Functional variants at the 11q13 risk locus for breast cancer regulate cyclin D1 expression through long-range enhancers

Analysis of 4,405 variants in 89,050 European subjects from 41 case-control studies identified three independent association signals for estrogen-receptor-positive tumors at 11q13. The strongest signal maps to a transcriptional enhancer element in which the G allele of the best candidate causative variant rs554219 increases risk of breast cancer, reduces both binding of ELK4 transcription factor and luciferase activity in reporter assays, and may be associated with low cyclin D1 protein levels in tumors. Another candidate variant, rs78540526, lies in the same enhancer element. Risk association signal 2, rs75915166, creates a GATA3 binding site within a silencer element. Chromatin conformation studies demonstrate that these enhancer and silencer elements interact with each other and with their likely target gene, CCND1.

Biocompatibility of an electrochemical sensor for continuous glucose monitoring in subcutaneous tissue

BACKGROUND

The continuous monitoring of glucose allows for tighter control of the glucose concentration and thus may prevent hyper- and hypoglycemia as well as long-term complications of diabetes. While most current systems depend on the transport of fluid to a glucose sensor outside the body, we investigate the possibility of implanting a reagent-based sensor directly into the skin. In this manuscript, the biocompatibility of an electrochemical sensor for continuous glucose monitoring was assessed in vitro and in vivo.

METHODS

Cytotoxicity was investigated in vitro using agar diffusion testing. In vivo biocompatibility was assessed by means of histomorphological examination of the surrounding tissue 10 days after sensor implantation in rats.

RESULTS

The grade of cytotoxicity of the individual sensor components in vitro was between none and mild based on agar diffusion testing. The complete sensor also showed no cytotoxic effects when coated with the co-polymer MPC (2-methacryloyloxyethyl phosphorylcholine, Lipidure CM 5206, NOF Corp., Tokyo, Japan) and when assessed under working conditions, i.e., when a bias voltage was applied to the sensor. Additionally, the hydrogen peroxide-which is inherently generated by the enzymatic glucose detection process using glucose oxidase (GOD)-is likely to have been sufficiently decomposed under these working conditions. Finally, no toxic leachable substances were found during the cytotoxicity testing of sensors and its extracts in vitro. In the in vivo experiments, the strongest foreign body reaction (FBR) was found near the GOD-electrode using a sensor without MPC coating and without a porous membrane. Covering the sensor with MPC, a porous membrane, or both led to a gradual decrease of the FBR down to the level of the negative control.

CONCLUSIONS

The electrochemical, reagent-based sensor with MPC coating and/or a porous membrane is suitable for continuous monitoring of glucose from a biocompatibility standpoint.

Adherence over 48 Weeks in An Antiretroviral Clinical Trial: Variable within Patients, Affected by Toxicities and Independently Predictive of Virological Response

Objectives

To investigate adherence to antiretroviral therapy over 48 weeks, to investigate the association between adherence and treatment-related symptoms and to investigate the impact of adherence on virological response over 48 weeks among established predictors of treatment success.

Methods

One-hundred-and-sixty HIV-1 infected protease inhibitor- and stavudine-naive patients participating in a trial of ritonavir/saquinavir versus ritonavir/saquinavir/ stavudine completed an adherence questionnaire and a symptom checklist at weeks 12, 24, 36 and 48. We calculated odds ratios between experienced symptoms and non-adherence. Regression models were used to determine predictors of HIV-1 RNA below 400 copies/ml at week 48, and of the area about the change from baseline over 48 weeks (ACFB) in serum HIV-1 RNA.

Results

The percentage of patients reporting missing medication, deviation from time schedule, and dietary prescriptions at separate time-points ranged from 12 to 15%, 32 to 35% and 17 to 22%, respectively. The percentage that changed their level of adherence during 48 weeks ranged from 29% for skipping medication to 48% for deviation from time-schedule. Experienced side-effects were associated with an increased likelihood of non-adherence. Not skipping medication was an independent predictor of both having a serum HIV-1 RNA below 400 copies/ml at week 48 and the ACFB over 48 weeks in serum HIV-1 RNA.

