Fluoroquinolone Prophylaxis Is Highly Effective for the Prevention of Central Line-Associated Bloodstream Infections in Autologous Stem Cell Transplant Patients.

Patients undergoing stem cell transplant (SCT) for the treatment of hematologic malignancy are at increased risk for central line-associated bloodstream infections (CLABSIs). The use of prophylactic antibiotics to prevent CLABSIs in the setting of autologous SCT is of unclear benefit. We aimed to evaluate the impact of levofloxacin prophylaxis on reducing CLABSIs in this high-risk population. Patients undergoing autologous SCT at a tertiary care hospital received levofloxacin prophylaxis from January 13, 2016 to January 12, 2017. Levofloxacin was administered from autologous SCT (day 0) until day 13, absolute neutrophil count > 500/mm3, or neutropenic fever, whichever occurred first. Clinical outcomes were compared with a baseline group who underwent autologous SCT but did not receive antibacterial prophylaxis during the previous year. The primary endpoint was incidence of CLABSIs assessed using Cox proportional hazards regression. A total of 324 patients underwent autologous SCT during the entire study period, with 150 receiving levofloxacin prophylaxis during the intervention period. The rate of CLABSIs was reduced from 18.4% during the baseline period to 6.0% during the intervention period. On multivariable analysis levofloxacin prophylaxis significantly reduced CLABSI incidence (hazard ratio, .33; 95% confidence interval [CI], .16 to .69; P = .003). There was also a reduction in the risk of neutropenic fever (odds ratio [OR], .23; 95% CI, .14 to .39; P < .001) and a trend toward a reduction in intensive care unit transfer for sepsis (OR, .33; 95% CI, .09 to 1.24; P = .10) in patients receiving levofloxacin prophylaxis. Notably, there was no increase in Clostridium difficile infection in the levofloxacin group (OR, .66; 95% CI, .29 to 1.49; P = .32). Levofloxacin prophylaxis was effective in reducing CLABSIs and neutropenic fever in patients undergoing autologous SCT. Further studies are needed to identify specific patient groups who will benefit most from antibiotic prophylaxis.

Successful transgenesis of the parasitic nematode Strongyloides stercoralis requires endogenous non-coding control elements.

Critical investigations into the cellular and molecular biology of parasitic nematodes have been hindered by a lack of modern molecular genetic techniques for these organisms. One such technique is transgenesis. To our knowledge, the findings reported here demonstrate the first heritable DNA transformation and transgene expression in the intestinal parasite Strongyloides stercoralis. When microinjected into the syncitial gonads of free-living S. stercoralis females, a construct fusing the S. stercoralis era-1 promoter, the coding region for green fluorescent protein (gfp) and the S. stercoralis era-1 3' untranslated region was expressed in intestinal cells of normally developing F1 transgenic larvae. The frequency of transformation and GFP expression among F1 larvae was 5.3%. By contrast, expression of several promoter::gfp fusions incorporating only Caenorhabditis elegans regulatory elements was restricted to abortively developing F1 embryos of S. stercoralis. Despite its lack of regulated expression, PCR revealed that one of these C. elegans-based vector constructs, the sur-5::gfp fusion, is incorporated into F1 larval progeny of microinjected female worms and then transmitted to the F2 through F5 generations during two host passages conducted without selection and punctuated by free-living generations reared in culture. Heritable DNA transformation and regulated transgene expression, as demonstrated here for S. stercoralis, constitute the essential components of a practical system for transgenesis in this parasite. This system has the potential to significantly advance the molecular and cellular biological study of S. stercoralis and of parasitic nematodes generally.

Outcome and Prognostic Indicators in Cats Undergoing Splenectomy for Splenic Mast Cell Tumors.

This was a multi-institutional retrospective study evaluating the outcome and clinical parameters associated with the postoperative prognosis of 36 cats with splenic mast cell tumors treated with splenectomy. Clinical parameters reviewed included signalment, clinical history, results of staging tests, surgical variables, administration of blood products, presence of metastasis, postoperative complications, administration of chemotherapy postoperatively, chemotherapy protocol, and response to chemotherapy. Overall median survival time was 390 days (range, 2-1737 days). Administration of a blood product (P < .0001), metastasis to a regional lymph node (P = .022), and evidence of either concurrent or historical neoplasia (P = .037) were negatively associated with survival. Response to chemotherapy (P = .0008) was associated with an improved median survival time. Larger-scale prospective studies evaluating different chemotherapy protocols are required to elucidate the discrepancy between lack of survival benefit with administration of chemotherapy and improvement in survival time with positive response to chemotherapy.

Expression and function of conserved nuclear receptor genes in Caenorhabditis elegans.

The Caenorhabditis elegans genome encodes 284 nuclear receptor (NR) genes. Among these 284 NR genes are 15 genes conserved among the Metazoa. Here, we analyze the expression and function of eight heretofore uncharacterized conserved C. elegans NR genes. Reporter gene analysis demonstrates that these genes have distinct expression patterns and that a majority of the C. elegans cell types express a conserved NR gene. RNA interference with NR gene function resulted in visible phenotypes for three of the genes, revealing functions in various processes during postembryonic development. Five of the conserved NR genes are orthologs of NR genes that function during molting and metamorphosis in insects. Functional studies confirm a role for most of these 'ecdysone cascade' NR orthologs during the continuous growth and dauer molts. Transcript levels for these genes fluctuate in a reiterated pattern during the molting cycles, reminiscent of the expression hierarchy observed in the insect ecdysone response. Together, these analyses provide a foundation for further dissecting the role of NRs in nematode development as well as for evaluating conservation of NR functions among the Metazoa.