Using genomic prediction to detect microevolutionary change of a quantitative trait.

Detecting microevolutionary responses to natural selection by observing temporal changes in individual breeding values is challenging. The collection of suitable datasets can take many years and disentangling the contributions of the environment and genetics to phenotypic change is not trivial. Furthermore, pedigree-based methods of obtaining individual breeding values have known biases. Here, we apply a genomic prediction approach to estimate breeding values of adult weight in a 35-year dataset of Soay sheep (Ovis aries). Comparisons are made with a traditional pedigree-based approach. During the study period, adult body weight decreased, but the underlying genetic component of body weight increased, at a rate that is unlikely to be attributable to genetic drift. Thus cryptic microevolution of greater adult body weight has probably occurred. Genomic and pedigree-based approaches gave largely consistent results. Thus, using genomic prediction to study microevolution in wild populations can remove the requirement for pedigree data, potentially opening up new study systems for similar research.

Randomized phase II study of cetuximab plus cisplatin/vinorelbine compared with cisplatin/vinorelbine alone as first-line therapy in EGFR-expressing advanced non-small-cell lung cancer.

BACKGROUND: The Lung Cancer Cetuximab Study is an open-label, randomized phase II pilot study of cisplatin and vinorelbine combined with the epidermal growth factor receptor (EGFR)-targeted monoclonal antibody cetuximab versus cisplatin and vinorelbine alone, in patients with advanced EGFR-expressing, non-small-cell lung cancer (NSCLC). End points of the study are activity, safety and pharmacokinetics. PATIENTS AND METHODS: Following randomization, for a maximum of eight cycles, patients received three-weekly cycles of cisplatin (80 mg/m(2), day 1) and vinorelbine (25 mg/m(2) on days 1 and 8) alone or following cetuximab treatment (initial dose 400 mg/m(2), followed by 250 mg/m(2) weekly thereafter). RESULTS: Eighty-six patients were randomly allocated to the study (43 per arm). Confirmed response rates were 28% in the cisplatin/vinorelbine arm (A) and 35% in the cetuximab plus cisplatin/vinorelbine arm (B). Median progression-free survival (PFS) was 4.6 months in arm A and 5.0 months in arm B, with PFS rates at 12 months of 0% and 15%, respectively. Median survival was 7.3 months in arm A and 8.3 months in arm B. The 24-month survival rates were 0% and 16%, respectively. The cetuximab combination was well tolerated. CONCLUSION: In the first-line treatment of advanced NSCLC, the combination of cetuximab plus cisplatin/vinorelbine demonstrated an acceptable safety profile and the potential to improve activity over cisplatin/vinorelbine alone.

Development of resistance to the growth inhibitory effects of transforming growth factor beta 1 during the spontaneous transformation of rat liver epithelial cells.

The temporary maintenance of a rat liver epithelial cell population at confluence before passaging followed by periods of rapid proliferation resulted in the generation of spontaneous transformants after about 108 population doublings. The appearance of morphologically aberrant transformants correlated directly with an increased resistance of the population to the growth inhibitory effects of transforming growth factor beta 1 (TGF-beta 1). Clonal cell lines derived from the transformants were resistant to TGF-beta 1 dependent inhibition of DNA synthesis. These cell lines were also highly tumorigenic and aneuploid, with characteristic gross chromosomal abnormalities, and they expressed a number of phenotypic markers common to rat liver epithelial cells transformed by oncogenes or chemicals. In contrast, apparently normal looking cell lines cloned from the same population were nontumorigenic and near diploid, with few chromosomal abnormalities, and they were as sensitive to TGF-beta 1 as early passage normal rat liver epithelial cells. Morphologically normal late passage rat liver epithelial cells were sensitive to transformation by the DNA hypomethylating agent 5-aza-2-deoxycytidine, in contrast to earlier passage cells, and this transformation was accompanied by the development of resistance to the growth inhibitory effects of TGF-beta 1. These findings suggest that acquisition of resistance to the effects of growth inhibitors such as TGF-beta 1 is an important and possibly essential stage in the spontaneous transformation of rat liver epithelial cells.

Fasting plasma lipid measurements following cisplatin chemotherapy in patients with germ cell tumors.

