Quaternary and Tertiary Carbon Centers Synthesized via Gallium-Catalyzed Direct Substitution of Unfunctionalized Propargylic Alcohols with Boronic Acids

(IPr)GaCl₃/AgSbF₆, AgSbF₆, and GaCl₃ catalyzed substitution of the hydroxyl of secondary and tertiary propargylic alcohols with organoboronic acids via C-C bond formation, and GaCl₃ effectively synthesized all-carbon quaternary propargylic centers. These catalysts performed the substitution at carbons bearing alkyl substituents, which has been problematic for other systems. Highly hindered carbon stereocenters were thus produced, including quaternary centers bearing doubly ortho-substituted aryl rings, that are difficult to access with traditional methods.

Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

A Multi-faceted Approach to Improving Breast Cancer Outcomes in a Rural Population, and the Potential Impact of Patient Navigation

The mastectomy rate in rural areas of the Northern Plains of the U.S. was 64 percent from 2000 through 2005. We implemented a breast cancer patient navigation (BPN) program in May 2007 to increase breast conservation (BC) rates.

METHODS

We analyzed mastectomy and BC rates among our 1,466 patients with either ductal carcinoma in situ (DCIS) or stage I/II invasive breast cancer treated from 2000 through 2012. We used interrupted time series (ITS) to compare rates in treatment following implementation of BPN. In addition, breast conservation rates were compared to population data from the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

The BC rates were 56 percent for navigated patients versus 37 percent for non-navigated patients (95 percent CI for difference: 14.8 to 25.6 percent). There was a consistent annual increase in treatment with BC versus a mastectomy (+2.9 percent/year, p-trend < 0.001). The BC rate of 60 percent in 2012 now mirrors those observed in the SEER database. The ITS did not find that the change in BC rates over time was significantly attributable to implementation of the BPN. Other secular trends may have contributed to the change in BC rates over time.

CONCLUSIONS

A number of factors may have contributed to an increase of BC rates over time, including physician and patient education, more radiation therapy options, and possibly a dedicated breast cancer PN program. This analysis demonstrates that overall breast cancer care among this rural and medically-underserved population is improving in our region and now parallels other regions of the country.

Abstract PL02-02: Lessons learned from the Walking Forward Program in recruiting American Indians on clinical trials

Purpose/Objective(s): American Indians (AIs) present with more advanced stages of cancer and, therefore, suffer from higher cancer mortality rates compared to non-AIs. Under the National Cancer Institute Cancer Disparities Research Partnership Program (CDRP), we have been researching methods of improving cancer treatment and outcomes since 2002, for AIs in Western South Dakota, through the Walking Forward (WF) Program.

Materials/Methods: This program consists of a) a culturally-tailored patient navigation program that facilitated access to innovative clinical trials in conjunction with a comprehensive educational program encouraging screening and early detection, b) surveys to evaluate barriers to access, c) clinical trials focusing on reducing treatment length as AIs live a median of 140 miles from the cancer center, d) a molecular study (ATM - Ataxia telangectasia mutation) to address whether there is a molecular profile that increases toxicity risks, and e) a recently funded project using mHealth (mobile) technology to address the high smoking rates in this population.

Results: To date, over 3,700 AIs have participated in various WF research studies. Critical outcomes include the establishment of trust within tribal communities, identification of barriers to cancer screening, creation of research infrastructure, higher completion rates and patient satisfaction for patients undergoing cancer treatment, enrollment of patients on phase II trials with excellent clinical outcomes, and the establishment of new research partners. Recent analysis suggests that AI cancer patients with screen detectable cancers are now presenting with earlier stages of disease and higher cure rates. Lessons learned will also be presented.

Conclusions: This NCI funded pilot program has achieved some initial measures of success. A research infrastructure has been created in a community setting to address new research questions and interventions. One critical objective of the CDRP program was to create sustainable, community research programs that has been achieved at our site.

Citation Format: Daniel G. Petereit, Shalini Kanekar, Ashleigh Guadagnolo, Amy Boylan, Kristin Cina, Linda Burhansstipanov. Lessons learned from the Walking Forward Program in recruiting American Indians on clinical trials. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr PL02-02. doi:10.1158/1538-7755.DISP13-PL02-02

Prevalence of ATM Sequence Variants in Northern Plains American Indian Cancer Patients

Purpose: To identify sequence variants of the ataxia telangiectasia mutated (ATM) gene and establish their prevalence rate among American Indian (AI) as compared with non-AI cancer patients.

Materials and Methods: DNA was isolated from blood samples collected from 100 AI and 100 non-AI cancer patients undergoing radiation therapy, and a blinded assessment of the ATM sequence was conducted. Quantitative PCR assessment of copy number for each exon was also performed. The main outcome measure was the prevalence of ATM variants in the two patient populations.

Results: No statistically significant differences for total prevalence of ATM variants among AI and non-AI patients were found. Of the 25 variants identified, 5 variants had a prevalence of >2%, of which 4 occurred at a rate of >5% in one or both groups. The prevalence of these four variants could meaningfully be compared between the two groups. The only statistically significant difference among the groups was the c.4138C > T variant which is predicted not to affect protein function, seen in 8% of AI versus 0% of non-AI patients (P = 0.007). No exonic copy number changes were found in these patients.

Conclusion: This study is the first to determine the prevalence of ATM variants in AIs.

Patient navigation for American Indians undergoing cancer treatment: utilization and impact on care delivery in a regional healthcare center

BACKGROUND

A study was undertaken to assess patient navigation utilization and its impact on treatment interruptions and clinical trial enrollment among American Indian cancer patients.

