Quality control of multidrug resistance assays in adult acute leukemia: correlation between assays for P-glycoprotein expression and activity

We have compared multiple assays for the P-glycoprotein (Pgp/MDR1) phenotype in fresh and thawed adult acute leukemia to validate and quantitate measures for the expression and function of Pgp. The results are related to the Pgp-expressing KB8 and KB8-5 call lines. The most sensitive assay was the measurement of modulation of the rhodamine 123 (R123) fluorescence by 2 micromol/L PSC833, followed by the modulation of the probe calcein-AM. We also found a good intralaboratory and interlaboratory correlation between the values of the R123/PSC833 assay for fresh as well as thawed samples. In addition, the affects of PSC833 on 3H-daunorubicin (DNR) accumulation, DNR fluorescence, and 3H- vincristine accumulation were very similar. The correlation between the DNR/PSC833 and R123/PSC833 test was r = .86 (N = 51). The modulation of drug accumulation by 8 micromol/L verapamil was the some as the PSC833 effect for DNR (117%, N = 21), but was higher for vincristine in every single case (161% v 121%, N = 22; P< .001), indicating additional verapamil effects, not related to Pgp. The correlation of the staining of viable cells for Pgp with the monoclonal antibody MRK16 was r = .77 (N = 52) for the R123/PSC833 functional test and r = .84 (N = 50) for the DNR/PSC833 test. From these results it could be calculated that a maximal increase of the mean DNR accumulation of about 50% can be achieved by blocking Pgp pump activity with PSC833 in leukemic blast samples with the highest mean Pgp expression. Subpopulations of blast calls with higher Pgp activity are likely to be present. Their relevance has to be studied further. The methods outlined here allow the reliable, quantitative monitoring of the Pgp/MDR1 phenotype in leukemias in multicentered, clinical Pgp modulation studies.     

Measurement of Cancer Health Literacy and Identification of Patients with Limited Cancer Health Literacy

Health literacy is related to a broad range of health outcomes. This study was designed to develop a psychometrically sound instrument designed to measure cancer health literacy along a continuum (CHLT-30), to develop another instrument designed to determine whether a patient has limited cancer health literacy (CHLT-6), and to estimate the prevalence of limited cancer health literacy. The Cancer Health Literacy Study involving 1,306 Black and White cancer patients was conducted between April 2011 and April 2013 in the Virginia Commonwealth University Massey Cancer Center and surrounding oncology clinics. A continuous latent variable modeling framework was adopted to dimensionally represent cancer health literacy, whereas discrete latent variable modeling was used to estimate the prevalence rates of limited cancer health literacy. Self confidence about engaging in health decisions was used as the primary outcome in external validation of new instruments. Results from a comprehensive analysis strongly supported the construct validity and reliability of the CHLT-30 and CHLT-6. For both instruments, measurement invariance tests ruled out item/test bias to explain gender and race/ethnicity differences in test scores. The limited cancer health literacy rate was 18%, a subpopulation consisting of overrepresented Black, undereducated, and low-income cancer patients. Overall, the results supported the conclusion that the CHLT-30 accurately measures cancer health literacy along a continuum and that the CHLT-6 efficiently identifies patients with limited cancer health literacy with high accuracy.     

Surgical management of epilepsy due to cerebral cavernomas using neuronavigation and intraoperative MR imaging

OBJECTIVES： Cure from seizures due to cavernomas might be surgically achieved dependent on both, the complete removal of the cavernoma as well as its surrounding hemosiderin rim. High field intraoperative MRI imaging （iopMRI） and neuronavigation might play a crucial role to achieve both goals. We retrospectively investigated the long-term results and impact of intraoperative 1.5T MRI （iopMRI） and neuronavigation on the completeness of surgical removal of a cavernous malformation （CM） and its perilesional hemosiderin rim as well as reduction of surgical morbidity.     

Muscle intrusion as a potential cause of carpal tunnel syndrome

Introduction: The aim of this study was to determine whether there is an association between flexor digitorum and lumbrical muscle intrusion into the carpal tunnel and carpal tunnel syndrome (CTS). Methods: Five hundred thirteen manual laborers (1026 wrists) were evaluated with ultrasound to determine whether those with CTS had more muscle intrusion into the carpal tunnel than those without CTS. One hundred ninety of the participants without CTS at baseline (363 wrists) were followed over 1 year to determine whether muscle intrusion at baseline predicted the development of CTS. Results: Participants with CTS had more muscle within the carpal tunnel with the wrist in the neutral (P = 0.026) and flexed (P = 0.018) positions than those without CTS. Baseline muscle intrusion did not predict development of CTS at 1 year. Conclusions: Muscle intrusion into the carpal tunnel is associated with CTS, but muscle intrusion alone does not predict the development of CTS over the course of a year. Muscle Nerve 50: 517–522, 2014     

LGBT people's knowledge of and preparedness to discuss end‐of‐life care planning options

Despite the devastating impact of HIV/AIDS, end‐of‐life care planning among lesbian, gay, bisexual and transgender (LGBT) communities is relatively under‐researched, especially in Australia. This paper reports findings of a survey of 305 LGBT people living in New South Wales, which examined their knowledge of and attitudes towards end‐of‐life care. The focus of this paper is their preparedness to discuss with healthcare providers any end‐of‐life care plans. The results highlight that while the majority of respondents were aware of three of the four key end‐of‐life care planning options available in New South Wales – enduring powers of attorney, enduring guardians and person responsible (only a minority had heard of advance healthcare directives) – a much smaller number of people had actually taken up these options. Only a minority of respondents were able to identify correctly who had the legal right to make treatment decisions for a person who is unconscious following a car accident. A small proportion of people had discussed end‐of‐life care options with general practitioners or another main healthcare provider, and only in very few cases were these issues raised by the practitioners themselves. Those most likely to not feel comfortable discussing these issues with practitioners included younger people, those not fully open about their sexuality to family members, and transgender people and others who do not define their gender as male or female. The paper highlights the importance of education strategies to raise awareness of the end‐of‐life care planning options among LGBT people, as well as strategies for increasing health providers' preparedness to discuss these issues with LGBT patients.