PURPOSE: Elevated total serum cholesterol levels have been reported recently in a group of patients with metastatic testicular cancer after treatment with cisplatin combination chemotherapy. We have studied the lipid profile of a similar group of patients in an attempt to confirm this observation. PATIENTS AND METHODS: Fasting plasma lipid concentrations were measured in 47 patients with advanced germ cell tumors who were previously treated with a cisplatin combination chemotherapy. The values obtained for mean total cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, apolipoprotein A1, and apolipoprotein B concentrations were compared with those obtained from a control group of 59 patients with germ cell tumors who were not treated with chemotherapy and with data from the New Zealand male population. Median time from the completion of chemotherapy to lipid measurement in the treated group was 50 months (range, 2 to 138 months). The median total dose of cisplatin given was 720 mg (range, 300 to 1,625 mg). RESULTS: Mean total plasma cholesterol concentrations in the cisplatin group (5.87 mol/L) and the control group (5.70 mmol/L) did not differ significantly (P > .4). There was no significant difference for any of the variables between the chemotherapy and control groups and those of the New Zealand male population. There was a trend toward higher mean triglyceride concentrations in the chemotherapy group, but this did not reach significance. CONCLUSIONS: We have not demonstrated an elevation in total plasma cholesterol after cisplatin chemotherapy as has been reported by previous investigators. Our results suggest that in these patients, cisplatin-containing combination chemotherapy is not associated with a significant adverse effect on plasma lipid profile.

Randomized phase II trial of infusional fluorouracil, epirubicin, and cyclophosphamide versus infusional fluorouracil, epirubicin, and cisplatin in patients with advanced breast cancer.

PURPOSE: We previously developed an inpatient regimen that consisted of infusional fluorouracil (5-FU), epirubicin, and cisplatin (ECisF), with a response rate of 86% in advanced breast cancer. The current phase II 2:1 randomized study investigated whether cyclophosphamide can be substituted for cisplatin (ECycloF) to reduce toxicity and allow the regimen to be administered on an outpatient basis without loss of efficacy. PATIENTS AND METHODS: Ninety-six women (median age, 49 years; range, 28 to 73) with breast cancer (59 metastatic, 37 locally advanced) received continuous infusional 5-FU (200 mg/m2/d via Hickman line) and six cycles of epirubicin (60 mg/m2 every 21 days) with either cyclophosphamide 600 mg/m2 every 21 days (38 metastatic, 24 locally advanced) or cisplatin 60 mg/m2 every 21 days (21 metastatic, 13 locally advanced). There were no significant differences in patient characteristics between these groups. RESULTS: ECycloF was better tolerated than ECisF in terms of lethargy (P = .005), stomatitis (P = .008), plantar palmar erythema (P = .02), constipation (P < .001), thrombosis (P = .0014), and nausea and vomiting (P = .05). Although there was a trend toward more anemia and leukopenia with ECisF (P =. 1), there was no significant difference in the rates of infection. Efficacy was comparable in terms of overall response (69% v 68%), complete response (CR; 13% v 15%), and median progression-free survival (9 v 8 months). CONCLUSION: ECycloF is an outpatient regimen with a lower incidence of severe nonhematologic toxicity than inpatient ECisF; it has comparable efficacy and is considerably more economical.

Clinical studies of apoptosis and proliferation in breast cancer.

The interaction between cell death and cell proliferation determines the growth dynamics of all tissues. Studies are described here which relate the changes in proliferation and apoptosis that occur in human breast cancer during medical therapeutic manoeuvres. Xenograft studies strongly support the involvement of increased apoptosis as well as decreased proliferation after oestrogen withdrawal, and limited studies in clinical samples confirm the involvement of both processes. Cytotoxic chemotherapy induces increases in apoptosis within 24 h of starting treatment. However, after 3 months therapy the residual cell population shows apoptotic and proliferation indices much below pretreatment levels. Further molecular studies of this "dormant" population are important to characterise the mechanism of their resistance to drug therapy. The early changes in proliferation and apoptosis may provide useful intermediate response indices.

Primary chemotherapy for early breast cancer.

