Copper trafficking: the solution structure of Bacillus subtilis CopZ

A sequence with a high homology (39% residue identity) with that of the copper-transport CopZ protein from Enterococcus hirae and with the same MXCXXC metal-binding motif has been identified in the genome of Bacillus subtilis, and the corresponding protein has been expressed. The protein, constituted by 73 amino acids, does bind copper(I) under reducing conditions and fully folded in both copper-bound and copper-free forms under the present experimental conditions. The solution structure of the copper-bound form was determined through NMR spectroscopy on an 15N-labeled sample. A total of 1508 meaningful nuclear Overhauser effects, 38 dihedral phi angles, and 48 dihedral psi angles were used in the structural calculations, which lead to a family of 30 conformers with an average rmsd to the mean structure of 0.32 +/- 0.06 A for the backbone and of 0.85 +/- 0.07 A for the heavy atoms. NMR data on the apoprotein also show that, also in this form, the protein is in a folded state and essentially maintains the complete secondary structure. Some disorder is observed in the loop devoted to copper binding. These results are compared with those reported for CopZ from E. hirae whose structure is well-defined only in the apo form. The different behaviors of copper-loaded E. hirae and B. subtilis are tentatively accounted for on the basis of the presence of dithiothreitol used in the latter case, which would stabilize the monomeric form. The comparison is extended to other similar proteins, with particular attention to the copper-binding loop. The nature and the location of conserved residues around the metal-binding site are discussed with respect to their relevance for the metal-binding process. Proposals for the role of CopZ are also presented.

Cancer pharmacogenomics, adoption by oncologists and patient benefit

Aim: The study aim was to understand physician experience and factors influencing the adoption of cancer pharmacogenomic (caPGx) testing by oncologists practicing in academic and nonacademic settings. Method: Anonymous paper surveys were distributed to oncologists practicing in North Carolina (USA). Results: Although 98% of oncologists see promise in utilizing PGx tests in their practice, few were comfortable with their knowledge (33%) or interpreting test results (37%). At one site, the survey was not distributed due to clinician unfamiliarity with the term ‘pharmacogenomics’. Compared with oncologists in academia, community oncologists were more likely to order the new Oncotype Dx™ test for colon cancer (33% vs 0; p = 0.0071), more likely to indicate future use of caPGx tests (94 vs 75%; p = 0.012) and less likely to have never ordered a caPGx test (2 vs 35%%; p < 0.001). Nearly every oncologist was interested in additional PGx education. Conclusion: A critical need exists to disseminate accurate and updated caPGx information to oncologists practicing in both academic and nonacademic settings.

Knowledge based lipid management system for general practitioners

The aim of this system is to provide computer generated interpretative reports with management advice for General Practitioners (GPs). The lipid domain was chosen because of its importance in preventive medicine. Request forms to elicit extra clinical information were designed and distributed to a group of randomly selected GPs. Interpretation of laboratory and clinical data categorizes patients according to risk of coronary heart disease. The management system is rule based and provides advice on lifestyle modifications, diet and drug intervention. Previous clinical and laboratory results are taken into account in determining a management strategy. To date 435 request forms have been processed: 309 (71%) from first visits and 126 (29%) from follow-up visits. Normal lipid profiles were found in 19% of cases. There was 93% agreement between management advice given by the system and the expert. The system has now been modified and further evaluation is under way.

Prospective evaluation of perceived barriers to medication adherence by patients on oral antineoplastics

6042

Background: Appropriate use of oral antineoplastics (OA), especially those with a food-effect, is a challenge for patients and clinicians. Patient adherence is essential to optimize outcomes, minimize toxicity, minimize bias in clinical trials, and reduce health care costs. As the use of OA grows, due to the narrow therapeutic margin, it is critical to understand the barriers to patient adherence. The purpose of this study was to analyze cancer patients’ use of OAs and identify opportunities to improve patient adherence. Methods: We developed and tested a 30-question survey to address frequency and reasons for reducing/skipping doses; sources of information for OA use; perceived importance of food-drug effects, and ease of understanding directions on vial label. Surveys, consisting of Likert scale and multiple choice questions, were distributed to adult cancer patients on OAs at the UNC Cancer Hospital clinics. Results: Seventy-seven patients taking OAs with CML, RCC, breast cancer, and GI tumors completed the survey with a response rate of 97%. This was a well-educated population with 71% having completed some college; 54% female and 58% older than 50 years. Forty-three percent of patients taking drugs with a significant food-drug effect (sorafenib, pazopanib, lapatinib, imatinib, nilotinib, and capecitabine) did not think about the last time they ate before taking their OA and 23% did not know that their OA had a food-drug effect. In addition, 21% of patients indicated they intentionally skipped/cut back on their OAs and 38% of those did not inform their physician. Although 97% reported no difficulty reading instructions on drug vial, nearly 20% had some difficulty understanding the directions. Conclusions: There are three main barriers associated with appropriate use of OAs: confusion or misunderstanding about the timing of drug with food; reducing/stopping drug without informing MD; and difficulty understanding directions on the drug vial label. A multipronged integrated approach involving the pharmacist, physician and nurse is needed to optimize communication of directions for optimal OA use.

