Influence of DNA Delivery Method on Gene Targeting Frequencies in Human Cells

Gene targeting can be used for genetic studies of human cell lines and has significant potential for somatic cell gene therapy. These applications are however restricted by the low frequency of homologous recombination in higher eukaryotes compared to the relatively efficient nonhomologous integration of transfected DNA into the genome. As part of our attempts to overcome this problem, we compared two widely used transfection methods for their efficiency in gene targeting. To our surprise we found that, for conditions that render similar frequencies of nonhomologous integrants, lipofection is much less efficient than electroporation in generating targeted clones. This suggests that nonhomologous and homologous recombination have different requirements for DNA delivery in human cells.     

Multiple gamma c-dependent cytokines regulate T-cell development

Mutations in the common gamma chain (gamma c) of cytokine receptors account for human X-linked severe combined immunodeficiency disease. gamma c contributes to ligand binding and signaling as a component of five cytokine receptors: interleukin-2-receptor (IL-2R), IL-4R, IL-7R, IL-9R and IL-15R. Here, Thomas Malek and colleagues discuss the contribution of individual gamma c-dependent cytokines in both conventional and intraepithelial T-cell development.     

Orofacial disease: update for the dental clinical team: 6. Complaints affecting particularly the lips or tongue

Certain lesions are exclusively or typically found in specific sites; these are discussed in this and the next two articles in this series.     

Laparoscopic splenectomy in patients with hematologic malignancies

BACKGROUND: Although laparoscopic splenectomy (LS) for benign hematologic disease is well accepted, its role in hematologic malignancies is not clearly defined. This study examined the efficacy and feasibility of LS for hematologic malignancies. METHODS: Records were reviewed from patients who underwent LS at two university hospitals. Charts from 77 open splenectomies for malignancy (OM) during the same period were also reviewed. RESULTS: Fifty-three patients underwent LS, 22 for hematologic malignancies (LM) and 31 for benign hematologic disorders (LB). Median splenic weight was greater in the LM group (930 g) than in the LB group (164 g, P = 0.001). LM was associated with longer operations and greater blood loss than was LB. LM had a 41% conversion rate. Morbidity, mortality, and transfusion rates were similar. Median hospital stay was shorter for LM (4 days) than for OM (6 days, P = 0.001). CONCLUSIONS: LS is feasible in hematologic malignancies but is associated with increased operative time and blood loss and a high conversion rate. Morbidity and mortality, however, was similar. Shorter hospital stays for LM compared with OM may translate into earlier recovery and initiation of antineoplastic therapy.     

Nursing workload associated with adverse events in the postanesthesia care unit

BACKGROUND: The authors used a nursing task inventory system to assess nursing resources for patients with and without adverse postoperative events in the postanesthesia care unit (PACU). METHODS: Over 3 months, 2,031 patients were observed, and each task/activity related to direct patient care was recorded and assigned points according to the Project Research in Nursing (PRN) workload system. PRN values for each patient were merged with data from an anesthesia database containing demographics, anesthesia technique, and postoperative adverse events. Mean and median PRN points were determined by age, sex, duration of procedure, and mode of anesthesia for patients with and without adverse events in the PACU. Three theoretical models were developed to determine the effect of differing rates of adverse events on the requirements for nurses in the PACU. RESULTS: The median workload (PRN points) per patient was 31.0 (25th-75th percentile, 25-46). Median workload was 26 points for patients with no postoperative events and 155 for > or = six adverse events. Workload varied by type of postoperative event (e.g., unanticipated admission to the intensive care unit, median workload = 95; critical respiratory event = 54; and nausea/vomiting = 33). Monitored anesthesia care or general anesthesia with spontaneous ventilation used less resources compared with general anesthesia with mechanical ventilation. Modeling various scenarios (controlling for types of patients) showed that adverse events increased the number of nursing personnel required in the PACU. CONCLUSIONS: Nursing care documentation based on requirements for individual patients demonstrates that the rate of postoperative adverse events affects the amount of nursing resources needed in the PACU.