The use of primary chemotherapy represents a novel approach being used with increasing frequency in the management of early breast cancer. Many studies now testify to the usefulness of this modality in increasing the frequency of breast conservation. The acceptance of high-risk breast cancer as a systemic, and therefore predominantly medical rather than a surgical, disease suggests, however, that its role is likely to be far more reaching. While some trials have so far suggested the possibility of a survival benefit for this approach, definitive conclusions are not yet possible and await the final mature results from several large randomized studies. Even if such studies do not show a large extra benefit for primary chemotherapy over existing adjuvant treatment, the use of the primary tumour as an in vivo model of individual chemosensitivity and the identification of molecular markers as early predictors of response, suggest that this approach will become an integral part of the modern multidisciplinary management of early breast cancer.

Dietary n-3 fatty acid supplementation reduces superoxide production and chemiluminescence in a monocyte-enriched preparation of leukocytes.

Consuming substantial quantities of n-3 fatty acids reduces atherogenesis in experimental models of atherosclerosis. The mechanisms of this beneficial effect remain uncertain. Monocyte-derived tissue macrophages are associated with atherogenesis, and inhibition of monocyte inflammatory activity could, hypothetically, be helpful in preventing atherosclerosis. We observed that stimulated human monocyte and/or macrophage production of superoxide and the occurrence of monocyte chemiluminescence, two indices of monocyte inflammatory activity, were significantly reduced by the ingestion of 6 g n-3 fatty acids/d for 6 wk. This effect was associated with a reduction of stearic and arachidonic acids whereas eicosapentaenoic and docosahexaenoic acid concentrations rose significantly. These results indicate that modest dietary n-3 fatty acid supplementation can reduce stimulated human-monocyte free-radical production and may impair the capability of macrophages derived from monocytes to promote oxidation of low-density-lipoprotein cholesterol and associated cellular toxicity.

Epirubicin, cisplatin and infusional 5-fluorouracil (5-FU) (ECF) in hepatobiliary tumours.

Hepatobiliary tumours are rare, often present late and have a poor prognosis, with no current effective systemic therapy available. This study aimed to evaluate the activity and toxicity of epirubicin, cisplatin and continuous infusional 5-fluorouracil (5-FU) (ECF) in patients with these tumours. From March 1991 to November 1993, 25 patients with advanced biliary tumours and 7 with hepatoma were treated with epirubicin 50 mg/m2 and cisplatin 60 mg/m2 intravenously (i.v.) day 1, each given every 21 days and 5-FU 200 mg/m2/day given as a continuous 24 h i.v. infusion throughout the treatment course. 8 of the 20 (40%) evaluable patients with biliary tumours responded. Median duration of response was 10 months. 2 of the 7 (29%) patients with hepatoma responded. The regimen was well tolerated with minimal haematological and non-haematological toxicity. This novel regimen is active in advanced hepatobiliary tumours.

Neonatal platelets are less reactive than adult platelets to physiological agonists in whole blood.

Previous studies have reported that the platelets of healthy term neonates have either diminished or normal reactivity compared to the platelets of adults. To circumvent the methodologic problems of previous studies, we used a whole blood flow cytometric method to study neonatal platelet reactivity to thrombin, a combination of ADP and epinephrine, and U46619 (a stable thromboxane A2 analogue). Inclusion in the assay of the peptide GPRP (an inhibitor of fibrin polymerization) enabled us to study platelet reactivity to human alpha-thrombin in whole blood. Umbilical cord blood and day 1 peripheral blood were collected from 30 healthy term neonates and compared to peripheral blood from 20 normal adults. In whole blood samples without added agonist, there were no significant differences between neonates and adults in the platelet binding of monoclonal antibodies 6D1 (GPIb-specific) or 7E3 (GPIIb-IIIa complex-specific). As determined by S12 (a P-selectin-specific monoclonal antibody), neither neonates nor adults had circulating degranulated platelets. However, in both cord and peripheral whole blood samples, neonatal platelets were significantly less reactive than adult platelets to thrombin, ADP/epinephrine, and U46619, as determined by the extent of increase in the platelet surface expression of P-selectin and the GPIIb-IIIa complex, and the extent of decrease in the platelet surface expression of the GPIb-IX complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Causes of end-stage renal failure in black patients starting renal replacement therapy.