Influence of anthracycline- and taxane-based neoadjuvant chemotherapy on tumor HER2 protein expression in locally advanced breast cancers: results from the I-SPY TRIAL (CALGB 150007/150012 & ACRIN 6657)

Abstract #703

Background: The I-SPY trial is a multi-institutional study of locally advanced breast cancers in which serial biopsies of breast tumors are performed at multiple timepoints, allowing comparison of tumor biomarker status before, during, and after therapy. Tumor HER2 status has an important role in predicting response to chemotherapy and targeted therapy in breast cancer. The aim of this study was to determine if the administration of neoadjuvant chemotherapy was associated with changes in tumor HER2 protein expression.&#x2028; Methods: Eligible patients had biopsy-confirmed primary breast cancer measuring at least 3 cm. Required initial treatment was an anthracycline based neoadjuvant chemotherapy regimen: AC followed by T (91%), AC without T (6%), and chemotherapy beyond AC +/- T 2%. Serial core biopsies were performed at baseline (T1), after one cycle of AC (T2), intra-regimen (T3), and pre-surgery (T4). Immunohistochemistry (IHC) for HER2 was performed centrally on core samples at T1 and T2 and on post-surgery (PS) excision/mastectomy specimens (for patients with residual tumor). HER2 results were classified as negative, indeterminate, or overexpressed using conventional scoring criteria. Tumor HER2 status was compared between timepoints T1 and T2, T2 and PS, and T1 and PS. Patients receiving Herceptin therapy were excluded from this analysis. Additional molecular analysis is being performed and the IHC results will be compared with gene expression and phospho-HER2 results.&#x2028; Results: 221 patients were enrolled and completed therapy. The median age was 49 years, with a range of 27-69. Median tumor size was 6 cm; 58% had clinically positive nodes. HER2 results were obtained centrally at baseline on 178 (80%) patients. 41 of 178 (23%) tumors were positive for HER2 overexpression. The overall pCR rate in HER2 positive patients was 52% compared to 19% for HER2 negative patients (p&lt;0.001). Patient HER2 results were compared at T1 and T2 (n=154), T2 and PS (n=81), and T1 and PS (n=89). Nine of the 32 (28%) HER2 positive patients with multiple timepoint HER2 results were excluded due to receiving Herceptin therapy. The tumor HER2 status between timepoints is summarized in the table below.&#x2028; &#x2028; Conclusions: Tumor HER2 protein expression levels appear stable in patients undergoing neoadjuvant chemotherapy with anthracycline- and taxane-based regimens. Rare tumors (2-3%) showed a change from a HER2 positive result to a HER2 negative result during chemotherapy; these findings may be related to tumor heterogeneity rather than a true treatment-induced change in HER2 status.&#x2028; Support: CALGB CA31964 and CA33601, ACRIN U01 CA079778 and CA080098, NCI SPORE CA58207.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 703.

Latex allergy: implications for healthcare personnel and infusion therapy patients

The health care arena has been dramatically impacted by the implementation of universal precautions and OSHA standards, mandating the use of disposable gloves. These directives promote the judicious use of gloves as a barrier against contact with blood and body fluids. An increasing number of hypersensitivity reactions to latex are being reported by the medical community. The FDA cites that 6%-7% of surgical personnel are latex sensitive as well as 18%-40% of spina bifida patients. Sensitivity reactions range from mild delayed symptomatology in the form of eczematous contact dermatitis, to severe systemic reactions including death. Besides gloves, latex is found in catheters, i.v. tubing, injection caps and anesthesia masks. Latex sensitivity creates yet another infusion therapy challenge for the i.v. clinician.