Conclusions

Adherence was an independent predictor of virological response over 48 weeks. The level of adherence is variable within patients over time. This suggests the need for continued adherence monitoring in all patients as part of standard medical practice.

A novel method for continuous online glucose monitoring in humans: the comparative microdialysis technique

The aim of this study was to prove the feasibility of continuous subcutaneous glucose monitoring in humans using the comparative microdialysis technique (CMT). The performance of the CMT was determined by comparing tissue glucose values with venous or capillary blood glucose values in healthy volunteers and type 1 diabetic subjects. The CMT is a microdialysis-based system for continuous online glucose monitoring in humans. This technique does not require calibration by the patient. Physiological saline with glucose (5.5 mM) is pumped in a stop-flow mode through a microdialysis probe inserted into the abdominal s.c. tissue. Tissue glucose concentration is calculated by comparing the dialysate and perfusate glucose concentrations. The time delay due to the measurement process is 9 min. We tested the CMT on six healthy volunteers and six type 1 diabetic patients for 24 h in our clinical setting. Comparisons were made to HemoCue analyzer (Angelholm, Sweden) capillary blood glucose measurements (healthy volunteers) and to venous blood glucose concentration determined with a Hitachi analyzer (diabetic patients). The mean absolute relative error of the CMT glucose values from the blood glucose values was 17.8+/-15.5% (n = 167) for the healthy volunteers and 11.0+/-10.8% (n = 425) for the diabetic patients. The mean difference was 0.42+/-1.06 mM (healthy volunteers) and -0.17+/-1.22 mM (diabetic patients). Error grid analysis for the values obtained in diabetic patients demonstrated that 99% of CMT glucose values were within clinically acceptable regions (regions A and B of the Clarke Error Grid). The study results show that the CMT is an accurate technique for continuous online glucose monitoring.

Motor performance of children during treatment for acute lymphoblastic leukemia

BACKGROUND

Daily life motor skills of children with acute lymphoblastic leukemia (ALL) were studied during treatment using the Movement Assessment Battery for Children (Movement ABC). In addition, the possible relation with vincristine treatment was investigated.

PROCEDURE

Seventeen children treated for ALL, aged 4-12 years, were compared to an age- and sex-matched control group.

RESULTS

The leukemia group performed more poorly than the control group on both fine and gross motor skills. In looking at the number of children with ALL who scored in the clinical range of the different subtests, problems in balance skills were found to be most pronounced at the end of induction therapy. Remarkably, half a year after reinduction therapy, problems with balance had decreased, whereas the number of children with fine motor problems had increased.

CONCLUSIONS

A relation between the gross motor problems and vincristine neurotoxicity seems plausible based on a descriptive analysis of the data, but this was not supported statistically.

The lipoxygenase sensor, a new approach in essential fatty acid determination in foods

Both an enzyme electrode and enzyme column with immobilized lipoxygenase, respectively, were used for the determination of essential fatty acids. The former was applied in a batch system, the latter was part of a fully automated flow injection analysis (FIA)-system. The oxygen consumption due to the lipoxygenase catalysed oxygenation of essential fatty acids was monitored amperometrically. Both systems were compared with regard to linear ranges of the calibration plots, sensitivities, detection limits, apparent Michaelis-Menten constants and lifetimes. The enzyme electrode showed different sensitivities for linoleic and alpha-linolenic acids, the most common essential fatty acids. The reason for this was not a second oxygenation step by lipoxygenase in case of alpha-linolenic acid, but a different dialytic behaviour of the two substrates. Hence, only the FIA-system was used for the determination of these fatty acids in real matrices such as vegetable oils and margarines. In the presence of detergent the triglycerides of the hydrophobic food samples were converted into water soluble glycerol and free fatty acids by a 15 min incubation with a ready to use lipase/esterase-mix, thus avoiding the use of organic solvents for analysis. Results obtained by the enzymatic FIA-system were in excellent agreement with those obtained by standard gas chromatography.