In the United States, blacks are more frequently diagnosed than whites with end-stage renal failure (ESRF) from primary hypertension or diabetic nephropathy. We performed a validation retrospective case-note study of all blacks with ESRF who started renal replacement therapy (RRT) at three teaching hospitals in London, England, during 1991 to 1995 to investigate and validate the causes of primary renal disease using standard criteria. We identified 144 black patients with a mean age of 52.0 +/- 16.0 (SD) years; 59% were men and 32% had renal histological data. One hundred forty-four whites who were matched for age, sex, and onset of RRT (42% with renal histological data) underwent a similar validation exercise. Before the validation, the principal working diagnosis in the black patients had been diabetic nephropathy in 35% (89%, type 2; 11%, type 1); primary hypertension, 19%; glomerulonephritis (GN), 18%; and uncertain cause, 15%. After validation analysis, this changed to diabetes, 38% (16% biopsy proven); uncertain, 24%; GN, 20%; and primary hypertension, only 10% (28% biopsy proven). Among the uncertain cases (n = 34), 19 patients had hypertension, but this could not be established as the primary disease; 94% of all blacks had hypertension, accelerated in 21%. Among whites, only 3.5% had primary hypertension, and this proportion was not changed by the validation study. Type 2 diabetes is the most common single cause of ESRF in black patients in London, and although hypertension is more common and more severe in blacks, the proportion of renal failure attributed to primary hypertension is overestimated, and the diagnosis is often made using inadequate criteria.

Comparison of in situ methods to assess DNA cleavage in apoptotic cells in patients with breast cancer.

BACKGROUND: Apoptosis has a role in many cellular processes including development, normal tissue homeostasis, and malignancy. This aspect of research is relatively new with distinct methods of analysing disparate biochemical and genetic events to measure apoptotic cells. The use of biotinylated nucleotides to identify DNA strand breaks is a commonly reported method of estimating cells numbers undergoing apoptosis; however, investigators report inconsistent results for a variety of reasons. AIMS AND METHOD: To compare two in situ techniques of measuring apoptosis: in situ nick translation (ISNT) and TdT mediated dUTP-biotin nick end labelling (TUNEL); and to assess DNA cleavage in 20 paired paraffin wax embedded breast cancer tissues from patients; one group who had received no prior treatment and one group who had received chemohormonal treatment. RESULTS AND CONCLUSIONS: Apoptotic scores obtained from paraffin wax embedded human breast cancer after using ISNT and TUNEL methods were not significantly different (p = 0.11). A strong correlation between scores obtained from the two techniques was found (r = 0.758, p < 0.0001). Optimisation of both techniques is crucial to ensure maximal assay performance in breast cancer tissue.

Renal impairment in elderly patients with hypertension and diabetes.

We investigated the prevalence of renal impairment in individuals with known hypertension or diabetes aged 50--75 years in two South London General PRACTICES: We initially interrogated the practice and hospital biochemistry databases for each individual's most recent serum creatinine. Individuals with no result recorded in the previous year were then invited for screening: 189/365 (51.8%) attended. Data were collected on 821 of a total potential population of 997. Taking a serum creatinine of 120 mmol/l as the upper limit of normal, the overall prevalence of renal disease in this population was 8.4%: 6.1% in the hypertensives, 12.6% in the diabetics and 16.9% in those with both. Significant proteinuria (> or =2+) was present in 3.9% of the total population: 2.2% of hypertensives, 8.3% of diabetics and 3.9% of those with both. At screening, 44.5% of individuals had inadequately controlled blood pressure. Renal impairment is common in this population at high risk of renal disease. Screening for renal disease in this population is simple, safe and gives a high yield of positive results.

Late referral of end-stage renal failure.

