Assessing mental workload during laparoscopic surgery

Although the use of performance efficiency measures (speed, movement economy, errors) and ergonomic assessments are relatively well established, the evaluation of cognitive outcomes is rare. This report makes the case for assessment strategies that include mental workload measures as a way to improve training scenarios and training/operating environments. These mental workload measures can be crucially important in determining the difference between well-intentioned but subtly distracting technologies and true breakthroughs that will enhance performance and reduce stress.     

Functional human CFTR produced by stable Chinese hamster ovary cell lines derived using yeast artificial chromosomes

The cystic fibrosis transmembrane conductance regulator gene (CFTR) encodes a transmembrane protein (CFTR) which functions in part as a cyclic adenosine monophosphate (cAMP)-regulated chloride channel. CFTR expression is controlled temporally and cell specifically by mechanisms that are poorly understood. Insight into CFTR regulation could be facilitated by the successful introduction of the entire 230 kb human CFTR and adjacent sequences into mammalian cells. To this end, we have introduced two different CFTR-containing yeast artificial chromosomes (YACs) (320 and 620 kb) into Chinese hamster ovary-K1 (CHO) cells. Clonal cell lines containing human CFTR were identified by PCR, and the genetic and functional analyses of one clone containing each YAC are described. Integration of the human CFTR-containing YACs into the CHO genome at a unique site in each cell line was demonstrated by fluorescence in situ hybridization (FISH). Southern blot analysis suggested that on the order of one copy of human CFTR was integrated per CHO cell genome. Fiber-FISH and restriction analysis suggested that CFTR remained grossly intact. Northern analysis showed full-length, human CFTR mRNA. Immunoprecipitation followed by phosphorylation with protein kinase demonstrated mature, glycosylated CFTR. Finally, chloride secretion in response to cAMP indicated the functional nature of the human CFTR. This study provides several novel results including: (i) functional human CFTR can be expressed from these YACs; (ii) CHO cells are a permissive environment for expression of human CFTR; (iii) the level of human CFTR expression in CHO cells is unexpectedly high given the lack of endogenous CFTR production; and (iv) the suggestion by Fiber-FISH of CFTR integrity correlates with functional gene expression. These YACs and the cell lines derived from them should be useful tools for the study of CFTR expression.      

Advances in sentinel node dissection in prostate cancer from a technical perspective

The most important feature of sentinel node biopsy for prostate cancer procedure is that staging can be improved. Sentinel nodes might be found outside the extended pelvic lymph node dissection template what renders the sentinel node additive of extended pelvic lymph node dissection. At the same time, staging within the template can be further refined. We reviewed the literature regarding the sentinel node biopsy procedure for prostate cancer. PubMed and Embase were searched for all English‐language publications from January 1999 to September 2014 by using the keywords as “prostate cancer” and “sentinel lymph node” plus “biopsy” “dissection” and/or “procedure.” The present review discusses step‐by‐step sentinel node biopsy for prostate cancer. Topics of discussion are: (i) preoperative sentinel node mapping (tracers and imaging); (ii) intraoperative sentinel node identification (surgical procedure and outcome); and (iii) novelties to improve sentinel node identification (pre‐ and intraoperative approaches). Conventional sentinel node mapping is carried out after the injection of a ^99mTc‐based tracer and subsequent preoperative imaging; for example, lymphoscintigraphy and single‐photon emission computed tomography/computed tomography. This approach allowed the detection of sentinel nodes outside the extended lymph node dissection template in 3.6–36% of men with intermediate‐ and high‐risk prostate cancer. Hereby, an overall false negative rate of sentinel nodes was reported between 0% and 24.4%. To further refine the intraoperative sampling procedure, novel imaging methods such as fluorescence imaging have been introduced. Prospective randomized comparison studies are required to confirm the added benefit of sentinel template directed nodal dissection. A proper and obtainable end‐point of such a study could be the number of removed positive nodes for carrying out nodal dissection with or without sentinel template directed dissection. Similarly, the clinical impact of novel imaging technologies requires further investigation.     

Percutaneous endoscopic lumbar discectomy: clinical and quality of life outcomes with a minimum 2 year follow-up

Background  

Percutaneous endoscopic lumbar discectomy is a relatively new technique. Very few studies have reported the clinical outcome of percutaneous endoscopic discectomy in terms of quality of life and return to work.     

P08 Comparing study in self-motivation learning： PBL vs LBL

In order to clarify which teaching form encourages student＇ s self-motivation learning ability better, we did a comparison experiment between problem-based learning （PBL）and lecture-based learning （LBL） in a 3rd year course in basic pharmacology. Of 224 students who participated （124 PBL, 100 LBL） in pharmacology course, the experimental group was divided into 6 teams（20 - 21 students for each team with one tutor）using PBL method with 7 clinical cases discussion while o.ther 100 students held in the same lecture-based format as the traditional LBL course as a control group. In 224 students, 50.4% using PBL method self-directed learning ability had increased compared with 35.3% in LBL teaching mode. The test score indicated that students using LBL teaching method scored overall higher than those using PBL mode, especially at objective items, this result was significant.. iy different（P =0.009）. However, as far as subjective items are concerned, students accepted PBL mode showed their superior advantages over the LBL ones. Similarly, the result was significantly different（ P =0.001 ）. On the whole, PBL method supported by appropriate technology and teachers, has allowed our students to analyze authentic situations as a doctor status and the active learning ability by self-motivation study will be undoubtedly beneficial for their becoming life-long learners and excellent doctors in the future.     

