Citations

MODERN ORTHOPEDIC SURGERY HAS become complex and technically sophisticated. Orthopedic surgeons and basic scientists have translated recent advances in chemistry, molecular biology, physiology, and biomaterials science into novel management options for their patients. In particular, the development of new synthetic bone graft substitutes (BGS) represents a rapidly evolving area. These synthetic biomaterials may be used alone, as scaffold, or as carrier for bioactive agents (proteins, antibiotics, blood derived or bone marrow derived agents, and cells). To date, most BGS materials available on the market have been classified as Bone Void Fillers (BVF) “intended to be gently packed into bone voids or gaps that are not intrinsic to the stability of the bony structure” [12]. These graft alternatives are subjected to varying degrees of regulatory scrutiny, and thus their true safety and effectiveness in patients may not be known prior to their clinical use [22]. Continuous innovation and the development of new implants raise important issues for technology testing, clinical performance, risk assessment and regulation. It is therefore not surprising that the development of standards for these implants represents an issue that increasingly confronts the professionals from industrial and health care sectors.

Purpose Nonhormonal treatment options have been investigated as treatments for hot flashes, a major clinical problem in many women. Starting in 2000, a series of 10 individual double-blind placebo-controlled studies has evaluated newer antidepressants and gabapentin for treating hot flashes. This current project was developed to conduct an individual patient pooled analysis of the data from these published clinical trials. Patients and Methods Individual patient data were collected from the various study investigators who published their study results between 2000 and 2007. Between-study heterogeneity for study characteristics and patient populations was tested via χ2 tests before a pooled analysis. The primary end point, the change in hot flash activity from baseline to week 4, for each agent was calculated via both weighted and unweighted approaches, using the size of the study as the weight. Basic summary statistics were produced for hot flash score and frequency using the following three statistics: raw change, percent reduction, and whether or not a 50% reduction was achieved. Results This study included seven trials of newer antidepressants and three trials of gabapentin. The optimal doses (defined by individual study results) of the newer antidepressants paroxetine, venlafaxine, fluoxetine, and sertraline decreased hot flash scores by 41%, 33%, 13%, and 3% to 18% compared with the corresponding placebo arms, respectively. The three gabapentin trials decreased hot flashes by 35% to 38% compared with the corresponding placebo arms. Conclusion Some newer antidepressants and gabapentin, within 4 weeks of therapy initiation, decrease hot flashes more than placebo.

Purpose Malignancies found in unexpected locations or with poorly differentiated morphologies can pose a significant challenge for tissue of origin determination. Current histologic and imaging techniques fail to yield definitive identification of the tissue of origin in a significant number of cases. The aim of this study was to validate a predefined 1,550-gene expression profile for this purpose. Methods Four institutions processed 547 frozen specimens representing 15 tissues of origin using oligonucleotide microarrays. Half of the specimens were metastatic tumors, with the remainder being poorly differentiated and undifferentiated primary cancers chosen to resemble those that present as a clinical challenge. Results In this blinded multicenter validation study the 1,550-gene expression profile was highly informative in tissue determination. The study found overall sensitivity (positive percent agreement with reference diagnosis) of 87.8% (95% CI, 84.7% to 90.4%) and overall specificity (negative percent agreement with reference diagnosis) of 99.4% (95% CI, 98.3% to 99.9%). Performance within the subgroup of metastatic tumors (n = 258) was found to be slightly lower than that of the poorly differentiated and undifferentiated primary tumor subgroup, 84.5% and 90.7%, respectively (P = .04). Differences between individual laboratories were not statistically significant. Conclusion This study represents the first adequately sized, multicenter validation of a gene-expression profile for tissue of origin determination restricted to poorly differentiated and undifferentiated primary cancers and metastatic tumors. These results indicate that this profile should be a valuable addition or alternative to currently available diagnostic methods for the evaluation of uncertain primary cancers.

Managing patients with myelofibrosis (MF), either those with primary MF or those whose MF has evolved from antecedent polycythemia vera or essential thrombocythemia, presents many challenges to the hematologist. MF patients have a range of debilitating disease manifestations (eg, massive splenomegaly, cytopenias, constitutional symptoms, and transformation to a treatment-refractory blast phase). Cure is potentially achievable through allogeneic stem cell transplantation; however, this therapy is either inappropriate or not feasible for the majority of patients. Therefore, remaining therapies are palliative but can be of significant value to some MF patients. In particular, management of symptomatic splenomegaly remains one of the most perplexing aspects of MF clinical care. Using medications is the simplest approach for reducing splenomegaly, yet achieving symptomatic response without undue myelosuppression is challenging. Splenectomy or radiotherapy offers benefit, but careful patient selection and close monitoring are required because both have the potential for dangerous adverse effects. Experimental medical therapies, such as JAK2 inhibitors, show promise and may soon play an important role in the management of symptomatic splenomegaly in MF patients. Future care of MF patients, including splenomegaly management, will continue to require the hematologist to select therapeutic options carefully in the context of realistic, achievable goals.

Abstract Background: Urinary albumin excretion is a sensitive diagnostic and prognostic marker for renal disease. Therefore, measurement of urinary albumin must be accurate and precise. We have developed a method to quantify intact urinary albumin with a low limit of quantification (LOQ). Methods: We constructed an external calibration curve using purified human serum albumin (HSA) added to a charcoal-stripped urine matrix. We then added an internal standard, 15N-labeled recombinant HSA (15NrHSA), to the calibrators, controls, and patient urine samples. The samples were reduced, alkylated, and digested with trypsin. The concentration of albumin in each sample was determined by liquid chromatography–tandem mass spectrometry (LC-MS/MS) and linear regression analysis, in which the relative abundance area ratio of the tryptic peptides 42LVNEVTEFAK51 and 526QTALVELVK534 from albumin and 15NrHSA were referenced to the calibration curve. Results: The lower limit of quantification was 3.13 mg/L, and the linear dynamic range was 3.13–200 mg/L. Replicate digests from low, medium, and high controls (n = 5) gave intraassay imprecision CVs of 2.8%–11.0% for the peptide 42LVNEVTEFAK51, and 1.9%–12.3% for the 526QTALVELVK534 peptide. Interassay imprecision of the controls for a period of 10 consecutive days (n = 10) yielded CVs of 1.5%–14.8% for the 42LVNEVTEFAK51 peptide, and 6.4%–14.1% for the 526QTALVELVK534 peptide. For the 42LVNEVTEFAK51 peptide, a method comparison between LC-MS/MS and an immunoturbidometric method for 138 patient samples gave an R2 value of 0.97 and a regression line of y = 0.99x + 23.16. Conclusions: Urinary albumin can be quantified by a protein cleavage LC-MS/MS method using a 15NrHSA internal standard. This method provides improved analytical performance in the clinically relevant range compared to a commercially available immunoturbidometric assay.