METHODS

Between February 2004 and September 2009, 332 American Indian cancer patients received patient navigation services throughout cancer treatment. The patient navigation program provided culturally competent navigators to assist patients with navigating cancer therapy, obtaining medications, insurance issues, communicating with medical providers, and travel and lodging logistics. Data on utilization and trial enrollment were prospectively collected. Data for a historical control group of 70 American Indian patients who did not receive patient navigation services were used to compare treatment interruptions among those undergoing patient navigation during curative radiation therapy (subgroup of 123 patients).

RESULTS

The median number of contacts with a navigator was 12 (range, 1-119). The median time spent with the navigator at first contact was 40 minutes (range, 10-250 minutes), and it was 15 minutes for subsequent contacts. Patients treated with radiation therapy with curative intent who underwent patient navigation had fewer days of treatment interruption (mean, 1.7 days; 95% confidence interval [CI], 1.1-2.2 days) than historical controls who did not receive patient navigation services (mean, 4.9 days; 95% CI, 2.9-6.9 days). Of the 332 patients, 72 (22%; 95% CI, 17%-26%) were enrolled on a clinical treatment trial or cancer control protocol.

CONCLUSIONS

Patient navigation was associated with fewer treatment interruptions and relatively high rates of clinical trial enrollment among American Indian cancer patients compared with national reports.

GB virus C/Hepatitis G virus infection is frequent in American children and young adults

The novel flavivirus GB virus C/hepatitis G virus (GBV-C/HGV) has been detected in approximately 2% of blood donors in the United States, and neutralizing antibody to the envelope protein (E2), a marker of previous infection with GBV-C/HGV, is present in approximately 9% of donors. The rate of GBV-C/HGV infection among American children is unknown. To determine whether viral infection might occur during childhood, 160 serum specimens (obtained from blood bank samples) from children and young adults with no history of transfusion were tested. Viral RNA and antibody to E2 were detected in 6.3% and 9.4% of subjects, respectively. Evidence of previous or current infection (viremia and/or antibody to E2) was detected in 13.8% of subjects, indicating that GBV-C/HGV infection appears to be common among American children and young adults, even in the absence of blood transfusion.

Lack of correlation of MRP and gamma-glutamylcysteine synthetase overexpression with doxorubicin resistance due to increased apoptosis in SV40 large T-antigen-transformed human mesothelial cells

PURPOSE

Evidence suggests that viral proteins such as simian virus large T-antigen (SV40 TAg) play a role in the response of cancer cells to chemotherapeutic agents. In this study, we investigated whether SV40 TAg-immortalized human mesothelial cells express drug resistance-related proteins and display resistance to chemotherapy, and whether SV40 TAg transformation affects apoptosis.

METHODS

We determined the mRNA and protein levels of the multidrug resistance-associated protein (MRP), gamma-glutamylcysteine synthetase heavy subunit (gamma-GCSh), and P-glycoprotein (product of the MDR1 gene) by RT-PCR and Western blotting, respectively, in normal human mesothelial (NHM) cell and SV40 TAg-transformed human mesothelial (Met-5A) cells. The effect of increasing concentrations of doxorubicin (DOX) on these cells was investigated using an MTT cytotoxicity assay, and the glutathione (GSH) content was measured spectrophotometrically. DOX accumulation in these cells was measured by treating the cells with [14C]DOX followed by scintillation counting. Cytoplasmic bNA fragmentation due to apoptosis following DOX treatment of the cells was quantitated by ELISA.

RESULTS

We showed that the MRP and gamma-GCSh genes, but not MDR1, are coordinately overexpressed in Met-5A cells compared with NHM cells. Expression of MRP protein as detected by an anti-MRP antibody correlated with increased GSH levels and decreased accumulation of [14C]DOX in Met-5A cells compared with NHM cells. However, Met-5A cells were twofold more sensitive to DOX than NHM cells. In addition, quantitative measurement of apoptosis when cells were treated with 0.05 and 0.5 microM DOX revealed that drug-induced apoptotic cell death was increased about 1.4- and 3.0-fold, respectively, in Met-5A cells compared with NHM cells.

CONCLUSIONS

These results suggest that increased levels of apoptosis might help overcome the DOX resistance effects of MRP/gamma-GCSh overexpression in SV40 TAg-transformed Met-5A cells.

Co-ordinated over-expression of the MRP and gamma-glutamylcysteine synthetase genes, but not MDR1, correlates with doxorubicin resistance in human malignant mesothelioma cell lines

While human malignant mesothelioma is extremely resistant to chemotherapy, its intrinsic resistance mechanisms remain largely unknown. In this study, we used normal human mesothelial cells and 5 human mesothelioma cell lines not previously exposed to chemotherapeutic agents to demonstrate that the mRNA for the multidrug resistance-associated protein (MRP) and gamma-glutamylcysteine synthetase (gamma-GCSh) heavy subunit genes, but not the P-glycoprotein (MDR1) gene, are co-ordinately over-expressed in mesothelioma cell lines. Expression of MRP as detected with an anti-MRP antibody correlated with decreased doxorubicin accumulation and resistance of mesothelioma cells to this drug. Our results strongly suggest roles for MRP and gamma-GCSh in chemoresistance in mesotheliomas.

Infrared emissivity of burn wounds

Emissivities of burn wounds and tissue samples have been measured in the wavelength range 8-14 microns using a non-contact method. Emissivities of wound tissues studied were in the range 0.976-0.992, greater than those of intact skin by 0.01-0.03. This will result in underestimates of the difference in temperature between wounds and normal skin of 0.1-0.2 degrees C.