NF-kappa B-mediated chemoresistance in breast cancer cells

BACKGROUND: Nuclear factor-kappa B (NF-kappa B) is a known survival pathway, and it may explain differential sensitivity to tumor necrosis factor-alpha (TNF-alpha) and chemotherapeutic-induced apoptosis in apoptotically sensitive (APO+) and apoptotically resistant (APO-) Michigan Cancer Foundation-7 breast cancer cells. METHODS: Crystal violet viability and luciferase reporter gene assays were used to determine the inhibitory concentration of viability at 50% (IC(50)) and the inhibitory concentration of activity at 50% (EC(50)) values in APO- and APO+ cells with the selective NF-kappa B inhibitor, BAY 11-7082 (BAY). The apoptotic reporter assay was used to determine the effects of the transfection of the inhibitory kappa B-dominant negative (I kappa B-DN) construct in conjunction with TNF, paclitaxel, or doxorubicin treatments in these cells. RESULTS: The concentrations at which 50% of cell viability is inhibited (IC(50)) and at which 50% of NF-kappa B activity is inhibited (EC(50)) for BAY in APO- and APO+ cells were 95.24 micromol/L and 1.53 micromol/L, respectively, and 7.62 micromol/L and 2.64 micromol/L, respectively. The IC(50) and the EC(50) values were equivalent for the APO+ cells (P =.665), but not for the APO- cells (P =.025). I kappa B-DN--transfection alone, or with TNF, doxorubicin, or paclitaxel treatments resulted in cell death of both APO- and APO+ cells as compared with vector-control; however, greater cytotoxicity was seen in the APO+ cells. Direct comparison of the APO+ cells versus the APO- cells revealed that these differences were significant (P =.05). CONCLUSIONS: Pharmacologic or molecular inhibition of the NF-kappa B pathway blocked cell survival in MCF-7 APO+ cells, while only molecular inhibition induced cytotoxicity in the APO- cells. Selective manipulation of the NF-kappa B pathway in combination with standard chemotherapeutic agents may lead to an increased potency and efficacy of these agents.     

Expression of cyclin D1 and retinoblastoma protein in Paget’s disease of the vulva and breast: an immunohistochemical study of 108 cases

Aims: Loss of retinoblastoma protein expression and overexpression of cyclin D1 have been implicated in the development and progression of some cancers. Paget’s disease of the vulva (PDV) and Paget’s disease of the breast (PDB) are uncommon conditions and the pathogenesis of these diseases is still unclear. The aim was to examine the expression of the retinoblastoma and cyclin D1 proteins in PDV and PDB and to correlate any differences between PDV and PDB, and in the presence or absence of an underlying carcinoma. Methods and results: Seventy‐two archival cases of PDV including 10 with invasive disease and 36 cases of PDB were evaluated immunohistochemically for the expression of cyclin D1 and retinoblastoma protein. Forty‐four percent (32/72) of cases of PDV showed loss of expression of the retinoblastoma protein, compared with 67% (24/36) of PDB cases. Fifty‐nine percent (41/69) of PDV overexpressed cyclin D1. In PDB, 8% (3/34) overexpressed cyclin D1. There were no significant differences in the expression of retinoblastoma and cyclin D1 in PDV cases with or without underlying invasive disease. There were significant differences between the expression of retinoblastoma (P = 0.03) and cyclin D1 (P < 0.001) in PDV compared with PDB. Conclusions: The differences in the expression of cyclin D1 and retinoblastoma may indicate the differences in the pathogenesis of PDV and PDB.     

Fit for practice: Project 2000 student nurses' views on how well the curriculum prepares them for clinical practice

This paper presents the findings from a small study, which compared student nurses' views on how well they felt the Project 2000 curriculum had prepared them for their first clinical placements. The views of two student nurse cohorts were obtained using a questionnaire developed for the purpose. The curriculum for the 'old' cohort allowed very little clinical time during the first 18 months and focused on academic classroom-based learning. The curriculum was subsequently restructured so that students on the 'new' curriculum experienced greater emphasis on practice and theory to practice links, and undertook their first clinical placement much earlier on in their course. Although statistical analysis of difference between the two cohorts suggests that students from the 'new' cohort felt they were better prepared, the actual differences in scores was small. The findings of this study provide only modest evidence of improvement in 'new' student nurses' views of how well they felt they had been prepared for their first placement.     

