Lack of a role for MRP1 in platinum drug resistance in human ovarian cancer cell lines.

The level of expression of the multidrug resistance-associated protein (MRP1) in a panel of human ovarian carcinoma cell lines and their variants with acquired cisplatin resistance was determined using Western blotting. No overexpression of MRP1 was detected in any of the cell lines. In addition, we have transfected the MRP1 gene into an intrinsically cisplatin-resistant cell line SKOV3, previously shown to have elevated levels of glutathione (GSH). The MRP1-transfected line SKOV3-S2 was shown to be cross-resistant to doxorubicin, vincristine and etoposide but not to paclitaxel, vinblastine and platinum agents, such as cisplatin, JM216 [bis-acetato-ammine-dichloro-cyclohexylamine platinum (IV)] and AMD473 [cis-ammine dichloro (2-methyl-pyridine) platinum (II)]. No cross-resistance to any of the platinum agents was observed in a MRP1-overexpressing human lung cancer cell line with acquired doxorubicin resistance. Reduction of GSH levels (80-90%) by buthionine sulphoximine (BSO) produced significant potentiation in cisplatin sensitivity in the parental SKOV3, the vector-alone control SKOV3-puro and the MRP1-transfected line SKOV3-S2. The degree of sensitization was similar in all cell lines (1.6-fold). However, selective sensitization by BSO to vincristine was observed in the MRP1-transfected line (4.1-fold) but not in the vector control. No significant differences were observed in cisplatin accumulation in the SKOV3-puro and the SKOV3-S2 cells, although both these transfected lines accumulated significantly more than the parental line. Our results suggest that MRP1 does not play a significant role in platinum resistance in the human tumour cell lines investigated in this study.     

Impact of Institution of a Stroke Program Upon Referral Bias at a Rural Academic Medical Center

ABSTRACT: Context: Referral bias reflecting the preferential hospital transfer of patients with intracerebral hemorrhage (ICH) has been demonstrated as the major contributing factor for an observed high nonrisk-adjusted in-hospital crude acute stroke mortality rate at a rural academic medical center. Purpose: This study was done to assess the impact of a clinical acute stroke program upon referral bias in August 2000. Methods: A chart review of acute stroke (DRG 14) discharges during 2001 from a rural academic medical center was compared with the same data from 1999. Results: The odds ratio of ICH in hospital-transfer patients compared with nonhospital-transfer patients decreased from 11.7 in 1999 to 3.2 in 2001 (P<.035). Conclusions: This study demonstrated the rapid magnitude and significance that clinical programs can have upon referral bias. Changes in referral bias may be more rapid at rural academic medical centers because of the relative lack of health care delivery competition.     

Exploring the decision-making preferences of people with colorectal cancer

OBJECTIVES: To explore patient views on participation in treatment, physical care and psychological care decisions and factors that facilitate and hinder patients from making decisions. DESIGN: Qualitative study using semi-structured interviews with patients. SETTING AND PARTICIPANTS: Three NHS Trusts in the north-west of England. Theoretical sampling including 41 patients who had been treated for colorectal cancer. RESULTS: For patients, participation in the decision-making process was about being informed and feeling involved in the consultation process, whether patients actually made decisions or not. The perceived availability of treatment choices (surgery, radiotherapy, chemotherapy) was related to type of treatment. Factors that impacted on whether patients wanted to make decisions included a lack of information, a lack of medical knowledge and trust in medical expertise. Patients perceived that they could have a more participatory role in decisions related to physical and psychological care. CONCLUSION: This study has implications for health professionals aiming to implement policy guidelines that promote patient participation and shared partnerships. Patients in this study wanted to be well informed and involved in the consultation process but did not necessarily want to use the information they received to make decisions. The presentation of choices and preferences for participation may be context specific and it cannot be assumed that patients who do not want to make decisions about one aspect of their care and treatment do not want to make decisions about other aspects of their care and treatment.     

Chronic inhalation exposure to mainstream cigarette smoke increases lung and nasal tumor incidence in rats.

An animal model of lung carcinogenicity induced by chronic inhalation of mainstream cigarette smoke would be useful for research on carcinogenic mechanisms, smoke composition-response relationships, co-carcinogenicity, and chemoprevention. A study was conducted to determine if chronic whole-body exposures of rats would significantly increase lung tumor incidence. Male and female F344 rats (n = 81 to 178/gender) were exposed whole-body 6 h/day, 5 days/week for up to 30 months to smoke from 1R3 research cigarettes diluted to 100 (LS) or 250 (HS) mg total particulate matter/m(3), or sham-exposed to clean air (C). Gross respiratory tract lesions and standard lung and nasal sections were evaluated by light microscopy. A slight reduction of survival suggested that the HS level was at the maximum tolerated dose as commonly defined. Cigarette smoke exposure significantly increased the incidences of non-neoplastic and neoplastic proliferative lung lesions in females, while nonsignificant increases were observed in males. The combined incidence of bronchioloalveolar adenomas and carcinomas in females were: HS = 14%; LS = 6%; and C = 0%. These incidences represented minima because only standard lung sections and gross lesions were evaluated. Mutations in codon 12 of the K-ras gene occurred in 4 of 23 (17%) tumors. Three mutations were G to A transitions and one was a G to T transversion. The incidence of neoplasia of the nasal cavity was significantly increased at the HS, but not the LS level in both males and females (HS = 6%, LS = 0.3%, C = 0.4% for combined genders). These results demonstrate that chronic whole-body exposure of rats to cigarette smoke can induce lung cancer.     

A cross-sectional study of quality of life in an elderly population (75 years and over) with atrial fibrillation: secondary analysis of data from the Birmingham Atrial Fibrillation Treatment of the Aged study

AIMS: To compare the quality of life (QoL) of those in atrial fibrillation (AF) aged 75 years and over with that of the general population, to explore what factors affect the QoL of those with AF, and to assess the sensitivity of the EuroQol (EQ-5D) and Short-Form 12 (SF-12) generic health questionnaires in detecting differences in health status in those with AF in this age group. METHODS AND RESULTS: The study population was 1762 men and women aged 75 years and over with confirmed AF who attended a randomization clinic for the Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study, a primary care based trial of stroke prevention. Patients self-completed the EQ-5D and SF-12 questionnaires, and a simple measure of disability (Rankin). Cardiovascular co-morbidities were collected and number of drugs used as an additional proxy for co-morbidity. Quality-of-life outcomes were compared with general population samples of the same age. On multiple regression, female gender, greater medication use, and disability were independently associated with lower QoL scores in AF. Those in AF with a Rankin score ≥2 had lower QoL scores, while those with a Rankin score <2 had higher scores than the general population. Increasing co-morbidity was associated with reduced QoL scores, with the EQ-5D and SF-12 Physical Component Score showing similar sensitivity to these associations, and the SF-12 Mental Component Score showing less sensitivity. CONCLUSION: In the absence of co-morbidity, chronic AF has little impact on generic QoL in an elderly non-acutely ill population.