Citations

Abstract The intensity of bone remodeling is a critical determinant of the decay of cortical and trabecular microstructure after menopause. Denosumab suppresses remodeling more than alendronate, leading to greater gains in areal bone mineral density (aBMD). These greater gains may reflect differing effects of each drug on bone microarchitecture and strength. In a phase 2 double-blind pilot study, 247 postmenopausal women were randomized to denosumab (60 mg subcutaneous 6 monthly), alendronate (70 mg oral weekly), or placebo for 12 months. All received daily calcium and vitamin D. Morphologic changes were assessed using high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia and QCT at the distal radius. Denosumab decreased serum C-telopeptide more rapidly and markedly than alendronate. In the placebo arm, total, cortical, and trabecular BMD and cortical thickness decreased (−2.1% to −0.8%) at the distal radius after 12 months. Alendronate prevented the decline (−0.6% to 2.4%, p = .051 to <.001 versus placebo), whereas denosumab prevented the decline or improved these variables (0.3% to 3.4%, p < .001 versus placebo). Changes in total and cortical BMD were greater with denosumab than with alendronate (p ≤ .024). Similar changes in these parameters were observed at the tibia. The polar moment of inertia also increased more in the denosumab than alendronate or placebo groups (p < .001). Adverse events did not differ by group. These data suggest that structural decay owing to bone remodeling and progression of bone fragility may be prevented more effectively with denosumab. © 2010 American Society for Bone and Mineral Research

Abstract It has been suggested recently that, although fluoride therapy may decrease the occurrence of vertebral fractures, it could increase the risk of hip fractures. To evaluate this possibility, we combined retrospective data from five medical centers that have had a large experience with this therapeutic regimen. In 416 osteoporotic patients who were followed for more than 1,000 patient-years of fluoride treatment, there were 17 nontraumatic hip fractures. This incidence of 1.6% per year is similar to the incidence, 1.9% per year, for 120 of the patients in this series who had been followed prospectively for 3 years prior to initiation of fluoride therapy. The expected incidence for women of the same age in the general community is 0.5% per year. Thus, untreated osteoporotic women are at increased risk for hip fracture, but treatment with fluoride seems neither to decrease nor to increase the incidence of hip fracture substantially.

ABSTRACTThe sulfonamides were the first drugs with antituberculous effects. Their use was abandoned and basically forgotten with the advent of streptomycin and isoniazid combination treatment. There is a widespread belief, apparently based on testing a single isolate on questionable media, thatMycobacterium tuberculosisis resistant to trimethoprim-sulfamethoxazole (TMP-SMX). We saw a complex immunocompromised patient with tuberculosis who was initially treated with TMP-SMX without antituberculous drugs and defervesced on this treatment. An isolate ofM. tuberculosisfrom this patient was found to be sensitive to TMP-SMX. We examined how frequentlyM. tuberculosisis sensitive to TMP-SMX. Isolates were tested for susceptibility to TMP-SMX on supplemented Middlebrook 7H10 plates. We found that 43 of 44 (98%) isolates ofM. tuberculosiswere susceptible to the combination of ≤1 μg/ml of TMP and 19 μg/ml of SMX (≤1/19 μg/ml). Thus, the vast majority of ourM. tuberculosisisolates were susceptible to TMP-SMX at an MIC similar to that forMycobacterium kansasii,Mycobacterium marinum, and sensitive rapidly growing mycobacteria, organisms successfully treated with TMP-SMX as part of the treatment regimen. It is possible that TMP-SMX may be useful in treating patients with multiple-drug-resistant and extended drug-resistant tuberculosis. We feel that a clinical trial looking at the effectiveness of TMP-SMX as an antituberculous drug is worthwhile.

Abstract Recently, many new drugs have been developed for the treatment of Waldenström macroglobulinemia (WM). To optimize the treatment according to the prognosis and to facilitate the comparison of trials, we developed an International Prognostic Scoring System for WM in a series of 587 patients with clearly defined criteria for diagnosis and for initiation of treatment. The median survival after treatment initiation was 87 months. Five adverse covariates were identified: advanced age (>65 years), hemoglobin less than or equal to 11.5 g/dL, platelet count less than or equal to 100 × 109/L, β2-microglobulin more than 3 mg/L, and serum monoclonal protein concentration more than 7.0 g/dL. Low-risk patients (27%) presented with no or 1 of the adverse characteristics and advanced age, intermediate-risk patients (38%) with 2 adverse characteristics or only advanced age, and high-risk patients (35%) with more than 2 adverse characteristics. Five-year survival rates were 87%, 68%, and 36%, respectively (P < .001). The ISSWM retained its prognostic significance in subgroups defined by age, treatment with alkylating agent, and purine analog. Thus, the ISSWM may provide a means to design risk-adapted studies. However, independent validation and new biologic markers may enhance its significance.

