Citations

Background— The Epidemiology of Diabetes Interventions and Complications (EDIC) study, a prospective observational follow-up of the Diabetes Control and Complications Trial (DCCT) cohort, reported persistent benefit of prior intensive therapy on retinopathy and nephropathy in type 1 diabetes mellitus. We evaluated the effects of prior intensive insulin therapy on the prevalence and incidence of cardiac autonomic neuropathy (CAN) in former DCCT intensive and conventional therapy subjects 13 to 14 years after DCCT closeout. Methods and Results— DCCT autonomic measures (R-R variation with paced breathing, Valsalva ratio, postural blood pressure changes, and autonomic symptoms) were repeated in 1226 EDIC subjects in EDIC year 13/14. Logistic regression models were used to calculate the odds of incident CAN by DCCT treatment group after adjustment for DCCT baseline covariates, duration in the DCCT, and quantitative autonomic measures at DCCT closeout. In EDIC year 13/14, the prevalence of CAN using the DCCT composite definition was significantly lower in the former intensive group versus the former conventional group (28.9% versus 35.2%; P =0.018). Adjusted R-R variation was significantly greater in the former DCCT intensive versus the former conventional group (29.9 versus 25.9; P <0.001). Prior DCCT intensive therapy reduced the risks of incident CAN by 31% (odds ratio, 0.69; 95% confidence interval, 0.51 to 0.93) and of incident abnormal R-R variation by 30% (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.96) in EDIC year 13/14. Conclusions— Although CAN prevalence increased in both groups, the incidence was significantly lower in the former intensive group compared with the former conventional group. The benefits of former intensive therapy extend to measures of CAN up to 14 years after DCCT closeout.

Lenalidomide is the first karyotype-selective therapeutic approved for the treatment of myelodysplastic syndromes (MDS) owing to high rates of erythroid and cytogenetic response in patients with chromosome 5q deletion [del(5q)]. Although haploinsufficiency for the RPS14 gene and others encoded within the common deleted region (CDR) have been implicated in the pathogenesis of the del(5q) phenotype, the molecular basis of the karyotype specificity of lenalidomide remains unexplained. We focused our analysis on possible haplodeficient enzymatic targets encoded within the CDR that play key roles in cell-cycle regulation. We show that the dual specificity phosphatases, Cdc25C and PP2Acα, which are coregulators of the G 2 -M checkpoint, are inhibited by lenalidomide. Gene expression was lower in MDS and acute myeloid leukemia (AML) specimens with del(5q) compared with those with alternate karyotypes. Lenalidomide inhibited phosphatase activity either directly (Cdc25C) or indirectly (PP2A) with corresponding retention of inhibitory phospho-tyrosine residues. Treatment of del(5q) AML cells with lenalidomide induced G 2 arrest and apoptosis, whereas there was no effect in nondel(5q) AML cells. Small interfering RNA (shRNA) suppression of Cdc25C and PP2Ac α gene expression recapitulated del(5q) susceptibility to lenalidomide with induction of G 2 arrest and apoptosis in both U937 and primary nondel(5q) MDS cells. These data establish a role for allelic haplodeficiency of the lenalidomide inhibitable Cdc25C and PP2Acα phosphatases in the selective drug sensitivity of del(5q) MDS.

