High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency.

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct "biased sequences" and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the "biased sequences" was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy

Clinical Characteristics of Hyponatremia

Background & aims : We investigated the contributing factors of hyponatremia in patients on nutrition support using bioelectrical impedance analysis (BIA). Methods : Thirty patients administered enteral or parenteral nutrition support for at least 72 hours were studied. We collected nutritional and electrolyte intake, serum biochemical parameters, and body composition measured by BIA. Patients were classified into two groups according to their serum sodium levels : (1) Normanatremia group, 135–145 mEq / L (n = 18) and (2) Hyponatremia group, less than 135 mEq / L (n = 12), and their characteristics were analyzed. Results : There were no significant differences between the Normonatremia and Hyponatremia groups in terms of energy, protein, and sodium intake. Serum biochemical parameters other than serum sodium and chloride levels were comparable between the two groups. On the other hand, the ratio of extracellular water to total body water (ECW / TBW) obtained by BIA was significantly higher in the Hyponatremia group than in the Normonatremia group. Further, an elevated ECW / TBW significantly and negatively correlated with serum albumin level. Conclusions : Regardless of sodium intake, higher ECW / TBW was associated with hyponatremia in patients on nutrition support. ECW / TBW may be an important clinical parameter relevant to the nutritional care of hyponatremia

Intracellular stability of 2′-OMe-4′-thioribonucleoside modified siRNA leads to long-term RNAi effect

Chemically modified siRNAs are expected to have resistance toward nuclease degradation and good thermal stability in duplex formation for in vivo applications. We have recently found that 2′-OMe-4′-thioRNA, a hybrid chemical modification based on 2′-OMeRNA and 4′-thioRNA, has high hybridization affinity for complementary RNA and significant resistance toward degradation in human plasma. These results prompted us to develop chemically modified siRNAs using 2′-OMe-4′-thioribonucleosides for therapeutic application. Effective modification patterns were screened with a luciferase reporter assay. The best modification pattern of siRNA, which conferred duration of the gene-silencing effect without loss of RNAi activity, was identified. Quantification of the remaining siRNA in HeLa-luc cells using a Heat-in-Triton (HIT) qRT–PCR revealed that the intracellular stability of the siRNA modified with 2′-OMe-4′-thioribonucleosides contributed significantly to the duration of its RNAi activity

Spermatic Cord Lymphoma: A Case Report and Literature Review

Spermatic cord lymphoma is a rare lethal disease. It has a poor prognosis even in stage I or II disease when treated locally, therefore, multidisciplinary treatment for early stage is recommended. On the other hand, the treatment of choice for stage III or IV spermatic cord lymphoma remains to be determined. It is said that spermatic cord lymphoma is clinicopathologically similar to primary testicular lymphoma, therefore the treatment of spermatic cord lymphoma has often been determined by reference to the recommended treatment for primary testicular lymphoma. Here we report a new case of spermatic cord lymphoma, which was found in stage IV disease. We also review thirty-three cases which have been reported as spermatic cord lymphoma to date, and discuss treatment options

Detection of liver HBc antigen and its antibody in sera from viral hepatitis by the immunofluorescent complement technique

Hepatitis B core antigen (HBc Ag) and hepatitis B surface antigen (HBs Ag) were detected in the liver tissue of a patient with chronic aggressive hepatitis by the immunofluorescent complement technique. The presence of anti-HBc was examined by the same method in 67 human sera previously tested for HBs Ag, anti-HBs and s-GPT levels. HBc Ag was localized mainly in the nucleus and sometimes in the cytoplasm of the hepatic cells. HBs Ag was found only in the cytoplasm. The focal area of HBc Ag positive hepatic cells seemed to correspond to the HBs Ag positive cells. Double staining demonstrated the simultaneous presence of HBs Ag and HBc Ag in individual cells. Anti-HBc positive serum was found in 46 (68.7%) cases. Forty-eight (71.6%) indicated a combination of HBs Ag and anti-HBc.</p