Purpose Acute graft-versus-host disease (GVHD) causes substantial morbidity and mortality after human leukocyte antigen (HLA)-identical sibling transplants. No large registry studies of acute GVHD risk factors have been reported in two decades. Risk factors may have changed in this interval as transplant-related techniques have evolved. Patients and Methods Acute GVHD risk factors were analyzed in 1,960 adults after HLA-identical sibling myeloablative transplant for acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), or chronic myeloid leukemia (CML) reported by 226 centers worldwide to the Center for International Blood and Marrow Transplant Research from 1995 to 2002. Outcome was measured as time from transplant to onset of grade 2 to 4 acute GVHD, with death without acute GVHD as a competing risk. Results Cumulative incidence of grade 2 to 4 acute GVHD was 35% (95% CI, 33% to 37%). In multivariable analyses, factors significantly associated with grade 2 to 4 acute GVHD were cyclophosphamide + total-body irradiation versus busulfan + cyclophosphamide (relative risk [RR] = 1.4; P < .0001), blood cell versus bone marrow grafts in patients age 18 to 39 years (RR = 1.43; P = .0023), recipient age 40 and older versus age 18 to 39 years receiving bone marrow grafts (RR = 1.44; P = .0005), CML versus AML/ALL (RR = 1.35; P = .0003), white/Black versus Asian/Hispanic race (RR = 1.54; P = .0003), Karnofsky performance score less than 90 versus 90 to 100 (RR = 1.27; P = .014), and recipient/donor cytomegalovirus-seronegative versus either positive (RR = 1.20; P = .04). Stratification by disease showed the same significant predictors of grade 2 to 4 acute GVHD for CML; however, KPS and cytomegalovirus serostatus were not significant predictors for AML/ALL. Conclusion This analysis confirmed several previously reported risk factors for grade 2 to 4 acute GVHD. However, several new factors were identified whereas others are no longer significant. These new data may facilitate individualized risk estimates and raise several interesting biologic questions.

Abstract A recent genome-wide association study found that genetic variants on chromosomes 3, 6, 7, 10, 11, 19 and X were associated with prostate cancer risk. We evaluated the most significant single-nucleotide polymorphisms (SNP) in these loci using a worldwide consortium of 13 groups (PRACTICAL). Blood DNA from 7,370 prostate cancer cases and 5,742 male controls was analyzed by genotyping assays. Odds ratios (OR) associated with each genotype were estimated using unconditional logistic regression. Six of the seven SNPs showed clear evidence of association with prostate cancer (P = 0.0007-P = 10−17). For each of these six SNPs, the estimated per-allele OR was similar to those previously reported and ranged from 1.12 to 1.29. One SNP on 3p12 (rs2660753) showed a weaker association than previously reported [per-allele OR, 1.08 (95% confidence interval, 1.00-1.16; P = 0.06) versus 1.18 (95% confidence interval, 1.06-1.31)]. The combined risks associated with each pair of SNPs were consistent with a multiplicative risk model. Under this model, and in combination with previously reported SNPs on 8q and 17q, these loci explain 16% of the familial risk of the disease, and men in the top 10% of the risk distribution have a 2.1-fold increased risk relative to general population rates. This study provides strong confirmation of these susceptibility loci in multiple populations and shows that they make an important contribution to prostate cancer risk prediction. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2052–61)

AbstractMotivation: A central problem in biomarker discovery from large-scale gene expression or single nucleotide polymorphism (SNP) data is the computational challenge of taking into account the dependence among all the features. Methods that ignore the dependence usually identify non-reproducible biomarkers across independent datasets. We introduce a new graph-based semi-supervised feature classification algorithm to identify discriminative disease markers by learning on bipartite graphs. Our algorithm directly classifies the feature nodes in a bipartite graph as positive, negative or neutral with network propagation to capture the dependence among both samples and features (clinical and genetic variables) by exploring bi-cluster structures in a graph. Two features of our algorithm are: (1) our algorithm can find a global optimal labeling to capture the dependence among all the features and thus, generates highly reproducible results across independent microarray or other high-thoughput datasets, (2) our algorithm is capable of handling hundreds of thousands of features and thus, is particularly useful for biomarker identification from high-throughput gene expression and SNP data. In addition, although designed for classifying features, our algorithm can also simultaneously classify test samples for disease prognosis/diagnosis.Results: We applied the network propagation algorithm to study three large-scale breast cancer datasets. Our algorithm achieved competitive classification performance compared with SVMs and other baseline methods, and identified several markers with clinical or biological relevance with the disease. More importantly, our algorithm also identified highly reproducible marker genes and enriched functions from the independent datasets.Availability: Supplementary results and source code are available at http://compbio.cs.umn.edu/Feature_Class.Contact: kuang@cs.umn.eduSupplementary information: Supplementary data are available at Bioinformatics online.

In prion-infected mice, both the Notch-1 intracellular domain transcription factor (NICD) and the disease-causing prion protein (PrP Sc ) increase in the brain preceding dendritic atrophy and loss. Because the drug LY411575 inhibits the γ-secretase-catalyzed cleavage of Notch-1 that produces NICD, we asked whether this γ-secretase inhibitor (GSI) might prevent dendritic degeneration in mice with scrapie. At 50 d postinoculation with Rocky Mountain Laboratory (RML) prions, mice were given GSI orally for 43–60 d. Because we did not expect GSI to produce a reduction of PrP Sc levels in brain, we added quinacrine (Qa) to the treatment regimen. Qa inhibits PrP Sc formation in cultured cells. The combination of GSI and Qa reduced PrP Sc by ≈95% in the neocortex and hippocampus but only ≈50% in the thalamus at the site of prion inoculation. The GSI plus Qa combination prevented dendritic atrophy and loss, but GSI alone did not. Even though GSI reduced NICD levels to a greater extent than GSI plus Qa, it was unable to prevent dendritic degeneration. Whether a balance between NICD and dendrite growth-stimulating factors was achieved with GSI plus Qa but not GSI alone remains to be determined. Although the combination of GSI and Qa diminished PrP Sc in the brains of RML-infected mice, GSI toxicity prevented us from being able to assess the effect the GSI plus Qa combination on incubation times. Whether less toxic GSIs can be used in place of LY411575 to prolong survival remains to be determined.