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Biomedical subjects

V Evans

Publications and source records attributed to V Evans.

At least 19 recordsLinked to original sources
PubMed2005

Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: an overview of the randomised trials.

BACKGROUND: In early breast cancer, variations in local treatment that substantially affect the risk of locoregional recurrence could also affect long-term breast cancer mortality. To examine this relationship, collaborative meta-analyses were undertaken, based on individual patient data, of the relevant randomised trials that began by 1995. METHODS: Information was available on 42,000 women in 78 randomised treatment comparisons (radiotherapy vs no radiotherapy, 23,500; more vs less surgery, 9300; more surgery vs radiotherapy, 9300). 24 types of local treatment comparison were identified. To help relate the effect on local (ie, locoregional) recurrence to that on breast cancer mortality, these were grouped according to whether or not the 5-year local recurrence risk exceeded 10% (<10%, 17,000 women; >10%, 25,000 women). FINDINGS: About three-quarters of the eventual local recurrence risk occurred during the first 5 years. In the comparisons that involved little (<10%) difference in 5-year local recurrence risk there was little difference in 15-year breast cancer mortality. Among the 25,000 women in the comparisons that involved substantial (>10%) differences, however, 5-year local recurrence risks were 7% active versus 26% control (absolute reduction 19%), and 15-year breast cancer mortality risks were 44.6% versus 49.5% (absolute reduction 5.0%, SE 0.8, 2p<0.00001). These 25,000 women included 7300 with breast-conserving surgery (BCS) in trials of radiotherapy (generally just to the conserved breast), with 5-year local recurrence risks (mainly in the conserved breast, as most had axillary clearance and node-negative disease) 7% versus 26% (reduction 19%), and 15-year breast cancer mortality risks 30.5% versus 35.9% (reduction 5.4%, SE 1.7, 2p=0.0002; overall mortality reduction 5.3%, SE 1.8, 2p=0.005). They also included 8500 with mastectomy, axillary clearance, and node-positive disease in trials of radiotherapy (generally to the chest wall and regional lymph nodes), with similar absolute gains from radiotherapy; 5-year local recurrence risks (mainly at these sites) 6% versus 23% (reduction 17%), and 15-year breast cancer mortality risks 54.7% versus 60.1% (reduction 5.4%, SE 1.3, 2p=0.0002; overall mortality reduction 4.4%, SE 1.2, 2p=0.0009). Radiotherapy produced similar proportional reductions in local recurrence in all women (irrespective of age or tumour characteristics) and in all major trials of radiotherapy versus not (recent or older; with or without systemic therapy), so large absolute reductions in local recurrence were seen only if the control risk was large. To help assess the life-threatening side-effects of radiotherapy, the trials of radiotherapy versus not were combined with those of radiotherapy versus more surgery. There was, at least with some of the older radiotherapy regimens, a significant excess incidence of contralateral breast cancer (rate ratio 1.18, SE 0.06, 2p=0.002) and a significant excess of non-breast-cancer mortality in irradiated women (rate ratio 1.12, SE 0.04, 2p=0.001). Both were slight during the first 5 years, but continued after year 15. The excess mortality was mainly from heart disease (rate ratio 1.27, SE 0.07, 2p=0.0001) and lung cancer (rate ratio 1.78, SE 0.22, 2p=0.0004). INTERPRETATION: In these trials, avoidance of a local recurrence in the conserved breast after BCS and avoidance of a local recurrence elsewhere (eg, the chest wall or regional nodes) after mastectomy were of comparable relevance to 15-year breast cancer mortality. Differences in local treatment that substantially affect local recurrence rates would, in the hypothetical absence of any other causes of death, avoid about one breast cancer death over the next 15 years for every four local recurrences avoided, and should reduce 15-year overall mortality.

Aged↗
PubMed2001

Lack of cross-species transmission of porcine endogenous retrovirus infection to nonhuman primate recipients of porcine cells, tissues, or organs.

BACKGROUND: Nonhuman primates (NHPs) have been widely used in different porcine xenograft procedures inevitably resulting in exposure to porcine endogenous retrovirus (PERV). Surveillance for PERV infection in these NHPs may provide information on the risks of cross-species transmission of PERV, particularly for recipients of vascularized organ xenografts for whom data from human clinical trials is unavailable. METHODS: We tested 21 Old World and 2 New World primates exposed to a variety of porcine xenografts for evidence of PERV infection. These NHPs included six baboon recipients of pig hearts, six bonnet macaque recipients of transgenic pig skin grafts, and nine rhesus macaque and two capuchin recipients of encapsulated pig islet cells. Serologic screening for PERV antibody was done by a validated Western blot assay, and molecular detection of PERV sequences in peripheral blood mononuclear cells (PBMCs) and plasma was performed using sensitive polymerase chain reaction and reverse transcriptase-polymerase chain reaction assays, respectively. Spleen and lymph node tissues available from six bonnet macaques and three rhesus macaques were also tested for PERV sequences. RESULTS: All plasma samples were negative for PERV RNA suggesting the absence of viremia in these xenografted animals. Similarly, PERV sequences were not detectable in any PBMC and tissue samples, arguing for the lack of latent infection of these compartments. In addition, all plasma samples were negative for PERV antibodies. CONCLUSION: These data suggest the absence of PERV infection in all 23 NHPs despite exposure to vascularized porcine organs or tissue xenografts and the use of immunosuppressive therapies in some animals. These findings suggest that PERV is not easily transmitted to these NHP species through these types of xenografts.