Association state of human red blood cell band 3 and its interaction with ankyrin

We have studied the association state of band 3, the anion channel and predominant transmembrane protein of the human red blood cell, and the anomalous stoichiometry and dynamics of its interaction with ankyrin, which acts as a link to the spectrin of the membrane skeletal network. Band 3 exists in benign nonionic detergent solutions as a dimer. Tetramer is formed irreversibly in the course of manipulations, particularly in ion-exchange chromatography. The dimer in solution binds ankyrin without self-associating. In ankyrin-free inside-out membrane vesicles and when incorporated into phosphatidylcholine liposomes, only some 10% to 15% of band 3 chains bind ankyrin at saturation. Moreover, in liposomes this was independent of protein:lipid ratio between 1:2 and 1:40. The bound fraction of band 3 remains with the detergent-extracted membrane cytoskeleton, but is released if the ankyrin has been cleaved with chymotrypsin before detergent treatment; thus, the attachment to the membrane cytoskeleton is entirely through ankyrin and not through other constituents such as protein 4.1. The ratio of band 3 to ankyrin in this complex implies that it consists of two chains of band 3 and one chain of ankyrin, at least after detergent extraction. The bound and free populations of band 3 exchange freely in the membrane. In the artificial liposome membrane binding of ankyrin to band 3 dimers cause association of the band 3 into higher aggregates, as seen in freeze-fracture electron microscopy. Successive manipulations of the red blood cell membrane, which are involved in the preparation of ghosts, of inside-out vesicles, and of inside-out vesicles stripped of peripheral proteins are accompanied by progressive aggregation of intramembrane particles, as judged by freeze-fracture electron microscopy. Thus the intramembrane particles are evidently stabilized in the intact cell by the peripheral protein network and the cytosolic milieu. Aggregation may be expected to limit the number of functional ankyrin binding sites. However, although extraneous ankyrin binds to the unoccupied binding site on the spectrin tetramers in intact ghost membranes, little or no ankyrin can bind to the unoccupied band 3 dimers in situ, perhaps by reason of occlusion of binding sites by the membrane skeletal network.     

Predictive factors for acute graft-versus-host disease in patients transplanted with HLA-identical bone marrow

To identify predictive parameters for incidence and severity of acute graft-versus-host disease (GVHD), 136 patients, transplanted with histocompatible marrow as therapy for aplastic anemia and hematologic malignancies, were examined using univariate and multivariate analyses. The risk of GVHD increased in patients with acute lymphocytic leukemia (p less than 0.05), in sex-mismatched donor-recipient pairs (p less than 0.01), and in patients older than 23.7 yr (p less than 0.05). No other commonly observed factors appeared to have any relationship to GVHD except the presence of certain alleles. The presence of a Cw4 allele or of the Bw21 specificities B49 and B50 were associated with significantly increased risks of GVHD (p less than 0.05), whereas the presence of Aw19 (or the related specificities A29, Aw30, Aw31 , Aw32, Aw33 ) was associated with a significantly decreased risk (p less than 0.01). Using these factors, a regression equation can be constructed that estimates the risk of a given patient to develop clinically significant acute GVHD.     

Cytoplasmic factor required for entry of malaria parasites into RBCs

Resealed ghosts of human RBCs, containing diluted cytosol, are susceptible to invasion by Plasmodium falciparum. If ATP is present, a dilution of up to about 30-fold, corresponding to an intracellular hemoglobin concentration of approximately 10 mg/mL, can be tolerated without total loss of susceptibility to invasion. Up to a dilution of about one-half this, the parasites also develop normally. When the cytosol is diluted by more than the critical amount, invasion of the resulting resealed ghosts falls off abruptly. If the diluent buffer is replaced by extraneous concentrated hemolysate, an indefinite dilution is possible without loss of invasion. There is thus an intracellular constituent, which must be present at a concentration above some critical level if the parasite is to enter the cell. The factor in question is not dialyzable. It is largely inactivated when the hemolysate is kept for approximately 1 day in the cold or for approximately 20 minutes at 45 degrees C. The inability of a heat- treated hemolysate to support invasion is not due to the generation of inhibitory products, because such a solution can be used as a diluent of a fresh hemolysate without inhibition of invasion. When the inactivated hemolysate is present as a major component, however, the parasites fail to develop to the trophozoite stage. The invasion-linked factor remains in the strongly adsorbed nonheme fraction when a batchwise separation from hemoglobin on an anion exchanger is made and is thus probably acidic in character; the adsorbed fraction, recovered from the ion-exchanger, substantially restores capacity for invasion when sealed into ghosts. Its activity is destroyed by treatment with trypsin. The adsorbed fraction contains many proteins. When fractionated on a gel filtration column by fast liquid chromatography, active material eluted at a volume corresponding to a mol wt for a globular protein in the region of 10,000. A component of apparent subunit mol wt of 13,000 was observed in sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) of this eluate fraction.