The clinical application of this finding would be increased if integrin expression could also be shown to be reliably measured on breast cancer cells obtained by fine needle aspiration cytology. Axillary operations may be planned as a single stage procedure from outpatients, and neoadjuvant therapy protocols may be developed without surgery to the axilla. Expression of the alpha 1, alpha 2, alpha 3, alpha 6, alpha v, beta 1, beta 3 and beta 5 integrin subunits were measured by immunohistochemistry and immunocytochemistry in 58 patients. Integrin measurement by both these methods were found to be closely associated using the kappa-test. Loss of expression of the alpha 1, alpha 2, alpha 3, alpha 6, alpha v, beta 1 and beta 5 integrin subunits measured by cytology and histology were each related to positive nodal status (chi(2) test). Measuring integrin expression on cytology is of clinical value and may prove to have prognostic significance.

Adult↗