Time-Action Analysis (TAA) of the Surgical Technique Implanting the Collum Femoris Preserving (CFP) Hip Arthroplasty. TAASTIC trial Identifying pitfalls during the learning curve of surgeons participating in a subsequent randomized controlled trial (An observational study)

<p>Abstract</p> <p>Background</p> <p>Two types of methods are used to assess learning curves: outcome assessment and process assessment. Outcome measures are usually dichotomous rare events like complication rates and survival or require an extensive follow-up and are therefore often inadequate to monitor individual learning curves. Time-action analysis (TAA) is a tool to objectively determine the level of efficiency of individual steps of a surgical procedure.</p> <p>Methods/Design</p> <p>We are currently using TAA to determine the number of cases needed for surgeons to reach proficiency with a new innovative hip implant prior to initiating a multicentre RCT. By analysing the unedited video recordings of the first 20 procedures of each surgeon the number and duration of the actions needed for a surgeon to achieve his goal and the efficiency of these actions is measured. We constructed a taxonomy or list of actions which together describe the complete surgical procedure. In the taxonomy we categorised the procedure in 5 different Goal Oriented Phases (GOP):</p> <p>1. the incision phase</p> <p>2. the femoral phase</p> <p>3. the acetabulum phase</p> <p>4. the stem phase</p> <p>5. the closure pase</p> <p>Each GOP was subdivided in Goal Oriented Actions (GOA) and each GOA is subdivided in Separate Actions (SA) thereby defining all the necessary actions to complete the procedure. We grouped the SAs into GOAs since it would not be feasible to measure each SA. Using the video recordings, the duration of each GOA was recorded as well as the amount of delay. Delay consists of repetitions, waiting and additional actions. The nett GOA time is the total GOA time – delay and is a representation of the level of difficulty of each procedure. Efficiency is the percentage of nett GOA time during each procedure.</p> <p>Discussion</p> <p>This allows the construction of individual learning curves, assessment of the final skill level for each surgeon and comparison of different surgeons prior to participation in an RCT. We believe an objective and comparable assessment of skill level by process assessment can improve the value of a surgical RCT in situations where a learning curve is expected.</p

Ligand binding to an Allergenic Lipid Transfer Protein Enhances Conformational Flexibility resulting in an Increase in Susceptibility to Gastroduodenal Proteolysis

Non-specific lipid transfer proteins (LTPs) are a family of lipid-binding molecules that are widely distributed across flowering plant species, many of which have been identified as allergens. They are highly resistant to simulated gastroduodenal proteolysis, a property that may play a role in determining their allergenicity and it has been suggested that lipid binding may further increase stability to proteolysis. It is demonstrated that LTPs from wheat and peach bind a range of lipids in a variety of conditions, including those found in the gastroduodenal tract. Both LTPs are initially cleaved during gastroduodenal proteolysis at three major sites between residues 39–40, 56–57 and 79–80, with wheat LTP being more resistant to cleavage than its peach ortholog. The susceptibility of wheat LTP to proteolyic cleavage increases significantly upon lipid binding. This enhanced digestibility is likely to be due to the displacement of Tyr79 and surrounding residues from the internal hydrophobic cavity upon ligand binding to the solvent exposed exterior of the LTP, facilitating proteolysis. Such knowledge contributes to our understanding as to how resistance to digestion can be used in allergenicity risk assessment of novel food proteins, including GMOs

Learning curves in hip fracture surgery

The aim of this study was to identify and characterise learning curves in hip fracture surgery. Operating times were collected and related to the number of procedures done by residents performing closed reduction and internal fixation using cannulated screws for intracapsular fractures of the hip and cephalomedullary nailing for trochanteric fractures, as well as hemiarthroplasty for displaced intracapsular fractures. The mean operating times decreased significantly for all four procedures studied, though at different rates. For cannulated screws, the mean duration of surgery decreased from 47.8 minutes to 30.1 minutes for procedures 21–25. For cephalomedullary nailing without distal locking, the mean operating time decreased from 73.3 minutes to 36.3 minutes. For cephalomedullary nailing with distal locking, the mean operating time decreased from 81.7 minutes to 56.9 minutes. The mean operating time for hemiarthroplasty decreased from 97.3 minutes to 66.0 minutes. Mean operating times decreased significantly for all procedures studied, though at different rates, indicating a unique learning curve for each procedure

In vitro digestion of starches in a dynamic gastrointestinal model:an innovative study to optimize dietary management of patients with hepatic glycogen storage diseases

Uncooked cornstarch (UCCS) is a widely used treatment strategy for patients with hepatic glycogen storage disease (GSD). It has been observed that GSD-patients display different metabolic responses to different cornstarches. The objective was to characterize starch fractions and analyze the digestion of different starches in a dynamic gastrointestinal in vitro model. The following brands of UCCS were studied: Argo (R) and Great Value (R) from the United States of America; Brazilian Maizena Duryea (R) and Yoki (R) from Brazil; Dutch Maizena Duryea (R) from the Netherlands. Glycosade (R), a modified starch, and sweet polvilho, a Brazilian starch extracted from cassava, were also studied. The starch fractions were analyzed by glycemic TNO index method and digestion analyses were determined by the TIM-1 system, a dynamic, computer-controlled, in vitro gastrointestinal model, which simulates the stomach and small intestine. The final digested amounts were between 84 and 86 % for the UCCS and Glycosade (R), but was 75.5 % for sweet povilho. At 180 min of the experiment, an important time-point for GSD patients, the digested amount of the starches corresponded to 67.9-71.5 for the UCCS and Glycosade (R), while it was 55.5 % for sweet povilho. In an experiment with a mixture of sweet polvilho and Brazilian Maizena Duryea (R), a final digested amount of 78.4 % was found, while the value at 180 min was 61.7 %. Sweet polvilho seems to have a slower and extended release of glucose and looks like an interesting product to be further studied as it might lead to extended normoglycemia in GSD-patients