Animals↗
PubMed2001

Lacryglobin in human tears, a potential marker for cancer.

Lacrygobin has been identified in human tears. This protein has high sequence homology to the mammaglobins, proteins upregulated in breast cancer and in breast cancer metastasis. In order to investigate the utility of tear screening for cancer tear samples were collected from patients with different types of cancer and compared to controls. Tear samples were taken from five controls and eight breast, six lung, five colon, one prostate and three ovary cancer patients. Tears were analysed using 2-D gel electrophoresis (n = 25) and 1-D electrophoresis (n = 3). Lacryglobin was present in the following percentage of patients: breast cancer (88%), lung (83%), colon (100%), ovary (33%), prostate (100%) and controls (60%). Two control patients with lacryglobin had a family history of breast and prostate cancer. Lacryglobin was detected in some but not all tear samples and further studies are warranted to investigate its potential as a marker for cancer.

Adult↗
PubMed2000

Targeting the Hprt locus in mice reveals differential regulation of Tie2 gene expression in the endothelium.

To study the in vivo expression of the murine Tie2 gene, we have targeted the hypoxanthine phosphoribosyltransferase (Hprt) gene locus to generate two single-copy transgenic mice: T1, containing the 2,100-bp Tie2 promoter upstream from the beta-galactosidase (LacZ) gene, and T5, which also included an enhancing element originating from the first intron of the Tie2 gene. Comparing T1 and T5 embryos at day E10.5 revealed differential endothelial cell-specific expression of LacZ, whereas colocalization analyses showed that the expression was confined to endothelial cells. Moderate reporter gene activity was observed in the brain and kidney of T1 adults, whereas extensive LacZ gene expression was seen in the vasculature of most organs of the T5 adults. This study demonstrates the feasibility of targeting the Hprt locus with endothelial cell-specific sequences to analyze the spatial-temporal expression of transgenes. Of particular importance is the observation that the analysis of a single transgene copy in a defined locus allows for an accurate and rapid comparison of transcriptional activity among regulatory DNA sequences.

Animals↗
PubMed2000

Modulation of tear film protein secretion with phosphodiesterase inhibitors.

A double-blind randomized clinical study was conducted to determine whether nicardipine hydrochloride was a useful treatment for dry eye.We examined its effect on the tear film, ocular surface and ocular comfort. Nicardipine hydrochloride, 3-isobutyl-1-methylxanthine and pilocarpine hydrochloride were dissolved in an artificial tear vehicle and applied topically to one eye of 12 subjects on separate days. Ocular physiology, ocular comfort and tear volume were assessed. The trial was repeated with nicardipine in an aqueous gel vehicle. Tears were collected and assessed for protein concentration and protein profile, using electrophoresis and mass spectrometry. Nicardipine induced conjunctival redness and symptoms of dryness and irritation. There was no change in total tear protein concentration or volume. An increase in a 68 kDa protein was observed, this was probably due to conjunctival vessel dilation and leakage of albumin. The adverse symptomatology and increased conjunctival redness experienced with nicardipine make it an undesirable treatment for dry eye.

1-Methyl-3-isobutylxanthine↗
PubMed2000

Herbs and the brain: friend or foe? The effects of ginkgo and garlic on warfarin use.

In the quest for longevity and as an alternative to Western medicine, there has been a resurgence in traditional remedies. However, several concerns have been raised about the increased use of herbal remedies, including potential interactions with "Western" medicines, the lack of quality control, the assessment of herbal clinical trials, and the adulteration of herbal remedies by traditional prescribers. Taking an herbal history is not usually a part of medical/nursing practice, and patients usually do not readily volunteer such information. In the cerebrovascular and cardiac settings, it is particularly important to gain such a history and to educate patients and family members about the potential interactions of herbal remedies with anticoagulants. Two herbal supplements in particular, ginkgo biloba and garlic, have demonstrated effects on warfarin.

Acute Disease↗
PubMed1999

A patient preference study comparing raltitrexed ('Tomudex') and bolus or infusional 5-fluorouracil regimens in advanced colorectal cancer: influence of side-effects and administration attributes.