AbstractWhile it is generally accepted that most partial and isolated medial collateral ligament (MCL) injuries can be treated non‐operatively, ideal treatment of the MCL in multi‐ligament knee injuries remains controversial. High failure rates with repair of the posterolateral corner in the multi‐ligament injured knee have been recently reported, favoring reconstruction instead. The same maybe true for MCL injuries, however evidence‐based treatment recommendations are lacking in the current orthopedic literature. The purpose of this study was to perform an evidence‐based systematic review of the operative management (repair and/or reconstruction) of the MCL in the setting of multi‐ligament knee injuries. A comprehensive search of MEDLINE and the Cochrane databases for all relevant articles published in English from 1978 to 2008 on the outcomes of surgical management (repair and/or reconstruction) of the MCL in the setting of combined ligament injuries was performed. Inclusion criteria included articles published in (1) English, (2) on human subjects, (3) between the years of 1978 and 2008, (4) had minimum 12‐month follow‐up, with a mean of at least 24 months, (5) on surgical management of MCL injuries, (6) associated with multi‐ligament injuries (three or more ligaments) and/or knee dislocation, and (7) reported objective outcome data on the respective patient cohorts. Exclusion criteria consisted of technique papers, case reports, studies that included fractures associated with MCL injury and those that included pediatric patients. The review identified eight relevant studies. Five articles focused on MCL repair, while three articles focused on MCL reconstruction. No prospective studies compared MCL repair or reconstruction with non‐operative treatment or directly compared MCL reconstruction with MCL repair. Currently there is a paucity of objective data on the outcomes regarding surgical management of MCL tears in the combined ligament injured knee. This systematic review demonstrated satisfactory results in both repair and reconstruction groups. Future objective outcome‐based studies as well as comparative studies are needed to further evaluate the optimal treatment modality before evidence‐based recommendations can be made. Therefore, individual treatment decisions for each patient should be based on the characteristics and nature of the injury.

Abstract Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. Conclusion: RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25.

This column discusses how to manage challenging patient behaviors. J Contin Educ Nurs 2008;39(9):390–391.

Abstract Resistance to temozolomide and radiotherapy is a major problem for patients with glioblastoma but may be overcome using the poly(ADP-ribose) polymerase inhibitor ABT-888. Using two primary glioblastoma xenografts, the efficacy of ABT-888 combined with radiotherapy and/or temozolomide was evaluated. Treatment with ABT-888 combined with temozolomide resulted in significant survival prolongation (GBM12: 55.1%, P = 0.005; GBM22: 54.4%, P = 0.043). ABT-888 had no effect with radiotherapy alone but significantly enhanced survival in GBM12 when combined with concurrent radiotherapy/temozolomide. With multicycle therapy, ABT-888 further extended the survival benefit of temozolomide in the inherently sensitive GBM12 and GBM22 xenograft lines. However, after in vivo selection for temozolomide resistance, the derivative GBM12TMZ and GBM22TMZ lines were no longer sensitized by ABT-888 in combination with temozolomide, and a similar lack of efficacy was observed in two other temozolomide-resistant tumor lines. Thus, the sensitizing effects of ABT-888 were limited to tumor lines that have not been previously exposed to temozolomide, and these results suggest that patients with newly diagnosed glioblastoma may be more likely to respond to combined temozolomide/poly(ADP-ribose) polymerase inhibitor therapy than patients with recurrent disease. [Mol Cancer Ther 2009;8(2):OF407–8]

Abstract For reasons largely unknown, Caucasian women are at a significantly higher risk of developing breast cancer than Asian women. Over a decade ago, mutations in BRCA1/2 were identified as genetic risk factors; however, the discovery of additional breast cancer genes and genes contributing to racial disparities are lacking. We report a functional germline mutation (polymorphism) in the galectin-3 gene at position 191 (rs4644) substituting proline with histidine (P64H), which results in susceptibility to matrix metalloproteinase cleavage and acquisition of resistance to drug-induced apoptosis. This substitution correlates with incidence of breast cancer and racial disparity. Genotype analysis of 338 Caucasian (194 disease free and 144 breast cancer patients) and 140 Asian (79 disease free and 61 breast cancer patients) women showed that the allele homozygous for H64 exists in disease free Caucasian and Asian women at a frequency of 12% and 5%, respectively, versus 37% and 82% in breast cancer patients. The data indicate that H/H allele is associated with increased breast cancer risk in both races. The data implicate galectin-3 H64 in breast cancer and explain, in part, the noted racial disparity, thus providing a novel target for diagnosis and treatment. [Cancer Res 2008;68(24):10045–50]