Effects of positive and negative pressure ventilation on cerebral blood volume of newborn infants

The effects of intermittent positive airway and continuous negative extrathoracic pressure ventilation on cerebral blood volume in preterm infants were studied using near infrared spectroscopy. In 12 infants continuous negative extrathoracic pressure caused a median decrease in cerebral blood volume of 0.14ml/100ml brain (95% confidence intervals (CI) 0.035–0.280) compared with no respiratory support. Oxygenated and deoxygenated haemoglobin also decreased, implying increased venous drainage as the main effect. In 17 infants intermittent positive pressure ventilation also caused a median reduction in cerebral blood volume of 0.06 ml/100 ml brain (95% CI 0.010–0.115) compared with endotracheal positive airway pressure. Deoxygenated haemoglobin increased by 0.07 ml/100 ml brain (95% CI 0.010–0.100) while oxygenated haemoglobin decreased by O.lOml/lOOml brain (95% CI 0.005–0.175). The increase in deoxygenated haemoglobin implies decreased venous drainage and the decrease in oxygenated haemoglobin implies that other factors may also be significant. Heart rate, blood pressure and oxygen saturation were monitored continuously and remained stable.     

A comparison between electrical impedance and strain gauge plethysmography for the study of cerebral blood flow in the newborn

This study investigates the possibility of using pulsatile transcephalic impedance changes, delta Z, for the continuous monitoring of cerebral blood flow, CBF, in the sick newborn infant. The performance of the impedance method is compared with the measurement of cranial flow, Fc, using a strain gauge for detecting the predicted changes in cerebral blood flow when the baby breathes 2% CO2 in air, or O2. In all five studies in which measurements were compared in air and CO2 the expected increases in Fc and delta Z were seen. In six of seven studies comparing measurements in air and O2 the expected fall in the variables was seen, indicating reduced cerebral blood flow. The problems of both these methods are discussed and we conclude that the impedance method is as good as the strain gauge method for detecting changes in cerebral blood flow.     

Effect of exogenous surfactant on total respiratory system compliance

We measured total respiratory system compliance (Crs) before and after instilling 25 mg artificial surfactant in 1 ml saline down the endotracheal tube of preterm babies requiring resuscitation at birth, and compared results with data from 6 similar babies receiving saline only. Surfactant did not produce a significant improvement in Crs.     

Which common clinical conditions should medical students be able to manage by graduation? A perspective from Australian interns

The objectives of the study were to report the development of a core curriculum that details the clinical conditions medical students should be able to manage upon graduation; and to canvass the opinion of interns (first-year postgraduate doctors) regarding their perceptions of the level of skill required to manage each condition. Literature relating to core curriculum development and training of junior medical officers was reviewed and stakeholders in the education and training of medical students and junior doctors in the state of New South Wales, Australia (intern supervisors, academics, registrars, nurses and interns) were consulted. The final curriculum spanned 106 conditions, 77 'differentiated' and 29 'undifferentiated'. Four levels of skill at which conditions should potentially be managed were also identified: 'Theoretical knowledge only'; 'Recognize symptoms and signs without supervision'; Initiate preliminary investigations, management and/or treatment without supervision'; and 'Total investigation, management and/or treatment without supervision'. The list of conditions in the curriculum was converted to a survey format and a one-in-two random sample of interns (n = 193) practising in New South Wales who graduated from the state's three medical schools were surveyed regarding the level of skill required for managing each clinical condition at graduation. A total of 51.3% of interns responded to the survey. Interns felt they should be able to initiate preliminary investigation, management and/or treatment for most conditions in the curriculum, with more than half acknowledging this level of management for 53 of the differentiated and 28 of the undifferentiated conditions. It is concluded that developing core curricula in medical education can involve multiple stakeholders, including junior doctors as the consumers of educational experiences. The data gathered may be useful to medical schools revising their curricula.     

Innovative designs in behavioural trials

Clinical trials that compare pharmacological and behavioural treatments require extra attention to design on the part of the investigators. Many of the standard control mechanisms for comparison of active drug to placebo and behavioural therapy to control therapy create problems when the two types of interventions are combined. The most important of these problems is the introduction of non-specific effects introduced by behavioural therapists and physicians that can bias the study. Solutions to these problems require procedures that are common to both types of studies and the introduction of more complex statistical designs to adequately control the proposed comparisons. It may also be necessary to have a robust statistical method to address informative censoring since patients assigned to behavioural therapy may drop out of the study for different reasons than patients who drop out of a pharmacological trial. In this paper we use the design of the Raynaud's Treatment Study to demonstrate methods that can be used to control for non-specific effects and differential drop-out from the study.