Current chemotherapy regimens used in advanced colorectal cancer (ACRC) are similar in terms of efficacy, but differ importantly in terms of side-effects and administration profiles. These differences may impact significantly on patients' lives. We have evaluated patient preferences between raltitrexed ('Tomudex') and 5-fluorouracil-based chemotherapy regimens, with regard to side-effect attributes (raltitrexed and Mayo regimens) and administration attributes (raltitrexed, Mayo, De Gramont and Lokich regimens) in a study based on 82 patients with ACRC. Patients completed a series of rating tasks on how 'upsetting' these attributes were to them using a visual analogue scale (VAS) in a structured interview conducted by a research nurse. Mucositis and asthenia were the most and least upsetting side-effects, respectively. The side-effect profile of raltitrexed was clearly preferred by 78% of patients versus 14% for Mayo (P < 0.001). When side-effects and administration attributes were combined into an overall profile, 91% of patients selected raltitrexed as their clearly preferred regimen, versus 6% for Mayo (P < 0.001). The administration regimen of raltitrexed was ranked most acceptable (mean rank score 1.5 compared with Mayo 2.6, De Gramont 2.7, and Lokich 3.3). Given similar palliative effects, patients with ACRC exhibit preferences for raltitrexed over other regimens, based on administration and/or side-effect attributes. Such preferences should constitute an important part of decisions relating to the choice of chemotherapy regimen in ACRC.

Adult↗
PubMed1998

Case study: nursing care of the patient with vertebral artery aneurysm treated by endovascular stenting and coil implantation.

As we move towards the 21st Century, it is evident that healthcare is significantly altered by advancements in technology. The following case study describes the first reported procedure in a human, in which a vertebral artery stent was inserted to act as a "bridge" for coil placement in the treatment of a wide-necked vertebral artery aneurysm. Due to the size, shape and calcification of the aneurysm, conventional neurosurgery and/or endovascular coiling were considered inappropriate obliterative mechanisms. Instead, a new therapy that combined surgical and endovascular techniques was successfully initiated. Therapies such as the stent procedure have only been successful in canine studies. Aneurysms unsuitable for conventional therapy, including clipping or endovascular techniques, were once thought untreatable. Stenting now provides the surgeon and patient with another therapeutic modality to better manage difficult wide-necked aneurysms.

Aneurysm↗
PubMed1998

Complex chitinolytic system of Aspergillus fumigatus.

Native polyacrylamide gels incorporating a glycol chitin substrate were used to detect several chitinolytic enzymes in the culture filtrate and cell surface, wall and mixed membrane fractions of Aspergillus fumigatus during the exponential phase of growth. Much of the cellular chitinase activity did not bind to concanavalin A (Con A) matrix and was heat-sensitive. In contrast, almost all chitinases secreted appeared to be heat-stable glycoproteins. The heavily glycosylated molecules, in a Con A-binding fraction, were the most immunologically-reactive components, as judged by their binding to anti-Aspergillus antibodies, present in the serum of patients with aspergillosis. Most of the cellular chitinases of A. fumigatus mycelium bound to an insoluble chitin matrix while most of the secreted chitinases did not bind to chitin.

Antibodies, Fungal↗
PubMed1993

Patient education: bridging the gap between inpatient and ambulatory care.

This article describes a model curriculum of perinatal education designed to bridge the gap between prenatal ambulatory care education and labor and delivery, postpartum and well child care in a high-risk population of inner city women. The curriculum, which consists of broad-based, maternal-child health information, was developed, implemented, and evaluated through an interdisciplinary approach. The initiative narrowed the preexisting gap between departments, increased clients' knowledge, and promoted positive changes in clients' behavior. The breadth of the curriculum content addresses the unquestionable need for perinatal education that will enhance compliance and empower clients toward health maintenance.

Adolescent↗
PubMed1991

HIV/AIDS education in a prenatal clinic: an assessment.

An HIV/AIDS education and counseling program was integrated into the routine medical care of women attending the prenatal clinic of a major urban, inner-city, teaching hospital that serves mostly indigent minority women in an area hard hit by the HIV/AIDS epidemic. Pre- and post-intervention questionnaires were administered to a consecutive historical Control Group (n = 98) who did not receive the HIV/AIDS information and an Intervention Group (n = 515) who received all information. The data support our hypothesis that an HIV/AIDS education program would increase the level of general knowledge, but fail to support our hypothesis of a positive effect on attitudes around HIV-antibody testing and an increase in desire for voluntary testing. Our hypothesis that women reporting more risk behaviors would be more likely to agree to HIV-antibody testing was only partially supported.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Incorporating HIV education and counseling into routine prenatal care: a program model.

This article reports how a prenatal clinic in a major urban teaching hospital has developed and integrated an HIV education and counseling program into routine prenatal care. The patient population served are predominantly minority women living in an inner-city community that has been disproportionately affected by the AIDS epidemic. Implementation of the patient program has required training and support for all professional staff. Staff training served as a foundation for this comprehensive patient program, which has reached all prenatal patients regardless of risk behavior. The program has succeeded in involving a large population of women in an educational program, has identified HIV-1 seropositive pregnant women through voluntary testing, and has provided them with the necessary medical and social work services. Principles of program development are identified for use in other settings.

Ambulatory Care↗
PubMed1980

Learning to take it easy.

Stress can be deadly and more and more people are seeking outside help in dealing with it. Leicestershire AHA is taking positive steps; Vivienne Evans, senior health education officer, describes a scheme to teach people who feel under threat from stress to relax.

England↗