We studied all new patients accepted for renal replacement therapy (RRT) in one unit from 1/1/96 to 31/12/97 (n = 198), to establish time from nephrology referral to RRT, evidence of renal disease prior to referral and the adequacy of renal management prior to referral. Sixty four (32.3%, late referral group) required RRT within 12 weeks of referral. Fifty-nine (29.8%) had recognizable signs of chronic renal failure > 26 weeks prior to referral. Patients starting RRT soon after referral were hospitalized for significantly longer on starting RRT (RRT within 12 weeks of referral, median hospitalization 25.0 days (n = 64); RRT > 12 weeks after referral, median 9.7 days (n = 126), (p < 0.001)). Observed survival at 1 year was 68.3% overall, with 1-year survival of the late referral and early referral groups being 60.5% and 72.5%, respectively (p = NS). Hypertension was found in 159 patients (80.3%): 46 (28.9%) were started on antihypertensive medication following referral, while a further 28 (17.6%) were started on additional antihypertensives. Of the diabetic population (n = 78), only 26 (33.3%) were on an angiotensin-converting-enzyme inhibitor (ACEI) at referral. Many patients are referred late for dialysis despite early signs of renal failure, and the pre-referral management of many of the patients, as evidenced by the treatment of hypertension and use of ACEI in diabetics, is less than optimal.

Fludarabine in lymphoproliferative disorders: the Royal Marsden Hospital experience.

Fludarabine 25 mg/m2 was given on five consecutive days every four weeks to 85 patients with B- and T-cell malignancies. The median number of courses given was five. All patients except one had received previous chemotherapy. The overall response rate in non-Hodgkin's lymphoma (NHL) was 50% (five complete responses (CR) and 19 partial responses (PR)). The response rate in chronic lymphocytic leukemia (CLL) was 43% (four CR and 12 PR). Responses were seen in all groups of B-cell malignancies, but no T-cell malignancies (n = 4) responded. The median duration of CR has not been reached and the median duration of PR was 14 months for NHL and 16 months for CLL. The median survival from starting fludarabine for patients who achieved a CR or PR in NHL has not been reached and the median duration of PR in CLL was 23 months. The median duration of survival in non-responders was five months. Fludarabine was well tolerated and the main toxicity was myelosuppression. Our results suggest that even in patients who have never responded to any chemotherapy, regardless of the number of treatment regimens previously given, there is a 36% chance of response. In addition, this is the first report of fludarabine activity in Franklin's disease.

Continuous infusional combination chemotherapy in inflammatory breast cancer: a phase II study.

Despite the introduction of systemic chemotherapy, inflammatory breast cancer (IBC) remains a disease with a poor prognosis. We performed this phase II study to evaluate the efficacy of infusional chemotherapy as initial treatment in patients with IBC. Fifty-four patients with newly diagnosed IBC were offered infusional chemotherapy and 34 accepted. The schedule consisted of continuous infusional ECF (bolus epirubicin and cisplatin, substituted by carboplatin or cyclophosphamide in some patients) plus continuous 5-FU, given three weekly for six cycles. Following chemotherapy patients went on to have surgery and/or radiotherapy. The chemotherapy was well tolerated and resulted in an overall response rate of 79% with 35% of patients achieving a complete clinical response. The median response duration, time to progression and overall survival were 12 months (4-89+ months), 12 months (4-89+ months) and 23 months (7-89+ months), respectively. Patients had a 5 year disease free and overall survival of 11% and 29%, respectively. Infusional ECF is well tolerated and achieves a high clinical response rate in patients with IBC, but survival results do not appear to be superior to those achieved with conventional bolus chemotherapy schedules.

Processes used by nurses to make decisions in the clinical practice setting.

A qualitative study was conducted to examine the processes nurses used to make decisions in actual practice settings. Nurse participants (n = 17) practicing in acute care settings were observed and interviewed to determine the covert cognitive processes that occurred while they were making decisions. Data were analyzed using a constant comparative method. Two decision-making categories emerged: goal-directed process and rule-out process. The goal-directed process was used to reach a goal. The rule-out process involved the development and elimination of hypotheses until only one remained. This process was used to determine what problems existed, the cause of a problem, or the action needed.

Role of ethics in modern health care: 2.

The first article in this two-part series examined the meaning of ethics, why nurses should bother with it, and what effect it has on the individual conscience-controlled practitioner. This article looks more closely at why nurses need to be aware of the implications of ethics in practice.

Role of ethics in modern healthcare: 1.

What is ethics and where does it leave the individual conscience-controlled practitioner? In this, the first of two articles on ethics in modern healthcare, the former question is examined.

The role of the nurse as the patient's advocate.

Advocacy is part of the nurse's role. Advocacy does not necessarily require confrontation. Nurses should not confuse acting in what they believe to be the patient's best interests with acting as a true patient advocate.